Thirty-five randomised controlled trials (56,444 participants, range 32 to 11,140) were included reporting 11 comparisons of ACEIs with placebo/no treatment, 12 comparisons of ACEIs with active treatment, 10 comparisons of ARBs with placebo and three comparisons of ARBs with active treatment. Study quality was generally good: 60% of studies had a Jadad score greater than 3 and 17 studies scored 5 (the maximum possible). Half of the studies met the allocation concealment criteria (details not reported for the other studies).
ACEIs: Compared with control (placebo or active treatment), ACEIs were associated with a statistically significant reduction in all-cause mortality (RR 0.87, 95% CI 0.78 to 0.98; 20 studies; Ι²=26%), cardiovascular deaths (RR 0.83, 95% CI 0.70 to 0.99; 13 studies; Ι²=40%) and major cardiovascular events (RR 0.86, 95% CI 0.77 to 0.95; 14 studies; Ι²=59%). Results were similar when ACEIs were compared with placebo or active treatment.
There was no evidence that the observed effects on all-cause mortality and cardiovascular deaths differed by subgroups including baseline blood pressure and type of diabetes. There was no evidence of publication bias for all-cause mortality.
Results were reported for cause-specific cardiovascular outcomes (myocardial infarction, heart failure and stroke).
ARBs: Compared with control (placebo or active treatment), there was no statistically significant effect on all-cause mortality (RR 0.94, 95% CI 0.82 to 1.08; 11 studies; Ι²=22%), cardiovascular deaths (RR 1.21, 95% CI 0.81 to 1.80; seven studies; Ι²=61%) and major cardiovascular events (RR 0.94, 95% CI 0.85 to 1.01; nine studies; Ι²=13%). Results were similar when ARBs were compared with placebo or active treatment.
There was insufficient data to allow meta-regression and subgroup analysis.
Results were reported for cause-specific cardiovascular outcomes (myocardial infarction, stroke and heart failure).