Small dense low-density lipoprotein cholesterol predicts long-term recurrence of coronary artery disease in patients without metabolic dyslipidemia

Abstract Background Small dense low-density lipoprotein (sdLDL) particles possess increased atherogenic potential, and are features of metabolic dyslipidemia. Purpose This study was aimed to investigate whether sdLDL cholesterol (sdLDL-C) and predominance of sdLDL could predict long-term coronary artery disease (CAD) events in stable CAD patients without metabolic dyslipidemia. Methods Serum levels of sdLDL-C measured by direct homogenous assay were evaluated in 396 male and 146 female patients with stable angiographically proven CAD who achieved target levels for both HDL-C (≥40 mg/dL) and triglyceride (<150 mg/dL). CAD events defined as sudden cardiac death, onset of acute coronary syndrome, and/or need for coronary revascularization were monitored for 12 years. Cut-points of sdLDL-C, LDL-C, non-HDL-C, HDL-C, apolipoprotein B (apoB), and sdLDL-C/LDL-C ratios were determined by receiver operating characteristic curves. Results First-time CAD events were observed in 110 male and 44 female patients. The Kaplan-Meier event-free survival curves and multivariable-adjusted Cox proportional hazards model showed that patients with sdLDL-C of ≥ 32.3 mg/dL and sdLDL-C/LDL-C ratios ≥0.32 presented with an increased risk for CAD events independent of LDL-C, non-HDL-C, apoB, triglyceride, and HDL-C. Conclusion Although sdLDL is a feature of metabolic dyslipidemia, high sdLDL-C and high sdLDL-C/LDL-C ratio can predict recurrence of long-term CAD events even in patients without metabolic dyslipidemia.The Kaplan-Meier event-free survival curFor image description, please refer to the figure legend and surrounding text.