Abstract
Background
Stroke affects 15 million people per year worldwide. Despite recent developments in acute stroke treatment, prevention remains very important. Stroke has a high rate of recurrence; therefore secondary prevention is also important. Many clinical approaches to control risk factors have been proposed. One of these approaches is the prescription of beta-blockers that have effects beyond the reduction of blood pressure, which can reduce the recurrence of stroke.
Objectives
To evaluate the efficacy of beta-blockers for preventing stroke recurrence and for reducing death and major vascular events in people with a previous stroke or transient ischaemic attack (TIA), and to determine their safety, particularly with regard to the development of diabetes mellitus.
Search methods
We searched the Cochrane Stroke Group Trials Register (May 2014), the Cochrane Central Register of Controlled Trials (CENTRAL) and theCochrane Database of Systematic Reviews (CDSR) (The Cochrane Library 2014, Issue 5), the Database of Abstracts of Reviews of Effects (DARE) (May 2014), MEDLINE (1966 to May 2014), EMBASE (1980 to May 2014), and Latin American and Caribbean Health Sciences Literature (LILACS) (1982 to May 2014). We also searched ongoing trials registers and reference lists.
Selection criteria
Randomised controlled trials (RCTs) that included participants with previous stroke or TIA due to arterial thrombosis or embolism. The intervention was any beta-blocker versus control, or beta-blocker plus other treatment versus other treatment.
Data collection and analysis
Two review authors independently screened the trials identified, appraised quality, and extracted data.
Main results
We included two RCTs involving 2193 participants in the review. Both studies randomised participants to either beta-blocker (atenolol 5 mg) or placebo and were of a high methodological quality. We noted no statistical differences among the groups in risks of fatal and non-fatal stroke (risk ratio (RR) 0.94, 95% confidence interval (CI) 0.76 to 1.18). For other outcomes analysed (major vascular events, death from all causes, death from cardiovascular causes) , we observed no significant differences between the groups. There were minor blood pressure reductions in the intervention group. Neither of the included studies reported the occurrence of diabetes among their outcomes or assessed quality of life. Adverse events were significantly more frequent in participants taking atenolol than in those given placebo, and were the most common reason given for discontinuing treatment (RR 1.85, 95% CI 1.45 to 2.35).
Authors’ conclusions
To date, no available evidence supports the routine use of beta-blockers for secondary prevention after stroke or TIA. More studies with larger samples are needed.
Plain language summary
Beta-blockers for preventing stroke recurrence
People who have had a stroke or a transient ischaemic attack (TIA) are at risk of having further strokes or heart attacks, or other serious circulatory problems. Beta-blockers are drugs that reduce heart rate and blood pressure, and have other effects that might also reduce the risks of stroke and heart attack. Searching for studies up to May 2014, we found two high quality trials involving 2193 participants that tested beta-blockers after stroke in people with a recent stroke or TIA. No clear evidence indicated that beta-blockers reduced the risk of stroke, heart attack, or death from vascular disease. Participants who received beta blockers instead of placebo showed significantly more adverse effects. More studies with larger samples are needed.
