title: Towards real-time cardiovascular magnetic resonance guided transarterial CoreValve implantation: in vivo evaluation in swine.
abstract: BACKGROUND
  Real-time cardiovascular magnetic resonance (rtCMR) is considered attractive for guiding TAVI. Owing to an unlimited scan plane orientation and an unsurpassed soft-tissue contrast with simultaneous device visualization, rtCMR is presumed to allow safe device navigation and to offer optimal orientation for precise axial positioning. We sought to evaluate the preclinical feasibility of rtCMR-guided transarterial aortic valve implatation (TAVI) using the nitinol-based Medtronic CoreValve bioprosthesis.
  
  
  METHODS
  rtCMR-guided transfemoral (n = 2) and transsubclavian (n = 6) TAVI was performed in 8 swine using the original CoreValve prosthesis and a modified, CMR-compatible delivery catheter without ferromagnetic components.
  
  
  RESULTS
  rtCMR using TrueFISP sequences provided reliable imaging guidance during TAVI, which was successful in 6 swine. One transfemoral attempt failed due to unsuccessful aortic arch passage and one pericardial tamponade with subsequent death occurred as a result of ventricular perforation by the device tip due to an operating error, this complication being detected without delay by rtCMR. rtCMR allowed for a detailed, simultaneous visualization of the delivery system with the mounted stent-valve and the surrounding anatomy, resulting in improved visualization during navigation through the vasculature, passage of the aortic valve, and during placement and deployment of the stent-valve. Post-interventional success could be confirmed using ECG-triggered time-resolved cine-TrueFISP and flow-sensitive phase-contrast sequences. Intended valve position was confirmed by ex-vivo histology.
  
  
  CONCLUSIONS
  Our study shows that rtCMR-guided TAVI using the commercial CoreValve prosthesis in conjunction with a modified delivery system is feasible in swine, allowing improved procedural guidance including immediate detection of complications and direct functional assessment with reduction of radiation and omission of contrast media.
authors.affiliation: Department of Cardiology, West-German Heart Center Essen, Essen University Hospital, University Duisburg-Essen, Hufelandstrasse 55, Essen, Germany. philipp.kahlert@uk-essen.de
authors.forename: Philipp
authors.initials: P
authors.lastname: Kahlert
authors.forename: Nina
authors.initials: N
authors.lastname: Parohl
authors.forename: Juliane
authors.initials: J
authors.lastname: Albert
authors.forename: Lena
authors.initials: L
authors.lastname: Schäfer
authors.forename: Renate
authors.initials: R
authors.lastname: Reinhardt
authors.forename: Gernot M
authors.initials: GM
authors.lastname: Kaiser
authors.forename: Ian
authors.initials: I
authors.lastname: McDougall
authors.forename: Brad
authors.initials: B
authors.lastname: Decker
authors.forename: Björn
authors.initials: B
authors.lastname: Plicht
authors.forename: Raimund
authors.initials: R
authors.lastname: Erbel
authors.forename: Holger
authors.initials: H
authors.lastname: Eggebrecht
authors.forename: Mark E
authors.initials: ME
authors.lastname: Ladd
authors.forename: Harald H
authors.initials: HH
authors.lastname: Quick
mesh_terms: D000818:Animals; D001021:Aortic Valve / Q000601:surgery*; D001024:Aortic Valve Stenosis / Q000175:diagnosis / Q000601:surgery*; D001705:Bioprosthesis; D006328:Cardiac Catheterization; D002406:Catheterization, Peripheral / Q000379:methods*; D004195:Disease Models, Animal; D005260:Female; D005263:Femoral Artery; D019918:Heart Valve Prosthesis Implantation / Q000379:methods*; D019028:Magnetic Resonance Imaging, Cine / Q000379:methods*; D016343:Monitoring, Intraoperative / Q000379:methods*; D011474:Prosthesis Design; D013348:Subclavian Artery; D013552:Swine; D013997:Time Factors