title: Two-year clinical outcomes of different drug-eluting stents with different polymer coating strategies in coronary artery heart disease: a multi-centre, randomised, controlled clinical trial.
abstract: BACKGROUND
  The persistence of polymer may be related to late and very late stent thrombosis. Recently, biodegradable polymer (BD) and polymer-free (PF) stents have become a focus for prevention of detrimental clinical events. However, the long-term efficacy of these types of stent compared to that of permanent polymer (PP) stents is unclear.
  
  
  RESULTS
  A total of 989 consecutive coronary heart disease (CHD) patients from five centres who required the implantation of drug-eluting stents (DES) were randomly divided into the PP (n = 321), PF (n = 327) and BD groups (n = 341). The primary endpoint was major adverse cardiac events (MACE). The secondary endpoints were stent thrombosis events, all-cause death and rehospitalisation. The study was designed to test the noninferiority of the PF and BD stents compared with that of the PP stent with respect to two-year MACE, using a noninferiority margin of 0.05. After clinical follow-up for 26.96 ± 12.99 months, the 2-year MACE rates were 6.17% in the PF group, 6.58% in the BD group and 7.24% in the PP group. The noninferiority testing produced lower limits of the one-sided 95% confidence interval of -0.0435 (P = 0.024) for the PF group and -0.0401 (P = 0.017) for the BD group. There were no significant differences in stent thrombosis events, all-cause death and rehospitalisation among the three groups (all P>0.05).
  
  
  CONCLUSIONS
  In this multicentre, randomised, controlled clinical trial, PF paclitaxel-eluting stents and BD rapamycin-eluting stents were shown to be noninferior to PP rapamycin-eluting stents in two-year clinical outcomes for the treatment for CHD.
authors.affiliation: Department of Cardiology, The Second Affiliated Hospital, Chongqing Medical University, Chongqing, PR China.
authors.forename: Yue
authors.initials: Y
authors.lastname: Zhang
authors.forename: Junle
authors.initials: J
authors.lastname: Shen
authors.forename: Zhifeng
authors.initials: Z
authors.lastname: Li
authors.forename: Aidong
authors.initials: A
authors.lastname: Zhu
authors.forename: Yuelong
authors.initials: Y
authors.lastname: Yuan
authors.forename: Ruihua
authors.initials: R
authors.lastname: Yue
authors.forename: Jia
authors.initials: J
authors.lastname: Yuan
authors.forename: Yuehui
authors.initials: Y
authors.lastname: Yin
authors.forename: Qiang
authors.initials: Q
authors.lastname: She
authors.forename: Yunqing
authors.initials: Y
authors.lastname: Chen
mesh_terms: D000368:Aged; D003327:Coronary Disease / Q000628:therapy*; D054855:Drug-Eluting Stents; D005260:Female; D006801:Humans; D008297:Male; D011108:Polymers; D011474:Prosthesis Design; D013997:Time Factors; D016896:Treatment Outcome
chemical_list: D011108:Polymers
keywords: Coronary heart disease; Drug-eluting stents; Major adverse cardiovascular events; Paclitaxel; Polymer; Rapamycin