Abnormal Coronary Anatomy in Patients with Transposition of the Great Arteries and Atrial Switch: A Predictor of Serious Cardiac Adverse Events?

Abstract

Sudden cardiac death and heart failure are well known long-term complications after atrial switch for D-transposition of the great arteries (D-TGA). Right systemic ventricular dysfunction is common and myocardial ischemia has been implicated as a putative mechanism for sudden death, with coronary anomalies prevalent in 30% of cases. We sought to assess an association between adverse events and coronary anomalies in patients with D-TGA and atrial switch surgery. An observational study was conducted in 3 tertiary centers (Montreal Heart Institute, Canada, Nationwide Children’s hospital, Chicago, USA and Hopital cardiologique Louis Pradel de Lyon, France). Adults with D-TGA and atrial switch surgery qualified for inclusion if they had a major adverse cardiovascular event (MACE), i.e., ventricular arrhythmia, sudden cardiac death, heart failure, cardiac transplantation, or cardiovascular death. The prevalence of coronary anomalies was compared to historical controls. Forty-five patients were included. Twenty-one (46.7%) patients experienced a ventricular arrhythmia and 35 (77.8%) suffered from symptomatic heart failure and/or severe right ventricular dysfunction. Twelve patients (26.7%) had congenitally abnormal coronary arteries. There was no difference in the prevalence of coronary anomalies between the cohort with a MACE and a pooled population of 647 historical controls with D-TGA (28.7%, p = 0.89). In conclusion, the prevalence of congenital coronary anomalies is not higher in patients with D-TGA and atrial switch surgery who had adverse cardiovascular events. It could be hypothesized that ischemic complications in this patient population are more likely to be related to a supply-demand mismatch of the distal microvasculature rather than proximal coronary anomalies.