The morphologic left ventricle that requires training by means of pulmonary artery banding before the double-switch procedure for congenitally corrected transposition of the great arteries is at risk of late dysfunction

Objective The aim of this study was to compare the outcome of the double-switch procedure for congenitally corrected transposition of the great arteries for patients completing morphologic left ventricle training by means of pulmonary artery banding with the outcome of patients whose morphologic left ventricle did not require training. Methods A retrospective study of all patients undergoing the double-switch procedure from 1991 through 2004 was performed. Patients were divided into 2 groups: those not requiring morphologic left ventricle training (n = 33) and those completing morphologic left ventricle training by means of pulmonary artery banding (n = 11). Results The time spent with the morphologic left ventricle conditioned at systemic pressures was longer for the group not requiring morphologic left ventricle training (median, 730 days; interquartile range, 399–1234 vs median, 436 days; interquartile range, 411–646; P = .19). The overall mortality (not requiring morphologic left ventricle training, 12.1%; requiring morphologic left ventricle training, 9.1%; P = 1) and rate of death/transplantation, development of moderate-to-severe morphologic left ventricle dysfunction, or both (not requiring morphologic left ventricle training, 21.2%; requiring morphologic left ventricle training, 45.5%; P = .14) were similar between groups. Actuarial freedom from death/transplantation with good morphologic left ventricular function was superior for patients whose morphologic left ventricle did not require training ( P = .04). The follow-up was not different between groups (not requiring training: median, 1435 days [interquartile range, 285–2570 days]; requiring morphologic left ventricle training: median, 568 days [interquartile range, 399–1465 days]; P = .14). On multivariate analysis, the completion of morphologic left ventricle training predicted death/transplantation, development of moderate-to-severe morphologic left ventricle dysfunction, or both ( P = .02). Conclusions The early results of the double-switch procedure in patients whose morphologic left ventricle required training compare favorably with those of patients whose morphologic left ventricle required no training. There is an increased risk of deterioration of morphologic left ventricle function over time in patients whose morphologic left ventricle requires training, and these patients need to be followed up regularly to detect this.