title: Impact of platelet reactivity on long-term clinical outcomes and bleeding events in Japanese patients receiving antiplatelet therapy with aspirin.
abstract: OBJECTIVE
  Aspirin is an antiplatelet drug widely used for the prevention of cardiovascular disease; however, it is known to increase bleeding events. A low response to aspirin was reported to correlate with poor prognosis in patients undergoing antiplatelet therapy with aspirin. The aim of this study was to evaluate the impact of the antiplatelet activity of aspirin on cardiovascular and bleeding events in Japanese patients.
  
  
  METHODS
  We analyzed the clinical course of 239 Japanese patients undergoing antiplatelet therapy with aspirin for a median of 64 months in this study. Their residual platelet reactivity was examined at enrollment and after 2 years. The co-primary endpoints were the occurrence of major adverse cardiac and cerebrovascular events (MACCEs) and bleeding events.
  
  
  RESULTS
  The annual incidence of MACCEs and major bleeding events was 3.7% and 0.48%, respectively. With defined criteria, 67 patients (28%) were classified as low responders based on the platelet aggregability measured at enrollment. Low response to aspirin was not associated with increased MACCEs, while it clearly increased MACCEs in patients less than 70 years old (low responders 36.9% vs. responders 14.8%, log rank p=0.008). Five major types of bleeding occurred in the responders, but not in low responders, although the difference was not statistically significant (p= 0.07).
  
  
  CONCLUSIONS
  Low response to aspirin was not associated with the increase of long-term MACCEs, while it increased MACCEs in patients less than 70 years old; however, it tended to decrease major bleeding events in Japanese patients.
authors.affiliation: Department of Cardiovascular Medicine, Graduate School of Medicine, Kyoto University, Kyoto, Japan.
authors.forename: Keiichiro
authors.initials: K
authors.lastname: Yamane
authors.forename: Tomoyuki
authors.initials: T
authors.lastname: Ikeda
authors.forename: Ryoji
authors.initials: R
authors.lastname: Taniguchi
authors.forename: Shin
authors.initials: S
authors.lastname: Watanabe
authors.forename: Mitsunori
authors.initials: M
authors.lastname: Kawato
authors.forename: Hirokazu
authors.initials: H
authors.lastname: Kondo
authors.forename: Ryutaro
authors.initials: R
authors.lastname: Shirakawa
authors.forename: Tomohito
authors.initials: T
authors.lastname: Higashi
authors.forename: Masanao
authors.initials: M
authors.lastname: Toma
authors.forename: Arata
authors.initials: A
authors.lastname: Tabuchi
authors.forename: Toshihiro
authors.initials: T
authors.lastname: Tamura
authors.forename: Kanako
authors.initials: K
authors.lastname: Takahashi
authors.forename: Haruyo
authors.initials: H
authors.lastname: Watanabe
authors.forename: Yuka
authors.initials: Y
authors.lastname: Yoshikawa
authors.forename: Toru
authors.initials: T
authors.lastname: Kita
authors.forename: Takeshi
authors.initials: T
authors.lastname: Kimura
authors.forename: Hisanori
authors.initials: H
authors.lastname: Horiuchi
mesh_terms: D000368:Aged; D001241:Aspirin / Q000627:therapeutic use*; D001792:Blood Platelets / Q000187:drug effects* / Q000378:metabolism*; D015992:Body Mass Index; D002318:Cardiovascular Diseases / Q000209:etiology / Q000517:prevention & control; D005260:Female; D005500:Follow-Up Studies; D006470:Hemorrhage / Q000139:chemically induced / Q000517:prevention & control*; D006801:Humans; D007564:Japan; D008297:Male; D008875:Middle Aged; D010975:Platelet Aggregation Inhibitors / Q000627:therapeutic use*; D011379:Prognosis; D012189:Retrospective Studies; D012307:Risk Factors; D013997:Time Factors; D016896:Treatment Outcome
chemical_list: D010975:Platelet Aggregation Inhibitors; D001241:Aspirin