292: Pulmonary arterial hypertension complicating arterial switch surgery for simple transposition of the great arteries-prevalence and outcomes

Pulmonary arterial hypertension after successful arterial switch operation (ASO) for simple transposition of the great arteries is a rare but important cause of late morbidity and mortality. However this complication is poorly characterised in the literature. In Here, we report the prevalence of this condition and its outcomes from the largest series of ASO procedures yet reported. Methods Between January 1985 and June 2011, 1137 arterial switch procedures were performed for simple TGA at the Hopital Necker Enfants Malades in Paris. All patients underwent ASO within the early neonatal period. In all cases, pulmonary pressure was evaluated at routine echocardiography and pulmonary hypertension was confirmed by right heart catheterisation. Results Of 1137 consecutive ASO cases, 8 patients (0.7%, 95% confidence interval 0.29-1.36%) developed severe PAH in the peri-operative period that persisted beyond 1 month post-operatively requiring PAH targeted therapy. Three of those resolved with treatment after 3, 4 and 5 months respectively. The prevalence of PAH in a general French paediatric population was estimated to be 3.7 per million. These data suggest that long-term survivors of the ASO have a relative risk for the development of PAH around 2000-fold (point estimate 1757-fold, 95% confidence interval 785-3932) compared to children without congenital heart disease. Conclusion Pulmonary hypertension is a severe complication of TGA which must be rapidly detected in order to initiate targeted therapy. Reversibility is indeed not excluded since last cases of our series have normalized their pulmonary pressure.