The number of angiographically documented coronary occlusions and the
incidence of Q-wave myocardial infarcts were retrospectively compared
in 348 patients with moderate coronary artery disease from the INTACT
study (International Nifedipine Trial on Antiatherosclerotic Therapy).
In only 68 out of 118 infarcts (58%) an occlusion of the respective c
oronary artery was found, suggesting a spontaneous recanalization rate
of 42%. On the other hand, only 68 out of 150 coronary occlusions (45
%) had resulted in a Q-wave infarct, Considering the high spontaneous
recanalization rate of the occlusions, it seemed possible that roughly
only every fourth coronary occlusion might result in a myocardial inf
arct. This hypothesis was confirmed in the prospective 3 years follow-
up of the identical patients during which 41 new occlusions developed
causing only 10 myocardial infarcts (24%). These findings might contri
bute to explain the relatively low incidence of clinically apparent co
ronary heart disease in the general population despite a high prevalen
ce of coronary artery disease.