Management of non-Q-wave myocardial infarction: role of diltiazem versus beta-blocker therapy.

Several large-scale, multicenter trials have been conducted to evaluate the effects of currently available calcium channel blockers on a variety of cardiac end points in patients with myocardial infarction. Results indicate that careful subgroup stratification is necessary if morbidity and mortality are to be favorably altered. Certain groups of patients who are at high risk of recurrent myocardial infarction (MI) or death must be targeted for more aggressive diagnosis and therapy. Subset analysis of the Multicenter Diltiazem Postinfarction Trial (MDPIT) provides detailed information about diltiazem's long-term benefit following non-Q-wave or inferior Q-wave MI, and its lack of efficacy in patients with extensive or prior MI. Concerning use of beta-blockers versus calcium channel blockers as secondary prevention following acute MI, the pathogenesis, clinical course, prognosis, anatomy, and histology of non-Q-wave MI differs appreciably from Q-wave MI, and hence it is logical to assume that secondary prophylaxis post-MI should differ for non-Q-wave versus Q-wave MI. It would appear that beta-blockers (particularly those agents without intrinsic sympathomimetic activity) are best suited for secondary prevention after Q-wave MI, whereas diltiazem is the only therapy of proven benefit for use after non-Q-wave MI.