Long-term Adverse Events of Nonischemic Functional Mitral Regurgitation in Patients With Heart Failure

Nonischemic functional mitral regurgitation (FMR) is accompanied by dire long-term consequences. The treatment revolves around correcting the underlying left ventricular dysfunction. This study reports the long-term adverse outcomes of nonischemic FMR.

We enrolled 200 patients with at-least-moderate nonischemic FMR undergoing medical treatment and/or cardiac resynchronization therapy between 2003 and 2019. MR severity and left ventricular dysfunction parameters were obtained. The endpoint outcomes were all-cause mortality, stroke, all-cause rehospitalization, and the need for heart transplantation. 

Two hundred participants, 104 men (52%) and 96 women (48%), with a median age of 61 years (interquartile range [IQR], 50-70) at diagnosis and a median follow-up of 2 years (IQR, 1-4), were enrolled. All-cause mortality, all-cause rehospitalization, and need for heart transplantation were significantly associated with lower left ventricular ejection fraction and tricuspid annular plane systolic excursion (TAPSE) at diagnosis (P < 0.05). Baseline MR severity was significantly associated with stroke (P = 0.026) and all-cause rehospitalization (P < 0.001).MR severity, New York Heart Association (NYHA) classification, left ventricular end-diastolic diameter, and TAPSE improved at follow-up (P < 0.001). ACEi/ARB (P = 0.008), nitrate (P = 0.001), and hydralazine (P = 0.006) were associated with MR severity improvement. A significant difference was observed between survival free of all-cause mortality according to left ventricular ejection fraction (P = 0.041).

We reported freedom from all-cause mortality, cardiac mortality, and composite endpoints (all-cause mortality, heart transplantation, and stroke) in nonischemic FMR patients. We detected a significant decline in MR severity and NYHA classification during follow-up. Overall, the FMR-associated mortality risk can be significantly reduced by adhering to treatment guidelines in a tertiary heart center. (Iranian Heart Journal 2024; 25(1): 27-41)