Abstract 1365: Remnant Lipoproteinemia is a Strong Predictor of Cardiac Events in Patients With Previous Myocardial Infarction After Achieving LDL-cholesterol Goal on Statin Therapy
NCEP ATP III guidelines recommend non-HDL-cholesterol (C) as a secondary target for management of dyslipidemia after achieving LDL-C goals on lipid-lowering therapy. Non-HDL-C includes remnant lipoprotein cholesterol which has proatherothrombogenic properties. This study examined predictive value of remnant lipoprotein levels for cardiac events in patients with previous myocardial infarction (MI) after achieving LDL-C goals on statin therapy.
Methods: Fasting serum levels of remnant lipoproteins (remnant-like lipoprotein particles cholesterol; RLP-C) were measured by an immunoseparation method in 179 consecutive patients with previous MI who had LDL-C levels <100 mg/dL on statin therapy. All patients were prospectively followed up for a period of ≤36 months or until occurrence of one of following cardiac events: cardiac death, non fatal MI, unstable angina requiring unplanned coronary revascularization, or heart failure requiring hospitalization.
Results: During follow-up period, 22 (24%) patients with higher levels of RLP-C (≥4.3 mg/dL, 50th percentile of the distribution) had cardiac events (10 patients in cardiac death, 2 in MI, 6 in unstable angina, 4 in heart failure), while 1 (0.01%) patient with lower levels of RLP-C (<4.3 mg/dL) had a cardiac event (1 in unstable angina) (p<0.0001). In multivariate Cox proportional hazards analysis using RLP-C, HDL-C, total apolipoprotein B (apoB), non-HDL-C and triglycerides levels as covariates, higher RLP-C levels (≥4.3 mg/dL) and lower HDL-C levels (<40 mg/dL in male, <50 mg/dL in female) were an independent predictor of the cardiac events (HR; 4.9 and 3.1, 95%CI 2.3–9.2 and 1.3–7.3, respectively, p=0.001 and 0.01), while apoB and non-HDL-C levels did not remain a significant predictor. The c-statistic showed that predictive value of higher levels of RLP-C was significantly superior to that of HDL-C levels, non-HDL-C levels and apoB (area under ROC curve: 0.73, 0.66, 0.58 and 0.55, respectively, p<0.001 for the differences).
Conclusions: RLP-C was an independent predictor of cardiac events in patients with previous MI who had achieved LDL-C goals on statin therapy. Remnant lipoprotein is an important therapeutic target in MI survivors after achieving LDL-C goals on statin therapy.