Utilization of Cardiac Magnetic Resonance Imaging for Assessing Myocardial Fibrosis in Prognosis Evaluation and Risk Stratification of Patients with Dilated Cardiomyopathy.

Abstract

Dilated cardiomyopathy (DCM) is the ultimate manifestation of the myocardial response to various genetic and environmental changes and is characterized mainly by impaired left ventricular systolic and diastolic function. DCM can ultimately lead to heart failure, ventricular arrhythmia (VA), and sudden cardiac death (SCD), making it a primary indication for heart transplantation. With advancements in modern medicine, several novel techniques for evaluating myocardial involvement and disease severity from diverse perspectives have been developed. Myocardial fibrosis is a significant contributor to VA events and SCD. Based on different pathological mechanisms, myocardial fibrosis can be categorized into replacement and interstitial forms. Late gadolinium enhancement (LGE) derived from cardiovascular magnetic resonance is the clinical gold standard for evaluating replacement myocardial fibrosis and exhibits high concordance with histological replacement fibrosis. However, because of the absence of normal tissue as a control, the LGE technique often fails to effectively visualize diffuse interstitial fibrosis. In such cases, T1 mapping and extracellular volume fraction mapping can be complementary or alternative methods to the LGE technique for detecting interstitial fibrosis. This review aimed to provide a comprehensive and precise assessment of myocardial fibrosis and to determine the use of cardiac magnetic resonance imaging for prognostic evaluation and risk stratification of patients with DCM.