Carole Chedid
email: carole.chedid@fondation-merieux.org

Eka Kokhreidze

Nestani Tukvadze

Sayera Banu

Mohammad Khaja

Mafij Uddin

Samanta Biswas

Graciela Russomando

Chyntia Carolina

Díaz Acosta

Rossana Arenas

Paulo Pr Ranaivomanana

Carolina Díaz Chyntia

Acosta

Crisca Razafimahatratra

Perlinot Herindrainy

Niaina Rakotosamimanana

Monzer Hamze

Mohamad Bachar

Rim Bayaa

Jean-Luc Berland

Giovanni Delogu

Hubert Endtz

Florence Ader

Delia Goletti

Jonathan Hoffmann

Association of baseline white blood cell counts with tuberculosis treatment outcome: a prospective multicentered cohort study

Keywords: tuberculosis, multi-drug resistance, treatment monitoring, white blood cells, lymphopenia, immunomonitoring

ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.

Introduction

Tuberculosis (TB) is the leading cause of death by infectious disease in the world, responsible for 1.5 million deaths in 2018 (World Health Organization Geneva 2019a). The treatment of active pulmonary TB lasts at least 6-months and can cause heavy side effects (World Health Organization Geneva 2017, 2019b). As a consequence, treatment adherence is poor, particularly in primary care settings [START_REF] Woimo | The prevalence and factors associated for antituberculosis treatment non-adherence among pulmonary tuberculosis patients in public health care facilities in South Ethiopia: a cross-sectional study[END_REF].

Mycobacterium tuberculosis culture from sputum samples is the gold standard for TB treatment monitoring [START_REF] Wallis | Tuberculosisadvances in development of new drugs, treatment regimens, host-directed therapies, and biomarkers[END_REF]). However, it is time-consuming and requires high level biosafety laboratories [START_REF] Horne | Sputum monitoring during tuberculosis treatment for predicting outcome : systematic review and metaanalysis[END_REF]. Sputum smear microscopy is quicker for treatment monitoring, but it has limited accuracy [START_REF] Ngabonziza | Diagnostic performance of smear microscopy and incremental yield of Xpert in detection of pulmonary tuberculosis in Rwanda[END_REF]). Hence, blood-based tests are a promising alternative. A variety of blood-based immunoassays, from interferon (IFN)-γ release assays to T cell activation tests, are being evaluated for treatment monitoring [START_REF] Cingolani | Impaired CD4 T-Cell Count Response to Combined Antiretroviral Therapy in Antiretroviral-Naive HIV-Infected Patients Presenting With Tuberculosis as AIDS-Defining Condition[END_REF][START_REF] Sali | Combined use of Quantiferon and HBHA-based IGRA supports tuberculosis diagnosis and therapy management in children[END_REF]. However, in low-resource countries, these tests need to be adapted to limited laboratory equipment [START_REF] Maclean | A sytematic review of biomarkers to detect active tuberculosis[END_REF]) and with a simple output [START_REF] Goletti | Can we predict tuberculosis cure? Current tools available[END_REF].

Hematological abnormalities -such as leukocytosis, neutrophilia, or lymphopenia -during pulmonary TB disease have been described in the literature since the eighties [START_REF] Morris | The haematological and biochemical changes in severe pulmonary tuberculosis[END_REF]. Low monocyte proportions have been associated with higher rates of progression towards active TB [START_REF] Rakotosamimanana | Biomarkers for risk of developing active tuberculosis in contacts of TB patients: a prospective cohort study[END_REF]. Neutrophilia and lymphopenia have been associated with higher risks of mortality during TB treatment [START_REF] Lowe | Neutrophilia independently predicts death in tuberculosis[END_REF]). However, many these studies were either small case-control studies [START_REF] Abay | Hematological Abnormalities of Pulmonary Tuberculosis Patients with and without HIV at the University of Gondar Hospital, Northwest Ethiopia: A Comparative Cross-Sectional Study[END_REF], focused on the risk of developing active TB disease [START_REF] Kurup | Hematological and Biochemistry Profile and Risk Factors Associated with Pulmonary Tuberculosis Patients in Guyana[END_REF], or assessed kinetics during treatment and not association with treatment failure [START_REF] Morris | The haematological and biochemical changes in severe pulmonary tuberculosis[END_REF][START_REF] Rakotosamimanana | Biomarkers for risk of developing active tuberculosis in contacts of TB patients: a prospective cohort study[END_REF].

Most available comprehensive studies were in low-burden, high-healthcare standards areas [START_REF] Ritchie | Serum inflammatory biomarkers as predictors of treatment outcome in pulmonary tuberculosis[END_REF].

Here, we describe a prospective multicentered cohort study conducted in five low-and middleincome countries across four continents: Bangladesh, Georgia, Lebanon, Madagascar, and Paraguay. Four of these countries are on the 2019 WHO high incidence TB country list (≥ 20 cases per 100,000 population), with the exception of Lebanon (11 cases per 100,000 population) (World Health Organization Geneva 2019a). The target population was adult, HIV-uninfected, drug-susceptible (DS-TB) and drug-resistant (DR-TB) pulmonary TB patients.

The primary objective of this study was to monitor the evolution of simple hematological parameters during pulmonary TB treatment in higher TB incidence settings: absolute WBC counts, lymphocyte, and monocyte proportions. These markers of inflammation were chosen because they are routinely monitored in primary care settings. The focus was kept on cellular parameters.

A secondary objective was to characterize their association with treatment failure, defined by sputum culture positivity (the gold standard) at the end of treatment, in relation with clinical and sociodemographic factors.

Materials and methods

Study design and sample population

Study design

This descriptive study was nested within a multicentered prospective cohort study evaluating the prognostic value of blood-based immunological markers for TB treatment monitoring, based in five partner institutions from the Mérieux Foundation GABRIEL network [START_REF] Komurian-Pradel | Enhancing research capacities in infectious diseases: The GABRIEL network, a joint approach to major local health issues in developing countries[END_REF]. with the approval of national TB programs: the international center for diarrheal diseases and research, Bangladesh (icddr,b)

Cohort recruitment, TB diagnosis and patient follow-up

We calculated that a sample size of 156 was required to reach a level of significance of 95% and a power of 80%, assuming an average rate of treatment failure of 10% (World Health Organization Geneva 2019a), a baseline prevalence of lymphopenia (<15% of total WBC) of 30%, and that treatment failure was three times more likely in patients with lymphopenia [START_REF] Lowe | Neutrophilia independently predicts death in tuberculosis[END_REF]. We aimed to include 200 participants to account for lower prevalence values, rates of failure, or missing data.

Patients were recruited if diagnosed with microbiologically confirmed pulmonary TB (positive culture and/or sputum smear and/or GeneXpert; see "Microbiological diagnosis" section for further detail). Patients with HIV or diabetes mellitus (defined by HBA1C levels > 6.5%; Cobas (Roche) automated analyzer) and children under 15 years were excluded. In downstream analyses, patients under immunocompromising treatment (corticosteroids, calcineurin inhibitors, biologics, or other chemotherapeutic agents), patients with negative cultures at inclusion, and patients who were lost-to-follow-up were excluded.

Patients were followed up: at inclusion (T0), after two months of treatment (T1), at the end of therapy (T2; 6 months for drug-susceptible (DS-TB) patients, 9 to 24 months for drug-resistant (DR-TB) patients), and two months after the end of therapy when possible (T3). All patients were on Directly Observed Treatment, Short Course (DOTS) and received treatment according to standard protocols [START_REF] Aung | Successful "9-month Bangladesh regimen" for multidrugresistant tuberculosis among over 500 consecutive patients[END_REF]World Health Organization Geneva 2017, 2019b). Detail of therapeutic regimens can be found in Supp. Table 1.

Microbiological diagnosis and definition of treatment outcome

At each visit, at least one sputum sample per patient was collected for culture (solid and/or liquid media) and smear microscopy (Ziehl-Neelsen and/or Auramine O staining). Molecular amplification of M. tuberculosis DNA was conducted at inclusion (GeneXpert MTB/RIF, Cepheid, Sunnyvale, CA). Drug susceptibility testing (DST) and diagnosis of multi-drug resistance were performed according to standard protocols (World Health Organization Geneva 2019b). Microbiological methods and DST protocols are detailed in Supp. Table 2.

Treatment outcomes were defined as follows: failed (positive sputum culture at T2); cured (negative sputum culture at T2 and no evidence of positive culture at T3); relapse or reinfection (culture conversion at T2 but positive culture recorded at T3); completed (patient not lost to follow up, but no available culture data at T2 or T3) (World Health Organization (WHO) 2013).

On-site whole blood collection and cell count

At each visit, 10 mL of whole blood were drawn, 1 mL of which was collected in EDTA tubes used for the present study. Complete blood counts were performed on automated analyzers (details of manufacturing references per study site are in Supp. Table 2).

Clinical data collection and standardization

Data collection forms were created with clinicians from partner sites and standardized to ensure dataset homogeneity. Follow-up sheets were used to track sample handling and time flow from collection in health centers to receipt in laboratories. All forms were translated into the local official language upon request from staff. Data were entered into the cloud-based database system CASTOR (CASTOR Electronic Data Capture, Version 1.4, Netherlands).

Descriptive statistical analysis

Data were cleaned and analyzed in R (version 3.6.2). As sample size was small, discrete variables were analyzed using Fisher's Exact test with Bonferroni's post-hoc test [START_REF] Kim | Statistical notes for clinical researchers: Chi-squared test and Fisher's exact test[END_REF].

