Objective:

To identify independent risk factors for intramyocardial hemorrhage (IMH) and develop a clinical risk score for predicting IMH in elderly patients with ST-segment elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (PCI).

Approach:

• Study Design: Single-center retrospective observational study of 232 elderly patients (≥60 years) with STEMI who underwent primary PCI and completed cardiac magnetic resonance (CMR) imaging 3–7 days post-procedure.
• Data Collection: Clinical, laboratory, angiographic, and procedural data were collected; patients were classified into IMH and non-IMH groups based on CMR findings.
• Statistical Analysis: Univariate and multivariate logistic regression analyses were performed to identify independent predictors and develop an integer-based risk score (IMH-RS).

Key Findings:

• The incidence of IMH was 33.2% (77/232).
• Independent predictors of IMH included renal insufficiency (OR = 2.95, 95% CI: 1.41–6.18), left anterior descending artery involvement (OR = 2.01, 95% CI: 1.02–3.97), door-to-balloon time >45 min (OR = 2.55, 95% CI: 1.36–4.78), triple-vessel disease (OR = 6.12, 95% CI: 2.51–14.88), elevated B-type natriuretic peptide (per 100 pg/L increase: OR = 1.25, 95% CI: 1.05–1.49), and reduced left ventricular ejection fraction (per 1% increase: OR = 0.94, 95% CI: 0.91–0.97).
• The IMH-RS score demonstrated good discrimination (AUC = 0.82) and effectively stratified patients into low, intermediate, and high-risk groups.

Interpretation:

IMH is common in elderly STEMI patients after primary PCI and is associated with several clinical and procedural factors.

Limitations:

• The study was conducted at a single center, which may limit generalizability.
• The retrospective design may introduce selection bias.

Conclusion:

The IMH-RS score provides a tool for risk stratification in elderly STEMI patients, integrating various clinical and procedural factors.