BACKGROUND: Surgical mitral valve repair for severe secondary mitral regurgitation (MR) remains controversial. The association of MR reduction and changes in left ventricular (LV) hemodynamics with survival has not been investigated. We investigated the independent associates of outcomes in heart failure patients with severe secondary MR who underwent surgical mitral valve repair.METHODS: Patients (n = 130, 62 ± 12 years old, 55% men) with chronic severe secondary MR and impaired LV ejection fraction (<0.50, mean 0.31 ± 0.10) treated with surgical mitral valve repair were included. Echocardiographic LV forward stroke volume and LV forward ejection fraction were measured at baseline and at discharge. All-cause mortality was the primary endpoint, and the combination of major adverse cardiac-related events and all-cause mortality was the secondary endpoint.RESULTS: At hospital discharge, 77% of patients showed no residual MR and 23% showed mild MR. LV volumes reduced significantly, whereas LV ejection fraction remained unchanged. In contrast, LV forward stoke volume (53 ± 24 mL versus 64 ± 22 mL, p < 0.001) and LV forward ejection fraction (0.32 ± 0.16 versus 0.48 ± 0.24, p < 0.001) significantly increased at discharge. During a median follow-up of 3.44 years, 33 patients (29%) died and 40 had major adverse cardiac-related events. On multivariable analysis, LV forward stroke volume after repair was independently associated with all-cause mortality (hazard ratio 0.98, p = 0.047) and with the combined endpoint (hazard ratio 0.98, p = 0.045) after correcting for other baseline, procedural, and postrepair characteristics.CONCLUSIONS: In patients with severe secondary MR treated with surgical repair, LV forward flow was independently associated with better survival and lower risk of the combined endpoint.