title: Incidence and potential mechanism of resolved, persistent and newly acquired malapposition three days after implantation of self-expanding or balloon-expandable stents in a STEMI population: insights from optical coherence tomography in the APPOSITION II study.
abstract: OBJECTIVE
  The aim of the current study was to investigate the frequency and mechanisms of sequential incomplete stent apposition (ISA) changes such as persistent, resolved or newly acquired ISA during the first three days after primary PCI (pPCI) in a matched segment-level analysis, with the comparison between self-expanding and balloon-expandable stents assessed by optical coherence tomography (OCT).
  
  
  RESULTS
  The current analysis is a substudy of the APPOSITION II study that included 69 patients (self-expanding: 35, balloon-expandable: 34) using serial optical coherence tomography (OCT) post procedure and three days after pPCI. In order to evaluate a temporal change in ISA, stented regions were segmented using fiduciary landmarks. In a total of 228 corresponding segments, persistent and newly acquired ISA were less frequently observed in self-expanding stents than in balloon-expandable stents (11.5% vs. 33.9%, p<0.01, 2.7% vs. 14.8%, p<0.01, respectively). New appearances of ISA were caused by tissue resorption, vasorelaxation and "early" recoil in balloon-expandable stents, and only tissue resorption in self-expanding stents.
  
  
  CONCLUSIONS
  Three days after pPCI, tissue resorption and vasorelaxation were biological factors associated with new appearance of ISA while "early" recoil of balloon-expandable stents was a mechanical factor. Both persistent ISA and newly acquired ISA occurred less frequently in self-expanding stents, resulting in a low number of ISA segments compared to balloon-expandable stents. Clinical Trials Registration Information: Randomised Comparison Between the STENTYS Self-expanding Coronary Stent and a Balloon-expandable Stent in Acute Myocardial Infarction (APPOSITION II). ClinicalTrials.gov Identifier: NCT01008085
authors.affiliation: Thoraxcenter, Erasmus Medical Center, Rotterdam, The Netherlands.
authors.forename: Shimpei
authors.initials: S
authors.lastname: Nakatani
authors.forename: Yoshinobu
authors.initials: Y
authors.lastname: Onuma
authors.forename: Yuki
authors.initials: Y
authors.lastname: Ishibashi
authors.forename: Antonios
authors.initials: A
authors.lastname: Karanasos
authors.forename: Evelyn
authors.initials: E
authors.lastname: Regar
authors.forename: Hector M
authors.initials: HM
authors.lastname: Garcia-Garcia
authors.forename: Corrado
authors.initials: C
authors.lastname: Tamburino
authors.forename: Jean
authors.initials: J
authors.lastname: Fajadet
authors.forename: Mathias
authors.initials: M
authors.lastname: Vrolix
authors.forename: Bernhard
authors.initials: B
authors.lastname: Witzenbichler
authors.forename: Eric
authors.initials: E
authors.lastname: Eeckhout
authors.forename: Christian
authors.initials: C
authors.lastname: Spaulding
authors.forename: Krzysztof
authors.initials: K
authors.lastname: Reczuch
authors.forename: Alessio
authors.initials: A
authors.lastname: La Manna
authors.forename: René
authors.initials: R
authors.lastname: Spaargaren
authors.forename: Davide
authors.initials: D
authors.lastname: Capodanno
authors.forename: Glenn
authors.initials: G
authors.lastname: Van Langenhove
authors.forename: Stefan
authors.initials: S
authors.lastname: Verheye
authors.forename: Patrick W
authors.initials: PW
authors.lastname: Serruys
authors.forename: Robert-Jan
authors.initials: RJ
authors.lastname: van Geuns
mesh_terms: D015906:Angioplasty, Balloon, Coronary / Q000009:adverse effects / Q000295:instrumentation*; D017023:Coronary Angiography; D003331:Coronary Vessels / Q000000981:diagnostic imaging / Q000473:pathology / Q000503:physiopathology; D005060:Europe; D057918:Fiducial Markers; D006801:Humans; D009203:Myocardial Infarction / Q000175:diagnosis / Q000503:physiopathology / Q000628:therapy*; D062645:Percutaneous Coronary Intervention / Q000009:adverse effects / Q000295:instrumentation*; D011474:Prosthesis Design; D015607:Stents; D013997:Time Factors; D041623:Tomography, Optical Coherence; D016896:Treatment Outcome; D014664:Vasodilation