title: Comparable vascular response of a new generation sirolimus eluting stents when compared to fluoropolymer everolimus eluting stents in the porcine coronary restenosis model.
abstract: BACKGROUND
  Novel sirolimus eluting stents (SES) have shown non-inferior clinical outcomes when compared to everolimus eluting stents (EES), however only limited preclinical data have been published. Therefore, we evaluate vascular response of a new generation biodegradable polymer SES (BP-SES: Alex Plus, Balton) and fluoropolymer EES (EES: Xience Pro, Abbott) in the porcine coronary restenosis model.
  
  
  METHODS
  A total of 40 stents were implanted with 120% overstretch in coronaries of 17 domestic swine: 16 BP-SES, 16 EES and 8 bare metal controls (BMS). Following 28 and 90 days, coronary angiography and optical coherence tomography (OCT) was performed, animals sacrificed and stented segments harvested for pathological evaluation.
  
  
  RESULTS
  At 28 days neointimal thickness in OCT was lowest in the BP-SES when compared to EES and BMS (0.18 ± 0.1 vs. 0.39 ± 0.1 vs. 0.34 ± 0.2 mm, respectively; p = 0.04). There was no difference in the proportion of malapposed or uncovered struts, although protruding covered struts were more common in BP-SES (14.8 ± 10% vs. 4.1 ± 4% vs. 3.7 ± 6%; p = 0.03). In pathology, the lowest neointimal thickness was confirmed in BP-SES (p < 0.05). The inflammation score was significantly lower in BP-SES and EES when compared to BMS (0.24 ± 0.1 vs. 0.4 ± 0.1 vs. 0.77 ± 0.4; p < 0.01) whilst EES and BP-SES had higher fibrin scores than BMS (1.2 ± 0.4 vs. 1.3 ± 0.3 vs. 0.17 ± 0.2; p < 0.01). At 90 days neointimal coverage and thickness in OCT was comparable between groups and healing in histopathology was complete.
  
  
  CONCLUSIONS
  New generation, BP-SES show similar vascular healing and biocompatibility profile with marginally higher degree of restenosis inhibition, when compared to fluoropolymer EES in the porcine coronary restenosis model.
authors.affiliation: Center for Cardiovascular Research and Development of American Heart of Poland, Katowice, Poland Silesian Center for Heart Diseases, Zabrze, Poland. p.buszman@ahp-ccrd.org.
authors.forename: Piotr P
authors.initials: PP
authors.lastname: Buszman
authors.forename: Magdalena J
authors.initials: MJ
authors.lastname: Michalak
authors.forename: Maciej
authors.initials: M
authors.lastname: Pruski
authors.forename: Carlos
authors.initials: C
authors.lastname: Fernandez
authors.forename: Michał
authors.initials: M
authors.lastname: Jelonek
authors.forename: Adam
authors.initials: A
authors.lastname: Janas
authors.forename: Claudine
authors.initials: C
authors.lastname: Savard
authors.forename: Beata
authors.initials: B
authors.lastname: Gwiazdowska-Nowotka
authors.forename: Aleksander
authors.initials: A
authors.lastname: Żurakowski
authors.forename: Wojciech
authors.initials: W
authors.lastname: Wojakowski
authors.forename: Paweł E
authors.initials: PE
authors.lastname: Buszman
authors.forename: Krzysztof
authors.initials: K
authors.lastname: Milewski
mesh_terms: D020341:Absorbable Implants; D000818:Animals; D017023:Coronary Angiography; D023903:Coronary Restenosis / Q000175:diagnosis / Q000601:surgery*; D003331:Coronary Vessels / Q000000981:diagnostic imaging / Q000601:surgery; D004195:Disease Models, Animal; D054855:Drug-Eluting Stents; D000068338:Everolimus / Q000494:pharmacology*; D005260:Female; D007166:Immunosuppressive Agents / Q000494:pharmacology; D008297:Male; D062645:Percutaneous Coronary Intervention / Q000379:methods*; D011108:Polymers; D011474:Prosthesis Design; D020123:Sirolimus / Q000494:pharmacology*; D013552:Swine; D041623:Tomography, Optical Coherence
chemical_list: D007166:Immunosuppressive Agents; D011108:Polymers; D000068338:Everolimus; D020123:Sirolimus
keywords: biodegradable polymer; everolimus eluting stent; new generation sirolimus eluting stent; porcine coronary restenosis model