Abstract 17031: Incidence of Life-Threatening Events in Children With Wolff-Parkinson-White Syndrome

Abstract

Introduction: Life-threatening events (LTE) in patients with Wolff-Parkinson-White Syndrome (WPW) are rare, with considerable variation in published rates. Existing data on LTE incidence represent selected populations or tertiary referral-based cohorts. Access to large observational datasets allows, for the first time, measurement of the risk of LTE in an unselected, contemporary WPW population. Methods: A retrospective cohort study was conducted using administrative claims from Truven Health Analytics (MarketScan ® ) to identify all WPW patients (aged ≤18 years) from both inpatient and outpatient encounters between January 2013 and December 2016. Prevalence of WPW was measured. A composite outcome, LTE, was defined as an episode that included ventricular fibrillation or cardiac arrest. Secondary outcomes included diagnoses of atrial fibrillation (AF) and supraventricular tachycardia (SVT). Factors associated with LTE were evaluated by creating multivariable models. Results: The prevalence of WPW in the study population was 0.025% (4,717/18,884,579). Subjects with WPW were 57% male, had a median age of 13 yrs (IQR 7-16 yrs), with coincident Ebstein’s anomaly in 1.9%, other congenital heart disease (CHD) in 12%, and cardiomyopathy (CM) in 2%. Over the study period, SVT was reported in 20.3% (n=957/4,717), and AF in 1.3% (n=61/4,717) of subjects. Patients with AF were 79% male (n=48/61), with median age 16 yrs (IQR 14-17 yrs), with CHD in 25% (n=15/61) and CM in 7% (n=4/61). LTE occurred in 23 subjects: 70% male (n=16/23), at median age 16 yrs (IQR 7-17 yrs), with CHD in 9% (n=2/23) and CM in 13% (n=3/23); AF was reported in 3 patients with LTE. The incidence of LTE was 1.4 events per 1000 person years of follow up (23/16,514). In a multivariate model including age, gender, CHD, and CM, the only independent predictor of LTE was CM (OR 10.2, 95% CI 2.4-31.1, p<0.001). Conclusions: Use of a large claims dataset allowed for evaluation of LTE risk in an unselected pediatric WPW population. This WPW-related LTE estimate of 1.4/1000 person years can serve as a benchmark for assessment of risk reduction interventions on a population level. Incidence of LTE in this unselected contemporary cohort is consistent with observed rates in prior reports from selected populations.