Abstract Background Despite Arrhythmogenic right ventricular cardiomyopathy (ARVC) being a predominant right ventricle (RV) disease, concomitant left ventricle (LV) involvement has been recognized. ARVC diagnosis is made through the RV-centric 2010 Task Force Criteria (TFC), but previous studies already suggested the use of echocardiographic strain measures to better depict RV and LV dysfunction in these patients. No data however is available on the additional value of combining biventricular strain in ARVC for risk stratification. Purpose To assess the prognostic value of measuring both LV global longitudinal strain (GLS) and RV free wall strain (FWLS) analysis in patients with ARVC. Methods A total of 204 patients who met the TFC for the ARVC spectrum were included. Patients were categorized based on a cut-off of -18% for strain impairment in both ventricles. The end-point was a composite of all-cause mortality, arrhythmic events, ICD therapy and heart failure events. Results Patients (age 41 ± 17 years, 55% males) were divided into impaired (n=33), discordant (either RV or LV impaired, n=70), and normal (n=101) strain groups (Fig. 1A). Definite and borderline ARVC were diagnosed in 78% and 39%, respectively, at the time of first available echocardiography. During a follow-up of 87 [24-136] months, 60 (29%) experienced the combined outcome, and a significant difference in event-free survival was observed (p<0.001) between the 3 groups (Fig. 1B). In the multivariate analysis (Fig. 2), the strain grouping remained associated with outcome (p=0.040) after adjusting for age, gender, history of syncope and definite ARVC diagnosis, which were also significantly associated with the endpoint at the univariate analysis. A sub-analysis including only definite and borderline ARVC patients confirmed that the strain grouping was an independent predictor of the composite endpoint (p=0.027). Conclusion Biventricular involvement by strain analysis has additional prognostic value in ARVC patients and outcome is worse for those with both RV and LV involvement.Strain groups and Kaplan Meier curvesMultivariate analysis