Calcium channel blockers in acute myocardial infarction and unstable angina: an overview.

OBJECTIVE: To assess the effects of calcium channel blockers on development of infarcts, reinfarction, and mortality. DESIGN: A systematic overview of all randomised trials of calcium channel blockers in myocardial infarction and unstable angina. PATIENTS: 19,000 Patients in 28 randomised trials. RESULTS: In the trials of myocardial infarction 873 deaths occurred among 8870 patients randomised to active treatment compared with 825 deaths among 8889 control patients (odds ratio of 1.06, 95% confidence interval of 0.96 to 1.18). There was no evidence of a beneficial effect on development and size of infarcts or rate of reinfarction. The results were similar in short term trials in which treatment was confined to the acute phase and those in which treatment was started some weeks later and continued for a year or two. There was no evidence of heterogeneity among different calcium channel blockers in their effects on any end point. The results were similar in the unstable angina trials (110 out of 561 patients treated with calcium channel blocker compared with 104 out of 548 controls developed a myocardial infarction; 14 out of 591 treated compared with nine out of 578 controls died). CONCLUSIONS: Calcium channel blockers do not reduce the risk of initial or recurrent infarction or death when given routinely to patients with acute myocardial infarction or unstable angina.