title: Serial analysis of the malapposed and uncovered struts of the new generation of everolimus-eluting bioresorbable scaffold with optical coherence tomography.
abstract: OBJECTIVE
  The aim of this study is to assess the serial changes in strut apposition and coverage of the bioresorbable vascular scaffolds (BVS) and to relate this with the presence of intraluminal masses at 6 months with optical coherence tomography (OCT).
  
  
  BACKGROUND
  Incomplete strut/scaffold apposition (ISA) and uncovered struts are related to a higher risk of scaffold thrombosis. Bioresorbable vascular scaffolds can potentially avoid the risk of scaffold thrombosis because of its complete resorption. However, during the resorption period, the risk of scaffold thrombosis is unknown.
  
  
  METHODS
  OCT was performed in 25 patients at baseline and 6 months. Struts were classified according to apposition, coverage, and presence of intraluminal masses. Persistent ISA was defined as malapposed struts present at baseline and follow-up, and late acquired ISA as ISA developing at follow-up, and scaffold pattern irregularities when the strut distribution suggested scaffold fracture.
  
  
  RESULTS
  At baseline, 3,686 struts were analyzed: 128 (4%) were ISA, and 53 (1%) were located over side-branches (SB). At 6 months, 3,905 struts were analyzed: 32 (1%) ISA, and 35 (1%) at the SB. Persistent ISA was observed more frequently than late acquired-ISA (81% vs. 16%, respectively; 3% were unmatchable). Late acquired ISA was associated with scaffold pattern irregularities, which were related to overstretching of the scaffold. Uncovered struts (63 struts, 2%) were more frequently observed in ISA and SB struts, compared with apposed struts (29% vs. 1%; p < 0.01). Intraluminal masses (14 cross-sections, 3%; in 6 patients, 24%) were more frequently located at the site of ISA and/or uncovered struts (39% vs. 2% and 13% vs. 2%, respectively; p < 0.01).
  
  
  CONCLUSIONS
  The lack of strut apposition at baseline is related to the presence of uncovered struts and intraluminal masses at 6 month. An appropriate balloon/artery ratio respecting the actual vessel size and avoiding the overstretching of the scaffold can potentially decrease the risk of scaffold thrombosis. (ABSORB Clinical Investigation, Cohort B [ABSORB B).
authors.affiliation: Thoraxcenter, Erasmus Medical Center, Rotterdam, the Netherlands.
authors.forename: Josep
authors.initials: J
authors.lastname: Gomez-Lara
authors.forename: Maria
authors.initials: M
authors.lastname: Radu
authors.forename: Salvatore
authors.initials: S
authors.lastname: Brugaletta
authors.forename: Vasim
authors.initials: V
authors.lastname: Farooq
authors.forename: Roberto
authors.initials: R
authors.lastname: Diletti
authors.forename: Yoshinobu
authors.initials: Y
authors.lastname: Onuma
authors.forename: Stephan
authors.initials: S
authors.lastname: Windecker
authors.forename: Leif
authors.initials: L
authors.lastname: Thuesen
authors.forename: Dougal
authors.initials: D
authors.lastname: McClean
authors.forename: Jacques
authors.initials: J
authors.lastname: Koolen
authors.forename: Robert
authors.initials: R
authors.lastname: Whitbourn
authors.forename: Dariusz
authors.initials: D
authors.lastname: Dudek
authors.forename: Pieter C
authors.initials: PC
authors.lastname: Smits
authors.forename: Evelyn
authors.initials: E
authors.lastname: Regar
authors.forename: Susan
authors.initials: S
authors.lastname: Veldhof
authors.forename: Richard
authors.initials: R
authors.lastname: Rapoza
authors.forename: John A
authors.initials: JA
authors.lastname: Ormiston
authors.forename: Hector M
authors.initials: HM
authors.lastname: Garcia-Garcia
authors.forename: Patrick W
authors.initials: PW
authors.lastname: Serruys
mesh_terms: D000368:Aged; D015906:Angioplasty, Balloon, Coronary / Q000009:adverse effects / Q000295:instrumentation*; D001315:Australia; D001672:Biocompatible Materials; D002317:Cardiovascular Agents / Q000008:administration & dosage*; D054855:Drug-Eluting Stents; D005060:Europe; D000068338:Everolimus; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009520:New Zealand; D011474:Prosthesis Design; D020123:Sirolimus / Q000008:administration & dosage / Q000031:analogs & derivatives*; D013927:Thrombosis / Q000175:diagnosis* / Q000209:etiology / Q000517:prevention & control; D013997:Time Factors; D041623:Tomography, Optical Coherence; D016896:Treatment Outcome; D014481:United States
chemical_list: D001672:Biocompatible Materials; D002317:Cardiovascular Agents; D000068338:Everolimus; D020123:Sirolimus