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

Sangho Hyun¹Jaeho Seung²Kwan Yong Lee^2,3*Sang Hyun Kim²Myunhee Lee⁴Andrew Yoon⁵Wonjae Lee⁶Byung-Hee Hwang²Eun Ho Choo²Chan Joon Kim⁷Jin-Jin Kim²Ha-Wook Park⁸Gyu Chul Oh²Yun-Seok Choi²Youngkeun Ahn⁹Kiyuk Chang²

• ¹Catholic University of Korea, Seoul, Republic of Korea
• ²Cardiovascular Center and Cardiology Division, Seoul St. Mary’s Hospital, The Catholic University of Korea, Seoul, Republic of Korea
• ³Cardiovascular Research Institute for Intractable Disease, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea
• ⁴School of Public Health, San Diego State University, San Diego, California, United States
• ⁵Carle Illinois College of Medicine, University of Illinois at Urbana–Champaign, Champaign, Illinois, United States
• ⁶Department of Internal Medicine, Seoul St. Mary's Hospital, The Catholic University of Korea, Seoul, Republic of Korea
• ⁷Cardiovascular Center and Cardiology Division, Uijeongbu St. Mary’s Hospital, The Catholic University of Korea, Uijeongbu, Republic of Korea
• ⁸Department of Cardiology, Bucheon Sejong Hospital, Bucheon, Republic of Korea
• ⁹Department of Cardiovascular Medicine, Chonnam National University Hospital, Gwangju, Republic of Korea

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.We analyzed 8,414 patients with successfully revascularized AMI. The subjects were divided into a high MII group (n=3708) or a low MII group (n=4706) 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).In the AMI cohort, a high MII score was strongly associated with long-term mortality and MACCE.