Abstract 10925: The Impact of a Positive Gene Test on Presentation and Disease Progression of Arrhythomogenic Right Ventricular Cardiomyopathy in Childhood

Abstract

Background: The impact of a pathogenic mutation on the presentation and disease progression in arrhythmogenic right ventricular cardiomyopathy (ARVC) during childhood is unknown. The aim of this study was to compare gene-positive (GP) and gene-negative (GN) patients who were evaluated for ARVC. Methods: For this retrospective study, serial clinical data for patients with a known pathogenic mutation for ARVC (GP) were compared to those for GN patients. Magnetic resonance, echocardiography, ECG, signal average ECG (SAECG), Holter, and clinical findings were recorded during each serial evaluation. Patients were classified into possible, borderline or definite ARVC according to the revised Task Force Criteria (rTFC). Patients with ‘no’ ARVC at the last visit were excluded from the follow-up analysis. Results: We included 23 GP and 94 GN patients. GN and GP patients were similar in age at presentation. More patients in the GN group (75% vs. 30%, p=0.001) were symptomatic at presentation. The groups did not differ in their initial rTFC category or in their rate of progression to more severe diagnostic categories . Z-scores for RV end-diastolic volume (EDV) tended to progress faster in the GP group (p=0.06), as did the RV outflow tract diameter by echocardiography (p=0.04). Z-scores for RV ejection fraction deteriorated faster in the GP group (p=0.03) and Z-scores for LV EDV increased more rapidly (p=0.04). Patients who were symptomatic on presentation did not progress more quickly in terms of rTFC grading as compared to asymptomatic patients. During a median follow-up of 3.6 years (0-13.9), 2 patients developed ventricular tachycardia, 3 out of 20 with an implanted defibrillator experienced appropriate shocks, and 2 underwent heart transplantation. There were no deaths. GP did not predict adverse events. Conclusion: Gene negative and gene positive children who undergo a work-up for ARVC are referred at similar ages to a tertiary care centre. GP patients experience a faster growth of LV and RV size and a more rapid deterioration of RV function. However, being GP is not associated with a faster progression to higher rTFC categories , development of symptoms, or adverse outcomes in the pediatric age group.