Cardiometabolic index is associated with inflammation-mediated vulnerable plaque and adverse prognosis in patients with acute coronary syndrome

Introduction This study aimed to investigate the relationship between Cardiometabolic Index (CMI) and inflammation-mediated vulnerable plaque and to compare the differences in the incidence of major adverse cardiovascular events (MACE) among patients with different plaque types. Methods A total of 270 patients with ACS who underwent Optical Coherence Tomography (OCT) imaging from January 2023 to January 2024 were included. Patients were categorized based on tertiles of CMI, and OCT was used to assess coronary plaque characteristics. The mediation package in R 4.4.2 was used to explore the potential mechanisms of inflammation in the association between CMI and vulnerable plaques. MACE was defined as a composite of all-cause mortality, non-fatal myocardial infarction, coronary revascularization, and ischemic stroke. Results Patients with higher CMI exhibited a greater prevalence of thin-cap fibroatheromas (TCFA) and macrophage infiltration. High-sensitivity C-reactive protein (hsCRP) mediated approximately 17.0% of the association between CMI and minimum FCT [Indirect effect = -5.21, 95% confidence interval (CI) = (-12.70, -1.27), P = 0.016]. COX regression analysis showed a positive correlation between CMI and MACE [hazard ratio(HR) = 1.59, 95% CI = 1.07-2.38, P = 0.022]. Subgroup analysis revealed that CMI was associated with MACE only in subgroups with TCFA, absence of calcification, minimal FCT < median, and maximum lipid arc≥median, with patients having TCFA/high CMI (HR=2.94,95% CI=1.15-7.54, P=0.025) or no calcification/high CMI (HR=2.88,95% CI=1.03-8.08, P=0.044) exhibiting poorer prognoses. Conclusion CMI is a significant predictor of vulnerable plaque and adverse prognosis in patients with ACS, with systemic inflammation emerging as a key mediator.