Inflammatory markers guide early risk stratification and prognosis in elderly patients with acute myocardial infarction.

High-sensitivity C-reactive protein (hs-CRP) has been associated with prognosis in acute myocardial infarction (AMI) patients, but data on its role in elderly individuals remains limited. This single-center, retrospective study included 590 elderly AMI patients, who were stratified into three groups based on hs-CRP tertiles. The incidence of adverse in-hospital events increased progressively across higher hs-CRP tertiles (17.2%, 25.5%, and 48%, P<0.001). Notably, patients who experienced these events had significantly higher hs-CRP levels compared to those without adverse outcomes (7.04 [2.38, 20.00] vs. 2.59 [1.06, 6.07], P<0.001). Multivariate logistic regression identified hs-CRP as an independent predictor of in-hospital outcomes in elderly AMI patients (Q3: OR 2.21, 95% CI 1.23-3.97, P=0.008). The area under the curve (AUC) for hs-CRP's predictive accuracy was 0.712 (95% CI 0.664-0.755, P<0.001). Furthermore, integrating hs-CRP into an established risk factor model significantly improved both reclassification and discrimination (Continuous NRI: 0.461, 95% CI 0.292-0.631, P<0.001; IDI: 0.046, 95% CI 0.025-0.067, P<0.001), although it did not substantially enhance the C-statistic (0.867 (95% CI 0.831-0.895, P<0.001) vs. 0.876 (95% CI 0.841-0.905, P<0.001) , P=0.183). These findings suggest that hs-CRP is a reliable and practical biomarker for predicting poor prognosis in elderly patients with AMI.