An imaging-based integrated CMR risk score robustly predicts adverse left ventricular remodeling after STEMI

Background Adverse left ventricular (LV) remodeling after ST-elevation myocardial infarction (STEMI) remains a principal mechanistic driver of subsequent heart failure and mortality. Although cardiac magnetic resonance (CMR) enables comprehensive quantification of infarct size and microvascular injury, the incremental prognostic value of a structured imaging-based risk score beyond clinical assessment has not been definitively established. Purpose To develop and internally validate an Integrated CMR Risk Score for early prediction of adverse LV remodeling following primary PCI. Methods Consecutive STEMI patients from the multicenter SINERGY-ACUTE project, undergoing early CMR (n=268), were evaluated. Adverse remodeling was defined as ≥20% increase in LV end-systolic volume or ≥10% decline in LVEF at follow-up. Independent predictors were identified using penalized multivariable logistic regression. The Integrated CMR Risk Score (0–5 points) incorporated: infarct size (highest tertile, 2 points), LVESV above median (1 point), presence of microvascular obstruction (MVO, 1 point), and intramyocardial hemorrhage (IMH, 1 point). Model discrimination was assessed by ROC analysis with DeLong testing. Incremental value was evaluated using ΔAUC, Net Reclassification Improvement (NRI), and Integrated Discrimination Improvement (IDI). Internal validation used 1000-bootstrap resampling. Calibration and decision curve analyses were performed. Results A total of 268 STEMI patients with early CMR was included in the study of whom 18 patients fulfilled criteria for adverse LV remodeling during the follow-up. Independent predictors of adverse LV remodeling were: infarct size (per 5% increase: OR 1.28, 95% CI 1.15–1.42; p<0.001), LVESV (per 10 mL: OR 1.21, 95% CI 1.10–1.35; p<0.001), MVO (OR 2.14, 95% CI 1.48–3.09; p<0.001), and IMH (OR 2.67, 95% CI 1.72–4.13; p<0.001). Clinical model AUC was 0.66 (95% CI 0.62–0.70) versus 0.79 (95% CI 0.75–0.83) for the Integrated Score (ΔAUC +0.13; p<0.001). Reclassification improved significantly (NRI 0.32; IDI 0.11; both p<0.001). Optimism-corrected AUC was 0.77. Calibration was preserved (slope 0.94; Hosmer–Lemeshow p>0.20). Remodeling rates increased stepwise (9%, 24%, 51% across score strata). Conclusions An Integrated CMR Risk Score combining infarct size, microvascular injury, and baseline LV remodeling parameters provides statistically robust, independently validated, and clinically meaningful prediction of adverse LV remodeling after STEMI, substantially outperforming clinical assessment alone and enabling early high-risk stratification.