Coronary anatomy and arteriography in patients with unstable angina pectoris.

A prospective series of 188 patients with the syndrome of unstable angina pectoris undergoing coronary arteriography was reviewed to determine the spectrum of anatomic coronary artery disease, suitability for coronary revascularization and in-hospital morbidity and mortality. Thirty-two patients demonstrated normal to moderately diseased coronary arteries. None of these patients sustained myocardial infarction or died. Twenty patients (10.6 percent) had normal coronary arteriograms. Of the 156 patients having severe coronary artery disease (greater than 70 percent stenosis), 20 patients (13 percent) had left main coronary artery disease. One hundred forty-two patients (91 percent) were potential candidates for coronary surgery; 14 were not candidates because of distal vessel disease or poor left ventricular function. During cardiac angiography or in the subsequent hospital period 12 patients sustained a myocardial infarction and 7 of these died. Of these seven, six had left main coronary artery disease and one had three vessel disease. In three patients who died (1.9 percent of those with severe coronary artery disease) the death may have been related to cardiac catheterization because evidence of myocardial necrosis began within 24 hours of study. Thus, patients with the syndrome of unstable angina pectoris usually presented with severe coronary artery disease and were candidates for coronary revascularization. The anatomic severity of coronary artery disease appeared to be the most important factor contributing to myocardlal infarction or death after cardiac catheterization. Mortality after catheterization was primarily associated with left main coronary artery disease.