Sudden Cardiac Death in Adult Congenital Heart Disease
What is the burden of sudden cardiac death (SCD) in adults with congenital heart disease (CHD), and are there any clinical predictors?
A multicenter case-controlled study was performed. Patients with nonarrhythmic causes of sudden death were excluded. Databases used for the study included the Dutch Concor database (includes 11,535 patients enrolled since 2001), the database of the Toronto Congenital Cardiac Care Centre for Adults (8,000 patients followed since 1980), and the University Hospital Leuven (6,255 adults enrolled since 1,970). Each case of sudden arrhythmic death was matched to two controls based on age, gender, diagnosis, type of surgical intervention, and date of surgical repair.
Of a total of 25,790 adults with CHD, there were 1,189 deaths (5%), of which 171 were sudden arrhythmic deaths. The underlying cardiac lesions were mild, moderate, and severe in 12%, 33%, and 55% of the SCD deaths, respectively. Clinical variables associated with SCD were previously documented supraventricular tachycardia (odds ratio [OR], 3.5; 95% confidence interval [CI], 1.5-7.9; p = 0.004), moderate to severe systemic ventricular dysfunction (OR, 3.4; 95% CI, 1.1-10.4; p = 0.034), moderate to severe subpulmonary ventricular dysfunction (OR, 3.4; 95% CI, 1.1-10.2; p = 0.03), increased QRS duration (OR 1.34 (per 10 ms increase), 95% CI, 1.10-1.34; p = 0.008), and QT dispersion (OR, 1.22 (per 10 ms increase), 95% CI, 1.22-1.48; p = 0.008).
The clinical parameters found to be associated with SCD in adults with CHD are similar to those for patients with acquired heart disease. Even patients with relatively mild disease are at risk for SCD.
This study confirms ventricular dysfunction, previous supraventricular tachycardia, and QRS parameters to be associated with SCD in adults with CHD. While robust data in adults with CHD inform guidelines regarding timing of implantable cardioverter-defibrillator (ICD) placement, such data are lacking in the adult CHD population. This study suggests that ventricular dysfunction of either a subpulmonary or systemic ventricle may identify high-risk patients. Additional studies will be necessary to develop formal guidelines as to timing of ICD patients. This study also stresses the importance of taking all possible measures to preserve ventricular function in young patients with CHD.
Keywords: Odds Ratio, Coronary Artery Disease, Myocardial Ischemia, Defibrillators, Ventricular Dysfunction, Risk Factors, Tachycardia, Heart Diseases, Death, Case-Control Studies, Ventricular Function, Confidence Intervals
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