Predictors of left ventricular ejection fraction recovery after guideline-directed medical therapy in patients with newly diagnosed dilated cardiomyopathy and baseline LVEF ≤35.

Background: Patients with newly diagnosed dilated cardiomyopathy (DCM) and a baseline left ventricular ejection fraction (LVEF) ≤35% generally have a poor prognosis. Early identification of patients who are unlikely to recover LVEF after guideline-directed medical therapy (GDMT) is clinically important for risk stratification, closer follow-up, repeated LVEF assessment, and timely reassessment of guideline-based device therapy eligibility. Methods: This retrospective cohort study enrolled 198 patients with newly diagnosed dilated cardiomyopathy (DCM) and baseline left ventricular ejection fraction (LVEF) ≤35%, all of whom received standardized guideline-directed medical therapy (GDMT) for 3∼6 months. Baseline and follow-up echocardiographic, electrocardiographic, clinical, and laboratory data were collected. The primary outcome was recovery of LVEF to >35% after treatment. The secondary outcome was the first occurrence of cardiovascular death or rehospitalization for heart failure during follow-up. Multivariable Firth Logistic regression was used to identify independent predictors and to develop a prediction model, which was internally validated using the area under the receiver operating characteristic curve (ROC AUC), the Hosmer-Lemeshow goodness-of-fit test, and decision curve analysis. Cox proportional hazards regression was used to evaluate predictors of long-term prognosis, and time-dependent ROC analysis was performed. Results: Multivariable Firth logistic regression showed that absence of left bundle branch block (LBBB) and higher apolipoprotein A1 (ApoA1) levels were independently associated with LVEF recovery to >35%. The presence of LBBB was strongly associated with a lower likelihood of LVEF recovery (OR = 0.02, 95% CI 0.00-0.13, Conclusions: The model may help with early risk stratification, closer surveillance, repeated LVEF assessment, and timely reassessment of guideline-based ICD eligibility. However, external validation is required before routine clinical application.