Prognostic Value of the Non-HDL-C/HDL-C Ratio for Predicting One-Year Major Adverse Cardiac and Cerebrovascular Events in Young Patients with Myocardial Infarction.

OBJECTIVE: Young patients with myocardial infarction (MI) remain at risk for recurrent cardiovascular events despite favorable short-term outcomes. The prognostic significance of the non-high-density lipoprotein cholesterol to high-density lipoprotein cholesterol (non-HDL-C/HDL-C) ratio in this population remains insufficiently studied. We aimed to evaluate its association with 1-year major adverse cardiac and cerebrovascular events (MACCE). METHOD: This retrospective, single-center study included 856 consecutive patients aged ≤50 years who were hospitalized with acute MI between January 2022 and January 2025, including 302 (35.3%) with STEMI and 554 (64.7%) with NSTEMI. The primary outcome was 1-year MACCE, defined as a composite of all-cause mortality, ischemic stroke, recurrent MI, and unplanned repeat coronary revascularization. Patients were categorized into low- and high-ratio groups using a receiver operating characteristic (ROC)-derived cutoff based on the Youden index. Associations were assessed using multivariable Cox proportional hazards models. RESULTS: During follow-up, 129 patients (15.0%) experienced MACCE. The optimal non-HDL-C/HDL-C cutoff was 4.43. The ratio was independently associated with 1-year MACCE (HR=1.568, 95% CI=1.463-1.681; P < 0.001), with consistent effects across the STEMI and NSTEMI subgroups (p for interaction=0.545). The non-HDL-C/HDL-C ratio showed the highest discriminatory performance among the lipid parameters (AUC=0.864), outperforming LDL-C, non-HDL-C, and the atherogenic index of plasma (DeLong P < 0.001). CONCLUSION: In this retrospective observational cohort, a higher non-HDL-C/HDL-C ratio was independently associated with an increased risk of 1-year MACCE in young patients with MI. Prospective multicenter studies are warranted to confirm these findings.