P324 - NEW LEFT HEART VOLUME OVERLOAD PARAMETER TO ENHANCE RISK STRATIFICATION IN PATIENTS WITH MITRAL REGURGITATION

Background: Mitral regurgitation (MR) is the backward flow of blood from the left ventricle into the left atrium during systole due to incomplete closure of the mitral valve. Several indices reflecting left heart volumetric and functional coupling have been associated with adverse clinical events in several cardiac conditions but remain to be studied in the context of mitral regurgitation (MR). The aim of this study was to determine the prognostic value of new parameter of left heart volume overload in patients with significant MR.

METHODS AND RESULTS: A total of 112 patients with at least moderate MR from the PROGRAM perspective observational cohort (NCT#01835054) were included. The left heart volume overload was assessed using the left heart diastolic volume (LHDV), which represents the sum of the volume of the left atrium and left ventricle in tele-diastole. The LHDV was indexed to body surface area (LHDVi). Optimal prognostic thresholds were determined using ROC curves and Youden index. The association between LHDV and LHDVi and the composite clinical endpoint of mortality and mitral valve surgery was assessed using Cox regression analyses.
The mean age of the cohort was 61.3±14.3 years, with 55% men (n=62). The principal comorbidities were hypertension (n=48 [43%]) and hyperlipidemia (n=34 [30%]). During a median follow-up of 5.05 (2.87-6.80) years, 49 (43.8%) patients underwent a mitral valve surgery (15 replacements, 34 repairs), 9 (8,0%) patients died and 58 (51,8%) reached the composite clinical endpoint. The LHDV and LHDVi were significantly associated with the composite clinical endpoint (HR [IC 95%]:1,01 [1,04-1,02] per 1 ml increase, p=0,002 and HR [IC 95%]:1,02 [1,01-1,03] per 1 ml/m2, p< 0,001, respectively). Thresholds of LHDV>162 ml and LHDVi >87 ml/m2 were significantly associated with an increased risk of composite endpoint (HR [IC 95%]:3,71 [2,14-6,42], p< 0,001 et HR [IC 95%]:3,73 [2,14-6,50], p< 0,001, respectively).

Conclusion: The LHDV, a marker of left heart volume overload is useful to enhance risk stratification in patient with moderate to severe MR. This parameter may help guide clinical decision-making, particularly in asymptomatic patients by identifying those at higher risk of adverse clinical outcomes.