Metoprolol controlled release/extended release in patients with severe heart failure: analysis of the experience in the MERIT-HF study.
OBJECTIVE
This study analyzed the effect of the beta(1)-selective beta-blocker metoprolol succinate controlled release/extended release (CR/XL) once daily on mortality, hospitalizations and tolerability in patients with severe heart failure.


BACKGROUND
There continues to be resistance to the incorporation of beta-blockers into clinical care, largely due to concerns about their benefit in patients with more severe heart failure.


METHODS
SA subgroup of patients from Metoprolol CR/XL Randomized Intervention Trial in chronic Heart Failure (MERIT-HF) in New York Heart Association (NYHA) functional class III/IV with left ventricular ejection fraction < 0.25 were identified (n = 795). The analysis was by intention-to-treat.


RESULTS
The mean ejection fraction at baseline was 0.19, and the yearly placebo mortality during follow-up was 19.1%. Treatment with metoprolol CR/XL compared to placebo resulted in significant reductions in all predefined mortality end points including: total mortality, 45 versus 72 deaths (risk reduction 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 CR/XL also reduced the number of hospitalizations for worsening heart failure by 45% compared with placebo (p < 0.0001). The NYHA functional class improved in the metoprolol CR/XL group compared with placebo (p = 0.0031). Metoprolol CR/XL was well tolerated, with 31% fewer patients withdrawn from study medicine (all causes) compared with placebo (p = 0.027).


CONCLUSIONS
This subgroup analysis of the MERIT-HF study shows that patients with severe heart failure receive a similar mortality benefit and a similar reduction in hospitalizations for worsening heart failure with metoprolol CR/XL treatment as those patients included in the total study.
Goldstein
S
S
Henry Ford Heart and Vascular Institute, Henry Ford Hospital, Detroit, Michigan 48202-2689, USA. SGOLDST1@HFHS.ORG
Fagerberg
B
B
Hjalmarson A
Kjekshus
J
J
Waagstein
F
F
Wedel
H
H
Wikstrand
J
J
D000319:Adrenergic beta-Antagonists / Q000008:administration & dosage*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003692:Delayed-Action Preparations; D005260:Female; D006333:Heart Failure / Q000188:drug therapy* / Q000401:mortality; D006760:Hospitalization; D006801:Humans; D008297:Male; D008790:Metoprolol / Q000008:administration & dosage* / Q000031:analogs & derivatives; D008875:Middle Aged; D015337:Multicenter Studies as Topic; D016032:Randomized Controlled Trials as Topic
D000319:Adrenergic beta-Antagonists; D003692:Delayed-Action Preparations; D008790:Metoprolol