Angiographic progression of coronary artery disease and the development of myocardial infarction.

There are few data on angiographic coronary artery anatomy in patients whose coronary artery disease progresses to myocardial infarction. In this retrospective analysis, progression of coronary artery disease between two cardiac catheterization procedures is described in 38 patients: 23 patients (Group I) who had a myocardial infarction between the two studies and 15 patients (Group II) who presented with one or more new total occlusions at the second study without sustaining an intervening infarction. In Group I the median percent stenosis on the initial angiogram of the artery related to the infarct at restudy was significantly less than the median percent stenosis of lesions that subsequently were the site of a new total occlusion in Group II (48 versus 73.5%, p less than 0.05). In the infarct-related artery in Group I, only 5 (22%) of 23 lesions were initially greater than 70%, whereas in Group II, 11 (61%) of 18 lesions that progressed to total occlusion were initially greater than 70% (p less than 0.01). In Group I, patients who developed a Q wave infarction had less severe narrowing at initial angiography in the subsequent infarct-related artery (34%) than did patients who developed a non-Q wave infarction (80%) (p less than 0.05). Univariate and multivariate analysis of angiographic and clinical characteristics present at initial angiography in Group I revealed proximal lesion location as the only significant predictor of evolution of lesions greater than or equal to 50% to infarction. This retrospective study suggests that myocardial infarction frequently develops from previously nonsevere lesions.(ABSTRACT TRUNCATED AT 250 WORDS)