Rare Coronary Artery Variants are Associated with Increased Mortality and Reinterventions Following the Arterial Switch Operation

Objective To determine the influence of coronary anatomy on long-term outcomes of the arterial switch operation (ASO). Methods We retrospectively reviewed patients with transposition of the great arteries or Taussig-Bing anomaly who underwent ASO at our institution between 1992 and 2022. The primary endpoint was freedom from a composite of death, transplant, or coronary reintervention. Results A total of 632 patients (median age: 5.0 days [IQR, 4.0-7.0]) underwent ASO. Coronary anatomy included: usual (n=411, 65%), circumflex from sinus 2 (n=89, 14%), inverted (n=55, 9%), single sinus (n=46, 7%), and intramural (n=31, 5%). Overall operative mortality was 3% (n=16) and highest among intramurals (n=3, 10%), though dropped to 0% in this group in the most recent decade. Median follow-up was 14.5 years [IQR, 6.0-20.3]. Twenty-year freedom from the primary endpoint was 95%±1% for usual anatomy, 99%±1% for circumflex from sinus 2, 90%±4% for inverted, 91%±4% for single sinus, and 80%±9% for intramural (P<0.001). Intramurals had the highest 20-year incidence of coronary reintervention (11%±8%). Cox modeling identified intraoperative coronary revision (HR 20.1, 95% CI:[9.4-53.9], P<0.001), Taussig-Bing anomaly (HR 4.9, 95% CI:[2.2-10.9], P<0.001), and an intramural coronary artery (HR 2.9, 95% CI: [1.0-8.2], P=0.04) to be risk factors for the composite endpoint. Conclusions Rare coronary artery variants—particularly intramural—are associated with increased mortality and coronary reinterventions after ASO. A low threshold for unroofing intramurals is likely associated with declining mortality and improved outcomes. Additional investigations are required to determine the long-term fate of the coronary arteries after ASO.