Metoprolol controlled release/extended release in patients with severe heart failure - Analysis of the experience in the MERIT-HF study

OBJECTIVES This study analyzed die effect of the beta(1)-selective beta-blo cker metoprolol succinate controlled release/extended release. (CR/XL) once daily on mortality, hospitalizations and tolerability in patients with sev ere heart failure. BACKGROUND There continues to be resistance to the incorporation of beta-bl ockers into clinical care, largely METHODS A subgroup of patients from Metoprolol CR/XL Randomized Interventio n Trial in chronic Heart Failure (MERIT-HF), in New York Heart Association (NYHA) functional class III/IV with left ventricular ejection fraction <0.2 5 were identified (n = 795). The analysis was by intention-to-treat. RESULTS The mean ejection fraction at baseline was 0.19, and the yearly pla cebo mortality during follow-up was 19.1%. Treatment with metoprolol CR/XL compared to placebo resulted in significant reductions in all predefined mo rtality end points including: total mortality, 45 versus 72 deaths (risk re duction 39%; 95% confidence interval 11% to 58%; p = 0.0086); sudden death, 22 vs. 39 deaths (45% [7% to 67%]; p = 0.024); and death due to worsening heart failure, 13 vs. 28 deaths (55% [13% to 77%]; p = 0.015). Metoprolol C R/XL also reduced the number of hospitalizations for worsening heart failur e by 45% compared with placebo (p < 0.0001). The NYHA functional class impr oved in the metoprolol CR/XL group compared with placebo (p = 0.0031). Meto prolol CR/XL was well tolerated, with 31% fewer patients withdrawn from stu dy medicine (all causes) compared with placebo (p = 0.027). CONCLUSIONS This subgroup analysis of the MERIT-HF study shows that patient s with severe heart failure receive a similar mortality benefit and a simil ar reduction in hospitalizations for worsening heart failure with metoprolo l CR/XL treatment as those patients included in the total study. (C) 2001 b y the American College of Cardiology.