[Predictive model for ejection fraction improvement at one year in patients with acute ST-segment elevation myocardial infarction complicated with heart failure with reduced ejection fraction].

To develop a predictive model for improvement of ejection fraction 1 year after heart failure with reduced ejection fraction (HFrEF) following acute ST-segment elevation myocardial infarction (STEMI). This nested case-control study included STEMI patients diagnosed with HFrEF from a prospective multicenter multimodality imaging cohort between August 2014 and March 2021. Based on the improvement of left ventricular ejection fraction (LVEF) at baseline and 1-year follow-up, the patients were classified into the heart failure with improved ejection fraction (HFimpEF) group and the persistent HFrEF group. The clinical data were collected, and cardiac histological changes were assessed using cardiac magnetic resonance imaging. Multivariate logistic regression analysis was performed to identify factors associated with ejection fraction improvement at one year, and a predictive model was developed and internally validated. The performance and clinical applicability of the model were evaluated using receiver operating characteristic (ROC) curves, calibration curves, and decision curve analysis. A total of 117 STEMI patients (102 males and 15 females) aged (61.6±11.6) years were included in the study. At the 1-year follow-up, there were 61 patients (52.1%)in the HFimpEF group,and 56 patients (47.9%) in the HFrEF group . Compared with persistent HFrEF group, patients in HFimpEF group had smaller baseline left ventricular end-systolic diameter (LVESD) [33.0 (30.0, 36.0) mm vs 35.5 (32.0, 39.0) mm], smaller infarct size [26.1% (20.3%, 36.0)% vs 40.6% (33.0%, 45.4)%], lower peak B-type natriuretic peptide (BNP) level [340.0 (190.5, 692.5) ng/L vs 636.0 (318.5, 1 188.8) ng/L], lower peak level of soluble suppression of tumorigenicity 2 (sST2) [36.7 (25.8, 60.5) μg/L vs 62.4 (30.6, 120.7) μg/L], and higher hematocrit [(43.5%±3.5%) vs (40.8%±5.6%)] (all <0.05). Multivariate logistic regression analysis revealed that smaller baseline LVESD (=0.825, 95%: 0.745-0.914), smaller infarct size (=0.967, 95%: 0.939-0.995), peak BNP level≤400 ng/L (=3.062, 95%: 1.283-7.306), peak sST2 level≤35 μg/L (=2.600, 95%: 1.040-6.501), and higher hematocrit (=1.109, 95%: 1.030-1.193) were predictors of LVEF improvement in STEMI patients with HFrEF. The predictive model formula: logit (P)=2.619-0.034×infarcted myocardium percentage (%)+1.119×(peak BNP level≤400 ng/L)+0.956×(peak sST2 level≤35 μg/L)+0.103×hematocrit (%)-0.192×LVESC (mm) (where peak BNP level≤400 ng/L and peak sST2 level≤35 μg/L are binary variables: Yes=1, No=0). The area under the ROC curve (AUC) was 0.805 (95%: 0.723-0.887), indicating good predictive ability. Calibration curves and decision curve analysis indicated good model consistency and clinical utility. Smaller LVESD, smaller infarct size, peak BNP level≤400 ng/L, peak sST2 level≤35 μg/L and higher hematocrit are predictive factors for LVEF improvement after STEMI. The predictive model has good performance for predicting HFimpEF.