title: Conformational change in coronary artery structure assessed by optical coherence tomography in patients with vasospastic angina.
abstract: OBJECTIVE
  The aim of this study was to investigate the conformational change of arterial structure in the vasospastic lesion with optical coherence tomography.
  
  
  BACKGROUND
  Coronary artery spasm plays an important role in the pathogenesis of ischemic heart diseases. The conformational change of each arterial layer during vasospasm has not been studied in detail.
  
  
  METHODS
  We assessed 19 coronary arteries (10 spasm and 9 nonspasm lesions) with optical coherence tomography during the provocation test for coronary spasm. An intimal bump was defined as 1 or more intimal projections into the lumen that disappeared after the administration of nitroglycerine (NTG). Intimal gathering was defined as a folding/gathering of the intima, resulting in multiple kinks in the luminal contour that resolved after the administration of NTG.
  
  
  RESULTS
  The spasm lesion more frequently showed an intimal bump at baseline and intimal gathering during spasm compared with the nonspasm lesion (spasm 80% vs. nonspasm 0%, p < 0.01, spasm 100% vs. nonspasm 0%, p < 0.01, respectively). The spasm lesion demonstrated a thicker maximum media thickness (spasm 0.24 ± 0.04 mm vs. nonspasm 0.12 ± 0.03 mm, p < 0.01) at baseline, whereas no differences were observed after the administration of NTG (spasm 0.13 ± 0.03 mm vs. nonspasm 0.13 ± 0.02 mm, p = 0.65).
  
  
  CONCLUSIONS
  Our results suggest that medial contraction occurs even in an asymptomatic state and facilitates the formation of an intimal bump in patients with vasospastic angina. Luminal narrowing during spasm is associated with intimal gathering without alteration of intimal area.
authors.affiliation: Harvard Medical School, 50 Blossom Street, Boston, Massachusetts 02114, USA. atanaka1@partners.org
authors.forename: Atsushi
authors.initials: A
authors.lastname: Tanaka
authors.forename: Kenei
authors.initials: K
authors.lastname: Shimada
authors.forename: Guillermo J
authors.initials: GJ
authors.lastname: Tearney
authors.forename: Hironori
authors.initials: H
authors.lastname: Kitabata
authors.forename: Haruyuki
authors.initials: H
authors.lastname: Taguchi
authors.forename: Shota
authors.initials: S
authors.lastname: Fukuda
authors.forename: Manabu
authors.initials: M
authors.lastname: Kashiwagi
authors.forename: Takashi
authors.initials: T
authors.lastname: Kubo
authors.forename: Shigeho
authors.initials: S
authors.lastname: Takarada
authors.forename: Kumiko
authors.initials: K
authors.lastname: Hirata
authors.forename: Masato
authors.initials: M
authors.lastname: Mizukoshi
authors.forename: Junichi
authors.initials: J
authors.lastname: Yoshikawa
authors.forename: Brett E
authors.initials: BE
authors.lastname: Bouma
authors.forename: Takashi
authors.initials: T
authors.lastname: Akasaka
mesh_terms: D000368:Aged; D003329:Coronary Vasospasm / Q000175:diagnosis* / Q000473:pathology; D003331:Coronary Vessels / Q000473:pathology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D041623:Tomography, Optical Coherence