Calcium antagonists after acute myocardial infarction.
Studies dealing with the evaluation of efficacy and safety of calcium-channel blocking agents in patients with myocardial infarction are not completely exhaustive. In this setting, three major issues have to be considered: the treatment of postinfarction angina, the prevention of sudden death and fatal or nonfatal reinfarction, and the potentially harmful inotropic action of these drugs. Calcium-channel blocking agents may exert their anti-ischemic effect either by increasing myocardial oxygen supply or by reducing myocardial oxygen demand, or both. The drug of choice will depend on the physiopathological setting of the individual patient and on the responsiveness to each specific compound (verapamil, dilitiazem, or dihydropyridines). The potential dangerous cardiodepressant action of this class of drugs, well documented in vitro, is sizable in vivo only for some of them (verapamil and derivatives, much less for diltiazem), but not for dihydropyridines. Thus, it does not generally represent a definite contraindication for patients also with potentially impaired left ventricular function. Up to the present, a number of studies have failed to demonstrate any beneficial effect of nifedipine and verapamil in the secondary prevention of myocardial infarction. Only diltiazem proved to be effective in increasing survival in patients with non-Q-wave myocardial infarction without left ventricular dysfunction. These data suggest the need for a careful stratification of patients into subgroups, in order to clarify who could actually benefit by these drugs.
Ferrario
M
M
Divisione di Cardiologia, Policlinico S. Matteo, IRCCS, Pavia, Italy.
Specchia
G
G
D002121:Calcium Channel Blockers / Q000627:therapeutic use*; D006801:Humans; D009203:Myocardial Infarction / Q000188:drug therapy* / Q000517:prevention & control; D012008:Recurrence
D002121:Calcium Channel Blockers