LUMEN DIAMETER OF NORMAL HUMAN CORONARY-ARTERIES - INFLUENCE OF AGE, SEX, ANATOMIC VARIATION, AND LEFT-VENTRICULAR HYPERTROPHY OR DILATION

Background. Precise knowledge of the expected "normal" lumen diameter at a given coronary anatomic location is a first step toward developing a quantitative estimate of coronary disease severity that could be more useful than the traditional "percent stenosis." Methods and Results. Eighty-three arteriograms were carefully selected from among 9,160 consecutive studies for their smooth lumen borders indicating freedom from atherosclerotic disease. Of these, 60 men and 10 women had no abnormalities of cardiac function, seven men had idiopathic dilated cardiomyopathy, and six men had left ventricular hypertrophy associated with significant aortic stenosis. Lumen diameter was measured at 96 points in 32 defined coronary segments or major branches. Measurements were scaled to the catheter, corrected for imaging distortion, and had a mean repeat measurement error of 0.12 mm. When sex, anatomic dominance, and branch length were accounted for, normal lumen diameter at each of the standard anatomic points could usually be specified with a population variance of +/-0.6 mm or less (SD) and coefficient of variation of <0.25 (SD/mean). For example, the left main artery measured 4.5+/-0.5 mm, the proximal left anterior descending coronary artery (LAD) 3.7+/-0.4 mm, and the distal LAD 1.9+/-0.4 mm. For the LAD, lumen diameter was not affected by anatomic dominance (right versus left), but for the right coronary artery, proximal diameter varied between 3.9+/-0.6 and 2.8+/-0.5 mm (p<0.01) and for the left circumflex, between 3.4+/-0.5 and 4.2+/-0.6 mm (p<0.01). Women had smaller epicardial arterial diameter than men (-9%; p<0.001), even after normalization for body surface area (p<0.01). Branch artery caliber was unaffected by the anatomic dominance but increased with branch length, expressed as a fraction of the origin-to-apex distance (p<0.001). Lumen diameter was not affected by age or by vessel tortuosity but was significantly increased among men with left ventricular hypertrophy (+17%; p<0.001) or dilated cardiomyopathy (+12%; p<0.001). Conclusions. This is a reference normal data set against which to compare lumen dimensions in various pathological states. It should be of particular value in the investigation of diffuse atherosclerotic disease.