In patients with transposition of the great arteries and an arterial switch operation (TGA-ASO) right ventricular outflow tract (RVOT) obstruction is a common complication requiring one or more RVOT interventions.
We aimed to assess cardiopulmonary exercise capacity and right ventricular function in patients stratified for type of RVOT intervention.
TGA-ASO patients (≥16 years) were stratified by type of RVOT intervention. The following outcome parameters were included: predicted (%) peak oxygen uptake (peak VO2), tricuspid annular plane systolic excursion (TAPSE), tricuspid Lateral Annular Systolic Velocity (TV S'), right ventricle (RV)-arterial coupling (defined as TAPSE/RV systolic pressure ratio), and N-terminal proBNP (NT-proBNP).
447 TGA patients with a mean age of 25.0 (interquartile range (IQR) 21-29) years were included. Patients without previous RVOT intervention (n = 338, 76%) had a significantly higher predicted peak VO2 (78.0 ± 17.4%) compared to patients with single approach catheter-based RVOT intervention (73.7 ± 12.7%), single approach surgical RVOT intervention (73.8 ± 28.1%), and patients with multiple approach RVOT intervention (66.2 ± 14.0%, p = 0.021). RV-arterial coupling was found to be significantly lower in patients with prior catheter-based and/or surgical RVOT intervention compared to patients without any RVOT intervention (p = 0.029).
TGA patients after a successful arterial switch repair have a decreased exercise capacity. A considerable amount of TGA patients with either catheter or surgical RVOT intervention perform significantly worse compared to patients without RVOT interventions.