title: Underexpansion and ad hoc post-dilation in selected patients undergoing balloon-expandable transcatheter aortic valve replacement.
abstract: OBJECTIVE
  This study sought to assess the clinical outcomes and hemodynamic performance associated with a strategy of underexpanding balloon-expandable transcatheter heart valves (THV) when excessive oversizing is a concern.
  
  
  BACKGROUND
  Transcatheter aortic valve replacement depends on the selection of an optimally sized THV. An undersized THV may lead to paravalvular regurgitation, whereas excessive oversizing may lead to annular injury.
  
  
  METHODS
  Patients (n = 47) who underwent transcatheter aortic valve replacement with an intentionally underexpanded THV (balloon-filling volume reduced ~10%) were compared with consecutive control patients who had nominal THV balloon deployment (n = 87). Pre- and post-procedural computed tomography imaging and echocardiography were performed to assess THV stent expansion and hemodynamics.
  
  
  RESULTS
  Underfilling resulted in THV underexpansion that was maximal at the THV inflow (85.0 ± 7.4% vs. 102.5 ± 6.2%, p < 0.001), in study versus control groups, respectively. The study group received larger THV, although annular injury was not observed. Post-dilation was required in 10.6% and 4.6% of patients of the study and control groups, respectively (p = 0.165). Echocardiographic THV area, gradient, paravalvular regurgitation, and in-hospital outcomes were similar.
  
  
  CONCLUSIONS
  Intentionally underexpanding balloon-expandable THV by underfilling the deployment balloon did not adversely affect procedural clinical outcomes, THV gradients, or THV areas. A strategy of underexpansion, with post-dilation as necessary, might play in role in reducing the risk of annular injury and paravalvular regurgitation in selected patients.
authors.affiliation: St. Paul's Hospital, University of British Columbia, Vancouver, British Columbia, Canada.
authors.forename: Marco
authors.initials: M
authors.lastname: Barbanti
authors.affiliation: St. Paul's Hospital, University of British Columbia, Vancouver, British Columbia, Canada.
authors.forename: Jonathon
authors.initials: J
authors.lastname: Leipsic
authors.affiliation: St. Paul's Hospital, University of British Columbia, Vancouver, British Columbia, Canada.
authors.forename: Ronald
authors.initials: R
authors.lastname: Binder
authors.affiliation: St. Paul's Hospital, University of British Columbia, Vancouver, British Columbia, Canada.
authors.forename: Danny
authors.initials: D
authors.lastname: Dvir
authors.affiliation: St. Paul's Hospital, University of British Columbia, Vancouver, British Columbia, Canada.
authors.forename: John
authors.initials: J
authors.lastname: Tan
authors.affiliation: St. Paul's Hospital, University of British Columbia, Vancouver, British Columbia, Canada.
authors.forename: Melanie
authors.initials: M
authors.lastname: Freeman
authors.affiliation: Aarhus University Hospital, Aarhus, Denmark.
authors.forename: Bjarne
authors.initials: B
authors.lastname: Norgaard
authors.affiliation: Aarhus University Hospital, Aarhus, Denmark.
authors.forename: Nicolaj
authors.initials: N
authors.lastname: Hansson
authors.affiliation: St. Paul's Hospital, University of British Columbia, Vancouver, British Columbia, Canada.
authors.forename: Anson
authors.initials: A
authors.lastname: Cheung
authors.affiliation: St. Paul's Hospital, University of British Columbia, Vancouver, British Columbia, Canada.
authors.forename: Jian
authors.initials: J
authors.lastname: Ye
authors.affiliation: St. Paul's Hospital, University of British Columbia, Vancouver, British Columbia, Canada.
authors.forename: Tae-Hyun
authors.initials: TH
authors.lastname: Yang
authors.affiliation: St. Paul's Hospital, University of British Columbia, Vancouver, British Columbia, Canada.
authors.forename: Kasia
authors.initials: K
authors.lastname: Maryniak
authors.affiliation: St. Paul's Hospital, University of British Columbia, Vancouver, British Columbia, Canada.
authors.forename: Rekha
authors.initials: R
authors.lastname: Raju
authors.affiliation: St. Paul's Hospital, University of British Columbia, Vancouver, British Columbia, Canada.
authors.forename: Angus
authors.initials: A
authors.lastname: Thompson
authors.affiliation: St. Paul's Hospital, University of British Columbia, Vancouver, British Columbia, Canada.
authors.forename: Philipp
authors.initials: P
authors.lastname: Blanke
authors.affiliation: St. Paul's Hospital, University of British Columbia, Vancouver, British Columbia, Canada.
authors.forename: Sandra
authors.initials: S
authors.lastname: Lauck
authors.affiliation: St. Paul's Hospital, University of British Columbia, Vancouver, British Columbia, Canada.
authors.forename: David
authors.initials: D
authors.lastname: Wood
authors.affiliation: St. Paul's Hospital, University of British Columbia, Vancouver, British Columbia, Canada. Electronic address: webb@providencehealth.bc.ca.
authors.forename: John
authors.initials: J
authors.lastname: Webb
mesh_terms: D000369:Aged, 80 and over; D001024:Aortic Valve Stenosis / Q000175:diagnosis / Q000601:surgery*; D006328:Cardiac Catheterization / Q000379:methods*; D017548:Echocardiography, Transesophageal; D005260:Female; D005500:Follow-Up Studies; D019918:Heart Valve Prosthesis Implantation / Q000379:methods*; D006801:Humans; D008297:Male; D061330:Multidetector Computed Tomography; D018579:Patient Selection; D011474:Prosthesis Design; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome
keywords: patient selection; transcatheter aortic valve replacement; underexpanded transcatheter heart valve