Abstract
BACKGROUND: Inflammation plays a crucial role in the pathophysiology of acute myocardial infarction (AMI), and various inflammatory markers have been associated with patient outcomes. The multi-inflammatory index (MII) has emerged as a potential prognostic indicator, but its relationship with AMI mortality remains unclear. METHODS: We analyzed 8,414 patients with successfully revascularized AMI. The subjects were divided into a high MII group (n = 3,708) or a low MII group (n = 4,706) using the MII score at admission. The MII score was calculated using the initial serum neutrophil, lymphocyte, and C-reactive protein (CRP). The primary and secondary outcomes were all-cause mortality and major adverse cardiac and cerebrovascular events (MACCE). RESULTS: Over a median follow-up of 5.13 years, the high MII group showed significantly higher incidences of all-cause mortality and MACCE than the low MII group (p < 0.001, each). Multivariate Cox regression identified a high MII score as an independent predictor of all-cause mortality and MACCE [adjusted hazard ratio (HR) 1.71; 95% confidence interval (CI) 1.55-1.89; p < 0.001, HR 1.53; 95% CI 1.40-1.67; p < 0.001]. MII score had statistically higher discriminative ability for predicting all-cause mortality than the conventional inflammatory marker, CRP (C-index 0.662; 95% CI 0.648-0.677 vs. 0.646; 95% CI 0.632-0.661, p < 0.001). The predictive accuracies of traditional clinical factor discrimination and reclassification for mortality were significantly improved upon the addition of high MII score (C-index 0.791 vs. 0.780; 95% CI 0.780-0.803; p < 0.001, NRI 0.018; 95% CI 0.014-0.021; p < 0.001). CONCLUSION: In the AMI cohort, a high MII score was strongly associated with long-term mortality and MACCE.