Objectives To analyse the relationship between low-density lipoprotein cholesterol (LDL-C)/high-density lipoprotein cholesterol (HDL-C) ratio on admission and cardiovascular events in patients with ST segment elevation myocardial infarction (STEMI) undergoing urgent percutaneous coronary intervention (PCI).

Methods A total of 387 patients who underwent urgent PCI with STEMI were enrolled. The patients were divided into two groups according to their median LDL-C/HDL-C ratio on admission: low LDL-C/HDL-C group (LDL-C /HDL-C ratio ≤ 2.50 mmol/L, n = 225) and high LDL-C/HDL-C group (LDL-C /HDL-C ratio > 2.50 mmol/L, n = 162). In the two groups, incidence of major adverse cardiovascular events (MACE) and readmission for cardiovascular events was collected during follow-up. MACE was defined as cardiovascular death, non-fatal MI, revascularisation, and stroke.

Results The median duration of follow-up was 399.20 ± 61.68 days. The incidences of stroke and MACE were higher significantly in high LDL-C/HDL-C group than in low LDL-C/HDL-C group (stroke: 5.7% vs. 1.8%, P = 0.040; MACE: 13.2% vs. 6.3%, P = 0.021). After adjusting various confounders, the incidences of stroke and MACE significantly correlated with LDL-C/HDL-C ratio (hazard ratio (HR) = 9.048, 95% confidence interval (CI): 1.026–79.792, P = 0.047; HR = 2.975, 95% CI: 1.004–8.819, P = 0.049, respectively); the incidence of readmission for cardiovascular events significantly correlated with LDL-C (HR = 8.055, 95% CI: 1.605–39.326, P = 0.01).

Conclusions The study suggested that the LDL-C/HDL-C ratio on admission had an impact on cardiovascular events, and the LDL-C/HDL-C ratio was a more useful predictor of cardiovascular events than the individual levels of LDL-C and HDL-C in patients with STEMI undergo urgent PCI.