QUANTIFICATION OF CORONARY ARTERIAL NARROWING IN CLINICALLY-ISOLATED UNSTABLE ANGINA-PECTORIS - ANALYSIS OF 22 NECROPSY PATIENTS

A quantitative analysis of the degree and extent of coronary arterial narrowing by atherosclerotic plaques in the entire lengths of each of the four major epicardial coronary arteries in 22 patients with unstable angina pectoris is described at necropsy, and the observations are compared to those in 20 control subjects. All 22 study patients died within three days of an aortocoronary bypass operation, and all 20 control subjects died of malignant neoplasms. Of 1,049 five mm long segments of the left main, left anterior descending, left circumflex and right coronary arteries examined in the 22 patients (average 48 per patient), 497 (47 per cent) were 76 to 100 per cent narrowed in cross-sectional area by atherosclerotic plaques (controls = 1 per cent); 304 (29 per cent) were 51 to 75 per cent narrowed (controls = 29 per cent); 454 (48 per cent) were 26 to 50 per cent narrowed and only 119 (11 per cent) segments were less than 26 per cent narrowed (controls = 22 per cent). The amount of severe (>75 per cent) narrowing of the right, left main, left anterior descending and left circumflex coronary arteries by atherosclerotic plaques was similar. The amount of severe (>75 per cent) narrowing in the distal one half of the right and left anterior descending coronary arteries was significantly (p < 0.05) less than in the proximal halves of these two arteries. The per cent of 5 mm segments of coronary artery narrowed 76 to 100 per cent in cross-sectional area in the study patients was not affected by the patients' sex, cardiac weight or by the presence of healed left ventricular infarcts. In the seven younger ({slanted equal to or less-than} 45 years) patients, however, significantly (p < 0.05) more 5 mm segments were narrowed >75 per cent than in the 15 older (>45 years) patients. © 1979.