Evolution of Functional Mitral Regurgitation and Prognosis in Medically Managed Heart Failure Patients With Reduced Ejection Fraction.

OBJECTIVES: The purpose of this study was to assess whether medical management may alter the severity of functional mitral regurgitation (FMR) and its prognosis in patients who have heart failure with reduced ejection fraction (HFrEF).

BACKGROUND: FMR in patients who have HFrEF is associated with a worse prognosis. It is uncertain to what extent medical management may alter the severity of FMR and its prognosis.

METHODS: The extent of FMR was assessed at baseline and after a median follow-up period of 50 months in 163 consecutive HFrEF patients (left ventricular ejection fraction <40%). Severe FMR was defined as mitral regurgitation (MR) grade 3-4. All of the patients received the maximal tolerable doses of their heart failure (HF) medications. Major adverse cardiac events were defined as a composite of all-cause death and the need for heart transplantation or hospitalization for HF and/or malignant arrhythmias.

RESULTS: A total of 50 (31%) patients had severe MR at baseline. During the follow-up period, 38% of the severe FMR patients showed an improvement to nonsevere FMR (MR grade <3), whereas 18% of the nonsevere FMR patients developed severe FMR despite optimal HF treatment. Cox regression analysis revealed that the presence of sustained severe FMR or worsening of FMR was the most important independent prognostic determinant with an adjusted odds ratio of 2.5 (95% confidence interval: 1.5 to 4.3, major adverse cardiac events 83% vs. 43%). In addition, those patients showed a 13% increase in left ventricular end-diastolic volume index (LVEDVI), whereas the patients with improvement in their severe MR showed a 2% decrease in LVEDVI (p = 0.01).

CONCLUSIONS: Severe FMR was successfully treated with medication in almost 40% and was associated with prevention of left ventricular adverse remodeling and with an improved long-term prognosis.