Anomalous circumflex coronary artery: benign or predisposed to selective atherosclerosis

Anomalous origin of the circumflex coronary artery from the right sinus of Valsalva is the most common coronary anomaly and is usually considered benign. Although several researchers in the past believed that aberrancy predisposes this vessel to accelerated atherosclerosis, this could not get wide acceptance owing to lack of convincing data. To examine the suggestion that atherosclerosis affects the anomalous circumflex artery more severely, the authors reviewed the clinical and angiographic features of patients with this anomaly identified from 2,684 coronary angiography procedures performed between January 1998 and March 2000 at their institution. The degree of atherosclerotic narrowing in the anomalous artery was compared with that in other coronary arteries in the same patient as well as in the nonanomalous circumflex arteries in controls. For comparison 3 control subjects were selected for each patient with anomalous circumflex artery, matched by age, sex, and clinical presentations. The results showed earlier and greater degree of atherosclerotic narrowing of the anomalous artery as compared to the other coronary arteries in the same patients as well as to nonanomalous circumflex arteries of age- and gender-matched control subjects with similar clinical characteristics. However, this predilection for atherosclerosis was evident only in anomalous vessels arising from the right side and pursuing a retroaortic course. The anomalous artery was responsible for myocardial infarction in 3 patients, all of whom were 60 years or older. Two of the patients with this anomaly and myocardial infarction underwent successful angioplasty with stent placement for symptomatic relief.