Sex-Specific Association of Left Ventricular Function With Mortality in Severe Mitral Regurgitation.

Abstract

The association between left ventricular (LV) systolic dysfunction and adverse outcomes in patients with severe degenerative mitral regurgitation (MR) may vary by sex. To investigate the sex-specific association of LV systolic function with mortality in patients with severe degenerative MR. This retrospective cohort study included consecutive patients who underwent surgery for severe degenerative MR at 2 tertiary hospitals in South Korea from 2006 to 2020. Preoperative LV ejection fraction (LVEF) and LV global longitudinal strain (LV-GLS) were measured, with absolute LV-GLS values reported. Patients were stratified by LVEF (≤55%, >55% to ≤60%, and >60%) and LV-GLS (<19.9%, ≥19.9% to <23.4%, and ≥23.4%) tertiles. Mortality status was verified through December 2023, with a median (IQR) follow-up duration of 8.2 (5.3-12.2) years. Data analysis was conducted in March 2024. Surgical MV repair or replacement. The primary outcome was all-cause mortality after MV surgery. Restricted cubic spline (RCS) curves visualized the association between LVEF, LV-GLS, and mortality for each sex. Among 1686 patients, 1088 (64.5%) were men and 598 (35.5%) were women. Women were older than men (median [IQR] age, 62 [51-70] vs 54 [45-63] years) and had higher LVEF and LV-GLS than men did. During the follow-up, 220 (13.0%) deaths occurred (117 men [10.8%]; 103 women [17.2%]). In Kaplan-Meier curves, mortality in men increased in the lowest LVEF (≤55%) and LV-GLS (<19.9%) groups, whereas women exhibited an earlier increase in mortality at higher LVEF (55%-60%) and LV-GLS (19.9%-23.4%) levels. Multivariable Cox analyses showed a higher mortality risk associated with LVEF less than or equal to 55% (adjusted hazard ratio [HR], 3.48; 95% CI, 1.84-6.58; P < .001) and 55% to 60% (adjusted HR, 2.21; 95% CI, 1.36-3.58; P = .001) compared with LVEF greater than 60% in women, but not in men (P for interaction by sex = .02). RCS curves showed an earlier increase in mortality risk at higher LVEF and LV-GLS levels in women. Similar trends were observed in asymptomatic patients. In this cohort study of patients with severe degenerative MR, women had an earlier increase in mortality risk associated with LV systolic dysfunction, suggesting the need to consider sex-specific criteria for early surgery in asymptomatic patients.