The goal is to inform in depth on transcatheter aortic valve replacement (TAVR) prosthesis mechanical behavior, depending on frame type, design, and size, and how it crucially impacts the oversizing issue in clinical use, and ultimately the procedure outcome. Transcatheter aortic valve replacement is an established therapy for high-risk patients suffering from aortic stenosis, and the indication for TAVR is progressively expanding to intermediate-risk patients. Choosing the optimal oversizing degree is crucial to safely anchor the TAVR valve—which involves limiting the risks for embolism, aortic regurgitation, conductance disturbance, or annulus rupture—and to increase the valve prosthesis performance. The radial force (RF) profiles of five TAVR prostheses were measured in vitro: the CoreValve 23 and 26 (Medtronic, Minneapolis, MN), the Acurate neo S (Symetis, Écublens, Vaud, Switzerland), and the SAPIEN XT 23 and 26 (Edwards Lifesciences, Irvine, CA). Measurements were run with the RX Machine equipment (Machine Solutions Inc., Flagstaff, AZ), which is used in ISO standard tests for intravascular stents. Test protocols were adapted for TAVR prostheses. With the prostheses RF profiles’ results, mechanical behavior differences could be described and discussed in terms of oversizing strategy and clinical impact for all five valves. Besides, crossing the prostheses’ RF profiles with their recommended size windows made the assessment of borderline size cases possible and helped analyze the risks when accurate measurement of patient aortic annulus proves difficult. The prostheses’ RF profiles bring new support in clinical decision-making for valve type and size in patients.
From the *Department of Cardiovascular Engineering, Institute of Applied Medical Engineering, Helmholtz Institute, RWTH Aachen University, Aachen, Germany
†Department for Thoracic and Cardiovascular Surgery, Heart and Diabetes Center NRW, Ruhr University Bochum, Bad Oeynhausen, Germany.
Submitted for consideration December 2016; accepted for publication in revised form June 2017.
Stephan Ensminger and Ulrich Steinseifer (senior authors) contributed equally to this work.
Disclosure: Buntaro Fujita received travel compensation from Edwards Lifesciences and Symetis. Stephan Ensminger is a Proctor and Consultant for Edwards Lifesciences and Proctor and member of SAB for JenaValve, and received Speaker Honoraria and travel compensation from Edwards Lifesciences, JenaValve, and Symetis. Ulrich Steinseifer is a Consultant for JenaValve and Biotronik. The other authors have no conflicts of interest to report.
Correspondence: Sandrine Egron, Department of Cardiovascular Engineering, Institute of Applied Medical Engineering, Helmholtz Institute, RWTH Aachen University, Aachen, Germany. Email: email@example.com.