Baffle Complications in Adults After Atrial Switch for Transposition of the Great Arteries

Background: Baffle complications, ie, leakage or stenosis, after an atrial switch operation (AtrSO) for transposition of the great arteries (TGA) are difficult to detect with the use of routine transthoracic echocardiography (TTE). We examined baffle interventions and the prevalence of baffle complications. Methods: This dual-centre study followed TGA-AtrSO patients for the occurrence of baffle interventions. In addition, in 2017-2019, prevalence of baffle complications was determined in patients undergoing routine contrast-enhanced (CE) TTE including various hemodynamic conditions and computed tomography (CT). Baffle leaks were defined as right-to-left shunting on CE-TTE and baffle stenosis as a systemic venous baffle diameter of < 10 mm on CT. Results: In total, 67 TGA-AtrSO patients were followed to a median age of 38 (interquartile range 34-42) years, for a median of 9 (6-13) years. Baffle interventions were documented in 24 patients (36%). Cumulative risk of baffle interventions was 25% after 15 years of follow-up. Prevalence of baffle complications was determined in 29/67 patients. In total, 4 (14%) had patent baffles, 11(38%) had leakage only, 5 (17%) had stenosis only, and 9 (31%) had both, while 24/29 (84%) were asymptomatic. Although baffle leaks were not associated with clinical characteristics, peak work rate during exercise TIE was lower in patients with vs without stenosis (89 +/- 24 W vs 123 +/- 21 W; P < 0.001). Conclusions: Baffle complications are common in TGA-AtrSO. The cumulative risk of baffle interventions was 25% after 15 years of follow-up. CE-TTE uncovered asymptomatic baffle leakage in the majority of patients, especially with examination during exercise. CT revealed baffle stenosis in almost half of the patients, which was associated with decreased exercise tolerance. Awareness of these findings may alter clinical follow-up.