Normality was assessed using the Shapiro-Wilk Normality Test (test statistics available in Supp. Table 3). Normal, continuous variables were analyzed with Student's t-test. Non-normal, continuous variables were analyzed with the Mann-Whitney test, or the Kruskal-Wallis rank sum test with Dunn's Kruskal-Wallis Multiple Comparisons post-hoc test [START_REF] Dunn | Multiple Comparisons Using Rank Sums[END_REF].

Repeated measures of non-independent continuous variables were analyzed using the Friedman rank sum test, with Wilcoxon-Nemenyi- McDonald-Thompson's post-hoc (Paro Pedro et al. 2015).

Logistic regression and Receiver Operating Characteristic (ROC) analyses

For these analyses, the assessed outcome was a recorded positive M. tuberculosis culture result at T2. Patients with unavailable culture data at T2 and patients with relapse were excluded from the analyses. The evaluated variables were leukocyte counts, lymphocyte proportions, and monocyte proportions at T0 or T1. If missing data exceeded 10% of the sample size, the variable was not considered. Otherwise, missing data were replaced by the most frequent group (categorical variables) or the mean (continuous variables). Highly skewed, non-normal continuous variables were log-transformed prior to analyses. Variables were first evaluated in univariate logistic regression analyses, then multivariate analyses were performed. Adjustment variables were selected as follows: sociodemographic variables of known clinical importance (e.g. sex, country of origin), TB risk factors (e.g. smoking), and additional sociodemographic variables that were at least moderately associated (p<0.10) with the outcome in univariate analyses (e.g. prison). Irrelevant adjustment variables were then removed by backward model selection. The combination of variables that minimized the Akaike Information Criterion (AIC) for most tested predictors, while including important adjustment variables, was selected (age, sex, smoking habit, drug sensitivity, country of origin). For lymphocyte proportions, odds ratios (OR) were calculated for each increase of 5.0% because the total range of measured values was 5.0-70.0%. Similarly, for absolute WBC counts, OR were calculated for each increase of 1000 cells per mm 3 .

For both ROC analyses and logistic regression, since the sample size was small, model performance metrics (respectively the Area Under the Curve (AUC) and the C-statistic) were corrected for optimism using bootstrap to assess model validity as described elsewhere [START_REF] Smith | Correcting for optimistic prediction in small data sets[END_REF].

Results

Demographic and clinical characteristics of the cohort.

Between December 2017 and February 2020, 198 eligible patients with culture confirmed active pulmonary TB were recruited in Dhaka (Bangladesh), Tbilisi (Georgia), Tripoli and Akkar (Lebanon), Antananarivo (Madagascar), and Asunción (Paraguay). As of July 2020, 152 of them were followed at least until the end of treatment and had available blood count data (Figure 1). As the T3 timepoint was later than the local TB program visits, the dropout rate was highest between T2 and T3 (26%).

Among patients followed until T2 at least, 18.4% (28/152) were diagnosed with DR-TB. The sociodemographic and clinical characteristics of DS-TB and DR-TB patients were comparable at inclusion (Table 1). The characteristics of patients at inclusion were compared between study sites (Supp. Table 4.). There was no significant difference in baseline absolute WBC counts and lymphocyte proportions between cohorts, but several other parameters differed. Monocyte counts were significantly higher in the Lebanon and Madagascar cohorts than in the other sites.

Patients in Bangladesh were younger than those recruited in Georgia and Paraguay. The body mass index (BMI) at inclusion of patients from Bangladesh and Madagascar was significantly lower than in the other study sites. Finally, BCG vaccination rates were significantly lower in the Georgia and Lebanon cohorts.

Microbiological characterization of treatment response over time and assessment of treatment outcome.

All enrolled patients were positive for sputum culture at inclusion. Most patients were also positive for sputum smear microscopy (78.2%, 119/152) and/or GeneXpert (98.6%, 150/152).

Culture positivity rates decreased significantly upon treatment (Table 2). No significant difference was detected between DR-TB and DS-TB patients (data not shown). At the end of treatment, 90.8% (138/152) of patients were cured, and eight had unavailable culture data and were classified as having completed treatment with no evidence of cure (5.3%, 8/152). One patient (0.7%, 1/152) was culture negative at T2 but had a positive culture result at T3, which was classified as relapse or reinfection. Treatment failure was observed in five DS-TB patients (3.3%, 5/152; Supp. Table 5 for demographic and microbiological characteristics).

Interestingly, 80% (4/5) of treatment failure patients had high sputum smear microscopy grades at baseline (2+ or 3+). At T1, two of them were culture positive and one was microscopy positive.

Absolute WBC counts and lymphocyte proportions vary significantly over the course of therapy.

In all cohorts (n=152), we observed a significant decrease in median absolute WBC counts during treatment (Figure 2.A.), and a significant increase in median lymphocyte proportions (Figure 2.B.). Monocyte proportions were heterogeneous between study sites and increased significantly only in the Bangladesh and Georgia cohorts (Figure 2.C.). At all timepoints, they were significantly higher in the Lebanon and Madagascar cohorts. Neutrophil responses were assessed in a subset of the cohort (n = 129) and also decreased significantly during treatment (Supp. Figure 1).

Early absolute WBC counts and lymphocyte proportions were significantly different between successfully and unsuccessfully treated TB patients.

Absolute WBC counts, lymphocyte and monocyte proportions were then compared between successfully and unsuccessfully treated patients with available culture data at T2 (n = 143;

Figure 3). At baseline and after 2 months, unsuccessfully treated patients had significantly higher absolute WBC counts (Figure 3 As the majority of treatment failure patients had high AFB at baseline (2+ or 3+), we compared WBC absolute counts and lymphocyte proportions according to AFB results. in a subset of all patients presenting with high AFB at baseline (51.7%, 74/143). In this subset, median WBC and lymphocyte counts were similar at baseline, but at T1, WBC counts were higher and lymphocyte proportions were lower in unsuccessfully than in successfully treated patients (Supplementary Figure 2).

Low baseline lymphocyte proportions are significantly associated with a positive sputum culture at the end of treatment

Sociodemographic characteristics and blood counts at T0 and T1 were compared between cured (n = 138) and failed (n = 5) patients, and logistic regression was performed (Table 3). In univariate analyses, significant associations with treatment failure were detected for lymphocyte proportions at baseline (OR 0.32, 95% CI 0.10-0.80, p = 0.032) and at 2 months (OR 0.32, 95% CI 0.11-0.68, p = 0.0091). No significant association was detected for absolute WBC counts or monocytes proportions at T0 and T1. In multivariate analyses, low lymphocyte proportions at T0 remained moderately associated with treatment failure (adjusted OR 0.090, 95% CI 0.0040-0.52, p = 0.042).

ROC analyses were then performed to identify a threshold discriminating successfully and unsuccessfully treated patients based on baseline WBC counts and lymphocyte proportions diction (Supp. Table 6). Baseline WBC counts predicted treatment outcome performed with an AUC of 0.788 (95% CI: 0.664-0.912; optimal cutoff >11,435 cells/mm 3 ). Baseline lymphocyte proportions performed with an AUC of 0.807 (95% CI: 0.671-0.943; optimal cutoff <16% of total WBC). The AUC of both variables combined into a new parameter performed better (AUC 0.841 95% CI 0.722-0.959).

Data was then stratified according to the ROC obtained cutoffs. Significant associations were observed in univariate analyses for patients absolute WBC > 11,450 cells/mm 3 (OR 8.45, 95% CI 1.21 -168, p = 0.031), and for patients with both WBC > 11,450 cells/mm 3 and lymphocytes < 16.0% at baseline (OR 877, 95% CI 1.37 -69.8, p = 0.019), but not for lymphocytes < 16.0% alone (p = 0.061). These variables remained moderately associated in multivariate analyses (WBC > 11,450 cells/mm 3 : p = 0.048; lymphocytes < 16.0%: p = 0.039; WBC > 11,450 cells/mm 3 and lymphocytes < 16.0%: p = 0.024).

Discussion

In this multicentered prospective study, we monitored the evolution of absolute WBC counts, lymphocyte and monocyte proportions during pulmonary TB treatment, and described their association with treatment failure in five cohorts (Bangladesh, Georgia, Lebanon, Madagascar, and Paraguay), four of which were in high-incidence TB countries. We included 152 HIVnegative, culture confirmed pulmonary TB patients, including 28 drug-resistant TB cases.

We showed that during treatment, the lymphocyte proportions increased significantly, whereas the absolute WBC counts decreased significantly. These trends are indicative of general clinical improvement in response to treatment, and are consistent with characteristics of successful therapy. WBC counts are usually higher in TB patients than in healthy individuals, with distinct lymphocyte rates before and after TB treatment [START_REF] Morris | The haematological and biochemical changes in severe pulmonary tuberculosis[END_REF][START_REF] Rakotosamimanana | Biomarkers for risk of developing active tuberculosis in contacts of TB patients: a prospective cohort study[END_REF]. No significant evolution of monocyte proportions during treatment was detected in our cohort, which is consistent with previous works [START_REF] Rakotosamimanana | Biomarkers for risk of developing active tuberculosis in contacts of TB patients: a prospective cohort study[END_REF].

Five patients had positive culture results at the end of treatment and were classified as treatment failure. Two of them had negative smears or cultures at T1, which was likely due to poor sputum quality. The main finding is that at baseline and after two months of treatment, unsuccessfully treated patients had significantly higher WBC counts and lower lymphocyte proportions than those successfully treated. In adjusted logistic regression analyses, treatment failure was significantly associated with high WBC counts and low lymphocyte proportions at baseline. This result is important because WBC counts are usually evaluated in TB patients at baseline and along the therapy course. They are cheap, quick tests that are used routinely in health care centers worldwide. They require a small volume of blood, their output is easy to interpret, and they can be performed without automated equipment. Therefore, they may be a helpful pointof-care tool to help clinicians identify which patients might be less responsive to treatment.

