Association of the cholesterol, high-density lipoprotein, and glucose (CHG) index with mortality after acute myocardial infarction: evidence from two large prospective cohorts

Patients with acute myocardial infarction (AMI) continue to face a considerable risk of death, even in the era of contemporary reperfusion and secondary prevention. Metabolic abnormalities may partly explain this residual risk. The cholesterol, high-density lipoprotein, and glucose (CHG) index, calculated as Ln{[total cholesterol (TC, mg/dL) × fasting blood glucose (FBG, mg/dL)]/[2 × high-density lipoprotein cholesterol (HDL-C, mg/dL)]}, is a recently proposed marker integrating lipid and glucose metabolism. We primarily aimed to examine the association between the CHG index and mortality in patients with AMI. We analyzed two prospective cohorts, including 8,782 patients with AMI from the China Acute Myocardial Infarction (CAMI) registry and 3,466 AMI patients undergoing percutaneous coronary intervention at Fuwai Hospital. Outcomes included in-hospital, 1-year, and 2-year all-cause mortality in the CAMI cohort, and all-cause mortality in the Fuwai Hospital cohort. Associations between the CHG index and mortality were assessed using Cox proportional hazards models and restricted cubic splines. Discrimination, reclassification, and decision curve analyses were performed as secondary exploratory analyses. In the CAMI cohort, higher CHG levels were associated with a graded increase in mortality risk. After multivariable adjustment, patients in the highest CHG tertile had higher risks of in-hospital mortality [hazard ratio (HR): 2.66, 95% confidence interval (CI): 1.63–4.32], 1-year mortality (HR: 2.44, 95% CI: 1.81–3.30), and 2-year mortality (HR: 2.41, 95% CI: 1.78–3.25) compared with those in the lowest tertile. Consistent findings were observed in the Fuwai Hospital cohort, in which the highest CHG tertile was associated with higher all-cause mortality after multivariable adjustment (HR: 2.16, 95% CI: 1.28–3.63). Restricted cubic spline analyses showed an approximately linear relationship between CHG and mortality. In secondary exploratory analyses, the CHG index yielded higher areas under the curve than the TyG index in both cohorts. In the CAMI cohort, adding CHG to the Global Registry of Acute Coronary Events (GRACE) score resulted in statistically significant but modest improvements in discrimination and reclassification and increased the net benefit in decision curve analysis. A higher CHG index was consistently associated with increased mortality risk after AMI across two independent cohorts, although its clinical utility requires further evaluation.