OBJECTIVE: To determine the incidence of angiographically evident coronary artery disease (CAD) of the anomalous left circumflex artery (ALCx). BACKGROUND: Due to the acute angulation of its origin from the aorta and its retroaortic course, some have proposed an increase in CAD in these vessels. METHODS: We performed a retrospective cohort study of all patients (n = 5205) presenting for left heart catheterization at the St Louis Veterans Affairs hospital from 2006-2012. Quantitative coronary angiography (QCA) was performed by two independent operators for all cases identified as having ALCx (n = 18). RESULTS: We identified 18 patients (0.346%) with this anomaly. Sixteen of 18 cases (89%) had atherosclerosis involving the ALCx. QCA performed on the ALCx for all 18 patients resulted in a mean stenosis of 61% (range, 10%-100%). Seven out of 18 patients (39%) had obstructive CAD of the ALCx with the majority (n = 6; 86%) also having concomitant obstructive disease in the left anterior descending (LAD) or right coronary artery (RCA). In the 5 cases where the ALCx underwent intervention, the mean diameter stent was 2.25 mm, with a mean length of 15 mm, indicating that these vessels were small in caliber with focal disease. At a mean follow-up of 18 months for all patients, there was 1 non-cardiac death in the non-intervened group, with the 17 remaining patients (94.7%) free of major adverse cardiovascular events (target lesion revascularization, target vessel revascularization, or death). CONCLUSIONS: This study suggests that indeed this most common anomaly appears to be benign in that its unique origin and/or retroaortic course do not increase the occurrence of atherosclerosis relative to the LAD and RCA.
OBJECTIVE: To determine the incidence of angiographically evident coronary artery disease (CAD) of the anomalous left circumflex artery (ALCx). BACKGROUND: Due to the acute angulation of its origin from the aorta and its retroaortic course, some have proposed an increase in CAD in these vessels. METHODS: We performed a retrospective cohort study of all patients (n = 5205) presenting for left heart catheterization at the St Louis Veterans Affairs hospital from 2006-2012. Quantitative coronary angiography (QCA) was performed by two independent operators for all cases identified as having ALCx (n = 18). RESULTS: We identified 18 patients (0.346%) with this anomaly. Sixteen of 18 cases (89%) had atherosclerosis involving the ALCx. QCA performed on the ALCx for all 18 patients resulted in a mean stenosis of 61% (range, 10%-100%). Seven out of 18 patients (39%) had obstructive CAD of the ALCx with the majority (n = 6; 86%) also having concomitant obstructive disease in the left anterior descending (LAD) or right coronary artery (RCA). In the 5 cases where the ALCx underwent intervention, the mean diameter stent was 2.25 mm, with a mean length of 15 mm, indicating that these vessels were small in caliber with focal disease. At a mean follow-up of 18 months for all patients, there was 1 non-cardiac death in the non-intervened group, with the 17 remaining patients (94.7%) free of major adverse cardiovascular events (target lesion revascularization, target vessel revascularization, or death). CONCLUSIONS: This study suggests that indeed this most common anomaly appears to be benign in that its unique origin and/or retroaortic course do not increase the occurrence of atherosclerosis relative to the LAD and RCA.