Larger studies on this topic are needed to assess whether early WBC or lymphocyte counts should be taken into account when considering changes to treatment composition or duration.

We hypothesize that patients with high baseline WBC counts and low lymphocyte proportions had highly inflammatory clinical patterns. In the context of mycobacterial infection, WBC counts are mostly reflective of neutrophil counts as markers of persisting inflammation or failure to clear the bacteria [START_REF] Srivastava | Beyond macrophages: The diversity of mononuclear cells in tuberculosis[END_REF]. Sustained inflammation in chronic TB infection has been described as an impairment of the TB-specific immune response, and a marker of active disease [START_REF] Sia | Immunology of Mycobacterium tuberculosis Infections[END_REF]. Previous studies have highlighted a correlation between elevated neutrophils, lymphopenia, and TB disease severity, based on chest X-rays [START_REF] Naghavi | Global, regional, and national age-sex specific mortality for 264 causes of death, 1980-2016: a systematic analysis for the Global Burden of Disease Study 2016[END_REF][START_REF] Panteleev | Severe Tuberculosis in Humans Correlates Best with Neutrophil Abundance and Lymphocyte Deficiency and Does Not Correlate with Antigen-Cpecific CD4 T-Cell Response[END_REF]. Therefore, a hypothesis is that in this cohort, patients with high baseline WBC and low lymphocytes also had more severe TB manifestations and were less likely to achieve cure.

We observed that in the subset of our cohort with high smear microscopy grades (n=74), WBC counts and lymphocyte proportions at baseline were not associated to the treatment outcome; however, significant associations were detected at T1. This suggests that in patients who possibly had a higher bacterial burden, cellular inflammatory markers did not stratify risks of failure at baseline, but persistent cellular differences between failed and cured patients were noticeable after the intensive phase of treatment. A limitation is that TB disease severity at baseline could not be assessed in our cohort other than with microscopy (through chest X-rays, Erythrocyte Sedimentation Rate (ESR) or hemoglobin measurements). Further work is needed to assess the relevance of the association of WBC and lymphocytes with treatment failure in cohorts with better defined disease severity.

Moreover, a feature of TB infection is a delayed initiation of adaptive response after infection, and lymphocyte anergy during chronic infection [START_REF] Urdahl | Initiation and regulation of T-cell responses in tuberculosis[END_REF]. This could indicate that M. tuberculosis specific adaptive immunity might be hindered during treatment in the patients with high WBC or low lymphocyte proportions. Alternatively, as blood counts are measured in the periphery, this may suggest that M. tuberculosis specific lymphocytes are localized in the lungs for infection clearance: their decreased frequency in peripheral blood would indicate a persisting infection. We observed that the majority of unsuccessfully treated patients (80%, 4/5) presented either high WBC counts or low lymphocyte proportions at baseline, and 60% (3/5) with both, suggesting that the mechanisms behind a persistently activated innate immune response and an anergic adaptive immune response during anti-TB therapy might be linked.

Consequently, whether systemic inflammation hinders TB treatment needs to be further investigated.

Our cohort included patients from developing countries, in diverse geographical areas, with varying sociodemographic backgrounds and living standards. In addition, we have enrolled both DS-TB and DR-TB patients, which implies different clinical presentations of the disease. This design suggests similar trends might be occurring in heterogeneous settings and clinical contexts. However, it creates major limitations and analytical challenges as it hinders the control of some patient-and pathogen-dependent factors such as antibiotic regimens, malnutrition levels, untested infections (e.g. parasites), mycobacterial strains, and genetic background. Moreover, the sample size was small. To account for these limitations, adjustment with the available patient-dependent factors as well as optimism corrections with a method adapted to small sample sizes [START_REF] Smith | Correcting for optimistic prediction in small data sets[END_REF]) was performed. However, the clinical interpretation of these results should remain cautious given the heterogeneity and size of the cohort. Another limitation was the important dropout rate, especially between T2 and T3 (26%, 40/152) as T3 was not a timepoint that fell within the time frame of national TB programs. As a consequence, it is likely that occurrences of TB relapse could not be recorded in our study.

In conclusion, this study confirms that WBC counts and lymphocyte proportions are simple biomarkers for TB treatment monitoring. In this cohort, early measurements of these parameters were associated with treatment failure; these results are encouraging but need to be confirmed on larger cohorts. Footnotes: Data are given as % (n) or median (interquartile range). Treatment failure was defined as a positive sputum culture result at T2 or T3. BMI: body mass index. OR: odds ratio. aOR: adjusted odds ratio. AIC: Akaike Information Criterion. C-statistic: concordance statistic (corrected for optimism). WBC: white blood cells. T0: baseline. T1: baseline + 2 months. T2: end of treatment. T3: end of treatment + 2 months. 1: adjusted for age, sex, country of origin, drug resistance strain, and smoking habit. 2: OR or aOR given for each increase in 1,000 units. 3: OR or aOR given for each increase in 5 units.

  in Dhaka, Bangladesh; the National Center for Tuberculosis and Lung Diseases (NTCLD) in Tbilisi, Georgia; the Laboratoire Microbiologie, Santé et Environnement (LMSE, Université Libanaise), in Tripoli, Lebanon; the Institut Pasteur de Madagascar in Antananarivo, Madagascar; and the Instituto de Investigationes en Ciencias de la Salud (Universidad Nacional de Asunción; IICS-UNA) in Asunción, Paraguay. Institutional Review Board of the NTCLD (IORG0009467); in Lebanon, the institutional review board of NINI hospital (IRB-F-01); in Madagascar, the Ministry of Public Health and the Ethical Committee for Biomedical Research (reference number: n°099 -MSANP/CERBM); in Paraguay, the Research Ethics Committee and the Scientific Committee of the IICS-UNA (IRB number: IRB00011984; Federalwide Assurance number: FWA00029097). All recruited patients provided written informed consent.

  .A.) and significantly lower lymphocyte proportions than successfully treated patients (Figure 3.B.). No significant difference was observed for monocyte proportions (Figure 3.C.).

Figure 1 .

 1 Figure 1. Inclusion and data collection process between December 2017 and July 2020.

Figure 2 .

 2 Figure 2. Dynamics of main white blood cell types over the course of TB treatment.

Figure 3 .

 3 Figure 3. Main white blood cell types over time stratified by sputum smear microscopy and

Table 2 . Microbiological characterization of treatment response and outcome definition.

 2

	Sputum culture results	Positive	Negative	Unavailable
	Timepoint
	T0	100% (152/152)	0	0
	T1	13.8% (21/152)	70.4% (107/152)	15.8% (24/152)
	T2	3.3% (5/152)	94.8% (144/152)	1.9% (3/152)
	T3	0.9% (1/112)	43.8% (49/112)	55.4% (62/112)
		All patients	DS-TB	DR-TB
	Treatment outcome
	Cured and completed 1	90.8% (138/152)	88.7% (110/124)	100% (28/28)
	Completed 2	5.3% (8/152)	6.5% (8/124)	0
	Failed 4	3.3% (5/152)	4% (5/124)	0
	Relapse or reinfection 5	0.7% (1/152)	0.8% (1/124)	0
	Footnotes: T0: baseline. T1: baseline + 2 months. T2: end of treatment. T3: end of treatment + 2
	months. DS-TB: drug-susceptible tuberculosis. DR-TB: drug-resistant tuberculosis.
	1: positive culture at T2. 2: negative culture at T2 but positive culture at T3. 3: negative culture at T2
	and no evidence of positive culture at T3. 4: patients not lost to follow-up, but with no available
	culture data at T2 or T3. Unavailable culture data were caused by contaminations or failure to
	expectorate sputum. Unavailable sputum smear microscopy results were caused either by technical
	issues or failure to expectorate enough sputum for both culture and smear.

Table 3 . Association of selected baseline sociodemographic and clinical factors with treatment outcome. Sociodemographic factors and clinical parameters at baseline and at 2 months Descriptive analysis (n = 143) Logistic regression -association with treatment failure

 3

				Univariate analysis			Multivariate analysis 1
	Cured (n = 138)	Failed (n = 5)	p	OR (95% CI)	p	aOR	p	AIC	Corrected C-statistic

tuberculosis treatment. 2019b.

Acknowledgments

We are grateful to the patients participating in our study and to the healthcare staff at our study sites.

Funding

This work was supported by Fondation Mérieux; Fondation Christophe et Rodolphe Mérieux; and Fondation AnBer. A minor part of the study was supported by the Italian Ministry of Health "Ricerca Corrente, Linea 3".

Author contributions

JH is the principal investigator, and initiated the project together with DG, NT, SBa, GR, NR, and MH. Data was collected by EK, MU, SBi, CA, PR, CR, PH, and RB. CC performed all statistical analyses and wrote the manuscript. All authors have contributed to the content and have given their final approval.

Conflicts of interest


D Saragaglia
email: dsaragaglia@yahoo.fr

G Favarel

J J Banihachemi

Traumatologie du VTT de descente : Étude épidémiologique prospective à propos de 138 cas totalisant 178 lésions Downhill mountain biking traumatology : prospective epidemiological study of 138 cases totaling 178 lesions

Keywords: epidemiology, traumatology, downhill mountain biking

The rise of downhill mountain biking has been significant since the early 1990s. Mountain biking and many accidents are related to high speeds. The aim of this study was to make an inventory of downhill mountain biking traumatology and to describe the causes and mechanisms of injuries. Material and methods 129 patients were included prospectively over the period from July 2014 to November 2016. This represented 138 admissions for 178 lesions. There were 92% men, and 8% women mean aged 27.9 years (11-69 years old).

