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Baylous K, Helbock R, Kovarovic B, Anam S, Slepian M, Bluestein D. In silico fatigue optimization of TAVR stent designs with physiological motion in a beating heart model. COMPUTER METHODS AND PROGRAMS IN BIOMEDICINE 2024; 243:107886. [PMID: 37925854 DOI: 10.1016/j.cmpb.2023.107886] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/29/2023] [Revised: 10/17/2023] [Accepted: 10/21/2023] [Indexed: 11/07/2023]
Abstract
BACKGROUND AND OBJECTIVE The rapid expansion of TAVR to younger, low-risk patients raises concerns regarding device durability. Necessarily, extended stent lifetime will become more critical for new generation devices. In vitro methods commonly used for TAVR stent fatigue testing exclude the effects of the beating heart. We present a more realistic in silico stent fatigue analysis utilizing a beating heart model in which TAVR stents experience complex, nonuniform dynamic loading. METHODS Virtual TAVR deployments were simulated in the SIMULIA Living Heart Human Model of a beating heart using stent models of the self-expandable nitinol 26-mm CoreValve and Evolut R devices, and a 27-mm PolyV-2. Stent deformation was monitored over three cardiac cycles, and fatigue resistance was evaluated for the nitinol stents using finite element analysis via ABAQUS/Explicit. The average strain and strain amplitude of each stent element were tracked, and established thresholds were applied to determine potential fatigue failure. Fatigue performance of control stents was compared to parametrically modified models with a 20% increase or decrease in strut width. RESULTS Stents with reduced strut width applied lower radial force against the contracting myocardium of the beating heart, resulting in larger displacements and higher strain values. Formulas relating in vivo strain to stent design do not account for this. In all models, there were elements in which strains exceeded fatigue failure. The PolyV-2 stent had far fewer failing elements since its struts were optimized to reduce the strain in stent joints, achieving better fatigue resistance in the stent crown and waist elements. Different stent sections showed markedly different fatigue resistance due to the varying loading conditions. CONCLUSIONS Our analysis indicates that previous studies underestimate strain amplitudes that may cause stent failure. This study demonstrates the utility of advanced in silico analysis of devices deployed within a beating heart that mimics in vivo loading, offering a cost-effective alternative to human or animal trials and establishing a platform to assess the impact of device design on device durability. The limited fatigue life of TAVR stents indicated here highlights a clinical complication that may eventually develop as younger, lower-risk TAVR patients, age.
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Affiliation(s)
- Kyle Baylous
- Department of Biomedical Engineering, Stony Brook University, Health Sciences Center, Stony Brook, NY 11794-8084, USA
| | - Ryan Helbock
- Department of Biomedical Engineering, Stony Brook University, Health Sciences Center, Stony Brook, NY 11794-8084, USA
| | - Brandon Kovarovic
- Department of Biomedical Engineering, Stony Brook University, Health Sciences Center, Stony Brook, NY 11794-8084, USA
| | - Salwa Anam
- Department of Biomedical Engineering, Stony Brook University, Health Sciences Center, Stony Brook, NY 11794-8084, USA
| | - Marvin Slepian
- Department of Medicine and Biomedical Engineering Sarver Heart Center, University of Arizona, Tucson, AZ 85721, USA
| | - Danny Bluestein
- Department of Biomedical Engineering, Stony Brook University, Health Sciences Center, Stony Brook, NY 11794-8084, USA.
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Oks D, Houzeaux G, Vázquez M, Neidlin M, Samaniego C. Effect of TAVR commissural alignment on coronary flow: A fluid-structure interaction analysis. COMPUTER METHODS AND PROGRAMS IN BIOMEDICINE 2023; 242:107818. [PMID: 37837886 DOI: 10.1016/j.cmpb.2023.107818] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/14/2023] [Revised: 09/07/2023] [Accepted: 09/15/2023] [Indexed: 10/16/2023]
Abstract
BACKGROUND AND OBJECTIVES Coronary obstruction is a complication that may affect patients receiving Transcatheter Aortic Valve Replacement (TAVR), with catastrophic consequences and long-term negative effects. To enable healthy coronary perfusion, it is fundamental to appropriately position the device with respect to the coronary ostia. Nonetheless, most TAVR delivery systems do not control commissural alignment to do so. Moreover, no in silico study has directly assessed the effect of commissural alignment on coronary perfusion. This work aims to evaluate the effect of TAVR commissural alignment on coronary perfusion and device performance. METHODS A two-way computational fluid-structure interaction model is used to predict coronary perfusion at different commissural alignments. Moreover, in each scenario, hemodynamic biomarkers are evaluated to assess device performance. RESULTS Commissural misalignment is shown to reduce the total coronary perfusion by -3.2% and the flow rate to a single coronary branch by -6.8%. It is also observed to impair valvular function by reducing the systolic geometric orifice area by -2.5% and increasing the systolic transvalvular pressure gradients by +5.3% and the diastolic leaflet stresses by +16.0%. CONCLUSIONS The present TAVR patient model indicates that coronary perfusion, hemodynamic and structural performance are minimized when the prosthesis commissures are fully misaligned with the native ones. These results support the importance of enabling axial control in new TAVR delivery catheter systems and defining recommended values of commissural alignment in upcoming clinical treatment guidelines.
