Calcium antagonists in myocardial infarction.

Calcium antagonists are effective cardioprotective agents in experimental models of myocardial infarction. However, clinical trials in acute myocardial infarction and in postinfarction secondary prevention led to conflicting results related to the small size of the majority of the trials and possible differences among individual agents with distinct ancillary properties. Furthermore, one has to consider separately the trials in patients with Q-wave infarction and in others with non-Q-wave infarction. Q-wave patients do not seem to benefit from therapy with calcium antagonists. However, the efficacy of early administration of verapamil or diltiazem cannot be ruled out as the available data are not conclusive, mainly because of the small size of the trials and the delay in administering the drugs. We have shown encouraging results with diltiazem, which, compared to placebo, decreased the infarct size measured with serial thallium SPECT defect scores, and increased left ventricular ejection fraction in acute Q-wave infarctions. Non-Q-wave infarction is another area where evidence of positive beneficial effects of diltiazem is strong, as shown by a recent trial conducted by Gibson et al. Diltiazem reduced the early reinfarction rate and postinfarction angina and 1-year cardiac mortality and nonfatal reinfarction rate. Consistent with these findings are results from subgroup analysis of the multicenter diltiazem postinfarction trial. Prophylactic use of diltiazem may be useful and should be considered in patients with non-Q-wave infarction along with aspirin, as no other treatment is yet available for this condition, at least for the time being and until the thrombolysis TIMI phase III trial is terminated.(ABSTRACT TRUNCATED AT 250 WORDS)