Abstract 20209: Outcomes in D-TGA Post Atrial Switch and L-TGA Are Predicted by BNP and Exercise Testing
Introduction: Advances in repair of congenital heart disease have allowed survival of patients to their third decades. Nevertheless, patients with D-transposition of the great arteries (D-TGA) post atrial switch and L-transposition (L-TGA) continue to have significant complications such as arrhythmia, heart failure, and sudden death, while traditional noninvasive measures of cardiac function such as echocardiography have been limited in predicting clinical events. Cardiopulmonary exercise testing has been used to assess risk of mortality in adults with TGA, and brain naturetic peptide (BNP) level has been correlated with reduced functional status. We hypothesized that exercise testing and BNP could predict clinical events in D-TGA and L-TGA.
Methods: We analyzed clinical events (defined as death, cardiac transplant, or hospitalization) and BNP values in 32 patients with D-TGA post atrial switch or L-TGA who underwent exercise testing from July 2001 to April 2010.
Results: Fifty-five clinical events occurred: TGA patients with clinical events had significantly lower %predicted VO2 (44.8±2% vs 66.8±3%, p<0.000001) and peak VO2 (17.2±0.8 ml/kg/min vs. 21.4±2 ml/kg/min, p=0.008) and higher BNP (356±70 pg/ml vs. 83±30 pg/ml, p<0.05 ) than patients who had no events. Event-free survival was significantly related to peak VO2 (p=0.003, r=0.44), %predicted VO2 (p= 0.003, r=0.45), and O2 Pulse (p=0.002, r=0.45) but inversely related to BNP (p=0.02, r=0.36).
Conclusions: Exercise testing and BNP are both predictive of clinical events in patients with D-TGA post atrial switch and L-TGA, and should help improve prognostic accuracy thereby improving patient selection for more aggressive management such as ICD implantation or invasive evaluation.
- © 2010 by American Heart Association, Inc.