Using the Platelet Function Analyzer-100 for monitoring aspirin therapy

• Published in: Thrombosis research Vol. 120; no. 2; pp. 161 - 172
• Main Authors: Poulsen, Tina Svenstrup, Mickley, Hans, Korsholm, Lars, Licht, Peter Bjørn, Haghfelt, Torben, Jørgensen, Bo
• Format: Journal Article
• Language: English
• Published: United States Elsevier Ltd 01.01.2007
• Subjects: Aged; Analysis of Variance; Aspirin - administration & dosage; Aspirin - therapeutic use; Case-Control Studies; Dose-Response Relationship, Drug; Female; Hematology, Oncology and Palliative Medicine; Humans; Male; Middle Aged; Myocardial Ischemia - blood; Myocardial Ischemia - drug therapy; Platelet Aggregation - drug effects; Platelet Aggregation Inhibitors - administration & dosage; Platelet Aggregation Inhibitors - therapeutic use; Platelet Function Tests - instrumentation; Platelet Function Tests - statistics & numerical data; Reproducibility of Results
• ISSN: 0049-3848; 1879-2472
• DOI: 10.1016/j.thromres.2006.08.010

The aim of the study was to evaluate the test characteristics of the Platelet Function Analyzer-100 (PFA-100) in patients treated with aspirin. The study consisted of two sub-studies. In study 1, 10 patients with ischemic heart disease (IHD) and 10 controls had platelet function assessed by optical platelet aggregation and the PFA-100 method in two 5-week periods. Patients with IHD were treated with aspirin 150 mg/day (first 5-week period), and 300 mg/day (second 5-week period), whereas the controls only received aspirin (150 mg/day) during the second 5-week period. From the results of study 1, we found that a cut-off value for the PFA-100 collagen/epinephrine cartridge <165 s identified patients not taking aspirin (sensitivity 0.91, specificity 1.00). A good agreement between the PFA-100 method and optical platelet aggregation was found. Within-subject variation for the PFA-100 collagen/epinephrine cartridge was ±28%, as compared to ±17% for the optical platelet aggregation. Study 2 included 298 aspirin treated patients who were admitted with symptoms suggestive of an acute myocardial infarction. Platelet function was assessed in duplicate by the PFA-100 collagen/epinephrine cartridge, and a 95% Limit of Agreement interval at [−65%, 65%] indicated a limited precision. We defined a cut-off value below which patients not taking aspirin can be identified. However, due to imprecision of the PFA-100 method repeated duplicate assessment of the collagen/epinephrine Closure Time is recommended.