Prognostic value of magnetic resonance imaging (MRI)-based cardiac adipose tissue in arrhythmogenic right ventricular cardiomyopathy.

Aim: The aim of this study was to explore the relationship between epicardial adipose tissue (EAT), paracardial adipose tissue (PaAT), pericardial adipose tissue (PeAT), and fat ratio with left ventricular (LV) involvement, assessing the prognostic significance of cardiac fat in arrhythmogenic right ventricular cardiomyopathy (ARVC).

Materials and methods: Ninety-two ARVC patients (mean age: 45.74 years; 63% male) were included and followed up for 92 months. Measured in cardiac magnetic resonance imaging (MRI) cine views, EAT, PaAT, PeAT, and fat ratio (EAT/PaAT) were analyzed to identify the association with major adverse cardiac events (MACEs) (sudden cardiovascular death, aborted cardiac arrest, heart failure hospitalization, and sustained documented ventricular tachycardia).

Results: Among the 92 participants, 28 (30.43%) MACEs occurred during the follow-up. Significantly higher EAT, PaAT, PeAT, and fat ratio were observed in patients with LV involvement than in those without (p = 0.001, p = 0.002, p = 0.001, p = 0.003, respectively) in violin plots. A worse prognosis in ARVC patients was associated with a higher volume of EAT (log rank p = 0.0031). In multivariate Cox regression analysis, EAT (Hazard Ratio [HR]: 1.056, 95% confidence interval [CI]: 1.011-1.103, p = 0.013) and 5-year risk score (HR: 1.018, 95% CI: 1.002-1.034, p = 0.030) were identified as independent prognostic predictors for MACEs. Additional prognostic information over conventional outcome predictors was provided by EAT (Uno C-statistics: 0.645 vs. 0.665, p = 0.007).

Conclusion: higher cardiac fat volume was found to be correlated with LV involvement. Independent risk factors for MACEs in ARVC were identified as EAT and 5-year risk score, and the incremental prognostic value to established predictors in ARVC was provided by EAT.