title: Characteristics of Late-Acquired Incomplete Stent Apposition: A Comparison With First-Generation and Second-Generation Drug-Eluting Stents.
abstract: OBJECTIVE
  This study aim was to investigate the morphometric parameters of late-acquired incomplete stent apposition (ISA) following use of Cypher sirolimus-eluting stent (SES; Cordis), Taxus paclitaxel-eluting stent (PES; Boston Scientific), and Resolute zotarolimus-eluting stent (ZES; Medtronic).
  
  
  BACKGROUND
  Characteristics of late-acquired ISA between first-generation and second-generation drug-eluting stents (DESs) have not been systematically examined.
  
  
  METHODS
  Late-acquired ISA was defined as separation of at least 1 stent strut from the vessel wall with evidence of blood speckle behind the strut, where poststent implantation intravascular ultrasound (IVUS) revealed complete apposition. A total of 30 late-acquired ISA cases (12 SES, 10 PES, 8 ZES) were included in this IVUS analysis. Corresponding cross-sections at post procedure were selected for comparison. Vessel, lumen, peristent tissue, and stent area were measured in the late-acquired ISA arc as referenced to stent center.
  
  
  RESULTS
  Late-acquired ISA area was 2.4 ± 1.5 mm² in SES, 2.2 ± 2.7 mm² in PES, and 0.9 ± 0.6 mm² in ZES (P=.02 for SES vs ZES). Vessel area increased from post procedure to follow-up in SES (4.6 ± 1.7 mm² to 7.0 ± 2.5 mm²; P<.01) and PES (3.6 ± 1.7 mm² to 5.7 ± 3.8 mm²; P=.06), but not in ZES. Vessel expansion was the main mechanism in SES and PES groups; however, tissue regression and stent recoil, as well as vessel expansion, also contributed to late-acquired ISA in ZES. Per-patient analyses demonstrated that vessel expansion was the predominant mechanism of late-acquired ISA in 83% of SES, 60% in PES, and 50% of ZES cases.
  
  
  CONCLUSIONS
  The magnitude and mechanism of late-acquired ISA appear to be different between first-generation and second-generation DESs, possibly due to varying vessel response to different stent component types.
authors.affiliation: Stanford University, Division of Cardiovascular Medicine, 300 Pasteur Drive, Room H3554, Stanford, CA 94305-5637 USA. crci-cvmed@stanford.edu.
authors.forename: Katsuhisa
authors.initials: K
authors.lastname: Waseda
authors.forename: Junya
authors.initials: J
authors.lastname: Ako
authors.forename: Teruyoshi
authors.initials: T
authors.lastname: Kume
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Fitzgerald
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Honda
mesh_terms: D000368:Aged; D015906:Angioplasty, Balloon, Coronary / Q000009:adverse effects / Q000295:instrumentation* / Q000379:methods; D017023:Coronary Angiography / Q000379:methods; D003324:Coronary Artery Disease / Q000175:diagnosis / Q000601:surgery; D054855:Drug-Eluting Stents / Q000009:adverse effects / Q000706:statistics & numerical data; D005260:Female; D006801:Humans; D007166:Immunosuppressive Agents / Q000494:pharmacology; D000069451:Long Term Adverse Effects / Q000175:diagnosis / Q000453:epidemiology / Q000209:etiology; D008297:Male; D008875:Middle Aged; D010043:Outcome and Process Assessment, Health Care; D017239:Paclitaxel / Q000494:pharmacology*; D020123:Sirolimus / Q000031:analogs & derivatives* / Q000494:pharmacology; D018084:Ultrasonography, Interventional / Q000379:methods; D014481:United States / Q000453:epidemiology
chemical_list: D007166:Immunosuppressive Agents; C489443:zotarolimus; D017239:Paclitaxel; D020123:Sirolimus