Predictive value of remnant lipoprotein for cardiovascular events in patients with coronary artery disease after achievement of LDL-cholesterol goals

Objectives Triglycerides-rich lipoproteins are related to residual cardiovascular risk in patients on lipid-lowering treatment who achieve low-density lipoprotein cholesterol (LDL-C) goals. This study examined the predictive value of remnant lipoprotein levels for cardiovascular events in patients with coronary artery disease (CAD) with LDL-C levels <100 mg/dL on lipid-lowering therapy. Methods Serum levels of remnant lipoproteins (remnant-like lipoprotein particles cholesterol; RLP-C) were measured by an immunoseparation method in 560 patients with CAD who had LDL-C levels <100 mg/dL on lipid-lowering therapy, including statin (58%), fibrate (13%) or diet only (29%). All the patients were followed prospectively for a period of ≤36 months or until occurrence of one of the following events: cardiac death, non fatal myocardial infarction, unstable angina requiring coronary revascularization, or ischemic stroke. Results During a mean follow-up period of 33 months, 40 events occurred. Stepwise multivariate Cox proportional hazard analysis showed that RLP-C was a significant predictor of cardiovascular events after adjustment for known risk factors and lipid variables including triglycerides, non-high-density lipoprotein (HDL)-C, and total apolipoprotein B (HR 1.53, 95% CI 1.35–1.97, p < 0.01). The c-statistics showed that addition of RLP-C had a greater incremental effect on the predictive value of conventional risk factors than addition of non-HDL-C or total apolipoprotein B. Conclusions RLP-C was superior to non-HDL-C for predicting cardiovascular events in CAD patients with LDL-C levels <100 mg/dL on lipid-lowering treatment. Remnant lipoprotein may therefore be an important target for residual risk reduction after LDL-C goals on lipid lowering therapy.