Incidence and predictors of sudden cardiac arrest in adults with congenital heart defects repaired before adult life.

Many adult survivors of repaired congenital heart disease (CHD) are at premature risk of death. Sudden cardiac arrest (SCA) is 1 of the leading causes of death but little is known about determinants for SCA in adults with repaired lesions. We sought to determine incidence and risk factors for SCA in a study population of 936 adults with previously repaired CHD who had completed follow-up at a single tertiary center during a mean period of 9 ± 7 years. Mean age at first examination in our institution was 21 ± 7 years. Diagnostic categories included tetralogy of Fallot (216), coarctation of the aorta (157), transposition complexes (99), single ventricle (55), and other CHD (409). During a total follow-up of 8,387 person-years, 22 patients (2.6 per 1,000 person-years) presented with SCA. Incidence of SCA varied widely between specific lesions; the highest incidence was observed in transposition complexes (10 per 1,000 person-years). Independent predictors of SCA were retrospectively identified using multivariate Cox proportional hazard modeling. Age at initial examination and severely impaired subaortic ventricular systolic function were independent risk factors for SCA (severe subaortic ventricular systolic dysfunction, adjusted hazard ratio 29, 95% confidence interval 11 to 72, p <0.001). SCA occurred in 23% of patients with severe subaortic ventricular systolic dysfunction versus 0.7% of patients with nonsevere decreased subaortic ventricular function (p <0.001). In conclusion, severe subaortic ventricular systolic dysfunction is a dominant multivariate predictor of SCA in an unselected population of adult survivors after surgery for CHD. Our data support the consideration of primary prevention strategies in these patients.