Results

Regarding the lesion assessment, lesions of the upper limbs (UL) predominated with 118 lesions (66%), followed by the lower limbs (LL) with 37 lesions (21%) and lesions of the body axis (23 lesions i.e 13%). Lesions of the shoulder and the shoulder girdle were by far the most frequent lesions (66 or 56% of lesions of the UL) with, among others, 25 fractures of the clavicle, 21 acromio-clavicular dislocations and 10 anterior shoulder dislocations. At the LL level, sprains of the knee were the most frequent with 7 sprains or 19% of lesions of LL. Finally, head trauma represented 43% of injuries to the body axis.

Conclusion

Downhill mountain biking accidents are dominated by trauma to the upper limbs, particularly trauma to the shoulder and shoulder girdle. Despite increasingly sophisticated protections, they are insufficient to prevent these lesions or at least reduce their incidence.

RÉSUMÉ

L'essor du VTT de descente est important depuis le début des années 1990. Sa pratique en montagne et les vitesses élevées sont à l'origine de nombreux accidents. Le but de cette étude était de faire un inventaire de la traumatologie du VTT de descente et de décrire les causes et les mécanismes lésionnels. Matériel et méthodes 129 patients ont été inclus de manière prospective sur la période de juillet 2014 à Novembre 2016. Cela représentait 138 venues en consultation pour 178 lésions. Il y avait 92 % d'hommes et 8% de femmes d'âge moyen 27,9 ans (11-69 ans). Résultats En ce qui concerne le bilan lésionnel, l'atteinte des membres supérieurs (MS) prédominait avec 118 lésions (66 %), suivi des membres inférieurs (MI) avec 37 lésions (21 %) et des lésions de l'axe du corps (23 lésions soit 13%). Les lésions de l'épaule et de la ceinture scapulaire étaient de loin les plus fréquentes (66 soit 56% des lésions des MS) avec, entre autres, 25 fractures de la clavicule, 21 disjonctions acromio-claviculaires et 10 luxations antéro-internes de l'épaule. Au niveau des MI, les entorses du genou prédominaient avec 7 entorses, soit 19% des lésions des MI. Enfin, les traumatismes crâniens représentaient 43 % des lésions de l'axe du corps.

Conclusion

Les accidents de VTT de descente sont dominés par les traumatismes des membres supérieurs et tout particulièrement l'épaule et la ceinture scapulaire. Malgré des protections de plus en plus sophistiquées, celles-ci sont insuffisantes pour prévenir ces lésions ou, tout au moins, en diminuer l'incidence.

Mots clés : Épidémiologie, Traumatologie, VTT de descente

INTRODUCTION

Le VTT de descente ou vélo de descente est une discipline sportive bien spécifique avec des règles et une définition donnée par l'Union Cycliste Internationale : « La descente est une course contre la montre dans laquelle le descendeur négocie sur des pistes spécialement aménagées une succession de passages tantôt rapides, tantôt techniques. Le coureur doit faire preuve d'engagement et posséder un sens aiguisé du pilotage pour affronter les racines, dévers, bosses, sauts et autres obstacles naturels rencontrés lors d'une descente. Les vitesses de pointes atteignent près de 80 km/h ». L'équipement du pilote se compose essentiellement de protections. Leur rôle est essentiel en cas de chute ou de collisions imprévues (arbres, pierres, branches, etc.). Il est souvent recommandé de porter au minimum un casque intégral, un masque ou des lunettes, une protection dorsale, des genouillères, des coudières et des gants longs. Comme autre protection on peut retrouver : un gilet de protection, une protection cervicale, des jambières et un sous-short de protection. À cela, peut s'ajouter des chaussures et des habits adaptées à la pratique. Le vélo de descente emprunte ses caractéristiques à la fois au VTT et au motocross. Il doit être avant tout résistant et doit disposer de suspensions efficaces. Les roues et le cadre sont spécialement conçus pour résister à d'importantes contraintes. La légèreté devenant de plus en plus importante, de nombreux pilotes ré-usinent et ajoutent des composants pour gagner quelques grammes précieux dans les pédalages et les relances.

La pratique du VTT de descente n'a fait qu'augmenter au cours de ces dernières années et la recrudescence des accidents nous a conduit à faire une étude prospective et à colliger tous les accidents recensés aux urgences de l'hôpital sud de Grenoble entre 2014 et 2016. Le but principal de cette étude était de donner un aperçu de la traumatologie de cette pratique sportive. Les objectifs secondaires étaient l'évaluation des circonstances, causes et mécanismes des accidents.

MATÉRIEL et MÉTHODES

Matériel

De juillet 2014 à Novembre 2016, nous avons inclus 129 patients dont 5 qui s'étaient présentés à plusieurs reprises. Le total s'élevait donc à 138 cas dont 33 qui comptabilisaient plusieurs lésions, soit un total de 178 lésions. Méthodes Il s'agit d'une étude épidémiologique, prospective, monocentrique. Tous les patients avaient donné leur accord pour participer à cette étude. Le critère d'inclusion principal était un traumatisme en VTT de descente pris en charge dans le cadre des urgences du service. Tous les dossiers étaient inclus sans distinction de l'âge, du sexe ou des comorbidités. Le diagnostic précis était validé le lendemain par l'équipe chirurgicale qui assurait le staff de contrôle. Les outils statistiques descriptifs ont été utilisés en première intention. Les paramètres quantitatifs ont été décrits par leur moyenne, minimum, maximum et écart type. Les paramètres qualitatifs ont été exprimés en effectifs et pourcentages. Le test du chi 2 a permis de comparer deux pourcentages pour savoir s'il y avait une différence significative ou non. Les analyses statistiques ont été effectuées avec le logiciel Excel.

RÉSULTATS

La population était essentiellement masculine avec 127 hommes (92%) et 11 femmes. L'âge moyen était de 27,9 ans pour une médiane de 27 avec des extrêmes de 11 et 69 ans. La distribution des âges est colligée dans la Figure 1. Les tranches d'âge les plus représentées étaient 10-20 ans et 20-30 ans avec respectivement 21 et 29%.

Inventaire des lésions traumatiques

Sur les 178 lésions, 155 se situaient au niveau des membres (87%) dont 66% aux membres supérieurs et 21% aux membres inférieurs (Figure 2). Le côté droit était intéressé autant que le gauche avec 80 traumatismes gauches et 74 droits. L'axe du corps (thorax, abdomen, rachis) était intéressé dans 23 cas (13%). Le taux de lésions par patient était de 1.3 lésions/patient. Les fractures étaient les plus fréquentes, suivies des entorses et des contusions (Figure 3).

Les lésions des membres supérieurs (Figure 4)

Nous avons comptabilisé 118 traumatismes : 66 lésions de l'épaule et de la ceinture scapulaire : 25 fractures de la clavicule, 21 disjonctions acromio-claviculaires, 10 luxations antéro-internes de l'épaule dont une récidivante, 7 contusions de l'épaule, 1 fracture du col chirurgical de l'humérus, 1 fracture de l'acromion et 1 du processus coracoïde ; 11 lésions du coude : 3 fractures de la tête radiale, 3 plaies extra-articulaires, 2 fractures de l'olécrane, 2 contusions et 1 luxation postérieure ; 11 lésions de l'avant-bras : 5 fractures des 2 os, 2 fractures de Galeazzi, 2 fractures métaphysaires distales du radius et 2 dermabrasions profondes ; 16 lésions du poignet : 6 fractures de l'extrémité distale du radius, 3 fractures du scaphoïde, 3 contusions, 2 luxations périlunaires du carpe, 1 décollement épiphysaire de l'extrémité distale du radius et une fracture de l'extrémité distale de l'ulna ; 14 lésions de la main : 6 entorses de la métacarpo-phalangienne du pouce dont 3 graves, 3 fractures des phalanges, 2 plaies des doigts sans lésion ostéotendineuse, 1 avulsion de l'ongle du 3 è doigt gauche, 1 entorse de la métacarpo-phalangienne du 4 è doigt droit et 1 entorse de l'interphalangienne proximale du 3 è doigt droit. 6) Nous avons comptabilisé 37 traumatismes : 3 contusions hyperalgiques de la hanche sans lésion osseuse sous-jacente ; 12 lésions du genou : 6 entorses dont 2 ruptures du ligament croisé antérieur et 1 rupture du ligament collatéral médial, 1 fracture du plateau tibial, 1 rupture du ligament croisé postérieur, 3 plaies extra-articulaires et 1 contusion hyperalgique ; 4 fractures des 2 os de la jambe et 2 dermabrasions étendues de la jambe ; 14 lésions de la cheville : 5 fractures bi ou tri-malléolaires, 5 entorses latérales dont une avec une lésion ostéochondrale du dôme talien, 1 luxation tibiotalienne, 1 entorse tibiofibulaire distale, 1 fracture du talus, une contusion hyperalgique de la cheville et, enfin, 2 entorses médiotarsiennes.

Les lésions des membres inférieurs (Figure

Les lésions de l'axe du corps (Figure 7)

Nous avons comptabilisé 23 traumatismes : 10 traumatismes crâniens sans perte de connaissance, tous chez des porteurs de casque ; 6 traumatismes thoraciques dont 2 avec des fractures de côte et 1 avec une fracture du manubrium sternal ; 3 contusions abdominales dont une associée à une plaie non pénétrante de l'abdomen ; 2 fractures du rachis lombaire peu déplacées et, enfin, une plaie profonde du pli inguinal droit et une dermabrasion étendue en regard de l'aile iliaque gauche.

Circonstances et caractéristiques des accidents

Malgré le caractère prospectif de cette étude, nous n'avons pu retrouver que 69 dossiers complets pour tous les items.

