Assessment of primary hemostasis by PFA-100 analysis in a tertiary care center.

We evaluated the utility of the PFA-100 platelet function analyzer in identifying disorders in platelet function and/or von Willebrand factor (vWF) in patients with various systemic disorders being followed at a tertiary care center. Closure times were determined with collagen/ ADP (CADP) and collagen/epinephrine (CEPI) cartridges for 305 patients, and abnormal results were further evaluated with platelet aggregometry and vWF analysis. Prolonged CADP and/or CEPI closure times were identified in 114 patients (37.3%), but most were isolated prolonged CEPI closure times predominantly due to aspirin therapy (79 patients). Prolonged CADP closure times were most frequently due to qualitative platelet defects and/or decreased vWF levels. Prolonged CADP closure times were encountered most frequently in patients with sickle cell disease and were associated with a decreased hematocrit. This study demonstrated that the PFA-100 analyzer can accurately assess vWF-dependent platelet function and detect other platelet defects under high shear stress in complex patient populations.