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The Process of TAVR Development. Stanton J Rowe CEO NXT Biomedical. Disclosure Statement of Financial Interest.
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The Process of TAVR Development Stanton J Rowe CEO NXT Biomedical
Disclosure Statement of Financial Interest I, Stanton Rowe, DO have a financial interest/arrangement or affiliation with one or more organizations that could be perceived as a real or apparent conflict of interest in the context of the subject of this presentation. Edwards Lifesciences shareholder, stock options
OK, you and your friends have looked into the future, and believe that you have the next big idea in TAVR…
(2009 to 2011) (2012 to 2015) Virginia Cardiac Services Quality Initiative database.
Areas to Improve • Vascular complications • Profile and vascular closure devices • Prolonged ventilation • General anesthesia, COPD • Atrial fibrillation • Age related incidence; higher age in TAVR • Discharge to facility • Multifactoral • Durability • How would you prove better durability with the least clinical implant duration?
Similarities and DissimilariesSurgical versus TAVR Valves • Similarities • Exposed largely to the same boundary conditions • Slight differences in removal of calcium in surgery • Expectations of durability are largely the same • Surgical valves tend to be placed in younger patients • VinV has changed the implications of late valve degeneration • TAVR tissues and SHV tissues are similar • Flow dynamics requirements are the same • Host response to implants are the same (early leaflet thickening)
Tissue Validation • Fixation Chemistry • Mechanical methods applied during Chemical Fixation • Testing techniques to assess Biomechanics • Uniaxial • Biaxial • Tensile stress/strain and bending properties • Crimp • Characterize the condition of leaflets, skirt, and attachment after loading, tracking, and deployment. In the clinical setting, crimp duration can vary therefore these studies should consider worst case crimp durations. • All testing for valve performance should be conducted on devices which have been crimped prior to testing.
Fatigue Testing: Accelerated Wear and Dynamic Failure Mode • 200x106 cycles to simulate five years of valve implant duration • Peak closed valve pressure difference of 90 +20/-0 mmHg for Aortic valves • Peak closed valve pressure difference of 120 +20/-0 mmHg for Mitral valves • Pressures differences should be continuously monitored throughout the duration of the test • Assessments: • Hydrodynamic assessments at intervals throughout the test to determine changes in performance • Visually examined every 25 x 106 cycles, or until failure • Macroscopic damage: • Abrasion, holes, tears, delamination, fraying, coaptation, dehiscence.
Hydrodynamic Testing • Pulsatile Flow Pressure drop and Pulsatile Flow Regurgitation • Annulus shape, under-deployment must be accounted for in the assessments of flow performance. • Broad range of cardiac conditions expected in the patient population (i.e. varied flow rates, pressures and beat rates) • Flow Visualization • Assess the flow characteristics of the valve using flow visualization or turbulence measurement techniques to characterize any induced jets, flow stasis, leaflet kinematics which might lead to early deterioration in-vivo. not recognized through standard pulsatile flow testing.
Delivery Systems • A low delivery catheter profile = <14Fr OD • Atraumatic tracking = optimum tracking and flexibility through the vasculature • Cost effective • Re-capturability and Re-positionability, for self-expanding frame based technologies • Ability to orient the rotational alignment with native commissures (Clocking) • Intuitive design = ease of use • Clear/smart position signaling • Marker-bands / clear visual markers under fluoroscopy • Stability during deployment • Ergonomic • Deployment time < 1min • Efficient or minimized loading (into Delivery system) process required for delivery of the device • Material stability • Shelf life > 2 years • Guide-wire compatibility • Smart packaging e.g. work with the delivery system for TAV loading
Regulatory • IDE • First in Human (FIH) • Early Feasibility Study (EFS) • Traditional Feasibility • Pivotal Clinical Trial (TAVI vs TAVI) • (CE Mark) • Pivotal Trial (CE Mark) • Design Dossier
Conclusion • TAVR has changed the treatment paradigm for aortic stenosis • It is a growing attractive space for development • However, the window for improving TAVR is narrow, the development time and cost are extensive, and established companies continue to raise the bar • The pathway is well established