Significance of Serum High-Density Lipoprotein Cholesterol Levels for Diagnosis of Coronary Stenosis as Determined by MDCT in Patients with Suspected Coronary Artery Disease

Aim: Since we previously reported that lower levels of HDL-C may be most useful for predicting coronary artery disease (CAD) as assessed by multi-detector row computed tomography (MDCT), we sought to confirm, among the levels of LDL-C, HDL-C, non-HDL-C (total cholesterol minus HDL-C) and the ratio of LDL-C to HDL-C (LDL-C/HDL-C), which is most closely related to the presence of CAD. Methods and Results: The subjects consisted of 506 consecutive patients with suspected CAD who underwent MDCT with (+) or without (-) statin treatment. The levels of LDL-C in the statin (-) group were similar in categories I, II and III according to the Japan Atherosclerosis Society (JAS) Guidelines 2007, whereas the levels of HDL-C significantly decreased and LDL-C/HDL-C significantly increased as the category number increased. In the statin (-) group, the prevalence of CAD in categories I, II and III was 0, 16 and 33%, respectively (p = 0.0018 for trend), in patients with good control of LDL-C levels according to the Guidelines. Multivariate logistic regression analysis was performed to examine the association between the presence of CAD and 11 possible factors. Age and HDL-C in the statin (-) group, and HDL-C in the statin (+) group were identified as significant independent variables that correlated with the presence of CAD. Receiver-operating characteristic curve analysis in the statin (-) and statin (+) groups showed a higher area under the curve for HDL-C than for LDL-C, non-HDL-C or LDL-C/HDL-C. In particular, the cut-off levels of HDL-C with the greatest sensitivity and specificity for the diagnosis of CAD in the statin (+) group were 55 mg/dL (sensitivity 0.816, specificity 0.510). Conclusions: HDL-C levels are most closely associated with the presence of CAD. In particular, we need to perform coronary CT for suspected CAD patients with lower HDL-C levels under statin treatment.