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

TL;DR

This study shows that cardiac MRI can help identify patients with non-ischemic heart disease at higher risk for serious events.

Contribution

The study demonstrates that T1 mapping and ECV from CMR improve risk prediction in NICM patients beyond traditional measures.

Findings

Higher native T1 mapping and ECV values were strongly linked to increased risk of heart events.

Reduced right ventricular ejection fraction also correlated with higher risk.

CMR metrics outperformed traditional measures in predicting outcomes.

Abstract

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.

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