title: Duration of clopidogrel-based dual antiplatelet therapy and clinical outcomes after endeavor sprint zotarolimus-eluting stent implantation in patients presenting with acute coronary syndrome.
abstract: BACKGROUND
  The optimal duration of dual antiplatelet therapy (DAPT) remains controversial in patients with acute coronary syndrome (ACS). We sought to compare outcomes after the implantation of zotarolimus-eluting stent (ZES) between patients with ACS who received clopidogrel-based DAPT for >6months and those treated for ≤6months.
  
  
  METHODS
  From a registry of patients treated with ZESs between October 2005 and January 2010, 1740 patients with ACS were selected for the present analysis. Landmark analyses were performed for ACS patients who were event-free at 6months follow-up (n=1674). The primary outcome was a major adverse cardiac and cerebrovascular event (MACCE), including all-cause death, myocardial infarction (MI), target vessel revascularization (TVR), stent thrombosis, or stroke. We also performed adjustments for the baseline characteristics of patients, using their propensity-score matching (n=469 pairs).
  
  
  RESULTS
  During a median follow-up of 22.5months, the rate of MACCE was 6.4% in patients with DAPT >6months (n=1140) and 4.7% in patients with DAPT ≤6months (n=534) (adjusted hazard ratio [HR] 1.05; 95% confidence interval [CI] 0.61-1.82; p=0.86). After propensity-score matching, DAPT >6months was not found to be associated with a lower incidence of MACCE compared with DAPT ≤6months (adjusted HR 0.80, 95% CI 0.44-1.45, p=0.46). The rates of all-cause death or MI, TVR, stent thrombosis, and stroke also did not differ significantly between two groups.
  
  
  CONCLUSIONS
  DAPT for >6months do not seem to be associated with improved clinical outcomes in patients with ACS undergoing percutaneous coronary intervention (PCI) with ZES.
authors.affiliation: Haeundae Paik Hospital, Inje University, Busan, Republic of Korea.
authors.forename: Pil Sang
authors.initials: PS
authors.lastname: Song
authors.affiliation: Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea. Electronic address: jyhahn@skku.edu.
authors.forename: Joo-Yong
authors.initials: JY
authors.lastname: Hahn
authors.affiliation: Haeundae Paik Hospital, Inje University, Busan, Republic of Korea.
authors.forename: Doo-Il
authors.initials: DI
authors.lastname: Kim
authors.affiliation: Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea.
authors.forename: Young Bin
authors.initials: YB
authors.lastname: Song
authors.affiliation: Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea.
authors.forename: Seung-Hyuk
authors.initials: SH
authors.lastname: Choi
authors.affiliation: Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea.
authors.forename: Jin-Ho
authors.initials: JH
authors.lastname: Choi
authors.affiliation: Kangwon National University Hospital, Chuncheon, Republic of Korea.
authors.forename: Dong Ryeol
authors.initials: DR
authors.lastname: Ryu
authors.affiliation: Keimyung University Dongsan Medical Center, Daegu, Republic of Korea.
authors.forename: Seung Ho
authors.initials: SH
authors.lastname: Hur
authors.affiliation: Chungnam National University School of Medicine, Daejeon, Republic of Korea.
authors.forename: Jin-Ok
authors.initials: JO
authors.lastname: Jeong
authors.affiliation: Kyungpook National University Hospital, Daegu, Republic of Korea.
authors.forename: Hun Sik
authors.initials: HS
authors.lastname: Park
authors.affiliation: Seoul National University Hospital, Seoul, Republic of Korea.
authors.forename: Hyo-Soo
authors.initials: HS
authors.lastname: Kim
authors.affiliation: Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea.
authors.forename: Hyeon-Cheol
authors.initials: HC
authors.lastname: Gwon
mesh_terms: D054058:Acute Coronary Syndrome / Q000628:therapy*; D000368:Aged; D002423:Cause of Death; D000077144:Clopidogrel; D054855:Drug-Eluting Stents; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D062645:Percutaneous Coronary Intervention / Q000379:methods*; D010975:Platelet Aggregation Inhibitors / Q000009:adverse effects / Q000627:therapeutic use*; D056910:Republic of Korea; D020123:Sirolimus / Q000031:analogs & derivatives* / Q000627:therapeutic use; D013988:Ticlopidine / Q000009:adverse effects / Q000031:analogs & derivatives* / Q000627:therapeutic use; D016896:Treatment Outcome
chemical_list: D010975:Platelet Aggregation Inhibitors; D000077144:Clopidogrel; C489443:zotarolimus; D013988:Ticlopidine; D020123:Sirolimus
keywords: Acute coronary syndrome; Dual antiplatelet therapy; Zotarolimus-eluting stents