Degrees of Cross-Sectional-Area Luminal Narrowing of the Four Major Epicardial Coronary Arteries in Patients With Otherwise Functionally and Anatomically Normal Hearts

Abstract

Described herein are necropsy findings in the 4 major (left main, left anterior descending, left circumflex, and right) epicardial coronary arteries in 86 patients aged 10-70 years who never had symptoms of myocardial ischemia, and at autopsy had otherwise anatomically normal hearts. All 86 died of a non-cardiovascular condition. In each of these patients all 4 major epicardial coronary arteries were excised intact from the heart, divided into 5-mm segments, and each segment prepared for histologic examination. The degrees of cross-sectional area (CSA) narrowingwere determined from histologic examination of each 5-mm segment. The degree of narrowing in each 5 mm segment was divided into 4 categories: 0% to 25%, 26% to 50%, 51% to 75%, and 76% to 100%. Twelve patients (14%) had ≥1 artery narrowed >75% in CSA, a single artery in 9 patients, and 2 arteries in each of 3 patients. In contrast to the relative infrequency of narrowing >75%, narrowing 51-75% was common, and was present in 36 (42%) of the 86 patients. Of the 258 major coronary arteries (excludes the left main) studied in the 86 patients, 15 (6%) were narrowed >75%, and 70 (24%) were narrowed 51% to 75% in CSA. Even mild narrowing (26% to 50%) of the left main coronary artery (66 patients) was generally accompanied by 51% to 75% or greater narrowing of at least one of the other major coronary arteries. In conclusion, even hearts which have functioned normally and are otherwise anatomically normal, usually have some degree of atherosclerotic plaque in the major epicardial coronary arteries.