title: Change in lumen eccentricity and asymmetry after treatment with Absorb bioresorbable vascular scaffolds in the ABSORB cohort B trial: a five-year serial optical coherence tomography imaging study.
abstract: OBJECTIVE
  The aim of the study was to investigate long-term changes in lumen eccentricity and asymmetry at five years after implantation of the Absorb bioresorbable vascular scaffold (BVS).
  
  
  RESULTS
  Out of 101 patients from the ABSORB cohort B trial, 28 patients (29 lesions) with serial optical coherence tomography (OCT) examination at four different time points (cohort B1: post-procedure, six months, two, and five years [n=13]; cohort B2: post-procedure, one, three, and five years [n=16]) were evaluated. The longitudinal variance in lumen diameter was assessed by asymmetry index (AI). An asymmetric lesion was defined as AI >0.3. The circularity of the lumen or scaffold was evaluated by the eccentricity index calculated as minimal divided by maximal luminal or scaffold diameter per cross-section. The lowest lumen eccentricity index within a scaffold segment (EIL) <0.7 was defined as an eccentric lesion. Post procedure, an eccentric lesion was observed in 72.4% and became concentric in 93.1% at five years (post EIL 0.67±0.05 vs. five-year EIL 0.80±0.10, p=0.03) with a modest reduction of the lumen area from baseline to five years by 0.75±0.32 mm2. Asymmetric lumen morphology was observed in 93.1% (n=27) post implantation and persisted until five-year follow-up. On serial OCT analyses, there was a substantial increase in the scaffold EI during the first two years (post 0.70±0.06, six months 0.76±0.08, two years 0.85±0.07); then, it remained stable whereas the lumen circularity improved further. There were no significant differences in major adverse cardiac events regarding the lumen morphology over the five-year follow-up.
  
  
  CONCLUSIONS
  In patients treated with the Absorb BVS, the cross-sectional circularity improved over five years while the variance in longitudinal diameters remained. Regaining of lumen circularity is mainly caused by reshaping of the scaffold during the first two years.
authors.affiliation: Academic Medical Center, Amsterdam, the Netherlands.
authors.forename: Pannipa
authors.initials: P
authors.lastname: Suwannasom
authors.forename: Yohei
authors.initials: Y
authors.lastname: Sotomi
authors.forename: Taku
authors.initials: T
authors.lastname: Asano
authors.forename: Jaryl Ng Chen
authors.initials: JN
authors.lastname: Koon
authors.forename: Hiroki
authors.initials: H
authors.lastname: Tateishi
authors.forename: Yaping
authors.initials: Y
authors.lastname: Zeng
authors.forename: Erhan
authors.initials: E
authors.lastname: Tenekecioglu
authors.forename: Joanna J
authors.initials: JJ
authors.lastname: Wykrzykowska
authors.forename: Nicolas
authors.initials: N
authors.lastname: Foin
authors.forename: Robbert J
authors.initials: RJ
authors.lastname: de Winter
authors.forename: John A
authors.initials: JA
authors.lastname: Ormiston
authors.forename: Patrick W
authors.initials: PW
authors.lastname: Serruys
authors.forename: Yoshinobu
authors.initials: Y
authors.lastname: Onuma
mesh_terms: D020341:Absorbable Implants; D000368:Aged; D017023:Coronary Angiography; D003331:Coronary Vessels / Q000473:pathology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D054457:Tissue Scaffolds; D041623:Tomography, Optical Coherence / Q000379:methods*