Thirty-six consecutive patients with evolving acute myocardial infarction underwent emergent coronary angiography and intracoronary thrombolysis with urokinase. Nineteen of the patients had had angina before the infarction (group A), whereas the infarction was unheralded in the remaining 17 (group B). Thirty-two vessels (88%) were patent at follow-up angiography performed after 3 to 4 weeks, and the residual stenosis was 87% +/- 14% in group A and 47% +/- 25% in group B (p less than 0.001). Coronary spasm was provoked by ergonovine maleate in four of 12 patients in group A (33%) and in three patients in group B (18%). Coronary revascularization was undertaken in nine patients in group A and three in group B. These results indicate that patients with angina preceding acute myocardial infarction are more likely to have significant stenosis even at the late follow-up stage and to have a more urgent need for subsequent coronary revascularization. It also seems apparent that thromboembolism in most patients and coronary spasm in a few patients without significant coronary narrowing play significant causal roles in the onset of acute myocardial infarction.
Adult Aged