Abstract 13202: Relationship Between Risk for Coronary Heart Disease and Serum Levels of Low-Density Lipoprotein Particles
Introduction: We investigated the real-world risk of coronary heart disease (CHD) associated with LDL particle number (LDL-P) among patients with established CHD or CHD risk equivalents from a large commercially insured US population.
Hypothesis: Risk for CHD events increases as serum levels of LDL-P increase, even after adjusting for LDL cholesterol (LDL-C).
Methods: Adult patients with ≥1 LDL-P result were selected from the HealthCore Integrated Research DatabaseSM. Index date was the date of the most recent LDL-P (for patients with no CHD events) or of the closest LDL-P preceding the most recent CHD event between 1/1/2006 and 9/30/2012. Patients without LDL-C results were excluded. Secondary prevention patients included those with CHD, diabetes mellitus (DM), or prescription fills for clopidogrel, at any point pre-index. Baseline characteristics were assessed over 6 months pre-index and patients were followed until occurrence of a CHD event (MI, angina, or revascularization identified from ICD-9-CM and CPT codes), death, or end of enrollment. Cox proportional hazard models compared the incidence of CHD events across LDL-P levels after adjusting for baseline demographics, comorbidities, and LDL-C level.
Results: We identified 15,569 patients (mean age 56.0 years, 44.4% female, 76% with DM, 26% with previous CHD event, 15% with fills for clopidogrel). Median follow-up was 10.1 months. The mean (SD) index LDL-P and LDL-C were 1441 (±467) nmol/L and 95 (±32) mg/dL, respectively. During the follow-up period, 8.3% of patients had ≥1 CHD event. CHD event risk increased by approximately 4% (HR: 1.04; 95% CI: 1.02-1.06; p<.0001) for each 100 nmol/L increase in LDL-P. Exceeding predefined LDL-P thresholds is similarly associated with a continuous increase in CHD event risk (Figure).
Conclusions: The findings from this study suggest that, after controlling for LDL-C, LDL-P is positively correlated with future CHD risk in a real-world sample of commercially insured patients.
- © 2013 by American Heart Association, Inc.