Predictive Value of Lipoprotein Indices for Residual Risk of Acute Myocardial Infarction and Sudden Death in Men With Low-Density Lipoprotein Cholesterol Levels

Abstract

Several epidemiologic studies have demonstrated that plasma low-density lipoprotein cholesterol (LDL-C) profile is a key risk indicator for coronary heart disease (CHD). However, almost half of all patients with CHD have normal LDL-C levels. A total of 7,931 male subjects aged ≥40 years from the general population with no cardiovascular history and no use of lipid-lowering agents were followed for incidence of acute myocardial infarction (AMI) and sudden death. Of the 4,827 participants with LDL-C levels <120 mg/dl, 55 subjects had a first AMI/sudden death during an average of 5.5 years of follow-up. After adjustment for confounding factors, multiadjusted hazard ratios (HRs) were increased by 1SD for non-high-density lipoprotein cholesterol (non-HDL-C; HR= 1.36, 95% confidence interval [CI], 1.02 to 1.81), total cholesterol (TC)/HDL-C ratio (HR= 1.40, 95% CI: 1.11 to 1.78) and LDL-C/HDL-C ratio (HR= 1.32, 95% CI: 1.02 to 1.73) but not for LDL-C (HR= 1.09, 95% CI: 0.82 to 1.44) and HDL-C (HR= 0.84, 95% CI: 0.68 to 1.04). When stratified as categorical variables on the basis of points with highest accuracy on receiver operating characteristic analysis, non-HDL-C levels >126 mg/dl (HR= 1.25, 95% CI: 1.03 to 1.51), TC/HDL-C ratio above 3.5 (HR= 1.22, 95% CI: 1.01 to 1.48) and LDL-C/HDL-C ratio >1.9 (HR= 1.25, 95% CI: 1.04 to 1.51) had increased multiadjusted HRs for AMI/sudden death. In conclusion, in men with LDL-C levels <120 mg/dl, non HDL-C, TC/HDL-C, and LDL-C/HDL-C ratios have predictive value for residual risk of AMI/sudden death.