[Calcium channel antagonists and myocardial ischemia or ischemia/reperfusion]

Abstract

Many theoretical and experimental studies suggest that calcium antagonists drugs should be useful in pathological situations of myocardial ischemia or ischemia/reperfusion. This therapeutic model was tested in controlled trials of angina, post-infarction and cardiac surgery. The authors undertook a meta-analysis of these trials using the occurrence of myocardial infarction or death as criteria of judgement. No long-term benefits seem to be associated with the dihydropyridines such as nifedipine and nicardipine in anginal patients. In unstable angina, betablockers seem to be more effective but the difference is not statistically significant. In the post-infarction period, nifedipine does not reduce the risk of recurrence of myocardial infarction and may even increase the mortality by 15%, though this was not significant in the 9,055 patients studied (p = 0.08). Verapamil and diltiazem globally reduce the risk of recurrent infarction by 21% (p = 0.009) but not mortality (p = 0.52). Because of the small numbers of patients and the low prevalence of observed events, no useful conclusions can be drawn from studies of calcium antagonists in cardiac surgery. The results of the validation of the therapeutic model "calcium antagonists in pathological situation of myocardial ischemia or ischemia/reperfusion" does not justify the labels "anti-ischemics" or "cardio protectors" often applied to the calcium antagonists.