Development and Validation of a Prognostic Nomogram Integrating CMR and Clinical Data for Predicting 1- to 3-Year Major Adverse Cardiovascular Events in New-Onset STEMI Patients Post-PCI

Background: Patients with ST-segment elevation myocardial infarction (STEMI) remain at risk for major adverse cardiovascular events (MACE) following percutaneous coronary intervention (PCI). Current risk scores lack detailed myocardial tissue characteristics from cardiac magnetic resonance (CMR) imaging for long-term prediction. The aim of this study was therefore to develop and validate a prognostic nomogram that integrates CMR and clinical data to better predict 1- to 3-year MACE in new-onset STEMI patients post-PCI. Methods: This retrospective study included patients who underwent PCI for new-onset STEMI between January 2020 and June 2022. Data from two centers were pooled. The combined cohort was then randomly divided into a derivation cohort (n = 107) for model development and an internal validation cohort (n = 46) for performance assessment. Univariate and multivariate Cox proportional hazards regression analyses were performed to identify independent risk factors and construct a nomogram. The predictive performance of this nomogram was assessed using C-indexes, time-dependent Receiver Operating Characteristic (ROC) curves, calibration curves, and decision curve analysis (DCA). Results: A total of 107 new-onset STEMI patients were included in the derivation cohort and 46 in the internal validation cohort. Cumulative MACE incidence rates at 1-, 2-, and 3- years were 20.6%, 34.6%, and 44.9% in the derivation cohort, and 21.7%, 34.8%, and 50.0% in the internal validation cohort, respectively. The final nomogram incorporated six independent predictors derived from both clinical and CMR data: the Gensini Score (hazard ratio [HR]: 1.012, 95% confidence interval [CI]: 1.003–1.020, p = 0.006), albumin (HR: 0.849, 95% CI: 0.769–0.938, p = 0.001), low-density lipoprotein cholesterol (LDL-C; HR: 1.377, 95% CI: 1.037–1.828, p = 0.027), Left Ventricular Ejection Fraction (LVEF; HR: 0.890, 95% CI: 0.833–0.951, p = 0.001), Left Ventricular End-Diastolic Volume (LVEDV; HR: 1.014, 95% CI: 1.003–1.025, p = 0.015), and the mean of Left Ventricular Wall Motion (LVWM; HR: 0.464, 95% CI: 0.288–0.747, p = 0.002), derived from both clinical and CMR data. The nomogram demonstrated good discriminatory ability in the derivation cohort (C-index: 0.803; 95% CI: 0.739–0.867) and moderate discrimination in the internal validation cohort (C-index: 0.693; 95% CI: 0.570–0.816). Calibration plots indicated good agreement between the predicted and observed MACE probabilities in both cohorts. DCA confirmed the potential clinical utility of the nomogram. Conclusion: Our validated prognostic nomogram, integrates CMR parameters and clinical data. It effectively discriminates high- and low-risk new-onset STEMI patients for 1-, 2-, and 3-year MACE following PCI. This tool may assist with risk stratification and in guiding personalized therapeutic strategies.