Could cardiac MR imaging with late gadolinium enhancement affect the risk stratification and outcome prediction in non-ischemic cardiomyopathies?

Abstract

Background: Cardiac MR (CMR) evaluating non-ischemic cardiomyopathies (NICMs) is superior 3D imaging with non-invasiveness, more accuracy and reproducibility of measurements. It provides comprehensive structural, functional information, tissue characterization, and assesses fibrosis by LGE.
Objective: The study aimed to investigate these imaging data and their prognostic value in NICM.
Patients and methods: 46 NICM patients were assessed by echocardiography/cardiac magnetic resonance (CMR). They were divided into 3 groups: dilated, hypertrophic and miscellaneous types. Late gadolinium enhancement (LGE) presence and myocardial extent/percentage were assessed with clinical follow up for a median of 1-year for any Major adverse cardiac events (MACE). For each group, univariate analysis of clinical/imaging risk factors in the associations with LGE/MACE was performed. Results: Twenty-six dilated cardiomyopathy patients, 62% had LGE and 31% had MACE. Using LGE as a predictor for MACE was statistically significant (p = 0.007). Using univariate analysis, the presence of LGE (p=0.00) and the extent of LGE (p < 0.0001) demonstrated the strongest unadjusted association with MACE. ROC curves revealed a cutoff value of LGE > 4.5% as MACE predictor. Twelve hypertrophic cardiomyopathy patients (67%) had LGE and (50%) had MACE. Using LGE as a predictor for MACE was statistically significant (p=0.014). Using univariate analysis, the presence of LGE (p=0.01) and the extent of LGE (p=0.01) demonstrated the strongest unadjusted association with MACE. ROC curves revealed a cutoff value of LGE > 4.5% as MACE predictor.
Conclusion: CMR with LGE is crucial in NICM evaluation with prognostic value; changing the way that myocardial disorders will be understood and managed in the near future.