Advanced Risk Stratification in Non-Ischemic Cardiomyopathy: The Prognostic Role of Cardiac Magnetic Resonance

Cardiac magnetic resonance (CMR) imaging has been considered crucial in non-ischemic cardiomyopathy (NICM). This study aims to evaluate the role of CMR in identifying risk factors for life-threatening events in patients with NICM and reduced left ventricular ejection fraction (LVEF). Methods: We analysed 57 (mean age 62.5 ± 11.4 years, 68.4% male) first-diagnosed NICM patients with reduced LVEF (mean 42 ± 9%). CMR assessments evaluated LVEF, right ventricular ejection fraction (RVEF), cardiac T1 mapping, extracellular volume (ECV), and the presence/extension of late gadolinium enhancement (LGE). Patients were monitored for a composite endpoint including sudden cardiac death (SCD), major ventricular arrhythmic events, and hospitalization for heart failure (HHF). Results: During a median follow-up lasting 543 days, 18 patients (31%) experienced cardiovascular events. A higher native T1 mapping value (1076 (1025-1120) ms vs. 999 (990-1037) ms, p < 0.001), a higher ECV (34 ± 6% vs. 28 ± 4,% p < 0.001) and a reduced RVEF (52 ± 13% vs. 60 ± 9%, p < 0.03) proved to be significantly correlated to an increased HHF, arrhythmic and SCD risk. Additionally, a native T1 mapping value exceeding 1018 ms demonstrated an increased risk (HR: 6.285; 95% CI: 2.044-19.326, p = 0.001) as well as an ECV greater than 28% (HR: 19.752; 95% CI: 2.622-148.817, p = 0.004) for composite endpoint. Conclusion: In NICM patients, elevated native T1 mapping and ECV values identified a high-risk subgroup for arrhythmic events while LVEF, and RVEF provide further risk stratification for the composite endpoint. CMR assessment may optimize risk stratification in NICM patients.