CAUSE OF ACUTE MYOCARDIAL-INFARCTION AFTER SUCCESSFUL CORONARY ANGIOPLASTY

Percutaneous transluminal coronary angioplasty is now accepted as effective therapy for selected patients with coronary artery disease.1 It has been suggested that patients with complete revascularization after coronary angioplasty have a lower incidence of subsequent myocardial infarction than those with incomplete revasculariiation. However, it is not known whether myocardial infarction after angioplasty is due to occlusion at the angioplasty site, at the site of an undilated stenosis or at the site of a previously nonobstructive lesion. In patients treated medically2,3 or with bypass surgery,4 subsequent myocardial infarction frequently occurs owing to occlusion at a site that previously had <50% stenosis. Thus, we hypothesized that occlusion at a site that did not contain an obstructive lesion during angioplasty is an important cause of myocardial infarction after successful angioplasty. If nonobstructive lesions are frequently the culprit, then complete revascularization would not prevent most myocardial infarctions. The purpose of this study was to determine if myocardial infarction after successful angioplasty is due to occlusion at the angioplasty site, at the site of an undilated obstructive stenosis or at sites that were not obstructive during angioplasty. © 1991.