ORIGINAL ARTICLESAspirin-resistant platelet aggregation in a cohort of patients with coronary heart diseasePamukcu, Burak; Oflaz, Huseyin; Onur, Imran; Oncul, Aytac; Umman, Berrin; Koylan, Nevres; Bugra, Zehra; Meric, Mehmet; Nisanci, YilmazAuthor Information Department of Cardiology, Istanbul Faculty of Medicine, Istanbul University, Istanbul, Turkey Received 16 February, 2007 Revised 4 March, 2007 Accepted 5 March, 2007 Correspondence to Burak Pamukcu, MD, Istanbul Universitesi, Istanbul Tip Fakultesi Kardiyoloji, Anabilim Dali Sekreterligi Capa, Istanbul 34390, Turkey Tel: +90 2124142000; fax: +90 2125340768; e-mail: [email protected] Blood Coagulation & Fibrinolysis: July 2007 - Volume 18 - Issue 5 - p 461-465 doi: 10.1097/MBC.0b013e32814db7e7 Buy Metrics Abstract Aspirin resistance could be defined as thrombotic and embolic cardiovascular events despite regular aspirin therapy. The study aimed to determine the profile and prevalence of aspirin resistance in coronary artery disease patients. We evaluated the prevalence of aspirin resistance in a cohort of 505 patients with the diagnosis of coronary artery disease taking 80–300 mg regular aspirin daily. Platelet functions were analyzed by the Platelet Function Analyzer (PFA)-100 with collagen and epinephrine cartridges and collagen and ADP cartridges. A closure time of 186 s or less with the collagen and epinephrine cartridge was defined as aspirin resistance. Of the patients, 118 (23.4%) were aspirin resistant by the PFA-100. Aspirin-resistant patients were more likely to be older than aspirin-sensitive patients (P = 0.024). No statistically significant differences between the aspirin-resistant and aspirin-sensitive individuals were present in gender, major risk factors of coronary artery disease, number and localization of involved coronary vessels, serum lipid levels, and blood counts. According to the high prevalence of coronary heart disease, many people are affected by aspirin resistance, which may play a role in adverse cardiovascular events. Monitoring of platelet function in patients with coronary heart disease may support the optimization of antiplatelet therapy with additional and/or alternative agents. © 2007 Lippincott Williams & Wilkins, Inc.