Abstract 3334: Metoprolol Prevents Worsening of Mitral Regurgitation in Patients with Asymptomatic Left Ventricular Systolic Dysfunction: Insight from the REVERT Trial
Background: Mitral regurgitation has been shown to portend a poor prognosis for patients (pts) with heart failure. In this study, we evaluated the effect of extended-release metoprolol succinate (MET) on the severity of mitral regurgitation in patients enrolled in REVERT, a multicenter trial of the effect of MET on left ventricular remodeling in pts with asymptomatic left ventricular systolic dysfunction (NYHA Class I).
Methods: 164 stable NYHA Class I pts with LVEF < 40% and LV end-diastolic volume index > 75 mL/m2 were randomized in double-blind fashion to placebo vs. MET 50 mg or 200 mg (MET50 or MET200) for 12 months. Pts underwent serial echocardiograms including color Doppler assessment of mitral regurgitation (MR) at baseline, and at 6 and 12 months. The echocardiograms were evaluated in blinded fashion by the core echocardiography laboratory. MR was graded semi-quantitatively as none, minimal, mild, moderate, or severe, based on the color Doppler assessment of the MR jet.
Results: At baseline, 7% of pts had no MR; 47%, 37%, 9%, and 0% had minimal, mild, moderate, or severe MR, respectively. The table⇓ demonstrates the percentage of pts in each treatment group who experienced worsening in the severity of MR from baseline (*p < 0.05 vs. placebo by Pearson’s chi-square test). Significantly fewer pts randomized to MET200 experienced worsening of MR at 12 months (or last observation) compared to placebo (15% vs. 31%; p=0.048). MET50 was not associated with a decrease in the progression of MR. Pts whose MR worsened had a smaller decrease in LV end-systolic volume index compared to pts whose MR did not worsen (−2.1 vs. −10.2 mL/m2; p=0.036).
Conclusions: MET200, but not MET50, prevented worsening of MR in a significant number of patients. The differences in progression of MR were associated with differences in reverse remodeling. These findings have important implications for the prevention and treatment of functional MR in pts with left ventricular systolic dysfunction.