Author + information
- Philipp Blanke, MD∗,
- Danny Dvir, MD∗,
- Anson Cheung, MD∗,
- Robert A. Levine, MD†,
- Christopher Thompson, MD∗,
- John G. Webb, MD∗ and
- Jonathon Leipsic, MD∗∗ ()
- ∗Center for Heart Valve Innovation, St. Paul's Hospital, University of British Columbia, Vancouver, British Columbia, Canada
- †Division of Cardiology, Department of Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
- ↵∗Reprint requests and correspondence:
Dr. Jonathon Leipsic, Department of Radiology, University of British Columbia, Centre for Heart Valve Innovation–St. Paul’s Hospital, 1081 Burrard Street, Vancouver V6Z 1Y6, British Columbia, Canada.
- mitral regurgitation
- transcatheter mitral valve implantation
- transcatheter mitral valve replacement
With the advent of transcatheter mitral valve replacement (TMVR) (1), the assessment of mitral annular dimensions by computed tomography (CT) is of increasing relevance. The nonplanar, saddle-shaped, 3-dimensional structure of the mitral annulus has been well established (2) with the posterior peak formed by the insertion of the posterior mitral valve leaflet, the anterior peak being in part continuous with the aortic annulus, and the nadirs located at the level of the fibrous trigones. The projected area of the saddle-shaped annulus extends well into the left ventricular outflow track (LVOT), which would lead to LVOT obstruction if a valve was implanted with a size corresponding to this projected area. Although it is anatomically correct and an important concept, we hypothesize that the saddle-shaped mitral annulus must be modified for device sizing and selection in TMVR. We propose that the anterior horn must be excluded for sizing, thereby creating a planar “D-shaped” annulus with its anterior border defined by a virtual line connecting both trigones.
In the context of TMVR, the method presented here may aid in selection of a device size that has the lowest possible risk of paravalvular leakage while not jeopardizing the integrity of the annulus or obstruction of the LVOT. Furthermore, CT allows for detailed geometric evaluation of the landing zone, and in particular the derivation of appropriate coaxial angles of deployment (Figures 1 to 7⇓⇓⇓⇓⇓⇓⇓).
Drs. Blanke, Cheung, and Leipsic are consultants for Neovasc and Edwards Lifesciences. Dr. Thompson has received teaching fees from Edwards Lifesciences. Dr. Webb is a consultant for Edwards Lifesciences. Drs. Blanke and Leipsic provide core lab CT services to Neovasc, Tendyne Holdings, and Edwards Lifesciences. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose.
- 2015 American College of Cardiology Foundation
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