Arrhythmic risk stratification in patients with clinically-suspected left ventricular arrhythmogenic cardiomyopathy
Abstract Background Arrhythmic risk of patients with left ventricular arrhythmogenic cardiomyopathy (LVAC) is unpredictable. Purpose To identify risk facors associated with major ventricular tachyarrhythmias (VTA) in clinically-suspected LVAC patients. Methods We enrolled 127 consecutive patients (69% males, age 46±13 y, LVEF 54±7%) with clinically-suspected LVAC. All patients presented with either major (VT, VF) or minor VTA (NSVT, frequent VEB), and underwent extensive diagnostic workup to rule-out alternative diagnoses. Medical treatment and ICD implant were clinically-driven. Prospective follow-up was obtained via sequential 24h-Holter ECG (2–4/y) with or without continuous arrhythmia monitoring (ICD or implantable loop recorders, ILR). The primary endpoint was occurrence of major VTA (VT/VF/ICD therapy) by 24-month follow-up. Results At presentation, 56 (44%) and 71 patients (56%) had, respectively, major and minor VTA. Variants in desmosomal genes were identified in 7 of the 9 patients with clinically-indicated genetic test. Delayed gadolinium enhancement (DGE, average 23±12% of the LV mass) had anteroseptal distribution in 43 cases (34%). Monitoring strategy included ICD (n=64), ILR (n=33), or sequential Holer ECGs (n=30). By 24-month follow-up, major VTA occurred in 32 patients (25%). At univariable anlysis, major VTA onset (HR 16.8, 95% CI 5.4–52.2, p<0.001) and anteroseptal DGE (HR 3.0, 95% CI 1.3–6.9, p=0.010) were significantly associated with major VTA by 24-month follow-up. Among patients presenting with minor VTA, the only factor significantly associated with the primary endpoint was anteroseptal DGE (3/4 vs. 14/67, p=0.004). Conclusion Our preliminary experience suggests that, in patients with clinically-suspected LVAC, major VTA onset and anteroseptal DGE are relevant risk factors for major arrhythmic events by 24-month follow-up. FUNDunding Acknowledgement Type of funding sources: None.