Mécanismes des lésions

Dans 57 cas, il s'agissait d'un choc direct (83%) contre l'environnement (sol, arbre) dans 86% des cas, contre son propre VTT dans 12% et contre un autre vététiste du groupe dans 2% des accidents. Dans 4 cas, il s'agissait d'un choc indirect (6%) (notamment pour les luxations de l'épaule). Enfin, dans 8 cas il s'agissait d'une torsion d'un membre inférieur (12%). Les déterminants de l'accident étaient définis, par les blessés, comme humains dans 63% des cas (Figure 8).

Niveau sportif

Il n'y avait aucun sédentaire dans cette série. La majorité, soit 42 cas (61%), faisait entre 3 heures et 10 heures de sport par semaine ; 17 patients faisaient plus de 10 heures par semaine (25 %) et 5 moins de 3 heures (7 %). Cinq étaient des sportifs de haut niveau (7 %) et 67 d'entre eux faisaient plusieurs sports, soit 97 %. Le niveau technique en VTT était considéré comme « débutant » par 17 patients (25 %) dont 9 qui n'avaient jamais fait de descente auparavant ; 38 se jugeaient « confirmé » (55 %) et 14 étaient « expert » (20 %). En moyenne, le VTT de descente était pratiqué depuis 4,9 +/-5,5 ans.

Circonstances des accidents

Dans 62 cas (90 %), les accidentés pratiquaient le VTT de descente en loisir. Onze accidents ont eu lieu au début de la sortie (16 %), 26 au milieu (38 %) et 32 en fin de sortie (46 %). Cinquante-huit patients étaient en groupe (84 %) lors de l'accident, 11 étaient seuls (16 %).

Le nombre moyen de personnes était de 3 +/-1,8 (1-10). Soixante-cinq ont été accidentés en été (94 %) et dans 61 cas (89 %) l'accident est survenu par beau temps. Concernant le type de terrain, 53 cas ont eu leur accident sur de la terre (77 %) et 52 sur une piste de station de sport d'hiver (75 %). Tous les patients portaient un casque dont 60 un casque intégral (86 %), et 9 un casque semi-intégral (14 %). Cinquante-trois portaient des coudières (76 %) et 50 un gilet (72 %). Le vélo utilisé était un VTT de descente dans 71% des cas (suspension avant et arrière > 150 mm), un vélo d'enduro dans 26% des cas (suspension entre 120 et 150 mm) et un vélo semi-rigide dans 3% (suspension avant uniquement).

Modalités thérapeutiques

Sur les 138 cas (178 lésions) de la série, 57 blessés ont dû être hospitalisés et parmi ceuxci, 56 ont nécessité une intervention chirurgicale soit 41% de la série globale et 31% des lésions. Les 81 restants ont été traités en ambulatoire, soit par traitement fonctionnel, soit par traitement orthopédique. La durée moyenne d'hospitalisation était de 1,17+/-2,1 jours (1-10).

DISCUSSION

Cette étude prospective a permis de colliger un nombre important d'accidents de VTT de descente sur une période étendue de juillet 2014 à novembre 2016. S'agissant d'une étude prospective, les critères d'inclusion ont été parfaitement respectés si bien que tous les autres accidents de VTT dits de loisir ont été éliminés, ce qui est rarement le cas dans la littérature où tous les accidents de VTT sont habituellement répertoriés [START_REF] Chow | Acute injuries from mountain biking[END_REF][START_REF] Jeys | Mountain biking injuries in rural England[END_REF][START_REF] Kim | Mountain Biking Injuries Requiring Trauma Center Admission: A 10-year Regional Trauma System Experience[END_REF][START_REF] Aleman | Mountain biking injuries in children and adolescents[END_REF][START_REF] Nelson | Mountain biking-related injuries treated in emergency departments in the United States, 1994-2007[END_REF][START_REF] Himmelreich | Mountain bike injuries in world-cup and recreational athletes[END_REF]. Sur les 178 lésions, 155 se situaient au niveau des membres (87%) dont 66% (118 cas) aux membres supérieurs et 21% aux membres inférieurs. L'épaule et la ceinture scapulaire avec 66 lésions (42%) étaient de loin la région anatomique la plus touchée. Les autres séries de la littérature consacrées à tous types de pratique [START_REF] Chow | Acute injuries from mountain biking[END_REF][START_REF] Jeys | Mountain biking injuries in rural England[END_REF][START_REF] Kim | Mountain Biking Injuries Requiring Trauma Center Admission: A 10-year Regional Trauma System Experience[END_REF][START_REF] Aleman | Mountain biking injuries in children and adolescents[END_REF] confirment ce taux élevé qui constitue une spécificité des accidents de VTT. Dans leur immense étude basée sur 217 433 traumatisés en VTT de 1994 à 2007, Nelson et al [START_REF] Nelson | Mountain biking-related injuries treated in emergency departments in the United States, 1994-2007[END_REF], ont également rapporté que les membres supérieurs étaient les plus atteints. Les auteurs ne citent pas de chiffre global sur les membres supérieurs, mais uniquement les fractures qui constituent la lésion la plus fréquente avec 18,9% du total des lésions, contre 31% dans notre série. Nous avions rapporté des taux identiques en 1994 dans la thèse d'Anne Chevalier qui faisait état de 60% de lésions des membres supérieurs sur un total de 173 lésions dont 137 qui intéressaient les membres. Ces lésions s'expliquent parfaitement par le mécanisme de la chute qui va projeter le cycliste vers l'avant ou sur le côté, celui-ci se réceptionnant alors sur le moignon de l'épaule [START_REF] Aleman | Mountain biking injuries in children and adolescents[END_REF] expliquant également le taux relativement faible de lésions des membres inférieurs (37 versus 118). Une chute sur la hanche pourrait provoquer des fractures du bassin ou du col du fémur mais, dans notre série, hormis 3 contusions hyperalgiques de la hanche nous n'avons pas retrouver cette lésion. Ces lésions des membres supérieurs ne sont pas confirmées par l'étude prospective de Becker et al. [START_REF] Becker | A prospective study of downhill mountain biking injuries[END_REF] consacrée, comme la nôtre, uniquement au VTT de descente. Dans ce travail, les auteurs ont rapporté une prédominance des lésions au niveau des membres inférieurs avec essentiellement des contusions et des dermabrasions. Ils avaient colligé 494 traumatismes dont 13% qualifiés de sévères et 65% de légers. La méthodologie de cette étude était complètement différente de la nôtre puisqu'elle avait été réalisée par questionnaire, de manière prospective, sur une série de 249 vététistes de descente durant la période avrilseptembre 2011. Étant donné qu'il s'agit d'accidents à haute énergie, on aurait pu s'attendre à beaucoup plus de lésions de l'axe du corps. Le taux n'est que de 13%, ce qui aurait pu être expliqué par un biais de recrutement, le service ne recevant que des lésions des membres et des lésions axiales bénignes, les autres lésions (polytraumatisés, traumatisés crâniens et/ou maxillo-faciaux graves, traumatismes viscéraux) étant orientés par les secours vers une autre structure plus appropriée. En fait, les autres séries de la littérature rapportent finalement peu d'urgences vitales. Jeys et al. [START_REF] Jeys | Mountain biking injuries in rural England[END_REF], sur une série de 84 cas, n'ont rapporté que 5% d'urgences vitales. Il en est de même de l'étude de Kim et al. [START_REF] Kim | Mountain Biking Injuries Requiring Trauma Center Admission: A 10-year Regional Trauma System Experience[END_REF] qui, sur une série de 399 lésions, ont rapporté 5% de lésions abdominales et 2% de lésions génito-urinaires. Enfin, durant la période 2012-2014, le centre de référence Rhône Alpin des polytraumatisés graves, à savoir le service de réanimation de l'hôpital nord du CHU de Grenoble, n'a pris en charge que 18 patients. A contrario, certains traumatismes bénins n'ont pas été colligés dans notre étude car les blessés n'ont pas jugé utile de se présenter au service des urgences. L'étude de Becker et al. [START_REF] Becker | A prospective study of downhill mountain biking injuries[END_REF] s'est affranchie de ce biais puisque les données ont été collectées via l'envoi d'un questionnaire par le registre d'un magazine de vélo très populaire. Le nombre important de lésions bénignes colligées minimise la notion de pratique sportive à risque. Cependant, des études à grande échelle comme celle de Nelson et al. [START_REF] Nelson | Mountain biking-related injuries treated in emergency departments in the United States, 1994-2007[END_REF] basée sur 217 433 traumatisés en VTT de descente de 1994 à 2007, peuvent faire douter de la pertinence des diagnostics lésionnels et de l'ensemble des données. En ce qui concerne les caractéristiques de la population, la prédominance masculine (92% d'hommes dans notre série) est également rapportée par Jeys et al. [START_REF] Jeys | Mountain biking injuries in rural England[END_REF] Il est très difficile de comparer les accidents de VTT de descente avec ceux du VTT dit de loisir car les études, comme nous l'avons déjà notifié, mélangent tous les types de pratique. Néanmoins, si l'on se réfère à la thèse de Anne Chevalier réalisée dans le même service, avec un nombre identique de patients, sur une même période mais, 20 ans plus tôt, l'accidentologie est exactement la même avec, cependant, un nombre d'hospitalisations et de traitements chirurgicaux nettement supérieurs (28% d'hospitalisation et 21% de traitements chirurgicaux versus 41% et 31%). Cette différence s'explique facilement par une prise de risque beaucoup plus importante souvent calquée sur les compétiteurs que certains blessés ont voulu imiter. Concernant la prévention des lésions de l'épaule et de la ceinture scapulaire, la solution résiderait peut-être dans l'absorption de l'énergie cinétique via un système d'airbag ou de coque plastique déformable sur le moignon de l'épaule. Enfin, pour les fractures qui ont lieu par choc indirect lors d'une chute bras tendu, seule la formation des vététistes à « tomber en boule » et « enrouler la chute », bras en croix contre le thorax permettrait d'éviter ce mécanisme de compression. On retrouve cet enseignement au judo dans la technique des « ukemis ». Quant aux dermabrasions, si fréquentes dans l'étude de Becker et al. [START_REF] Becker | A prospective study of downhill mountain biking injuries[END_REF], leur incidence pourrait être largement diminuée par le port de combinaisons adaptées.

