Abstract 15126: Myocardial Tissue Reverse Remodeling After Guideline-directed Medical Therapy in Idiopathic Dilated Cardiomyopathy

Abstract

Background: The prognosis of idiopathic dilated cardiomyopathy (DCM) patients has improved remarkably in the recent decades with guideline-directed medical therapy (GDMT) and some patients undergo left ventricular reverse remodeling (LVRR). Objectives: We aim to study the dynamic changes of myocardial tissue characteristics by cardiovascular magnetic resonance (CMR), and investigate the association between myocardial tissue characteristics and cardiac functional remodeling in DCM patients after treatment. Methods: A total of 133 prospectively and consecutively enrolled DCM patients underwent baseline and follow-up CMR examinations with a median interval of 13.7 months (IQR: 12.2-18.5 months). The CMR protocol included cine, late gadolinium enhancement (LGE), pre- and post-contrast T1, and T2 mapping. LVRR was defined as an absolute increase in LV ejection fraction (EF) of >10% to a final value of ≥ 35% with a relative decrease in LV end-diastolic volume (EDV) of >10%. Results: Forty-two (31.6%) patients experienced LVRR during follow-up. At baseline, new onset heart failure, lower LVEF and the absence of LGE were independent predictors of LVRR. Patients with LVRR showed significant decrease of myocardial native T1, indexed matrix and cell volumes, while patients without LVRR also showed significant albeit smaller decrease of native T1 and indexed matrix and cell volumes. The changes of myocardial tissue characteristics were significantly correlated with the improvement of LVEF and indexed LVEDV. Conclusions: In idiopathic DCM patients, significant improvements in myocardial tissue characteristics were observed and accompanied with the improvement in LVEF and reduction in indexed LVEDV after GDMT.