Small Dense Low Density Lipoprotein and Cardiovascular Events in Patients With Acute Coronary Syndrome Undergoing Percutaneous Coronary Intervention: A Cohort Study From China

Background : Residual risk remained significant despite effective low density lipoprotein cholesterol (LDL-C) lowering treatment. Small dense low density lipoprotein cholesterol (sdLDL-C) as part of LDL-C has been found to be predictor of coronary heart disease (CHD) and cardiovascular (CV) events in patients with stable CHD independently of LDL-C. However, to date, few studies have explored the role of sdLDL-C in patients with acute coronary syndromes (ACS) undergoing percutaneous coronary intervention (PCI). Accordingly, this study aimed to evaluate the association of sdLDL-C with CV events in patients with ACS undergoing PCI. Methods: Patients hospitalized with ACS undergoing PCI were enrolled and followed up for 18 months. The risk of sdLDL-C for CV events was compared according to sdLDL-C quartiles. The primary outcome was the composite of death, nonfatal myocardial infarction, nonfatal stroke and unplanned repeat revascularization. A Cox proportional hazards regression model was performed to estimate the risk of CV events. Subgroup analysis according to diabetes status and dichotomized low-density lipoprotein cholesterol (LDL-C) and triglyceride (TG) level based on median value were performed separately for cardiovascular risk. Results: A total of 6092 patients were included in the analysis (age: 60.2±10.13 years, male: 75.3%, BMI: 25.9±3.33 kg/m 2 , dyslipidemia: 74.1% and diabetes: 44.5 %). During 18 months of follow-up, 320 (5.2%) incident CV events occurred. Compared to the lowest sdLDL-C quartile group, patients in the highest quartile had a greater risk of CV events after multivariable adjustment (HR: 1.92; 95% CI: 1.37-2.70). In the subgroup analyses, this greater risk remained significant in patients, regardless of high or low LDL-C or TG (dichotomized by the median value) and diabetes status. Conclusions: Patients with elevated sdLDL-C have a higher risk of CV events in Chinese patients with ACS undergoing PCI, providing additional value for better risk assessment.