Are patients with non-ischemic cardiomyopathy less deserving of primary prevention device implantation?

Introduction The role of implantable devices in preventing sudden cardiac death in heart failure patients with non-ischemic cardiomyopathy in primary prevention remains uncertain, primarily due to inconsistent evidence regarding their impact on outcomes such as mortality compared to medical therapy alone. Objective This study aimed to evaluate differences in outcomes between patients undergoing implantable cardioverter-defibrillator (ICD) or cardiac resynchronization therapy defibrillator (CRT-D) implantation for primary prevention based on etiology (ischemic heart disease [IHD] vs non-ischemic heart disease [NIHD]). Additionally, predictors of outcomes were assessed over a median follow-up of 35 months. Methods A retrospective analysis between 2020 and 2024 included 165 patients who underwent ICD/CRT-D implantation for primary prevention. Data collected included demographic characteristics, cardiovascular risk factors, documented arrhythmias, device type, and administered therapies (medical or device-based). Outcomes studied included hospitalization due to heart failure, myocardial infarction, stroke, or death. Predictors of outcome were identified using multivariate logistic regression. Results Of the 165 patients (median age 65 [58–73] years; 77.0% male), 69.6% had IHD and 30.4% NIHD. IHD patients were more likely to have hypertension (HT) (67.6% vs 47.7%, p=0.023) and dyslipidemia (76.5% vs 56.8%, p=0.019), while NIHD patients had more atrial fibrillation (AF) (40.9% vs 20.6%, p=0.015). Median left ventricular ejection fraction was lower in IHD (30% [25–40], p<0.001). Both groups received very similar medical and device-based treatment regimens (shocks and therapies), with no differences in terms of documented arrythmias. No significant differences in composite outcomes were observed between IHD and NIHD patients. Predictors of adverse outcomes included female gender (OR=4.141, 95% CI: 1.305–13.144, p=0.016), HT (OR=3.553, 95% CI 1.025–12.311, p=0.046), and AF (OR=4.004, 95% CI 1.243–12.896, p=0.020). Conclusion Patients undergoing device implantation for primary prevention had similar outcomes regardless of etiology, supporting the potential benefit of this therapy in both NIHD and IHD populations. Female gender, HT, and AF were significant predictors of adverse outcomes, consistent with prior findings in literature, while etiology was not shown to influence prognosis.