Abstract 14182: Myocardial Fibrosis and Reverse Remodelling in Nonischaemic Dilated Cardiomyopathy

Abstract

Introduction: In nonischaemic dilated cardiomyopathy (NICM), myocardial fibrosis can be detected by cardiovascular magnetic resonance (CMR) as late gadolinium enhancement (LGE) and is associated with worse prognosis. Hypothesis: Absence of myocardial fibrosis is associated with left ventricular reverse remodelling (LV-RR). Methods: One-hundred-and-twenty-five NICM patients (age 51±16 years, 82 male) were enrolled and underwent baseline CMR; patients with ischaemic, valvular, congenital heart disease, other cardiomyopathies or contraindications to CMR were excluded. After a 24-month follow-up on optimal medical therapy, all patients underwent a second CMR; patients who died, underwent device implantation or declined a second CMR, were also excluded from the study. LGE was quantified on post-contrast CMR images. LV-RR was defined as an increase in LV ejection fraction ≥10 U or decrease in LV end-diastolic volume ≥10% at follow-up. Results: Mean LV ejection fraction was 41±11% at baseline, 47±12% at follow-up: LV-RR was observed in 59 patients (47%), with no age or gender difference (p=NS) . LGE was present in 69 (54%) patients at baseline (mean extent 12±6 g), without significant differences at follow-up (mean extent 13±7 g). Patients experiencing LV-RR during follow-up presented a baseline worse LV ejection fraction (36±12%) than no-LV-RR patients ( 45±9%, p<0.01), greater LV volumes (123±38 vs. 110±22 ml/m2, p=0.02) and worse right ventricular ejection fraction (54±12% vs. 59±10%, p=0.02) . Nevertheless, only 17 (29%) LV-RR patients presented LGE compared to 31 (47%, p=0.04) no-LV-RR patients. Moreover, among LGE-positive patients (n=48), only 17 (35%) developed LV-RR, while among LGE-negative patients (n=77), 42 (55%) developed LV-RR (p=0.04). Multivariate regression analysis showed that the absence of LGE at baseline CMR was a strong predictor of LV-RR (p=0.02), even after correction for age, New York Heart Association class, LV volumes and systolic function. Conclusions: In patients with idiopathic dilated cardiomyopathy, absence of LGE was a strong independent predictor of LV-RR at 2-year follow-up, irrespective of the initial clinical status and the severity of ventricular dilatation and dysfunction.