Study designs of evaluations included in the review
Randomised trials in which patients were randomised to beta-blocker therapy or no beta-blocker therapy. Trials in which patients were randomised to beta-blocker or an alternate therapy were excluded. In addition, studies were included if the patient was enrolled due to heart failure.
Average duration and treatment of trials was 13 months, although follow-up ranged from 1 to 23 months. In fact, 11 of 24 trials involved less than 6 months follow-up.
Specific interventions included in the review
Oral beta-blockers included in the review were acebutolol, metoprolol, labetalol, bucindolol, nebivolol, carvedilol and bisoprolol. Beta-blockers were given in addition to treatments for heart failure, including a diuretic, an angiotensin-converting enzyme (ACE) inhibitor and digoxin.
Participants included in the review
Patients with congestive heart failure. Typically patients had mean NYHA (New York Heart Association) functional class at baseline of 2.5, mean left ventricular ejection fraction of 24%, average age of 58 years and 78% were male.
Outcomes assessed in the review
Total mortality during treatment period (average duration of treatment and follow-up was approximately 13 months).
How were decisions on the relevance of primary studies made?
The authors do not state how the papers were selected for the review, or how many of the authors performed the selection.