title: Hemodynamic impact of changes in bifurcation geometry after single-stent cross-over technique assessed by intravascular ultrasound and fractional flow reserve.
abstract: BACKGROUND
  Angiographic stenosis of a sidebranch (SB) ostium is common after single-stent cross-over, but it is usually not hemodynamically significant. We evaluated the relationship between the mechanisms of SB stenosis and its hemodynamic significance.
  
  
  RESULTS
  We used preinterventional and post-interventional intravascular ultrasound (IVUS) of the main branch (MB) and the SB and post-intervention fractional flow reserve (FFR) of the SB to assess 40 nonleft main bifurcation lesions after a single stent cross-over. Although post-stenting angiographic diameter stenosis >50% was seen in 19 (48%) SB lesions, only 6 (15%) showed FFR < 0.80. Carina shift was seen in all but one lesion; and plaque shift superimposed on the carina shift was found in 18 (45%) lesions. The change in plaque area at the SB ostium positively correlated with preprocedural plaque burden at the carina of distal MB r = 0.341, P = 0.031). Plaque shift was more common in lesions with FFR < 0.80 vs. ≥0.80 (83% vs. 38%, P = 0.041); and FFR < 0.80 was more frequent in lesions with plaque shift superimposed on carina shift versus isolated carina shift (28% vs. 5%, P = 0.041).
  
  
  CONCLUSIONS
  Although carina shift was the main mechanism of SB lumen loss after a single stent cross-over technique, plaque shift superimposed on carina shift appeared to be necessary to cause a hemodynamically significant stenosis (FFR < 0.80). However, post-procedural IVUS assessment did not accurately predict the functional significance.
authors.affiliation: Department of Cardiology, University of Ulsan College of Medicine, Asan Medical Center, Seoul, South Korea.
authors.forename: Soo-Jin
authors.initials: SJ
authors.lastname: Kang
authors.forename: Won-Jang
authors.initials: WJ
authors.lastname: Kim
authors.forename: Jong-Young
authors.initials: JY
authors.lastname: Lee
authors.forename: Duk-Woo
authors.initials: DW
authors.lastname: Park
authors.forename: Seung-Whan
authors.initials: SW
authors.lastname: Lee
authors.forename: Young-Hak
authors.initials: YH
authors.lastname: Kim
authors.forename: Cheol Whan
authors.initials: CW
authors.lastname: Lee
authors.forename: Gary S
authors.initials: GS
authors.lastname: Mintz
authors.forename: Seong-Wook
authors.initials: SW
authors.lastname: Park
authors.forename: Seung-Jung
authors.initials: SJ
authors.lastname: Park
mesh_terms: D000368:Aged; D017023:Coronary Angiography; D003324:Coronary Artery Disease / Q000175:diagnosis / Q000503:physiopathology / Q000628:therapy*; D023921:Coronary Stenosis / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000209:etiology / Q000503:physiopathology; D003331:Coronary Vessels / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D005260:Female; D053805:Fractional Flow Reserve, Myocardial; D006439:Hemodynamics; D006801:Humans; D008297:Male; D008875:Middle Aged; D062645:Percutaneous Coronary Intervention / Q000009:adverse effects / Q000295:instrumentation* / Q000379:methods; D058226:Plaque, Atherosclerotic; D011237:Predictive Value of Tests; D015607:Stents; D013997:Time Factors; D016896:Treatment Outcome; D018084:Ultrasonography, Interventional
keywords: carina shift; fractional flow reserve; intravascular ultrasound; plaque shift