Fifteen RCTs (17 arms) were included (n=47,694, range 248 to 22,576). A total of 23,451 participants were on calcium channel blockers, 16,251 on other antihypertensives and 7,992 on placebo. All RCTs were deemed high quality (Jadad score 3 to 5 points).
Calcium channel blockers versus controls (other antihypertensives or placebo): There was no statistically significant difference between the calcium channel blocker group and controls in all-cause mortality (15 comparisons), cardiovascular mortality (14 comparisons), non-fatal myocardial infarction (15 comparisons) and heart failure (11 comparisons); there was significant statistical heterogeneity for the outcome of heart failure (I2=69.2%). There was a significantly reduced risk in the calcium channel blocker group compared to controls of stroke (RR 0.79, 95% CI 0.70 to 0.89; 11 comparisons, I2=0%) and angina pectoris (RR 0.82, 95% CI 0.72 to 0.94, I2=78.7%, random effects). Results were similar for dihydropyridines and non-dihydropyridines.
When compared with placebo alone, risk of heart failure was reduced in the calcium channel blocker group by 28% (p<0.0001). The results of other comparisons of calcium channel blockers versus placebo alone and calcium channel blockers versus other antihypertensives alone were reported in the review, as were the results of sensitivity analyses.
There was no evidence of significant publication bias.