Author + information
- Received April 16, 2018
- Revision received June 4, 2018
- Accepted June 13, 2018
- Published online September 3, 2018.
- Janarthanan Sathananthan, MBChB, MPHa,
- Stephanie Sellers, PhDb,
- Aaron Barlow, BSc, PhDb,
- Rob Fraser, MScd,
- Viktória Stanová, Dipl-Inge,
- Anson Cheung, MDa,
- Jian Ye, MDa,
- Abdullah Alenezi, MDa,
- Dale J. Murdoch, MBBSa,
- Mark Hensey, MB BCh BAOa,
- Danny Dvir, MDf,
- Philipp Blanke, MDa,
- Régis Rieu, PhDe,
- David Wood, MDa,
- Phillippe Pibarot, DVM, PhDc,
- Jonathan Leipsic, MDa and
- John Webb, MDa,∗ ()
- aCentre for Heart Valve Innovation, St Paul’s Hospital, University of British Columbia, Vancouver, Canada
- bCentre for Heart Lung Innovation, St Paul's Hospital, Vancouver, Canada
- cQuebec Heart & Lung Institute, Laval University, Quebec, Canada
- dViVitro Labs, Victoria, Canada
- eLBA UMR_T24, IFSTTAR, Aix-Marseille University, Marseille, France
- fDepartment of Cardiology, University of Washington, Seattle, Washington
- ↵∗Address for correspondence:
Dr. John Webb, St. Paul’s Hospital, 1081 Burrard Street, Vancouver, British Columbia V6Z 1Y6, Canada.
Objectives This study assessed the effect of overexpansion beyond labeled size (diameter) of transcatheter heart valves through an ex vivo bench study.
Background Transcatheter heart valves function optimally when expanded to specific dimensions. However, clinicians may sometimes wish to overexpand balloon-expandable valves to address specific clinical challenges. The implications of overexpansion have assumed considerable importance, and objective information to guide practice is limited.
Methods We evaluated SAPIEN 3 transcatheter heart valves (Edwards Lifesciences, Irvine, California). Valves (diameters of 23, 26, and 29 mm) were expanded to nominal dimensions, and then incrementally overexpanded with balloons sized 1-, 2-, and 3-mm larger than the recommended diameter. Valves underwent visual, microcomputed tomography, and hydrodynamic evaluation at various degrees of overexpansion.
Results SAPIEN 3 valves with labeled diameters of 23, 26, and 29 mm could be incrementally overexpanded to midvalve diameters of 26.4, 28.4, and 31.2 mm, respectively. With overexpansion, there was visible restriction of the valve leaflets, which was particularly evident with the smaller valves. After maximal overexpansion of a 26-mm valve a leaflet tear was observed. High-speed video demonstrated impaired leaflet motion of both the 23- and 26-mm valves and hydrodynamic testing documented a regurgitant fraction for the 23- and 26-mm valves above accepted international standards. The maximally overexpanded 29-mm SAPIEN 3 still had relatively normal leaflet motion and excellent hydrodynamic function. Durability was not specifically evaluated.
Conclusions Overexpansion of balloon-expandable valves is possible. However, excessive overexpansion may be associated with impaired hydrodynamic function, acute leaflet failure, and reduced durability. Smaller valves may be at greater risk with overexpansion than larger valves. Overexpansion is best avoided unless clinical circumstances are compelling.
Dr. Cheung has served as a consultant to Abbot Vascular, Medtronic, and Neovasc. Dr. Ye has served as a consultant for Edwards Lifesciences. Dr. Dvir has served as a consultant for Edwards Lifesciences, Medtronic, and St Jude Medical. Dr. Blanke has served as a consultant for Edwards Lifesciences. Dr. Wood is a consultant to Edwards Lifesciences. Dr Pibarot has received grant support from Edwards Lifesciences and Medtronic. Dr. Leipsic has received institutional research support from Edwards Lifesciences and Medtronic. Dr. Webb has served as a consultant for Edwards Lifesciences and ViVitro Labs. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose.
- Received April 16, 2018.
- Revision received June 4, 2018.
- Accepted June 13, 2018.
- 2018 American College of Cardiology Foundation