Risk Stratification of Sudden Cardiac Death in Non-Ischemic Cardiomyopathy: Towards Arrhythmogenic Substrate Assessment in Cardiac MRI

Motivation: Identifying arrhythmogenic substrates in non-ischemic cardiomyopathy (NICM) patients is crucial for assessing the risk of sudden cardiac death (SCD). Goal(s): This study aims to evaluate the prognostic value of T1 mapping metrics compared to late gadolinium enhancement (LGE) in predicting SCD-related events. Approach: We enrolled 837 NICM patients who underwent T1 mapping MRI. The primary endpoint was a composite of SCD-related events, including SCD, appropriate defibrillator shocks, and resuscitated cardiac arrest. Results: Over 58.3 months, LGE ≥ 7.2%, extracellular volume (ECV) fraction ≥ 31.8%, and native T1 z-score ≥ 2.1 were significantly associated with increased SCD risk. Impact: Our findings suggest that LGE and ECV metrics can enhance risk stratification and support personalized prognostic strategies in managing NICM patients, improving clinical decision-making.