Determination of Aspirin Responsiveness by Use of Whole Blood Platelet Aggregometry
| Autor: | Philipp Schlick, Thomas Hohlfeld, Evangelos Giannitsis, Hugo A. Katus, Boris Ivandic, Peter Staritz |
|---|---|
| Rok vydání: | 2007 |
| Předmět: |
Adult
Male medicine.medical_specialty Ticlopidine Adolescent Platelet Aggregation Pyridines Clinical Biochemistry Drug Resistance Blood Donors Coronary Artery Disease In Vitro Techniques chemistry.chemical_compound Sex Factors Reference Values Internal medicine Electric Impedance medicine Humans Platelet Antipyretic Aged Aged 80 and over Aspirin biology business.industry Biochemistry (medical) Middle Aged Clopidogrel Surgery Thromboxane B2 Endocrinology chemistry biology.protein Platelet aggregation inhibitor Female Collagen Thromboxane-A synthase business Platelet Aggregation Inhibitors medicine.drug |
| Zdroj: | Clinical Chemistry. 53:614-619 |
| ISSN: | 1530-8561 0009-9147 |
| Popis: | Background: Insufficient platelet inhibition is associated with an increased cardiovascular risk in up to 30% of patients taking regular doses of aspirin. We describe an assay to study aspirin responsiveness. Methods: We performed impedance aggregometry on diluted whole blood with 1 mg/L collagen and 0.5 mmol/L arachidonic acid (AA). We measured thromboxane B2 (TXB2) by RIA. We examined 66 healthy control individuals, 144 aspirin users with stable coronary artery disease (CAD), and 245 CAD patients treated with aspirin and clopidogrel. Nonresponsive samples were incubated with excess dl-lysinmonoacetylsalicylic acid. Results: Assay imprecision (CV) was 9.8% and 8.2% at mean (SD) 6-min impedance of 13.7 (2.8) Ω and 13.6 (2.3) Ω for collagen and AA, respectively. Collagen induced stronger aggregation (P = 0.0199) in women [n = 28, 14.6 (2.4) Ω] than in men [n = 38, 13.1 (2.9) Ω], even after sample incubation with 0.1 mmol/L acetylsalicylic acid (ASA) or 1 μmol/L terbogrel, a combined inhibitor of thromboxane synthase and receptors. The sex association persisted in aspirin users, but not if clopidogrel was also taken. A 6-min impedance >8 Ω with collagen (mean − 2 SD of the controls) was taken as evidence of nonresponsiveness, particularly if incubation with ASA did not inhibit aggregation further (>2 Ω). Compared with AA, collagen identified more nonresponsive samples among aspirin users (15%) and CAD patients who also received clopidogrel (10%). Incubation with ASA improved inhibition of aggregation in 70% of samples and consistently reduced TXB2 formation during aggregation. Conclusions: Impedance aggregometry may prove useful to study aspirin responsiveness, and incubation with ASA may help to identify nonresponders and classify resistance. |
| Databáze: | OpenAIRE |
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