A Cardiac Magnetic Resonance–Based Risk Stratification for Life‐Threatening Ventricular Tachyarrhythmias in Heart Failure: The SNE₂ Score

Risk stratification for sudden cardiac death (SCD) mainly relies on severely reduced left ventricular ejection fraction (LVEF), but its poor predictive efficacy fails to meet clinical needs. Myocardial scarring identified using cardiac magnetic resonance (CMR) imaging has emerged as a potent risk indicator for SCD and life-threatening ventricular tachyarrhythmias (LTVTA). This study aimed to develop a risk prediction score for SCD and ventricular tachyarrhythmias in symptomatic heart failure. Consecutive patients with nonischemic heart failure undergoing CMR were monitored from 2018 to 2024. A risk stratification score was developed by integrating CMR parameters with clinical variables. Among the 199 patients, the median LVEF was 32.7%, and the average age was 50.3 ± 15.2 years. During a median observation period of 3 years, 21 (10.5%) patients experienced LTVTA. Among multiple CMR parameters, the presence of late gadolinium enhancement (LGE) was the only independent risk factor for LTVTA. The final risk scoring model comprised the presence of LGE (hazard ratio, 10.68; p = 0.023), assigned a score of 2; syncope (hazard ratio, 4.41; p = 0.003), assigned a score of 1; and nonsustained ventricular tachycardia (hazard ratio, 3.82; p = 0.004), assigned a score of 1. A total score of ≥ 3 was considered high risk. Harrell's C-statistic was 0.814 in the derivation cohort and 0.785 in the external validation cohort. The 3-year cumulative risks for the low- and high-risk groups were 3.6% and 32.8%, respectively. Among CMR parameters, the presence of LGE was identified as the sole independent and strong risk marker of LTVTA. The novel scoring model may assist in the preliminary screening of patients with symptomatic heart failure with a potentially elevated risk.