It was extended-release metoprolol (containing a succinate salt) that was used in MERIT-HF
, (1) so the recommendation to use metoprolol in heart failure applies only to the extended release formulation.
Packer replied that while interesting, this "has to be taken with a grain of salt" because the patient numbers in the MERIT-HF
subgroup analysis were too small draw firm conclusions, a point conceded by the Swedish investigator.
TABLE Selected trials of beta-blockers for systolic dysfunction Mortality reduction 95% Study Drug N (%) CI (%) US Carvedilol (1) Carvedilol 1094 (65) 39-80 COPERNICUS (2) Carvedilol 2289 (35) 19-48 MERIT-HF (3) Metoprolol 3991 (34) 19-46 CIBIS II (4) Bisoprolol 2647 (34) 19-47 BEST (5) Bucindolol 2708 (9) -0.2-22 Mean duration Statistically of follow-up Study significant?
(3.) Effect of metoprolol CR/XL in chronic heart failure: Metotprolol CR/XL Randomized Intervention Trial in Congestive Heart Failure (MERIT-HF).
Patients with NYHA class IV heart failure represented 3.6% and 17% of the MERIT-HF and CIBIS-II study populations, respectively.
The results of CIBIS-II, MERIT-HF, and US Carvedilol stratified by heart failure etiology indicated a decrease in mortality in patients with both ischemic and nonischemic heart failure.
The limited number of patients with NYHA class IV heart failure enrolled in MERIT-HF make comparative benefit speculations unreliable.
The number of patients with nonischemic heart failure receiving [Beta]-blocker therapy was largest in MERIT-HF, followed by US Carvedilol and CIBIS-II. Of these, US Carvedilol was the only trial to demonstrate a statistically significant decrease in mortality in patients with nonischemic heart failure receiving [Beta]-blocker therapy. This may indicate that greater benefit can be derived with carvedilol than with bisoprolol or metoprolol therapy in patients with nonischemic heart failure.
In the Metoprolol CR/XL Randomized Intervention Trial in Heart Failure (MERIT-HF), nearly 4,000 patients with New York Heart Association class II-TV congestive heart failure (CHF) in 14 countries were randomly assigned to metoprolol or placebo on top of standard triple drug therapy with an angiotensin-converting enzyme inhibitor, diuretics, and diogxin.
In MERIT-HF, adding metoprolol to standard triple-drug therapy saved an extra four lives per 100 treated patients per year.
It's also entirely appropriate to prescribe these agents in patients with asymptomatic left ventricular dysfunction, even though such patients weren't included in MERIT-HF or the other large trials.
Effects of controlled-release metoprolol on total mortality, hospitalizations, and well-being in patients with heart failure: the Metoprolol CR/XL Randomized Intervention Trial in Congestive Heart Failure (MERIT-HF