CONSLUSION

Les accidents de VTT de descente sont dominés par les traumatismes des membres supérieurs et tout particulièrement de l'épaule et de la ceinture scapulaire. Malgré des protections de plus en plus sophistiquées, celles-ci sont insuffisantes pour prévenir ces lésions ou, tout au moins, en diminuer l'incidence. Les recherches doivent continuer pour essayer de trouver des protections plus efficaces.

Conflits d'intérêts : Aucun

  mais à un degré moindre (70% d'hommes). La moyenne d'âge des patients est un peu plus élevée dans notre série (27,9 ans) que dans celle de Jeys et al. (22,4 ans ; 8-71). Compte tenu du prix d'un VTT de descente (2000 à 3000 euros minimum) et du prix des différents accessoires, il est facile de comprendre qu'il ne peut s'agir que d'une population autonome sur le plan financier, ou pour les plus jeunes qu'ils soient issus d'une famille aisée.

Légendes des figures

Figure 1: Distribution des âges. Figure 2: Localisation des lésions. Figure 3: Types des lésions. Figure 4: Répartition des lésions des membres supérieurs. Figure 5: Lésions de la ceinture scapulaire. Figure 6: Répartition des lésions des membres inférieurs. Figure 7: Lésions de l'axe du corps. Figure 8: Déterminants de l'accident.

Distribution des âges

Membre Supérieur 66%

Membre inférieur 21%

axe du corps 13%

Localisation des lésions


MD, PhD Augustin Coisne
email: augustin.coisne@chru-lille.fr

MD, PhD François Pontana

MD Samy Aghezzaf

MD a ; Stéphanie Mouton

MD Hélène Ridon

MD a ; Marjorie Richardson

MD a : Anne-Sophie Polge

MD e ; Benjamin Longère

MD e ; Valentina Silvestri

MD e ; Julien Pagniez

MD f ; Antoine Bical

MD f ; Natacha Rousse

MD f ; Pavel Overtchouk

MD h ; Juan F Granada

MD i ; Rebecca T Hahn

MD, PhD f ; Thomas Modine

MD, PhD David Montaigne

Utility of 3-Dimensional Transoesophageal Echocardiography for Mitral Annular Sizing in Transcatheter Mitral Valve Replacement Procedures: A Cardiac Computed Tomography Comparative Study

Keywords: Transcatheter Mitral Valve Replacement, Mitral Annulus, 3-dimensions, Multimodality Imaging, Heart Team

Background. 3-dimensional transoesophageal echocardiography (3D-TEE) is frequently used as an initial screening tool in the evaluation of patients who are candidates to Transcatheter Mitral Valve Replacement (TMVR). However, little is known about the imaging correlation with the gold-standard computed tomography (CT) imaging. We aimed at testing the quantitative differences between these two modalities and finding the best 3D-TEE parameters for TMVR screening.

Methods. We included 57 patients referred to our Heart Valve Clinic for TMVR with prostheses specifically designed for the mitral valve. Mitral annulus (MA) analyses were performed using commercially available software in 3D-TEE and CT.

Results. 3D-TEE was feasible in 52 patients (91%). Although 3D-TEE measurements were slightly lower than in CT, both measurements of projected MA area and perimeter showed excellent correlation with small differences between the two modalities (r=0.88 and r=0.92 respectively, p<0.0001). Correlations were significant but lower for MA diameters (r=0.68 to 0.72, p<0.0001) and mitro-aortic angle (r=0.53, p=0.0001). ROC curve analyses showed that 3D-TEE had a good ability to predict TMVR screening success defined by constructors based on CT measurements with a range of 12.9 to 15cm² for MA area (AUC=0.88-0.91, p<0.0001), 128 to 139mm for MA perimeter (AUC=0.85-0.91, p<0.0001), 35 to 39mm for anteroposterior diameter (AUC=0.79-0.84 p<0.0001) and 37 to 42mm for posteromedial-anterolateral diameter (AUC=0.81-0.89, p<0.0001).

Conclusion. 3D-TEE measurements of MA dimensions display strong correlation with CT

measurements in patients undergoing TMVR screening process. 3D-TEE should be proposed as a reasonable alternative to CT in this vulnerable population.

INTRODUCTION

Recent early clinical reports suggest that Transcatheter Mitral Valve Replacement (TMVR) is a viable therapeutic solution for inoperable or high-risk patients with symptomatic severe mitral regurgitation (MR) [START_REF] Muller | Transcatheter Mitral Valve Replacement for Patients With Symptomatic Mitral Regurgitation: A Global Feasibility Trial[END_REF][START_REF] Bapat | Early Experience With New Transcatheter Mitral Valve Replacement[END_REF][START_REF] Barbanti | Transcatheter Mitral Valve Implantation Using the HighLife System[END_REF]. However, the advancement of TMVR solutions face several challenges including the careful selection of device size to match the individual dimensions and the geometry of the mitral annulus (MA). [START_REF] Blanke | Predicting LVOT Obstruction in Transcatheter Mitral Valve Implantation: Concept of the Neo-LVOT[END_REF][START_REF] Regueiro | Transcatheter Mitral Valve Replacement: Insights From Early Clinical Experience and Future Challenges[END_REF] We have recently shown that despite the availability of several TMVR prosthesis with different dimensions a very high rejection rate still occurs due to anatomy and prosthesis mismatch in size or risk of neo-left ventricular outflow tract (LVOT) obstruction. [START_REF] Coisne | Transcatheter Mitral Valve Replacement: Factors Associated with Screening Success and Failure[END_REF] Cardiac computed tomography (CT) is currently the imaging modality of choice for MA sizing for TMVR screening [START_REF] Blanke | Multimodality Imaging in the Context of Transcatheter Mitral Valve Replacement: Establishing Consensus Among Modalities and Disciplines[END_REF]. Recent studies have suggested that 3-dimensional (3D) transoesophageal echocardiography (TEE) is a promising tool for assessing characteristics of MR and MA using dedicated software [START_REF] Van Wijngaarden | Three-dimensional assessment of mitral valve annulus dynamics and impact on quantification of mitral regurgitation[END_REF][START_REF] Jolley | Three-Dimensional Mitral Valve Morphology and Age-Related Trends in Children and Young Adults with Structurally Normal Hearts Using Transthoracic Echocardiography[END_REF][START_REF] Fattouch | Multiplane two-dimensional versus real time three-dimensional transesophageal echocardiography in ischemic mitral regurgitation[END_REF]. Pitfalls of CT include radiation exposure, motion artifact (due to arrhythmias or patient factors) and the need for iodinated contrast.

Candidates for TMVR often have renal insufficiency [START_REF] Schueler | Predictors for short-term outcomes of patients undergoing transcatheter mitral valve interventions: analysis of 778 prospective patients from the German TRAMI registry focusing on baseline renal function[END_REF] and it is thus important to find alternative imaging methods to avoid contrast administration in this frail population. Mak et al. showed that 3D-TEE seems a promising complementary tool to CT for sizing the TMVR [START_REF] Mak | Three-Dimensional Echocardiography Compared With Computed Tomography to Determine Mitral Annulus Size Before Transcatheter Mitral Valve Implantation[END_REF]. However, the best 3D-TEE parameters to size the prosthesis are still unclear.

In the present study, we aimed to 1) compare MA sizing using a novel 3D-TEE method to CT measurements in candidates for TMVR with various prostheses and 2) find the best 3D-TEE parameters for TMVR screening.

METHODS

Study population and design

From November 2016 to May 2019, we prospectively studied all consecutive patients with severe MR referred to our Heart Valve Centre for percutaneous implantation because of highrisk for MR surgery. Inclusion criteria were: age > 18 years with severe (grade III-IV) and symptomatic (New York Heart Association functional class ≥ 2) chronic MR. Patients were excluded from TMVR screening if they had severe mitral annulus calcification, left atrial or LV thrombus, prior mitral valve surgery, indications for standard cardiac surgery or suitable anatomy for mitral valve repair using the MitraClip™ system (Abbott Structural, Santa Clara, California) according to our Heart Team decision. The local ethics committee approved the protocol and patients gave informed consent

Echocardiography

A comprehensive transthoracic (TTE) and transoesophageal echocardiography (TEE) using 2and 3-D imaging was performed in our department according to current guidelines [START_REF] Lang | Recommendations for cardiac chamber quantification by echocardiography in adults: an update from the American Society of Echocardiography and the European Association of Cardiovascular Imaging[END_REF][START_REF] Hahn | Guidelines for performing a comprehensive transesophageal echocardiographic examination: recommendations from the American Society of Echocardiography and the Society of Cardiovascular Anesthesiologists[END_REF][START_REF] Mitchell | Guidelines for Performing a Comprehensive Transthoracic Echocardiographic Examination in Adults: Recommendations from the American Society of Echocardiography[END_REF] using state-of-the-art echocardiographic ultrasound systems (Vivid 9 or Vivid 95, GE Healthcare, Horten, Norway) under local anaesthesia before the procedure. All measurements were obtained by TTE expect MA dimensions.

