Arrhythmia and survival in patients >18 years of age after the Mustard procedure for complete transposition of the great arteries

Increasing numbers of patients who underwent Mustard repair as children are now adults. Loss of sinus rhythm, supraventricular arrhythmias, and sudden death have been described in pediatric series. However, little is known about the clinical course of adult patients. This retrospective cohort study examined 86 consecutive adults (age >18 years) who had undergone the Mustard procedure and were referred to an adult congenital cardiac clinic for ongoing follow-up. The incidence and predictors of arrhythmia, congestive heart failure, and death were determined. The median follow-up period was 8 years after age 18 or 23 years after Mustard repair. There were 8 deaths (9%), 2 were sudden. Congestive heart failure (CHF) requiring hospital admission occurred in 9 patients (10%). Pulmonary hypertension and systemic ventricular dysfunction were independent risk factors for death or CHF. Only 29 patients (34%) remained arrhythmia-free. Forty-one patients (48%) had at least 1 episode of supraventricular tachycardia (SVT), with most patients (30, 73%) having atrial flutter. SVT after the age of 18 was associated with CHF. Pulmonary hypertension, systemic ventricular dysfunction, and junctional rhythm before age 18 were independent risk factors for SVT. Pacemakers were implanted in 19 patients (22%); 13 of those were beyond age 18. Thus, adult survivors of the Mustard procedure continue to be at risk for premature death, CHF and supraventricular tachyarrhythmia.