Remnant Lipoprotein Levels in Fasting Serum Predict Coronary Events in Patients With Coronary Artery Disease

TLDR

Remnant lipoproteins are atherogenic, yet routine clinical assays have been unavailable due to a lack of practical, validated methods. This study prospectively examined whether fasting remnant lipoprotein levels measured by a new immunochemical method predict coronary events in patients with coronary artery disease. The authors used a newly developed immunochemical assay employing anti‑apoA‑1 and anti‑apoB‑100 antibodies to quantify remnant lipoproteins in 135 CAD patients and followed them for up to 36 months for major coronary events. Patients in the highest tertile of fasting remnant lipoprotein levels (>5.1 mg cholesterol/dL) had a significantly higher risk of coronary events, and remnant levels were an independent predictor after adjusting for traditional risk factors, indicating that fasting remnant measurement can aid CAD risk assessment.

Abstract

Remnant lipoproteins are atherogenic, but assays of remnants have not been available in routine clinical laboratories because of the lack of practical and validated methods. A simple and reliable method for such an assay, using an immunochemical approach, has recently been developed. This study prospectively examined whether remnant lipoprotein levels in fasting serum, measured by our method, may have prognostic value in patients with coronary artery disease (CAD).Remnant lipoprotein levels in fasting serum were measured in 135 patients with CAD by an immunoaffinity mixed gel containing anti-apolipoprotein (apo) A-1 and anti-apoB-100 monoclonal antibodies. Patients were followed up for </=36 months until occurrence of 1 of the following clinical coronary events: recurrent or refractory angina pectoris requiring coronary revascularization, nonfatal myocardial infarction, or cardiac death. Kaplan-Meier analysis demonstrated a significantly higher probability of developing coronary events in patients with the highest tertile of remnant levels (>5.1 mg cholesterol/dL; 75th percentile of distribution of remnant levels) than in those with the lowest tertile of remnant levels (</=3.3 mg cholesterol/dL; 50th percentile of the distribution). Higher levels of remnants were a significant and independent predictor of developing coronary events in multivariate Cox hazard analysis including the following covariates: extent of coronary artery stenosis, age, sex, smoking, hypertension, diabetes mellitus, hypercholesterolemia, low HDL cholesterol, and hypertriglyceridemia.Higher levels of remnant lipoproteins in fasting serum predict future coronary events in patients with CAD independently of other risk factors. Thus, measurement of fasting remnant levels, assessed by the current immunoseparation method, may be helpful in assessment of CAD risk.