Objectives To compare the effects of angiotensin II receptor blockers and angiotensin-converting enzyme inhibitors on the risk of myocardial infarction, stroke, cardiovascular mortality and total mortality. Methods We conducted a meta-analysis of randomized comparative trials between angiotensin II receptor blockers and angiotensin-converting enzyme inhibitors. Inclusion criteria were publication in peer-reviewed journals indexed in Medline, randomized comparison of angiotensin II receptor blockers vs. angiotensin-converting enzyme inhibitors, or angiotensin II receptor blockers + angiotensin-converting enzyme inhibitors vs. angiotensin-converting enzyme inhibitors, report of major complications including myocardial infarction, stroke, cardiovascular mortality or all-cause mortality; average follow-up of at least 1 year in at least 200 patients. Results Six trials fulfilled the inclusion criteria, for a total of 49 924 patients. In the pooled estimate, there were no significant differences between angiotensin II receptor blockers and angiotensin-converting enzyme inhibitors on the risk of myocardial infarction (odds ratio 1.01; 95% confidence interval 0.95-1.07; P = 0.75), cardiovascular mortality (odds ratio 1.03; 95% confidence interval 0.98-1.08; P = 0.23) and total mortality (odds ratio 1.03; 95% confidence interval 0.97-1.10; P=0.20). This was the case also when the analysis involved only the comparison between angiotensin-converting enzyme inhibitors and angiotensin II receptor blockers. Overall, the risk of stroke was slightly lower with angiotensin II receptor blockers than angiotensin-converting enzyme inhibitors (odds ratio 0.92; 95% confidence interval 0.85-0.99; P=0.037), the direct angiotensin-converting enzyme inhibitors and angiotensin II receptor blockers comparison showing a nonsignificant trend in a similar direction. Statistical heterogeneity among trials was not significant, with a low to null inconsistency statistic, for stroke (P=0.67), myocardial infarction (P=0.86), cardiovascular mortality (P=0.14) and total mortality (P=0.12). Conclusion This overview suggests that angiotensin II receptor blockers are as effective as angiotensin-converting enzyme inhibitors on the risk of myocardial infarction, cardiovascular mortality and total mortality. Angiotensin II receptor blockers may be slightly more protective than angiotensin-converting enzyme inhibitors on the risk of stroke.
