Background: The benefit of prophylactic implantable cardioverter defibrillators (ICDs) in patients with severe systolic dysfunction of non-ischemic origin is still unclear, and the identification of patients at risk for sudden cardiac death remains a major challenge.
Aims/Methods: We retrospectively reviewed all consecutive patients with non-ischemic dilated cardiomyopathy (NICM) who underwent prophylactic ICD implantation between 2008 and 2020 in two tertiary centers. Our main goal was to identify the predictors of appropriate ICD therapies (anti-tachycardia pacing [ATP] and/or shocks) in this cohort of patients.
Results: A total of 224 patients were included. After a median follow-up of 51 months, 61 patients (27.2%) required appropriate ICD therapies. Patients with appropriate ICD therapies were more frequently men (87% vs. 69%,
p = 0.006), of younger age (59 years, (53–65) vs. 64 years, (57–70);
p = 0.02), showed more right bundle branch blocks (RBBBs) (15% vs. 4%,
p = 0.007) and less left bundle branch blocks (LBBBs) (26% vs. 47%,
p = 0.005) in the ECG, and had higher left ventricular end-diastolic (100 mL/m
2, (90–117) vs. 86, (71–110);
p = 0.011) and systolic volumes (72 mL/m
2, (59–87) vs. 61, (47–81),
p = 0.05). In a multivariate competing-risks regression analysis, RBBB (HR 2.26, CI 95% 1.02–4.98,
p = 0.043) was identified as an independent predictor of appropriate ICD therapies.
Conclusion: RBBBs may help to identify patients with NICM at high risk of ventricular arrhythmias and requiring ICD intervention.
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