Increased platelet responsiveness following coronary stenting Heparin as a possible aetiological factor in stent thrombosis

18 patients undergoing Palmaz-Schatz stenting (treated with full anticoagulation) and 18 patients undergoing elective angioplasty (total n=36). The study also included patients with unstable angina treated with low molecular weight heparin or unfractionated heparin in vivo, and in vitro studies.

Palmaz-Schatz stenting with full anticoagulation (heparin)

Elective angioplasty

Platelet activation antigen expression (fibrinogen binding to activated GPIIb-IIIa, and surface expression of P-selectin, GPIb and GPIIb-IIIa antigens) measured by whole blood flow cytometry at rest and on stimulation with adenosine diphosphate and thrombinsurrogate