Forty-one studies (3,327 patients) were included: 36 (2,914 patients) following coronary artery bypass graft surgery, 2 (221 patients) following valve surgery and 3 (192 patients) following mixed types of surgery.
The authors stated that the majority of the included studies were unblinded. The median Jadad score was 1 (range: 1 to 4). Funnel plots were not presented, but the authors stated that they did not indicate the presence of publication bias.
CAs did not affect mortality (n=11); the OR was 1.01 (95% CI: 0.46, 2.22, P=1). When nimodipine studies were excluded, the OR was 0.66 (95% CI: 0.26, 1.70, P=0.4). There was no significant heterogeneity.
CAs significantly reduced MI (n=22); the OR was 0.58 (95% CI: 0.37, 0.91, P=0.02). There was no significant heterogeneity.
CAs significantly reduced ischaemia (n=20); the OR was 0.53 (95% CI: 0.39, 0.72, P<0.001). There was no significant heterogeneity.
CAs did not significantly reduce SVT (n=15); the OR was 0.73 (95% CI: 0.48, 1.12, P=0.15). There was significant heterogeneity among the studies. Subgroup analyses indicated that non-dihydropyridines significantly reduced SVT (OR 0.62, 95% CI: 0.41, 0.93, P=0.02), whereas dihydropyridines non significantly increased SVT (OR 2.69, 95% CI: 0.57, 12.64, P=0.2).
CAs increased post-operative creatinine clearance non significantly (n=5); the increase was 7.65 mL/minute (95% CI: -4.21, 19.51, P=0.2). There was significant heterogeneity between the studies. Post-hoc analyses were conducted to investigate this heterogeneity.
There were no significant differences between the CA and non-CA arms of the studies in any of the adverse events investigated.
Further results, including the effects of individual drugs, post-hoc, secondary and subgroup analyses, were reported in the review.