Arterial Switch Operation: Early and Late Outcome for Intramural Coronary Arteries

Abstract

Intramural coronary artery course (IMCA) is associated with an increased risk of coronary event and mortality after the arterial switch operation (ASO). We describe early and late outcomes at our institution from 1996 to 2006. Operation notes for all patients who underwent ASO within 60 days of birth were reviewed, and those with IMCA were identified. Mortality and morbidity were obtained from discharge summary, predischarge electrocardiogram, and echocardiogram. Follow-up included clinical review, electrocardiogram, echocardiography, dobutamine stress echocardiography, and angiography. Eighteen patients of 215 in the cohort (8.4%) had IMCA. Intramural coronary artery course was more common in patients from French Polynesia (6 of 17; 35.3% versus 12 of 198; 6.1%; p=0.001). Early mortality for patients with IMCA was 1 of 18 (5.6%) compared with 6 of 197 (3%) for those without IMCA (p=0.46). One IMCA patient was lost to follow-up. The remaining 16 are alive and asymptomatic. Of the 13 who underwent angiography, 2 had minor coronary artery stenoses at initial nonselective aortic root angiography. Both stenoses resolved at subsequent selective coronary angiography. None of the 11 who underwent dobutamine stress echocardiography had inducible ischemia. We report a high prevalence of IMCA in an ASO population, particularly among patients referred from French Polynesia. Intramural coronary artery course was not a risk factor for mortality after ASO. Angiography demonstrated excellent short-term and long-term structural outcome for IMCA.