BACKGROUND:
Controlled and uncontrolled studies suggested that beta-blockade improves ventricular
function in congestive heart failure. Several trials suggested that beta-blockers may also
reduce mortality. In the Beta-Blocker Heart Attack Trial, patients with a history of heart
failure had less cardiac and sudden-death mortality than those who did not. Patients with a
low ejection fraction in the Cardiac Arrhythmia Suppression Trial who were treated with
beta-blockade also had a reduction in mortality. The Metoprolol in Dilated Cardiomyopathy
trial randomized patients with dilated cardiomyopathies to treatment with metoprolol or
placebo. There was a trend toward reduction in a morbidity and mortality endpoint in patients
treated with metoprolol, but this was due entirely to a reduction in the need for cardiac
transplantation. Thus, despite a reasonable theoretical basis and suggestive clinical
studies, the concept that beta-blockers reduced mortality in congestive heart failure
patients was unproved.
DESIGN NARRATIVE:
Randomized, double-blind, multicenter. Patients were assigned to standard therapy plus the
addition of a beta-blocker (bucindolol) versus a placebo. The primary endpoint was total
mortality. A radionuclide ventriculogram was performed within 60 days of randomization.
History, physical examination, clinical laboratory studies, chest x-ray, electrocardiogram,
and plasma norepinephrine levels were obtained within 14 days of randomization. Patients were
stratified by hospital, congestive heart failure etiology, ejection fraction, and gender, and
were assigned to a treatment group by an adaptive balancing scheme ("biased coin"
randomization). Patients were randomized to either placebo plus standard congestive heart
failure treatment or to the beta-blocker plus standard congestive heart failure treatment and
followed for a minimum of 18 months. The over three year recruitment period began in May 1995
at the first 35 sites. An additional 55 sites began recruitment on August 14, 1995.
Recruitment ended in December, 1998 with the enrollment of 2,708 patients.