Association Between the Atherogenic Index of Plasm and 10-year Mortality in Patients with Acute Coronary Syndrome: Prospective Cohort Study

Background The atherogenic index of plasma (AIP) is a potential marker for cardiovascular risk, but its association with mortality in acute coronary syndrome (ACS) patients remains unclear. This study aimed to evaluate the relationship between AIP and mortality risk in ACS patients, with stratified analyses by sex and age. Methods This cohort study enrolled 2,200 patients with ACS, stratified according to AIP quartiles. The association between AIP levels and all-cause mortality was evaluated using Cox proportional hazards regression models during the 10-year follow-up period. Additionally, sex- and age-stratified analyses were performed, and potential non-linear relationships were examined using two-piecewise linear regression models. Results Higher AIP levels were associated with reduced mortality risk (HR: 0.58, 95% CI: 0.42–0.79, P < 0.001), consistent in adjusted models (Model 1: HR: 0.53, 95% CI: 0.35–0.79, P = 0.002; Model 2: HR: 0.54, 95% CI: 0.36–0.81, P = 0.003). In sex-stratified analyses, no significant association was found in females, but males in the highest AIP quartile had a lower mortality risk (HR: 0.64, 95% CI: 0.43–0.95, P = 0.03). Patients aged > 65 years also showed a significant association (HR: 0.55, 95% CI: 0.37–0.84, P = 0.005). Non-linear analyses revealed a threshold effect in females, with an inflection point at 0.08. Conclusion Elevated AIP levels were associated with reduced mortality risk in ACS patients, particularly in males and older individuals. These findings suggest AIP may aid in risk stratification and personalized management of ACS, warranting further validation.