• Arrhythmic risk stratification
• Arrhythmogenic cardiomyopathy
• cardiac magnetic resonance
• prognosis

Aims: Arrhythmogenic right ventricular cardiomyopathy (ARVC) is associated with a high risk of sudden cardiac death (SCD). Three different prediction models for the indication of implanted cardioverter defibrillator (ICD) are now available: the 5-year ARVC risk score, the International Task Force Consensus (ITFC) and the Heart Rhythm Society (HRS) criteria. The aim of this study was compared these three prediction models in a validation cohort of patients with definite ARVC and assess the additional value of cardiac magnetic resonance (CMR).
Methods: In a cohort of 140 patients with definite ARVC, the 5-year ARVC risk score, the ITFC and the HRS criteria were compared for the prediction of a major combined endpoint of SCD, appropriate ICD intervention and resuscitated cardiac arrest.
Results: During the follow-up 48 major events occurred. The 5-year ARVC risk score with a threshold >10%, derived from the maximally selected rank statistic, predicted 46 (96%) events the ITFC criteria 38 (79%) and the HRS criteria 36 (75%). At the decision curve analysis for ICD implantation, a 5-year ARVC risk score >10% showed a greater net benefit than ITFC and the HRS criteria over a wide range of threshold probability of events. CMR showed a 100% sensitivity and negative predictive value. Finally, at multivariate analysis including the 3 risk models and CMR parameters, only HRS criteria and LV involvement on CMR were independent predictor of major events. A negative CMR showed excellent event free survival irrespective of the risk prediction model while in patients with positive CMR each of the risk models allowed incremental risk stratification.
Conclusions: The 5-year score with a threshold of >10% was the most effective for predicting events than the ITFC and the HRS criteria. CMR showed an excellent negative predictive value and the presence of LV involvement was independently associated with arrhythmic. Combination of CMR phenotype expression with 5-year ARVC risk score allows additional risk stratification of patients with definite ARVC.