Left ventricular stroke volume index predicts outcomes in asymptomatic chronic severe primary mitral regurgitation

Abstract

Severe primary mitral regurgitation (MR) linked to substantial morbidity and mortality. However, racial differences impact the left ventricular size, which subsequently influence specific echocardiographic parameters. In this context, the left ventricular stroke volume index (LVSVi) may serve as a valuable prognostic indicator. This study aims to examine the association between LVSVi and a composite endpoint of all-cause mortality or mitral valve (MV) surgery. We conducted a retrospective study on asymptomatic chronic severe primary MR patients over a 5-year follow-up period. Among 77 patients with asymptomatic severe primary MR (mean age, 56.9 years; 55 male patients, 71.4%), an increase of 1 mL/m2 in LVSVi, calculated from the left ventricular outflow tract area, was independently associated with an 8.2% reduction in the odds of reaching the composite endpoint of all-cause mortality or MV surgery (adjusted odds ratio, 0.918; 95% confidence interval, 0.856–0.986; P = 0.018). The receiver operating characteristic curve for LVSVi demonstrated an area under the curve of 0.726 (P = 0.002), with a threshold of ≤ 35 mL/m2 yielding a sensitivity of 81% and specificity of 50% for predicting the composite outcome. The 5-year event-free survival was significantly lower in patients with LVSVi ≤ 35 mL/m2 compared to those with LVSVi > 35 mL/m2 (22.9% vs. 67.0%; Breslow test, P < 0.001). In patients with asymptomatic chronic severe primary MR, LVSVi was the significant echocardiographic parameter influencing the outcomes of MV surgery and mortality. This study supported the hypothesis generation that LVSVi may serve as a prognostic marker in this specific population.