Comparison of Cardiac Magnetic Resonance Imaging Findings and Outcome in Different Types of Cardiomyopathy

Abstract

Introduction: Nondilated left ventricular cardiomyopathy (NDLVC) is a recently recognized subtype of cardiomyopathy. This study aimed to evaluate and compare the phenotypic characteristics of dilated cardiomyopathy (DCM) and NDLVC using cardiac magnetic resonance imaging (CMR), and to investigate the prognostic implications associated with these conditions.

Methods: A total of 144 patients were enrolled and categorized into three groups. Group 1 included patients with left ventricular ejection fraction (LVEF) < 40%, corresponding to NDLVC with reduced ejection fraction (NDLVC-REF). Group 2 comprised those with LVEF between 40% and 50%, classified as NDLVC with mildly reduced ejection fraction (NDLVC-MREF). Group 3 consisted of patients diagnosed with DCM. All participants were followed for a median duration of 12 months to assess a composite cardiac endpoint.

Results: During the follow-up period, atrial fibrillation was more commonly observed in the NDLVC groups. In contrast, the DCM group exhibited a higher burden of myocardial late gadolinium enhancement (LGE). Most patients in the NDLVC groups did not present with LGE. The septal wall was the most frequently involved region of the left ventricle, and the midwall pattern was the most common LGE distribution across all groups. Notably, patients who experienced a composite cardiac event (CCE) demonstrated a higher prevalence of myocardial replacement fibrosis.

Conclusion: The prognosis of NDLVC has shown recent improvements. It may be appropriate to consider NDLVC as part of a spectrum that includes DCM. However, further research is required to elucidate the prognostic risk factors associated with this condition.