Angiotensin receptor blockers in preventing stroke: A systematic review and meta-analysis of randomized controlled trials

Angiotensin converting enzyme inhibitors (ACEIs) and angiotensin receptor blockers (ARBs) are widely used in patients who are at high risk of cardiovascular events. A consensus has emerged that ACEIs can reduce the risk of stroke. This programme of overviews of randomized trials was established to investigate the effects of ARBs on the risk of stroke in patients at risk for cardio-cerebrovascular events. Electronic databases were searched up toJanuary 2009, for randomized clinical trials comparing ARBs with other active treatments and placebo in patients at risk for cardio-cerebrovascular events. Data were extracted for patients’ characteristics, interventions, quality of trials, and rates of stroke. The efficacy measures were the odds ratios of strokes. We did separate overviews of trials comparing ARBs with placebo, with ACEIs, and with calcium antagonists. The pooled effects were calculated using the random effects model. Twenty three with 1832 patients were included in the analysis. The overview of placebo-controlled trials (11 trials, 44961 patients) revealed ARBs was associated with a significant reduction in the risk of stroke, with a pooled odds ratio of 0.91 (0.84 to 0.98). In the overview of trials comparing ARBs with ACEIs (6 trials, 26537 patients), there were no significant reduced risks of stroke with ARBs (odds ratio 0.93, 0.84 to 1.03). In the overviews comparing ARBs with calcium antagonists (4 trials, 22446 patients), no significant difference was found, with a pooled ratio of 1.16 (0.91 to 1.48). Evidence of the benefits of ARBs on the risk of stroke is provided by the overviews of placebo-controlled trials. There was no evidence of differences when comparing ARBs with ACEIs, and with calcium antagonists. Therefore, ARBs should be regarded as suitable treatments for preventing stroke in patients who are at high risk of cardiovascular events. Key words: Stroke, angiotensin receptor blockers, meta-analysis.