Cardiometabolic index as a novel prognostic biomarker for cardiovascular events in post-percutaneous coronary intervention patients with ST-segment elevation myocardial infarction: two-center retrospective study

The Cardiometabolic Index (CMI) is a recognized metabolic marker, but its predictive efficacy for major adverse cardiovascular events (MACEs) in patients with ST-segment elevation myocardial infarction (STEMI) remains uncertain. The primary aim of this study is to investigate the predictive value of CMI for long-term outcomes in patients with STEMI, focusing on inflammation’s mediating effects. We analyzed data from 905 consecutive STEMI patients undergoing primary percutaneous coronary intervention, with 785 included in the final analysis. The primary endpoint was a composite of cardiovascular death, non-fatal myocardial infarction, revascularization for unstable angina, and rehospitalization for congestive heart failure. We used Cox regression models and subgroup analyses to explore the relationships between CMI and these outcomes, and employed mediation analysis to assess the role of inflammation, specifically using the lymphocyte to C-reactive protein ratio (LCR). Over an average follow-up of 11 months, 296 MACEs occurred. Multivariable Cox regression showed a significant positive association between CMI and the incidence of MACEs (Hazard Ratio [HR]: 4.584, 95% CI: 3.134–6.704), non-fatal myocardial infarction (HR: 2.142, 95% CI: 1.110–4.135), revascularization (HR: 7.911, 95% CI: 3.986–15.700), and rehospitalization for heart failure (HR: 6.243, 95% CI: 2.779–14.023), but not with cardiovascular death. Mediation analysis indicated that LCR mediated −13.7% and −19.5% of the associations of CMI with MACEs and heart failure rehospitalization, respectively. Elevated CMI is positively associated with MACEs and rehospitalization for heart failure in STEMI patients, with partial mediation through inflammatory pathways. CMI may thus be a valuable prognostic tool for this patient group.