3D TEE reconstruction for measurement of the MA was performed off-line on a dedicated workstation using a commercially available software (4D Auto MVQ, GE Healthcare -Echopac, version 203, Horten, Norway) (Figure 1). Briefly, a 3D volume of the MA set was acquired guided by a multiplane 2D-TEE view. The mid diastolic frame was selected. An alignment step was performed to ensure standardized and expected views where vertical axis crosses through the center of the mitral valve while the horizontal axis is parallel to the mitral valve. Six landmarks were then placed: two mitral annulus points, two anterior/posterior points, the coaptation plus the aorta point. A complete 3D reconstruction of the mitral annulus was automatically performed but which can be edited by the operator. Finally, a review stage was performed to check the 3D model in all slices (Biplane, Scallops and Commissures) and several MA dimensions and geometry were determined by the 4D Auto MVQ software.

Cardiac Computed Tomography

Contrast-enhanced cardiac CT images were also acquired for screening and procedure planning. CT examinations were performed using a multiphase retrospectively electrocardiogram-gated data acquisition. Briefly, mitral annular measurements were made at 60% of the cardiac cycle based on a saddle shape (or projected) orifice contour [START_REF] Thériault-Lauzier | Quantitative multi-slice computed tomography assessment of the mitral valvular complex for transcatheter mitral valve interventions part 1: systematic measurement methodology and inter-observer variability[END_REF][START_REF] Thériault-Lauzier | Quantitative multi-slice computed tomography assessment of the mitral valvular complex for transcatheter mitral valve interventions part 2: geometrical measurements in patients with functional mitral regurgitation[END_REF] (Figure 2) and mitral annular segmentation was performed using a dedicated software (3mensio, Pie Medical Imaging. Bilthoven, The Netherlands) as previously described [START_REF] Blanke | Multimodality Imaging in the Context of Transcatheter Mitral Valve Replacement: Establishing Consensus Among Modalities and Disciplines[END_REF][START_REF] Blanke | A simplified Dshaped model of the mitral annulus to facilitate CT-based sizing before transcatheter mitral valve implantation[END_REF].

All CT measurements were performed by the same cardiovascular radiologist with 12 years of experience in cardiac CT and with 3 years' experience using this software. These measurements included MA area, 3D and projected perimeters, antero-posterior and posteromedial-anterolateral diameter and mitro-aortic angle.

Screening for TMVR

TMVR screening was performed for several dedicated prostheses (Intrepid™ [Medtronic, Minneapolis, Minnesota] (outer diameters 43-46-50mm), Tendyne™ [Abbott Structural, Santa Clara, California] (sizes ranging from 33 to 41) and HighLife™ [HighLife, Paris, France] (outer diameter 26.5mm). The final suitability decision was given by the manufacturer based on CT measurements of projected MA area, projected MA perimeter, antero-posterior (AP) and posteromedial-anterolateral (PM-AL) diameter, mitro-aortic angle and risk of neo-LVOT obstruction. This screening classified patients as being suitable for TMVR implantation, or not suitable because of too large or too small mitral annulus anatomy.

Statistical analysis

Continuous variables were tested for normality with Shapiro test, and were displayed as mean±SD. Continuous variables with no Gaussian distribution were displayed as median (IQR). Categorical variables were displayed as percentages of individuals. Linear regression was used to explore the correlation between 3D-TEE and CT measurements using Pearson correlation coefficient. Comparisons between 2 measurements were performed using a paired t-test. Agreement between these two methods was displayed with plots using Bland-Altman method. [START_REF] Bunting | A Practical Guide to Assess the Reproducibility of Echocardiographic Measurements[END_REF]. All 3D-TEE measurements were performed by an observer (AC) blinded to patient information and CT analysis. Interobserver variability was quantified in 10 patients with a second observer (SA) blinded to all measurements with intraclass correlation coefficient with 95% confidence intervals. Receiver Operating Characteristics (ROC) curve analyses were used to determine the 3D-TTE cut-offs with the higher discriminating power to predict exclusion from TMVR due to too large or too small anatomy. Statistics were performed using MedCalc v16.4 (Olstead, Belgium).

RESULTS

Characteristics of patients referred to the Heart Team and eligible for TMVR screening Among the 57 patients included, 2 patients had a truncated LV view with commissures out of the 3D data set and 3 patients had inadequate image quality due to severe pulmonary disease.

Patients were elderly (77±9 years), with a sex ratio of nearly 1 and few diabetic patients (21%). Most of the patients (60%) were in NYHA 3 or 4. Almost a half presented with chronic kidney disease and 15% had previous cardiac surgery. These characteristics translates into high EuroScore II and STS predicted risk of mortality, 3.05 [2.00-6.08] and 5.75 [3.67-8.70], respectively. MR mechanism was mainly primary (60%) with a posterior mitral valve leaflet mostly involved (58%). LV function was normal (ejection fraction>60%) in 26 patients (50%) and moderately impaired (ejection fraction between 30% and 60%) in 26 patients (50%). No patient had severe LV dysfunction (ejection fraction <30%). 33 patients (63.5%) had previous and paroxysmal atrial fibrillation (AF). No patient was in AF at the time of the CT of TEE acquisition.

Comparison of 3D-TEE and CT measurements

Both projected MA area and perimeter measurements were the parameters with the best concordance with CT, showing excellent correlation (r=0.88, p<0.0001 and r=0.92, p<0.0001, respectively) with small differences between the two modalities (-0.05±0.72, p=0.68 and 1.09±3.39, p=0.54 respectively by paired t-test) (Table 1, Figures 3). Correlation was significant but lower for MA diameters (r=0.72, p<0.0001 for AP diameter and r=0.68, p<0.0001 for PM-AL diameter) and mitro-aortic angle (r=0.53, p=0.0001).

In Bland-Altman analysis, 3D-TEE measurements were slightly smaller than CT measurements for most measurements with the following differences: mean projected MA area difference = 0.1cm² (range, 3.6 to -3.4cm²), projected MA perimeter difference = -0.6mm (range, 13.7 to -15mm), A-P diameter difference = -2mm (range, 6.8 to -10.7mm) and PM-AL diameter difference = -2.8mm (range, 6.7 to -12.4mm) (Figures 3).

Intraclass correlation coefficient for the 10 patients tested was 0.97 (0.79-0.99) for projected MA area, 0.87 (0.50-0.98) for projected MA perimeter, 0.94 (0.55-0.99) for A-P diameter, 0.93 (0.53-0.99) for PM-AL diameter and 0.60 (-1.88-0.94) for mitro-aortic angle. Mitral annulus dimensions by TEE and CT according to MR mechanism are given in Supplemental Table 1.

Receiver Operating Characteristic Curve Analyses for prediction too large or too small

annulus with 3D-TEE Among the 52 patients screened for TMVR, 34 patients (65%) were refused, 20 (38%) for a too large annulus and 14 (27%) for a too small annulus including 11 with risk of LVOT obstruction. Screening success rate was significantly higher in secondary than in primary MR, respectively 71.4% vs. 19.4%, p=0.0008.

ROC curve analyses showed that 3D-TEE had a good ability to predict too large anatomy as defined by constructors based on CT measurements with a cut-off of 15cm² for projected MA area (area under the curves (AUC) =0.91, p<0.0001), 139mm for projected MA perimeter (AUC=0.91, p<0.0001), 39mm for A-P diameter (AUC=0.84, p<0.0001) and 42mm for PM-AL diameter (AUC=0.89, p<0.0001) (Table 2). In addition, the discrimination ability of 3D-TEE to predict too small annulus defined on CT sizing was also good with a cut-off of 12.9cm² for projected MA area (AUC=0.88, p<0.0001), 128mm for projected MA perimeter (AUC=0.85, p<0.0001), 35mm for A-P diameter (AUC=0.79, p=0.003) and 37mm for PM-AL diameter (AUC=0.81, p<0.0001) (Table 3). Importantly, predictions for screening were always consistent between 3D-TEE and CT. ROC curves analyses for predicting too large or too small annulus with 3D-TEE are given in Supplemental Figures 2.

Implantation results

Among the 18 patients with screening success, 2 died before TMVR and 16 underwent TMVR. 14 patients (87.5%) had successful implantation without complication, 1 (6.25%) presented severe paravalvular leak, and 1 (6.25%) moderate intravalvular leak. 1 patient presented a significant LVOT obstruction (max aortic velocity = 3.4m/s) but without clinical signs. All the results of the implantations are given in Supplemental Table 2.

DISCUSSION

Exploring 52 eligible patients referred to our Heart Valve Clinic for a TMVR with a variety of dedicated prostheses, we found that 3D-TEE measurements of MA dimensions is 1) feasible in 90% of the cases (52/57), 2) displays good interobserver agreement and correlations with CT measurements and 3) poses very high accuracy to predict TMVR screening success as defined by manufacturer recommendations for CT measurements.

