Aortic coarctation and long-term morbidity after arterial switch operation: a multicentre international cohort study.

Background In patients with dextro-transposition of the great arteries, cardiovascular interventions and complications are common after the arterial switch operation (ASO). While complex anatomy-typically defined by ventricular septal defects (VSDs)-is often linked to these outcomes, the independent role of aortic coarctation (CoA) remains unclear.Methods We analysed 502 adults from the EPOCH (European collaboration for Prospective Outcome research in Congenital Heart disease)-ASO multicentre registry (median age 25.5 years). The primary outcome was time to first right ventricular outflow tract (RVOT)-related intervention. Secondary outcomes included left ventricular outflow tract (LVOT)-related interventions and cardiovascular complications. Associations were assessed using adjusted Cox regression and Andersen-Gill models.Results CoA emerged as the strongest independent predictor of RVOT interventions (HR 2.62), LVOT interventions (HR 10.75) and cardiovascular complications (HR 2.16). In contrast, VSD (complex anatomy) showed weaker or no associations. CoA also predicted higher recurrence rates of both RVOT and LVOT interventions.Conclusions Among adults post-ASO, CoA-not VSD-is the dominant anatomical driver of long-term morbidity. These patients require targeted surgical attention and structured, lifelong follow-up to mitigate future complications.Trial Registration Number NCT04335448.