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, transplantation, and coronary reintervention.

Results: A total of 632 patients (median age, 5.0 days; interquartile range [IQR], 4.0-7.0 days) underwent ASO. Coronary anatomy included the following categories: usual (n = 411; 65%), circumflex (Cx) 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 in patients with intramural cardiac anatomy (n = 3; 10%), although it dropped to 0% in this group in the most recent decade. The median duration of follow-up was 14.5 years (IQR, 6.0-20.3 years). Twenty-year freedom from the primary endpoint was 95 ± 1% for usual anatomy, 99 ± 1% for Cx from sinus 2, 90 ± 4% for inverted, 91 ± 4% for single sinus, and 80 ± 9% for intramural (P < .001). Intramurals had the highest 20-year incidence of coronary reintervention (11 ± 8%). Cox modeling identified intraoperative coronary revision (hazard ratio [HR], 20.1; 95% confidence interval [CI], 9.4-53.9; P < .001), Taussig-Bing anomaly (HR, 4.9; 95% CI, 2.2-10.9; P < .001), and an intramural coronary artery (HR, 2.9; 95% CI, 1.0-8.2; P = .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 needed to determine the long-term fate of the coronary arteries after ASO.