Increased lipid binding to thrombi in coronary artery disease. Findings in patients without premedication in native (not anticoagulated) test systems.

Abstract

Thrombi and clots were produced from native (i.e., not anticoagulated) platelet-rich and platelet-poor plasma from patients with coronary artery disease and control subjects who had not taken any medication known to influence plasma lipids, coagulation, or platelet aggregation. The clotting times were recorded, and the lipid content of clots, thrombi, platelets, plasma, and high density lipoprotein was analyzed. Thrombi produced from native platelet-rich plasma were 46% heavier in coronary artery disease patients and contained about 20% more phospholipids and free cholesterol and about twice the amount of triglycerides and esterified cholesterol in both absolute and relative amounts with respect to the corresponding lipids of plasma plus platelets. The elevated content of lipids not only increases the size of the thrombi but also changes their quality because of an increased content in plasmatic lipids, as platelets contain only trace amounts of triglycerides and cholesterol esters. In agreement herewith, fibrinogen and maximal amplitude on the thrombelastogram were increased in coronary artery disease patients, whereas the thrombus-forming time and clotting times of platelet-poor and platelet-rich plasma were shortened, indicating accelerated coagulation and activation of platelets. Analysis of these results suggests a disturbed interrelation in coronary artery disease between lipids and hemostasis, in which platelets, high density lipoprotein, and lipoproteins rich in triglycerides and cholesterol esters may play a role.