Clinical utility of the platelet function analyzer (PFA-100) for the assessment of the platelet status in patients with congestive heart failure (EPCOT trial)

Background: Data from small studies have shown the presence of platelet abn ormalities in patients with congestive heart failure (CHF). We sought to ch aracterize the diagnostic utility of platelet function analyzer (PFA-100) i n the CHF population. Methods: Blood samples were obtained for measurement of adenosine diphosphate (ADP)/collagen and epinephrine/ collagen shear-ind uced closure time (CT), whole blood aggregation, platelet contractile force , activity of glycoprotein (GP) IIb/IIIa, and P-selectin receptors in 100 c onsecutive outpatients with CHF. Results: Substantial interindividual varia bility of platelet characteristics exists in patients with CHF. There were no statistically significant differences when patients were divided by the incidence of vascular events, emergency revascularization needs, survival, or etiology of heart failure. Aspirin use did not affect instrument reading s as well. CT correlates well with wholeblood aggregometry (r(2)=.587) and less with CP IIb/IIIa activity (r(2).326). No correlation has been observed for the CT with the platelet-bound P-selectin (r(2)=.041) and plate-let co ntractile force measures (r(2)=.028). Conclusions: PFA-100 is indeed capabl e to serc e as a platelet analyzer and may be successfully used as a screen ing device. However, patients with heart failure enrolled in the EPCOT tria l exhibited a marginal, sometimes oppositely directed changes in the platel et function, challenging the diagnostic utility of PFA-100 to serve as a us eful tool for the identification of platelet abnormalities, predicting clin ical outcomes, or for the monitoring of antiplatelet strategies in this pop ulation. (C) 2001 Elsevier Science Ltd. All rights reserved.