title: Comparative analysis method of permanent metallic stents (XIENCE) and bioresorbable poly-L-lactic (PLLA) scaffolds (Absorb) on optical coherence tomography at baseline and follow-up.
abstract: OBJECTIVE
  Fully bioresorbable Absorb poly-L-lactic-acid (PLLA) scaffolds (Abbott Vascular, Santa Clara, CA, USA) are a novel approach for the treatment of coronary narrowing. Due to the translucency of the material (PLLA), the optical coherence tomography (OCT) measurement methods used in the ABSORB trials were unique but not applicable for permanent metallic stents. When the Absorb scaffold and metallic stents are compared in the context of randomised trials, it is challenging to compare the two devices using the conventional methods. The primary purpose of this report is to explain the biases in conventional methodologies applied for metallic stents and for PLLA scaffolds at baseline and follow-up, and to propose a new standard methodology that enables us to compare two different devices using an almost identical and methodological language.
  
  
  RESULTS
  A consensus amongst multiple core labs and expert researchers of OCT was reached on a new standard OCT measurement methodology that enables us to compare these two different devices. In brief, the proposed OCT methods are summarised as follows. 1) Both endoluminal and abluminal scaffold/stent contours should be traced. 2) Consistently, endoluminal and abluminal incomplete stent apposition areas should be measured. 3) The area occupied by scaffold/stent struts should be quantified directly or virtually. 4) The strut area should be systematically excluded from the flow area as well as the neointimal area. 5) Additional information on the degree of embedment could be reported using the interpolated lumen contour. Interobserver variability of the proposed method was excellent (intraclass correlation 0.89-100).
  
  
  CONCLUSIONS
  A standardised OCT measurement methodology is proposed. This should be implemented in ongoing and future trials comparing the Absorb scaffolds and metallic stents.
authors.affiliation: Thoraxcenter, Erasmus Medical Center, Rotterdam, The Netherlands.
authors.forename: Shimpei
authors.initials: S
authors.lastname: Nakatani
authors.forename: Yohei
authors.initials: Y
authors.lastname: Sotomi
authors.forename: Yuki
authors.initials: Y
authors.lastname: Ishibashi
authors.forename: Maik J
authors.initials: MJ
authors.lastname: Grundeken
authors.forename: Hiroki
authors.initials: H
authors.lastname: Tateishi
authors.forename: Erhan
authors.initials: E
authors.lastname: Tenekecioglu
authors.forename: Yaping
authors.initials: Y
authors.lastname: Zeng
authors.forename: Pannipa
authors.initials: P
authors.lastname: Suwannasom
authors.forename: Evelyn
authors.initials: E
authors.lastname: Regar
authors.forename: Maria D
authors.initials: MD
authors.lastname: Radu
authors.forename: Lorenz
authors.initials: L
authors.lastname: Räber
authors.forename: Hiram
authors.initials: H
authors.lastname: Bezerra
authors.forename: Marco A
authors.initials: MA
authors.lastname: Costa
authors.forename: Peter
authors.initials: P
authors.lastname: Fitzgerald
authors.forename: Francesco
authors.initials: F
authors.lastname: Prati
authors.forename: Ricardo A
authors.initials: RA
authors.lastname: Costa
authors.forename: Jouke
authors.initials: J
authors.lastname: Dijkstra
authors.forename: Takeshi
authors.initials: T
authors.lastname: Kimura
authors.forename: Ken
authors.initials: K
authors.lastname: Kozuma
authors.forename: Kengo
authors.initials: K
authors.lastname: Tanabe
authors.forename: Takashi
authors.initials: T
authors.lastname: Akasaka
authors.forename: Carlo
authors.initials: C
authors.lastname: Di Mario
authors.forename: Patrick W
authors.initials: PW
authors.lastname: Serruys
authors.forename: Yoshinobu
authors.initials: Y
authors.lastname: Onuma
mesh_terms: D020341:Absorbable Implants; D017023:Coronary Angiography / Q000379:methods; D054855:Drug-Eluting Stents / Q000009:adverse effects; D000068338:Everolimus / Q000627:therapeutic use; D005500:Follow-Up Studies; D006801:Humans; D062645:Percutaneous Coronary Intervention / Q000379:methods; D011091:Polyesters; D011474:Prosthesis Design; D041623:Tomography, Optical Coherence / Q000379:methods
chemical_list: D011091:Polyesters; C033616:poly(lactide); D000068338:Everolimus