Role of calcium antagonists in progression of arteriosclerosis. Evidence from animal experiments and clinical experience. Part II. Clinical experience with preventive effects of calcium channel blockers in atheromatous coronary artery disease.

Experimental evidence for antiatheromatous of effects of calcium antagonists has been impressive. Clinical experience has, in contrast, been more difficult to obtain. Primary prevention with calcium antagonists has not been studied due to obvious difficulties. Secondary prevention, however, has been investigated: Several studies have addressed influence of calcium antagonists upon atheromatous arterial wall changes as demonstrated by quantitative coronary angiocardiography. A review of these studies reveals considerable methodological problems. For nifedipine it could be demonstrated, however, that the occurrence of "new lesions" can be retarded to a certain extent (3-6). Nicardipine has been studied, but the preventive effect reported cannot be considered valid, because distribution of risk factors to the study groups was not statistically homogeneous. Another approach has been the application of calcium antagonists to patients with acute myocardial infarction. Here, vascular and myocardial effects come into play. In non-Q-wave, i.e. not transmural infarction, the calcium antagonist diltiazem definitely has preventive effects as regards re-infarction (2). The large multicenter post-myocardial infarction trial MDPIT showed an improvement of cardiac envent rate and re-infarction. This effect was seen only if pulmonary congestion was not present. Calcium antagonists have negative effects if cardiac failure is present. Verapamil was shown to have beneficial effects in acute myocardial infarction in the large DAVIT trials. Here again, the effect was only seen if heart failure was not present. Otherwise negative results were recorded. Nifedipine demonstrated only borderline myocardial protective effects in acute myocardial infarction (7). We conclude that calcium antagonists have vascular and myocardial protective effects.(ABSTRACT TRUNCATED AT 250 WORDS)