Determinants of outcome in patients with heart failure with reduced ejection fraction & secondary mitral regurgitation

Background: The outcome of secondary mitral regurgitation (MR) in patients with heart failure is poor. Survival is related to the severity of MR. We sought to investigate the effect of left ventricular contractility, the ratio of left ventricular end-diastolic volume (LVEDV) to effective orifice area (EROA) and the ratio of regurgitant volume (RVol) to stroke volume (SV) on cardiovascular survival.

Methods: 188 patients with a left ventricular ejection fraction (LVEF) < 50% and secondary MR were included. Groups were divided into tertiles. The Kaplan Meier method and log rank test were used to identify differences in survival between groups. Cox regression was used to identify independent predictors of cardiac mortality.

Results: Median follow-up was 30.4 months. Patients with a more abnormal global longitudinal strain (GLS) had lower survival, p = 0.001. There was no difference in survival between patients with an LVEF <30%, 30%-40% and >40%, p = 0.27. Patients with a higher RVol/SV ratio had lower survival than those with a lower ratio, p < 0.0001. Patients with a lower LVEDV/EROA ratio had worse survival than those with a higher ratio, p < 0.0001. Independent predictors of cardiovascular mortality were GLS (<5.6%) hazard ratio (HR) 2.7, the ratio of RVol/SV (>1.38) HR 4.96 and the ratio of LVDEV to EROA (<263) HR 4.49.

Conclusion: The main determinants of cardiovascular mortality in patients with secondary MR and heart failure are more abnormal GLS, lower LVEDV/EROA ratio and higher RVol/SV ratio. These may help risk stratify patients to help determine the optimal management strategy.