title: Endothelium-dependent coronary vasomotor response and neointimal coverage of zotarolimus-eluting stents 3 months after implantation.
abstract: BACKGROUND
  Zotarolimus-eluting stents (ZES) have a higher rate of neointimal coverage than the first-generation drug-eluting stents on optical coherence tomography (OCT).
  
  
  OBJECTIVE
  To determine whether neointimal coverage of stent struts detected by OCT can be used as a surrogate for endothelial function after ZES implantation.
  
  
  METHODS
  Cross-sectional observational study.
  
  
  METHODS
  Three months after ZES implantation.
  
  
  METHODS
  OCT was performed in 20 patients with a ZES at 3 months after stent implantation to evaluate strut coverage. Endothelium-dependent coronary vasomotion was estimated by infusing incremental doses of acetylcholine into the coronary ostium. The vascular response was measured in the 10&emsp14;mm segments proximal and distal to the stent.
  
  
  RESULTS
  Of 20 ZES, 15 (75%) were covered completely with neointima, but the remaining 5 ZES had exposed struts. The high-dose acetylcholine infusion produced significant vasoconstriction in the proximal (-9.8±10.1%) and the distal stent segment (-29.7±22.7%). However, the degree of vasoconstriction to acetylcholine varied between individuals (from -0.6% to -77%). Although no relationship was observed between coronary vasomotor response (percentage change in diameter after acetylcholine administration) and average neointimal thickness, the number of cross-sections with uncovered struts showed an inverse correlation with coronary vasomotor response in proximal and distal stent segments (r=-0.57, p=0.007 and r=-0.83, p<0.001, respectively).
  
  
  CONCLUSIONS
  The existence of exposed struts was associated with abnormal vasoconstriction to acetylcholine at 3 months after ZES implantation. The findings suggest that complete neointimal coverage of stent struts assessed by OCT could be used as a surrogate for vasomotion impairment at 3 months after ZES implantation.
authors.affiliation: Hyogo College of Medicine, Cardiovascular Division, 1-1 Mukogawa-cho, Nishinomiya-city, Hyogo 6638501, Japan. kfujii@hyo-med.ac.jp
authors.forename: Kenichi
authors.initials: K
authors.lastname: Fujii
authors.forename: Daizo
authors.initials: D
authors.lastname: Kawasaki
authors.forename: Katsumi
authors.initials: K
authors.lastname: Oka
authors.forename: Hirokuni
authors.initials: H
authors.lastname: Akahori
authors.forename: Masashi
authors.initials: M
authors.lastname: Fukunaga
authors.forename: Hisashi
authors.initials: H
authors.lastname: Sawada
authors.forename: Motomaru
authors.initials: M
authors.lastname: Masutani
authors.forename: Masaaki
authors.initials: M
authors.lastname: Lee-Kawabata
authors.forename: Takeshi
authors.initials: T
authors.lastname: Tsujino
authors.forename: Mitsumasa
authors.initials: M
authors.lastname: Ohyanagi
authors.forename: Tohru
authors.initials: T
authors.lastname: Masuyama
mesh_terms: D000109:Acetylcholine / Q000494:pharmacology; D000368:Aged; D000369:Aged, 80 and over; D000787:Angina Pectoris / Q000188:drug therapy; D003331:Coronary Vessels / Q000187:drug effects* / Q000294:innervation; D054855:Drug-Eluting Stents; D004730:Endothelium, Vascular / Q000187:drug effects; D005260:Female; D006801:Humans; D007166:Immunosuppressive Agents / Q000494:pharmacology*; D008297:Male; D058426:Neointima / Q000188:drug therapy*; D011446:Prospective Studies; D020123:Sirolimus / Q000031:analogs & derivatives* / Q000494:pharmacology; D041623:Tomography, Optical Coherence; D014662:Vasoconstrictor Agents / Q000494:pharmacology; D014665:Vasodilator Agents / Q000494:pharmacology; D014666:Vasomotor System / Q000187:drug effects*; D014945:Wound Healing / Q000187:drug effects
chemical_list: D007166:Immunosuppressive Agents; D014662:Vasoconstrictor Agents; D014665:Vasodilator Agents; C489443:zotarolimus; D000109:Acetylcholine; D020123:Sirolimus