With commercially available software and improvement in 3D technology, 3D-TEE has the unique capacity of showing the MA and the mitral valve from an en face perspective with a high temporal and spatial resolution. It is thus probably one of the best methods for visualizing and exploring the anatomy and dynamism of the MA. [START_REF] Grewal | Mitral annular dynamics in myxomatous valve disease: new insights with real-time 3-dimensional echocardiography[END_REF][START_REF] Faletra | Anatomy of mitral annulus insights from non-invasive imaging techniques[END_REF] Usefulness of MA evaluation using 3D-TEE has been reported in patients undergoing surgical [START_REF] Chen | Three-Dimensional Echocardiographic Assessment of Mitral Annular Physiology in Patients With Degenerative Mitral Valve Regurgitation Undergoing Surgical Repair: Comparison between Early-and Late-Stage Severe Mitral Regurgitation[END_REF][START_REF] Sugeng | Realtime three-dimensional transesophageal echocardiography in valve disease: comparison with surgical findings and evaluation of prosthetic valves[END_REF] or percutaneous [START_REF] Mantegazza | Comprehensive Assessment of Mitral Valve Geometry and Cardiac Remodeling With 3-Dimensional Echocardiography After Percutaneous Mitral Valve Repair[END_REF] mitral valve repair, and in ischemic MR [START_REF] Fattouch | Multiplane two-dimensional versus real time three-dimensional transesophageal echocardiography in ischemic mitral regurgitation[END_REF] or in the presence of mitral annular disjunction [START_REF] Lee | Functional Implication of Mitral Annular Disjunction in Mitral Valve Prolapse: A Quantitative Dynamic 3D Echocardiographic Study[END_REF]. Only one prior study showed its usefulness in TMVR sizing for a dedicated prosthesis [START_REF] Mak | Three-Dimensional Echocardiography Compared With Computed Tomography to Determine Mitral Annulus Size Before Transcatheter Mitral Valve Implantation[END_REF]. In line with the latter study, we found an excellent correlation between 3D-TEE and CT for MA area and perimeter measurements (r=0.88 and r=0.92 respectively) and a good correlation for PM-AL diameter (r=0.68), despite different software for TEE MA sizing. The lower correlation for PM-AL diameter may be due to a suboptimal resolution in the lateral part of the coronal plane in 3D-TEE, reducing the ability to distinguish blood from tissue [START_REF] Khalique | Aortic annular sizing using a novel 3-dimensional echocardiographic method: use and comparison with cardiac computed tomography[END_REF]. We showed larger MA dimensions (MA area and perimeter=14.8cm² and 137.8mm respectively) than Mak et al. (11.4cm² and 123mm respectively) or other studies [START_REF] Aruta | Comparison of mitral annulus geometry between patients with ischemic and non-ischemic functional mitral regurgitation: implications for transcatheter mitral valve implantation[END_REF][START_REF] Veronesi | Quantification of mitral apparatus dynamics in functional and ischemic mitral regurgitation using real-time 3-dimensional echocardiography[END_REF]. This can be explained by the characteristics of our population, i.e. older patient, with a higher proportion of primary and severe MR. Indeed, in line with Mak et al. findings, we found that primary MR were associated with larger MA measurements (Supplemental Table 1). We also found lower screening success rates in primary MR. These differences in TMVR screening between primary and secondary MR should be explored in further studies. TEE-derived MA area between 12.9 and 15cm² and MA perimeter between 128 and 139mm can predict screening success with specificity satisfying accuracy (Figure 4). We did not included patients with AF at the time of the acquisition. The way to manage AF both for CT and 3D-TEE acquisition and analysis should be explored in further studies.

Almost a half of patients referred for TMVR presented with chronic kidney disease in our centre. Thus, using 3D-TEE measurements of MA as first-line imaging modality appears clinically relevant to avoid iodinated contrast injection mandatory with screening CTs. Even if the final decision will be taken with CT analysis, our study is the first to propose range of 3D-TEE measurements to predict TMVR screening success for the currently available TMVR sizes.

Limitations

The software uses a semi-automated segmentation algorithm to initiate a 3D model from where MA measurements are calculated, with an inherent risk of giving inaccurate 3D models. A review step is thus mandatory to confirm the accuracy of the model. Though this step may lead to discrepancies, the interobserver variability was at least good in our study.

Moreover, current software allows MA analysis during one moment of the cardiac cycle.

Since MA area is highly dynamic, with a 20-30% reduction during LV contraction (29), a dynamic evaluation with a multiphasic annular assessment would probably improve the annular sizing. Although the final suitability decision was given by the manufacturer, the criteria for suitability was the same for the 3 devices. However, this criterion must be confirmed in the future. Even if we present data from the most used prosthesis, as the companies produce different size devices, the cut-offs will change depending on the company and must be confirmed in further studies. Poor image quality still an issue for 3D-TEE analysis in almost 10% of the screened population. Unfortunately, both TEE or CT did not give us any clues regarding postoperative issues. The high LVOT gradient and the significant MR observed in 3 patients were actually secondary to per-procedure issues and calcifications that are in our mind hardly predicted even a posteriori by pre-op screening. Finally, we report the current largest TVMR population with 3D-TEE, CT and screening for dedicated TMVR prosthesis. However, our results and ranges of 3D-TEE measurements should be tested in larger populations.

Clinical perspectives

3D-TEE is feasible and useful to measure MA dimensions in patients referred for TMVR, displaying good interobserver agreement and correlations with CT measurements and high accuracy to predict TMVR screening success. It might be proposed as a reasonable alternative to avoid unnecessary CTs in this vulnerable population CONCLUSION 3D-TEE measurements of MA dimensions are feasible in daily practice to predict TMVR screening success with acceptable accuracy and interobserver agreement, and good correlations with CT measurements.

FIGURE LEGENDS Figure 1. Mitral annulus sizing using 3D-TEE MVQ software

A, A 3D volume of the mitral annulus set is acquired from a multiplane 2D-TEE view. B, Alignment step is mandatory to ensure standardized and expected views where vertical axis crosses through the center of the mitral valve while the horizontal axis is parallel to the mitral valve. C, 6 landmarks are then placed (two mitral annulus points, two anterior/posterior points, the coaptation plus the aorta point. D, A complete 3D reconstruction of the mitral annulus is finally performed. Once all lines have been checked, area (E), perimeter (F) or PM-AL diameter (yellow line, G) for example are determined by the 4D Auto MVQ software. 3D: Three dimensional; PM-AL: Posteromedial-anterolateral; TEE: Transoesophageal Echocardiography

Figure 2. CT mitral annulus measurements

A, Mitral annular segmentation is manually performed using a dedicated software (3mension, Pie Medical Imaging. Bilthoven, The Netherlands) by placing 16 points around the annulus. B, the software automatically generates the 3D reconstruction of the mitral annulus with its parameters on a short-axis view and C, the corresponding aorto-mitral angle on a 3-chamber view

Supplemental Figures 1. ROC curves analyses for prediction too large (A) or too small (B) annulus with 3D-TEE

  ABBREVIATIONS LIST

Figures 3 .

 3 Figures 3. Bland-Altman plots and correlations for comparison of 3D-TEE and CT mitral annulus measurements. Comparison of A) MA area, B) MA perimeter, C) A-P diameter and D) PM-AL diameter. P-value by linear regression 3D: Three dimensional; AP: Antero-posterior; MA: Mitral Annulus; PM-AL: Posteromedial-anterolateral; TEE: Transoesophageal Echocardiography

Figure 4 .

 4 Figure 4. Ranges of 3D-TEE measurements for TMVR suitability AP: Antero-posterior; PM-AL: Posteromedial-anterolateral

Figure 1 .

 1 Figure 1. Mitral annulus sizing using 3D-TEE MVQ software

Figure 2 .Figures 3 .

 23 Figure 2. CT mitral annulus measurements

Figure 4 .

 4 Figure 4. Ranges of 3D-TEE measurements to predict TMVR screening success

Table 1 : Comparison between TEE and CT measurements

 1

		3D-TEE	CT	∆ ∆ ∆ ∆ 3D-TEE -CT	Absolute % error	R	p-value
	Projected MA area (cm²)	14.8 ± 3.7	14.8 ± 3.5	-0.05 ± 0.72	5.96 (3.64-9.83)	0.88	<0.0001
	Projected MA perimeter (mm)	137.8 ± 17.8	138.8 ± 16.3	1.09 ± 3.39	2.25 (1.52-4.34)	0.92	<0.0001
	A-P diameter (mm)	39.4 ± 5.8	41.4 ± 6.2	2.06 ± 1.18	8.28 (5.69-10.0)	0.72	<0.0001
	PM-AL diameter (mm)	41.3 ± 6.2	44.2 ± 5.8	2.84 ± 1.19	9.09 (6.11-11.06)	0.68	<0.0001
	Anterior leaflet length (mm)	28.2 ± 5.3	32.3 ± 6.4	4.12 ± 1.17	15.88 (9.75-22.07)	0.28	0.05
	Mitro-aortic angle (°)	117.5 ± 15.5	115.5 ± 26.5	-2.07 ± 4.28	7.81 (6.08-11.24)	0.53	0.0001
		AL: Anterolateral; A-P: AnteroPosterior; MA: Mitral Annulus; PM: Posteromedial.

Table 2 : ROC analyses for prediction too large annulus with 3D-TEE

 2

		AUC	p-value	Cut-off	Sensitivity	Specificity
	3D-TEE
	MA area (cm²)	0.91	<0.0001	15	88.9	87.9
	MA perimeter (mm)	0.91	<0.0001	139	83.3	87.9
	A-P diameter (mm)	0.84	<0.0001	39	94.4	60.6
	PM-AL diameter (mm)	0.89	<0.0001	42	83.3	84.9
	Anterior leaflet length (mm)	0.67	0.03	26	88.9	39.4
	Mitroaortic angle (°)	0.65	0.06	112	66.7	68.8
	AL: Anterolateral; A-P: AnteroPosterior; MA: Mitral Annulus; PM: Posteromedial

Table 3 : ROC analyses for prediction too small annulus with 3D-TEE

 3

		AUC	p-value	Cut-off	Sensitivity	Specificity
	3D-TEE
	MA area (cm²)	0.88	<0.0001	12.9	81.8	82.5
	MA perimeter (mm)	0.85	<0.0001	128	72.7	85
	A2-P2 diameter (mm)	0.79	0.003	35	72.7	90
	PM-AL diameter (mm)	0.81	<0.0001	37	72.7	82.5
	Anterior leaflet length (mm)	0.74	0.007	24	54.6	85
	Mitroaortic angle (°)	0.52	0.79	120	90.9	30.8
	AL: Anterolateral; A-P : AnteroPosterior; MA: Mitral Annulus; PM: Posteromedial

D.

E.