Predictive Value of the Electrical Risk Score for Ventricular Arrhythmias in Heart Failure Patients with Primary Prevention Implantable Cardioverter Defibrillators

Background: Implantable cardioverter defibrillators (ICDs) are essential for the primary prevention of sudden cardiac death in heart failure (HF); however, appropriate shocks increase mortality and impair quality of life. The electrical risk score (ERS) is an electrocardiographic (ECG)-based composite index with proven prognostic value, but its ability to predict ventricular arrhythmias in HF remains unclear. This study aims to evaluate the predictive value of the ERS for ventricular arrhythmia-related ICD shocks in HF patients undergoing primary prevention ICD implantation. Methods: In this study, 91 patients with HF were followed for 12 months after ICD implantation. The ERS was calculated from baseline ECGs. Patients were grouped based on ERS (<3 vs. ≥3), according to receiver operating characteristic curve analysis. Multivariate logistic regression was used to evaluate predictors of appropriate ICD shocks, and predictive performance was compared using the DeLong test. Results: Thirty-five patients (38.5%) experienced at least one appropriate ICD shock. The median ERS was significantly higher in the shock group compared to the non-shock group (p < 0.001). Patients with ERS ≥ 3 had significantly higher rates of the anti-tachycardia pacing therapy (p < 0.001) and HF-related hospitalization (p = 0.004). ERS was an independent predictor of ICD shocks (p < 0.001), with superior discriminative performance (AUC 0.882) compared to most ECG markers, including frontal QRS T angle, QRS duration, Tp-e interval, and heart rate. Conclusions: The ERS was associated with ventricular arrhythmia-related ICD shocks in HF patients undergoing primary prevention ICD implantation. The ERS may identify patients at increased arrhythmic risk and guides follow-up and ICD management.