CMR predictors of left ventricular ejection fraction improvement and clinical outcomes in non-ischemic dilated cardiomyopathy: a multicenter retrospective study

Background non-ischemic dilated cardiomyopathy (NIDCM) is one of the major causes of acute and chronic heart failure (HF) and the most frequent indication for heart transplantation. Recently, the definition of heart failure with improved ejection fraction (HFimpEF) has been introduced but data regarding the cardiovascular magnetic resonance (CMR) parameters associated with improvement in left ventricular ejection fraction (LVEF) remain limited. Purpose the aim of the present study was to assess the CMR features associated with one-year improvement of LVEF in patients with NIDCM and reduced LVEF. Methods we conducted a retrospective multicenter observational study of patients with newly diagnosed NIDCM and reduced LVEF (≤ 40%). One-year improvement in LVEF was defined as ≥10% increase from baseline and a follow-up LVEF >40% assessed by echocardiography. The primary endpoint was the difference in CMR characteristics between patients with or without improved LVEF at one year. The secondary endpoint was the one-year incidence of clinical events (death, HF, stroke or malignant arrhythmias) or ICD implantation. Uni and multivariate logistic regression models were used to assess the association between CMR characteristics and the LVEF improvement. Uni and multivariate Cox regression models were applied to investigate CMR predictors of the secondary outcome. A p-value < 0.05 was considered significant. Results between 2018 and 2025, 100 NIDCM patients with reduced LVEF were enrolled. 48 patients showed LVEF improvement at one year. Patients with improved LVEF had lower indexed values of left ventricular mass (66 vs 78 g/m2, p = 0.006), right ventricular volume (75 vs 88 ml/m2, p = 0.009) and left atrial volume (48 vs 58 ml/m2, p = 0.03). Moreover, patients with improved LVEF had lower CMR-derived post-capillary wedge pressure (PCWP - 16 vs 18 mmHg, p = 0.004). LGE and septal LGE were more prevalent in patients without LVEF improvement (77% vs 38% of patients, p < 0.001 and 58 vs 29% of patients, p =0.004 respectively). The absence of LGE (OR 0.21, 95% CI 0.08-0.54, p = 0.01), absence of septal LGE (OR 0.33, 95% CI 0.14-0.77, p = 0.01) and PCWP (OR 0.86, 95% CI 0.75 – 0.98, p = 0.02) were independently associated with LVEF improvement. At one year, the secondary outcome occurred in 36 (36%) patients. Baseline LVEF was the only independent predictor of the secondary outcome (HR 0.90, 95% CI 0.86 – 0.95, p < 0.001). Patients with LGE who did not show LVEF improvement had the worst one-year prognosis (HR 3.09, 95% CI 1.32 – 7.22, p = 0.009). Conclusions in NIDCM patient with reduced LVEF, CMR-derived PCWP and LGE were independently associated with LVEF improvement. Patients with LGE who did not exhibit LVEF improvement had the highest risk of clinical events or ICD implantation at one year.Predictors of LVEF improvement Secondary outcome