Presence of a Ventricular Septal Defect and the Mustard Operation Are Risk Factors for Late Mortality After the Atrial Switch Operation

Abstract

Survival and functional status of patients with transposition of the great arteries treated by atrial switch are reported to be reasonably good within the first 15 postoperative years. However, in some patients, the function of the systemic right ventricle deteriorates, leading to significant morbidity or even to late mortality. This study seeks to identify risk factors for late death. Records of 329 patients after the Senning operation and 88 after the Mustard operation at a single center were retrospectively reviewed for demographic, anatomic, and echocardiographic predictors and outcomes. Mean follow-up interval was 19.1+/-6.5 years and was 95% complete. Survival 25 years after the Mustard procedure was 75.9+/-4.8% and after the Senning procedure was 90.9+/-2.3% (P=0.002). Mustard patients died more often of arrhythmia than Senning patients (P<0.001) and needed more baffle-related reoperations (P<0.0001). Ventricular septal defect closure at the time of the atrial switch operation (hazard rate=2.3; 95% confidence interval, 1.1 to 4.7; P=0.025) and the Mustard operation (hazard rate=2.0; 95% confidence interval, 1.01 to 3.8; P=0.045) emerged as independent risk factors for late mortality in multivariate analysis. At follow-up, 85.8% of the patients led a normal life with full-time work, and 11.8% were able to do part-time work. Only 2.4% experienced noticeable limitation of activities. Our patient data reveal satisfactory results at long term in this historic collective. Patients who had undergone ventricular septal defect closure at the time of the atrial switch operation and those who had undergone a Mustard operation are at higher risk for late death. Close follow-up, especially of these subgroups, is warranted.