# The association between multi-inflammatory index and long-term mortality in post-myocardial infarction patients treated with percutaneous coronary intervention

## TL;DR

A high multi-inflammatory index (MII) is linked to higher long-term mortality and cardiac events in patients who had a heart attack and underwent a specific treatment.

## Contribution

This study shows that the MII is a better predictor of long-term outcomes than traditional markers like CRP in post-heart attack patients.

## Key findings

- High MII scores were independently associated with increased all-cause mortality and major adverse cardiac events.
- MII outperformed CRP in predicting mortality with a higher C-index.
- Adding MII improved the accuracy of traditional clinical models for predicting mortality.

## Abstract

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.

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).

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).

In the AMI cohort, a high MII score was strongly associated with long-term mortality and MACCE.