The role of aspirin resistance on outcome in patients with acute coronary syndrome and the effect of clopidogrel therapy in the prevention of major cardiovascular events

• DOI: 10.1007/s11239-006-8952-4
• Publication Date: 2006-09-28T14:27:38Z
• Authors: Burak Pamukcu; Huseyin Oflaz; Aytac Oncul; Berrin Umman; Fehmi Mercanoglu; Mustafa Ozcan; Mehmet Meric; Yilmaz Nisanci
• Keywords: Male; Ticlopidine; Aspirin; Platelet Function Tests; Drug Resistance; Myocardial Infarction; Coronary Artery Disease; Kaplan-Meier Estimate; Platelet Glycoprotein GPIIb-IIIa Complex; Middle Aged; Clopidogrel; 3. Good health; 03 medical and health sciences; Treatment Outcome; 0302 clinical medicine; Humans; Female; Angina, Unstable; Prospective Studies; Platelet Aggregation Inhibitors; Follow-Up Studies

Aspirin resistance may increase up to more then threefold the risk of major cardiovascular events (MACE) in patients with stable coronary artery disease.The aim of our study was to determine; the prevalence of aspirin resistance in patients with acute coronary syndromes, the role of aspirin resistance on outcome in the follow-up and the effect of clopidogrel therapy in the prevention of MACE in aspirin resistant subjects.We detected the prevelance of aspirin resistance in 105 patients with acute coronary syndrome. Platelet functions were analyzed in Platelet Function Analyzer (PFA)-100 (Dade Behring, Germany) with collagen and/or epinephrine (Col/Epi) and collagen and/or ADP (Col/ADP) cartridges. Primary end points of the study were myocardial infarction, unstable angina, cardiac death.19% (n = 20) of patients were aspirin resistant by PFA-100. In the follow-up, MACE occured in 9 patients (45%) with aspirin resistance and in 10 patients (11.7%) with aspirin sensitive platelet aggregation (p = 0.001). Multivariate analysis showed that aspirin resistance was an independant predictor of MACE. The prevalence of MACE in patients who were on clopidogrel treatment for 12 months were lower compared to those who were on a clopidogrel treatment for the first six months (p = 0.040).We determined that the MACE risk in patients with acute coronary syndromes having detected aspirin resistance, was higher at statistically significant levels compared to patients having aspirin sensitive platelet aggregation. Our results showed that aspirin resistance, was an independant predictor of MACE in patients with acute coronary syndrome.