1. A new definition of aspirin non-responsiveness by Platelet Function Analyzer-100™ and its predictors
- Author
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Mustafa Çalışkan, Ali Ünal, Servet Çetin, Fahri Bayram, Adnan Abaci, Yucel Yilmaz, and Mustafa Cetin
- Subjects
Male ,medicine.medical_specialty ,Platelet Function Tests ,Drug Resistance ,Coronary Artery Disease ,Sensitivity and Specificity ,Coronary artery disease ,Standard definition ,Predictive Value of Tests ,Diabetes mellitus ,Internal medicine ,Diabetes Mellitus ,Humans ,Medicine ,Platelet ,Aspirin ,business.industry ,Hematology ,General Medicine ,Middle Aged ,medicine.disease ,Diet ,Surgery ,Aspirin therapy ,Predictive value of tests ,Multivariate Analysis ,Cardiology ,Population study ,Female ,business ,Platelet Aggregation Inhibitors ,medicine.drug - Abstract
Aspirin non-responsiveness has been described as having a normal closure time (CT) by platelet function analyzer (PFA)-100 assay despite confirmed treatment with aspirin. There is no standard definition of aspirin non-responsiveness by PFA-100, with a variety of cut-off values having been used. We proposed an alternative definition of aspirin non-responsiveness by PFA-100 assay.One hundred eighty-four patients with diagnosis of stable coronary artery disease or diabetes mellitus were included in the study. Blood samples were drawn before and after the 7 days of aspirin therapy. An individual was labelled as aspirin non-responder if his/her post-aspirin CT was not 2SD above his/her baseline CT, where SD was calculated from the baseline CTs of the study population. Aspirin non-responsiveness was also defined as having a normal post-aspirin CT (or =193 s) regardless of pre-aspirin CT.The baseline CT ranged 82-187 s (mean 129.1 +/- 27.5, median 128 s) in the study population. At the end of 1 week of aspirin administration, CT increased to a mean of 260.7 +/- 63.6 s (range 102-301). According to our definition, 28 (15.2%) of 184 patients were aspirin non-responders. Univariate analysis indicated that aspirin non-responsiveness was closely associated with gender (P = 0.012) diabetes (P = 0.006), smoking (P = 0.0496) and hypertension (P = 0.021). Multivariate analysis identified diabetes (P = 0.016) as the only significant independent predictor for the presence of aspirin non-responsiveness. Thirty-four of 184 patients (18.5%) classified as aspirin non-responders according to the second criteria. Seven patients with prolongation of post-aspirin CT more than 2SD were classified as aspirin non-responders by the second criteria. Only 1 patient without prolongation of CT more than 2SD was classified as aspirin responsive by the second criteria.Definition of aspirin non-responsiveness as post-aspirin CTsor =193 s might overestimate the prevalence of aspirin non-responsiveness. Nevertheless, definition of aspirin non-responsiveness by PFA-100 must be standardized and its utility as a predictor of cardiovascular events needs to be further investigated.
- Published
- 2006