title: Clinical relevance of aspirin resistance in patients with stable coronary artery disease: a prospective follow-up study (PROSPECTAR).
abstract: Aspirin resistance may increase the risk of major adverse cardiac events (MACE) more than threefold in patients with stable coronary artery disease (CAD). This study aimed to determine the prevalence of aspirin resistance in patients with stable CAD, the role of aspirin resistance on outcome in the follow-up, and the effect of clopidogrel therapy in MACE prevention in aspirin-resistant individuals. We detected the prevalence of aspirin resistance in 234 patients with stable CAD. Platelet function was determined by PFA-100 with collagen and/or epinephrine and collagen and/or ADP cartridges. The mean follow-up time was 20.6 +/- 6.9 months. The primary endpoints of the study were occurrence of myocardial infarction, unstable angina, stroke and cardiac death. Of patients, 22.2% (n = 52) were aspirin resistant by PFA-100. During follow-up, MACE occurred in eight patients (15.4%) with aspirin resistance and in 20 patients (11.0%) with aspirin-sensitive platelet aggregation (P = 0.269). MACE increased in aspirin-resistant patients after termination of clopidogrel therapy. Eleven patients experienced MACE after cessation of clopidogrel therapy (P < 0.001). The MACE risk in patients with stable CAD having detected aspirin resistance was similar compared with patients having aspirin-sensitive platelet aggregation by PFA-100. The MACE prevalence increased during follow-up, however, just after cessation of clopidogrel therapy.
authors.affiliation: Istanbul Faculty of Medicine, Department of Cardiology, Istanbul University, Istanbul, Turkey. bpamukcu@istanbul.edu.tr
authors.forename: Burak
authors.initials: B
authors.lastname: Pamukcu
authors.forename: Huseyin
authors.initials: H
authors.lastname: Oflaz
authors.forename: Imran
authors.initials: I
authors.lastname: Onur
authors.forename: Aytac
authors.initials: A
authors.lastname: Oncul
authors.forename: Mustafa
authors.initials: M
authors.lastname: Ozcan
authors.forename: Berrin
authors.initials: B
authors.lastname: Umman
authors.forename: Fehmi
authors.initials: F
authors.lastname: Mercanoglu
authors.forename: Mehmet
authors.initials: M
authors.lastname: Meric
authors.forename: Yilmaz
authors.initials: Y
authors.lastname: Nisanci
mesh_terms: D000368:Aged; D000787:Angina Pectoris; D001241:Aspirin / Q000494:pharmacology* / Q000627:therapeutic use; D000077144:Clopidogrel; D003324:Coronary Artery Disease / Q000150:complications* / Q000188:drug therapy* / Q000453:epidemiology / Q000401:mortality; D003643:Death; D004351:Drug Resistance; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction; D010974:Platelet Aggregation / Q000187:drug effects; D010979:Platelet Function Tests; D015995:Prevalence; D020521:Stroke; D016019:Survival Analysis; D013988:Ticlopidine / Q000031:analogs & derivatives / Q000627:therapeutic use; D016896:Treatment Outcome
chemical_list: D000077144:Clopidogrel; D013988:Ticlopidine; D001241:Aspirin