Incidence and clinical characteristics of sudden cardiac death in adult congenital heart disease

Background: The life expectancy of adults with congenital heart disease (CHD) has significantly improved in recent decades, with non-cardiovascular causes of death now competing with traditional cardiovascular causes. The risk of sudden cardiac death (SCD), a devastating event, still remains elevated above that of the general population.

Methods: We reviewed 2935 patients in our adult CHD database (age≥16years, seen at least once in our centre) and documented all cases of SCD between 2000-2015. Incidence and characteristics of SCD cases by congenital defect and complexity of disease were determined.

Results: We documented 35 cases of SCD, with an incidence of 0.4 deaths/1000patientyears (py). Incidence in simple, moderate and complex congenital categories was 0.04/1000py, 0.57/1000py and 2.0/1000py respectively. The highest risk category was Eisenmenger syndrome, with an incidence of 4.8 deaths/1000py. Moderate risk lesions included transposition of the great arteries (atrial switch surgery or congenitally corrected) and Fontan circulations. Repaired tetralogy, atrial septal defect and left ventricular outflow tract lesions were all relatively low risk. We observed a high prevalence of atrial arrhythmias (43%) and QRS prolongation (mean 132ms) in our SCD cases.

Conclusions: The adult CHD population remains at an elevated risk for SCD, particularly in the setting of complex underlying defects. Moderate to high risk lesions include Eisenmenger syndrome, transposition of the great arteries (atrial switch or congenitally corrected) and Fontan circulations.