Prognostic Value of Magnetic Resonance Phenotype in Patients With Arrhythmogenic Right Ventricular Cardiomyopathy

16noBackground: Cardiac magnetic resonance (CMR) is widely used to assess tissue and functional abnormalities in arrhythmogenic right ventricular cardiomyopathy (ARVC). Recently, a ARVC risk score was proposed to predict the 5-year risk of malignant ventricular arrhythmias in patients with ARVC. However, CMR features such as fibrosis, fat infiltration, and left ventricular (LV) involvement were not considered. Objectives: The authors sought to evaluate the prognostic role of CMR phenotype in patients with definite ARVC and to evaluate the effectiveness of the novel 5-year ARVC risk score to predict cardiac events in different CMR presentations. Methods: A total of 140 patients with definite ARVC were enrolled (mean age 42 ± 17 years, 97 males) in this multicenter prospective registry. As per study design, CMR was performed in all the patients at enrollment. The novel 5-year ARVC risk score was retrospectively calculated using the patient's characteristics at the time of enrollment. During a median follow-up of 5 years (2 to 8 years), the combined endpoint of sudden cardiac death, appropriate implantable cardioverter-defibrillator intervention, and aborted cardiac arrest was considered. Results: CMR was completely negative in 14 patients (10%), isolated right ventricular (RV) involvement was found in 58 (41%), biventricular in 52 (37%), and LV dominant in 16 (12%). During the follow-up, 48 patients (34%) had major events, but none occurred in patients with negative CMR. At Kaplan-Meier analysis, patients with LV involvement (LV dominant and biventricular) had a worse prognosis than those with lone RV (p < 0.0001). At multivariate analysis, the LV involvement, a LV-dominant phenotype, and the 5-year ARVC risk score were independent predictors of major events. The estimated 5-year risk was able to predict the observed risk in patients with lone RV but underestimated the risk in those with LV involvement. Conclusions: Different CMR presentations of ARVC are associated with different prognoses. The 5-year ARVC risk score is valid for the estimation of risk in patients with lone-RV presentation but underestimated the risk when LV is involved.reservedmixedAquaro G.D.; De Luca A.; Cappelletto C.; Raimondi F.; Bianco F.; Botto N.; Lesizza P.; Grigoratos C.; Minati M.; Dell'Omodarme M.; Pingitore A.; Stolfo D.; Ferro M.D.; Merlo M.; Di Bella G.; Sinagra G.Aquaro, G. D.; De Luca, A.; Cappelletto, C.; Raimondi, F.; Bianco, F.; Botto, N.; Lesizza, P.; Grigoratos, C.; Minati, M.; Dell'Omodarme, M.; Pingitore, A.; Stolfo, D.; Ferro, M. D.; Merlo, M.; Di Bella, G.; Sinagra, G