title: Assessment of biochemical aspirin resistance at rest and immediately after exercise testing.
abstract: Some aspirin-treated patients experience thromboembolic events, a phenomenon termed 'aspirin resistance', which may be clinical or biochemical by definition. Physical exercise is known to enhance platelet secretion and aggregability. To evaluate the presence of biochemical aspirin resistance at rest and immediately after exercise in individuals with stable coronary artery disease or coronary artery disease risk factors. We prospectively enrolled 101 patients who had received 100 or 300 mg/day enteric-coated aspirin for at least 7 days. Biochemical aspirin resistance (defined as normal collagen-epinephrine closure time < 165 s) was studied using the standardized platelet function analyzer. Of the 101 patients, 63 were aspirin sensitive both at rest and immediately after exercise, 18 exhibited biochemical aspirin resistance both at rest and after exercise, and 20 were aspirin sensitive at rest but exhibited biochemical aspirin resistance immediately after exercise. The results of exercise testing were similar in all three groups (each P > 0.05). Our results indicate that in almost 20% of the patients, aspirin did not seem to protect against exercise-induced platelet activation, despite the presence of aspirin sensitivity at rest. We did not, however, determine the extent to which the biochemical aspirin resistance noted in our study applied to clinical events.
authors.affiliation: Department of Cardiology, Baskent University Faculty of Medicine, Ankara, Turkey. gulmezoyku@yahoo.com
authors.forename: Oyku
authors.initials: O
authors.lastname: Gulmez
authors.forename: Aylin
authors.initials: A
authors.lastname: Yildirir
authors.forename: Ugur
authors.initials: U
authors.lastname: Bal
authors.forename: Necibe Didem
authors.initials: ND
authors.lastname: Konas
authors.forename: Alp
authors.initials: A
authors.lastname: Aydinalp
authors.forename: Ozlem
authors.initials: O
authors.lastname: Demir
authors.forename: Ilyas
authors.initials: I
authors.lastname: Atar
authors.forename: Cagatay
authors.initials: C
authors.lastname: Ertan
authors.forename: Bulent
authors.initials: B
authors.lastname: Ozin
authors.forename: Haldun
authors.initials: H
authors.lastname: Muderrisoglu
mesh_terms: D000368:Aged; D001241:Aspirin / Q000494:pharmacology*; D004351:Drug Resistance / Q000502:physiology*; D015444:Exercise / Q000502:physiology; D005080:Exercise Test / Q000187:drug effects*; D005260:Female; D006801:Humans; D008297:Male; D015539:Platelet Activation / Q000187:drug effects; D010975:Platelet Aggregation Inhibitors / Q000494:pharmacology; D010979:Platelet Function Tests; D012146:Rest / Q000502:physiology*
chemical_list: D010975:Platelet Aggregation Inhibitors; D001241:Aspirin