Fifth decennium after the arterial switch operation for transposition of the great arteries.

Background: From 1977 onwards, patients with both simple and complex transposition of the great arteries (TGA) have been treated with the arterial switch operation (ASO) in the Wilhelmina Children's Hospital/University Medical Center Utrecht the Netherlands. In this study, we compared mortality and morbidity between two patient groups: A. operated before and B. after 1991, specifically focusing on late ventricular function and reinterventions. Methods: A single institution retrospective cohort study was performed on patients who had an ASO for either simple or complex TGA. Data were collected from medical records. The entire patient cohort (n = 283) was divided in a group with more than 30 years of follow-up (A) and a group with less than 30 years of follow-up (B). Clinical and standardized echocardiographic follow-up was evaluated. Results: Group A consisted of 79 patients, of whom follow-up was available in 59 patients (median follow-up 34.8 years, IQR 33.0-36.9). Group B consisted of 204 patients, of whom 195 long-term survivors (median follow-up 14.9 years, IQR 10.0-21.2). Early survival was best in group B (A: 67.8% vs. B: 96.6%, p < 0.001), whereas late mortality (in total 1.8%) was similar for both groups. Reinterventions, corrected for follow-up time, were more frequent in group A (p = 0.005). In total 65 patients (25.1%) required 105 late reinterventions including 4 late aortic valve replacements. The mode of reinterventions has shifted over time, from surgical to more catheter-based (p = 0.03). The vast majority of patients functioned in NYHA class I. In contrast to the recent cohort, who have a normal average LVEF (%), the average LVEF in the oldest cohort was in the bottom percentile of normal range. Conclusion: The majority of patients in their fifth decade after ASO are in functional class I. Early outcome improved showing reduced mortality and need for reoperation. However, a trend towards reduced left ventricular function and late aortic valve replacements justify further research.