Platelet adhesion mediated by von Willebrand factor in patients with early onset coronary heart disease

Abstract

Objective: To study von Willebrand factor (VWF)-mediated adhesion of platelets to collagen surface under conditions of high shear rates in patients with premature coronary artery disease (CAD).
Materials and Methods: The study included 84 patients with stable CAD, including 62 men under the age of 55 years with manifestation of CAD before age 50, and 22 women under the age of 65 years with manifestation of CAD before age 60. The control group included 64 patients: 26 men under 55 and 38 women under 65 without CAD. Whole blood samples were placed into the microfluidic device with a pump. Blood was perfused through the cell over surface coated with collagen at shear rate of 1300 s-1. The platelet adhesion was measured by the intensity of scattered laser light after 15-minute blood circulation. Measurements were performed before and after addition of monoclonal antibodies (mAb) to platelet glycoprotein (GP) Ib receptors into blood samples and then compared between the two groups.
Results: After the addition of mAb to platelet GPIb receptors to blood samples, platelet adhesion decreased by 77% (57.2; 84.6) in patients with premature CAD and by 29.5% (-6.9; 59.3) , in control patients (p<0.001). After adjusting for traditional risk factors, the decrease in platelet adhesion equal or above the median value was strongly associated with premature CAD (OR=5.2, 95% Cl 2.1–12.6; p <0.001). Plasma levels of VWF did not affect platelet adhesion before and after the addition of mAb to GPIb.
Conclusion: More pronounced decrease at increased rate with platelets adhesion in response to blocking their GPIb receptors with VWF in patients with early development of CAD, by comparison for patients without this disease, indicates on the possible role of “excessive” interactions of VWF with platelets in the pathogenesis of early development of CAD.