Myocardial Tissue Reverse Remodeling after Guideline-directed Medical Therapy in Idiopathic Dilated Cardiomyopathy

Background – The prognosis of idiopathic dilated cardiomyopathy (DCM) patients has improved remarkably in recent decades with guideline-directed medical therapy (GDMT). Left ventricular reverse remodeling (LVRR) is one of the major therapeutic goals. Whether myocardial fibrosis or inflammation would reverse associated with LVRR remains unknown.

Methods – A total of 157 prospectively enrolled DCM patients underwent baseline and follow-up CMR examinations with a median interval of 13.7 months (interquartile range: 12.2-18.5 months). LVRR was defined as an absolute increase in LV ejection fraction (LVEF) of >10% to the final value of ≥ 35% and a relative decrease in LV end-diastolic volume (EDV) of >10%. Statistical analyses were performed using paired t-test and student t-test, logistic regression analysis, and linear regression analysis.

Results – Forty-eight (31%) patients reached LVRR. At baseline, younger age, worse NYHA class, new-onset heart failure, lower LVEF, absence of late gadolinium enhancement (LGE), lower myocardial T2, and extracellular volume (ECV) were significant predictors of LVRR. During the follow-up, patients with and without LVRR both showed a significant decrease of myocardial native T1 (LVRR: [baseline]1303.0±43.6ms; [follow-up]1244.7±51.8ms; without LVRR: [baseline]1308.5±80.5ms; [follow-up]1287.6±74.9ms, both p < 0.001), matrix and cellular volumes while no significant difference was observed in T2 or ECV values after treatment.

Conclusions – In idiopathic DCM patients, the absence of LGE, lower T2, and ECV values at baseline are significant predictors of LVRR. The myocardial T1, matrix, and cell volume decrease significantly in patients with LVRR after GDMT.