Long-Term Follow-up of Adults Following the Atrial Switch Operation for Transposition of the Great Arteries - A Contemporary Cohort.

BACKGROUND: The atrial switch operation for transposition of the Great Arteries (TGA) (Mustard or Senning Procedure) provides excellent short-term survival. Significant long-term concerns exist for these patients, however, including the ability of the right ventricle to maintain systemic perfusion and the risk of arrhythmia. We seek to describe long-term mortality and morbidity of this group of adult patients.

METHODS: Consecutive patients who had undergone an atrial switch procedure, who were aged over 16 years and who were followed up at our tertiary level adult congenital heart disease (ACHD) service in Sydney, Australia since 2000 were included. We documented mortality using a National Death Index and analysed the prospectively defined composite endpoint of "Serious Adverse Events" including death, heart failure hospitalisation and/or documented ventricular arrhythmia.

RESULTS: There were 83 patients included; mean age at most recent follow-up was 35 ± 5 years. Overall survival was 82% at 35 years and 22% of patients experienced a serious adverse event. Atrial and ventricular arrhythmias occurred in 45% and 7% of patients respectively. Eighteen (22%) patients required a pacemaker and six (7%) required implantable cardiac defibrillator (ICD) implantation. Significant right ventricular dysfunction was present in 26% of patients on their most recent visit and this, or requirement for permanent pacing, was associated with an increased risk of serious adverse events (OR 10.22, p<0.001), (OR 4.998, p=0.04) respectively.

CONCLUSIONS: Significant mortality and morbidity accrues by mid-adult life after an atrial procedure for TGA. Right ventricular dysfunction and permanent pacing are associated with serious adverse events.