title: Chronic stent recoil plays an important role in restenosis of the right coronary ostium.
abstract: OBJECTIVE
  The efficacy of coronary stenting of aorto-ostial atherosclerotic lesions is still unclear. We investigated the frequency and mechanism of stent restenosis at this particular lesion.
  
  
  METHODS
  Fifty-five consecutive patients with 64 native aorto-ostial lesions in the right coronary artery (RCA, n = 38) and the left main trunk (LM, n = 26) were treated by conventional stenting. Determinants of angiographic restenosis were established. The mechanism of stent restenosis was evaluated using post-stenting and follow-up intravascular ultrasound (IVUS) findings.
  
  
  RESULTS
  Restenosis was more frequent in the RCA than in the LM (50% compared with 19%, P < 0.03) and determinants included diabetes mellitus (63% compared with 21%, P < 0.03), calcium deposition (58% compared with 5%, P < 0.003), smaller stent cross-sectional area (SA) (as demonstrated by post-stenting IVUS studies, 8.1 +/- 1.4 mm compared with 10.2 +/- 2.2 mm, P < 0.01), larger plaque burden (64 +/- 6% compared with 57 +/- 8%, P < 0.03) and less circular expansion at the aorto-coronary junction. Serial IVUS examination was performed in 11 patients with restenosis of the right coronary ostium. The mean reduction in the SA was 21% at the aorto-coronary junction (6.4 +/- 1.9 mm, P < 0.003), whereas the SA at the distal edge was unchanged. Thirty-three per cent of late luminal loss was due to chronic stent recoil.
  
  
  CONCLUSIONS
  These findings suggest that stenosis of the right coronary ostium is a high-risk lesion for stent restenosis. In addition to excessive intimal growth, chronic stent recoil might be an important etiologic factor at this particular location.
authors.affiliation: Ohashi Hospital, Toho University School of Medicine, Tokyo, Japan. t-taro@sd5.so-net.ne.jp
authors.forename: Taro
authors.initials: T
authors.lastname: Tsunoda
authors.forename: Masato
authors.initials: M
authors.lastname: Nakamura
authors.forename: Masamichi
authors.initials: M
authors.lastname: Wada
authors.forename: Naoki
authors.initials: N
authors.lastname: Ito
authors.forename: Yoko
authors.initials: Y
authors.lastname: Kitagawa
authors.forename: Masanori
authors.initials: M
authors.lastname: Shiba
authors.forename: Suguru
authors.initials: S
authors.lastname: Yajima
authors.forename: Raisuke
authors.initials: R
authors.lastname: Iijima
authors.forename: Rintaro
authors.initials: R
authors.lastname: Nakajima
authors.forename: Masato
authors.initials: M
authors.lastname: Yamamoto
authors.forename: Takuro
authors.initials: T
authors.lastname: Takagi
authors.forename: Takashi
authors.initials: T
authors.lastname: Yoshitama
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Anzai
authors.forename: Takahiro
authors.initials: T
authors.lastname: Nishida
authors.forename: Tetsu
authors.initials: T
authors.lastname: Yamaguchi
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D019917:Blood Vessel Prosthesis Implantation; D017023:Coronary Angiography; D003324:Coronary Artery Disease / Q000000981:diagnostic imaging / Q000601:surgery; D023903:Coronary Restenosis / Q000175:diagnosis / Q000209:etiology*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications / Q000175:diagnosis / Q000209:etiology*; D015607:Stents; D016896:Treatment Outcome; D018084:Ultrasonography, Interventional