Effect of Low High-Density Lipoprotein Level on Endothelial Activation and Prothrombotic Processes in Coronary Artery Disease—A Pilot Study

High-density lipoproteins (HDL) play an important role in the prevention of atherosclerosis. The aim of the study was to assess the relationship between serum HDL-C concentration and proinflammatory/prothrombic activation in coronary artery disease (CAD) patients. The study group included 27 acute myocardial infarction (AMI) patients and 30 stable angina pectoris (SA) patients. The control group consisted of 23 people without cardiac symptoms. In the AMI and SA groups, a lower HDL-C and a higher LDL-C/HDL-C index were observed. The SA patients had lower total cholesterol, LDL-C, sE-selectin ligand, as well as higher triglycerides and CD40 concentration in comparison with both the control and AMI groups. A higher von Willebrand Factor and intercellular adhesion molecule-1 were found in both study groups. Low HDL-C concentration in the CAD patients may intensify pro-inflammatory endothelial activation and prothrombotic processes. A low concentration of HDL-C and a high value of the LDL-C/HDL-C index seem to be better indices of atherogenic processes than the LDL-C concentration alone.