Distribution and severity of coronary artery disease in 500 patients with angina pectoris.

The distribution and severity of coronary disease in 500 patients with angina pectoris and at least one area of 50% or greater reduction of luminal diameter in a major coronary artery were compared with respect to patients' age and coronary arterial pattern. The coronary arterial patterns were separated into right (360 patients), mixed (89 patients), and left (51 patients) systems, depending upon the blood supply to the inferior surface of the left ventricle. The following relationships were noted: 1) In patients with angina pectoris, the distribution and severity of coronary artery disease is similar from the third to eighth decade. 2) Coronary arterial stenoses of 50-70% of greater reduction of luminal diameter involve most frequently the proximal portion of the major vessels. Coronary artery disease is multivessel in nature in 80% of cases. In single vessel disease the left anterior descending artery is involved most frequently. 3) The left main coronary artery is moderately to severely obstructed less frequently in individuals with left (2%) as compared to right (8%) and mixed (10%) systems. Otherwise, the distribution of coronary artery disease is similar in right, mixed, and left systems. 4) Coronary artery disease is a diffuse rather than a focal process. As demonstrated by coronary arteriography, patients with coronary artery disease have smaller vessels throughout the arterial tree as compared with individuals free of evident coronary atherosclerosis.