Risk Stratification in Arrhythmogenic Right Ventricular Cardiomyopathy/Dysplasia Without an Implantable Cardioverter-Defibrillator.

Objectives: The purpose of this study was to identify clinical factors associated with arrhythmic events and sudden cardiac death (SCD), and to evaluate the prognostic value of electrophysiological study (EPS) in arrhythmogenic right ventricular cardiomyopathy/dysplasia (ARVC/D) patients without implantable cardioverter-defibrillators (ICDs).

Background: ARVC/D is an inherited cardiomyopathy characterized by a risk of SCD. Few studies have evaluated predictive factors of ventricular arrhythmias (VAs) in patients without ICDs.

Methods: Between 2000 and 2010, all consecutive patients with ARVC/D without ICDs and with EPS at diagnosis were enrolled. Patients that received an ICD during follow-up were censored at the date of implantation, and in that case, only VAs that occurred before ICD implantation were analyzed. Risk factors for any VA event were determined by Cox regression. Patients that only experienced SCD or aborted cardiac arrest (ACA) were reported.

Results: A total of 137 consecutive patients (78% male) diagnosed with ARVC/D without ICD were enrolled. 31% had sustained ventricular tachycardia at diagnosis. After mean follow-up of 42 ± 31 months, 19 patients experienced an episode of sustained VA and 5 patients experienced a SCD/ACA. No event occurred in asymptomatic patients. Left ventricular ejection fraction ≤50% (p = 0.024), positive EPS (p = 0.017), and physical activity >6 h/week (p = 0.025) were independently associated with occurrence of VAs. SCD/ACA exclusively occurred in male probands with definite diagnosis and syncope.

Conclusions: In this cohort of ARVC/D patients without ICD, left ventricular ejection fraction ≤50%, positive EPS, and physical activity >6 h/week were independent predictors of VAs, whereas asymptomatic patients at diagnosis were at low risk. EPS predicted all VAs but had limited value to predict SCD/ACA.