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Affiliation(s)
- David Oks
- Barcelona Supercomputing Center, Computer Applications in Science and Engineering, Plaça d'Eusebi Güell, 1-3, 08034, Barcelona, Spain; ELEM Biotech SL, Plaça Pau Vila, 1, Bloc A, Planta 3, Porta 3A1, 08003, Barcelona, Spain.
| | - Guillaume Houzeaux
- Barcelona Supercomputing Center, Computer Applications in Science and Engineering, Plaça d'Eusebi Güell, 1-3, 08034, Barcelona, Spain
| | - Mariano Vázquez
- Barcelona Supercomputing Center, Computer Applications in Science and Engineering, Plaça d'Eusebi Güell, 1-3, 08034, Barcelona, Spain; ELEM Biotech SL, Plaça Pau Vila, 1, Bloc A, Planta 3, Porta 3A1, 08003, Barcelona, Spain
| | - Michael Neidlin
- Department of Cardiovascular Engineering, Institute of Applied Medical Engineering, Medical Faculty, RWTH Aachen University, Pauwelstraße 20, 52074, Aachen, Germany
| | - Cristóbal Samaniego
- Barcelona Supercomputing Center, Computer Applications in Science and Engineering, Plaça d'Eusebi Güell, 1-3, 08034, Barcelona, Spain
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Huang X, Zhang G, Zhou X, Yang X. A review of numerical simulation in transcatheter aortic valve replacement decision optimization. Clin Biomech (Bristol, Avon) 2023; 106:106003. [PMID: 37245279 DOI: 10.1016/j.clinbiomech.2023.106003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/10/2023] [Revised: 05/08/2023] [Accepted: 05/15/2023] [Indexed: 05/30/2023]
Abstract
BACKGROUND Recent trials indicated a further expansion of clinical indication of transcatheter aortic valve replacement to younger and low-risk patients. Factors related to longer-term complications are becoming more important for use in these patients. Accumulating evidence indicates that numerical simulation plays a significant role in improving the outcome of transcatheter aortic valve replacement. Understanding mechanical features' magnitude, pattern, and duration is a topic of ongoing relevance. METHODS We searched the PubMed database using keywords such as "transcatheter aortic valve replacement" and "numerical simulation" and reviewed and summarized relevant literature. FINDINGS This review integrated recently published evidence into three subtopics: 1) prediction of transcatheter aortic valve replacement outcomes through numerical simulation, 2) implications for surgeons, and 3) trends in transcatheter aortic valve replacement numerical simulation. INTERPRETATIONS Our study offers a comprehensive overview of the utilization of numerical simulation in the context of transcatheter aortic valve replacement, and highlights the advantages, potential challenges from a clinical standpoint. The convergence of medicine and engineering plays a pivotal role in enhancing the outcomes of transcatheter aortic valve replacement. Numerical simulation has provided evidence of potential utility for tailored treatments.
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Affiliation(s)
- Xuan Huang
- Department of Cardiovascular Surgery, West China Biomedical Big Data Center, West China Hospital/West China School of Medicine, Sichuan University, Chengdu, Sichuan, China; Med-X Center for Informatics, Sichuan University, Chengdu, Sichuan, China
| | - Guangming Zhang
- Center for Computational Systems Medicine, School of Biomedical Informatics, The University of Texas Health Science Center at Houston, Houston, TX 77030, USA
| | - Xiaobo Zhou
- Center for Computational Systems Medicine, School of Biomedical Informatics, The University of Texas Health Science Center at Houston, Houston, TX 77030, USA; McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, TX 77030, USA; School of Dentistry, The University of Texas Health Science Center at Houston, Houston, TX 77030, USA
| | - Xiaoyan Yang
- Department of Cardiovascular Surgery, West China Biomedical Big Data Center, West China Hospital/West China School of Medicine, Sichuan University, Chengdu, Sichuan, China; Med-X Center for Informatics, Sichuan University, Chengdu, Sichuan, China.
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4
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Bressloff NW. Leaflet Stresses During Full Device Simulation of Crimping to 6 mm in Transcatheter Aortic Valve Implantation, TAVI. Cardiovasc Eng Technol 2022; 13:735-750. [PMID: 35230649 PMCID: PMC9616759 DOI: 10.1007/s13239-022-00614-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/03/2021] [Accepted: 02/02/2022] [Indexed: 01/27/2023]
Abstract
BACKGROUND With continuing growth in transcatheter aortic valve implantation for the treatment of a failing aortic valve, there is increasing interest in prosthetic valve durability and the potential damage caused to leaflets by stress. Whilst most available research into the computational prediction of leaflet stresses using finite element analysis, FEA, has focussed on variations during dynamic loading, very little appears to have been reported for the impact of crimping, even though awareness of this effect is widespread. Potentially, this has been due to the difficulty of performing full model simulations of crimping to clinically meaningful diameters. METHOD A full model comprising a self-expanding frame, skirt and leaflets has been developed and crimped to a final diameter of 6 mm. A detailed description is provided of the FEA setup, emphasising the importance of the skirt definition needed to successfully crimp to this small diameter. Then, an analysis of leaflet folding and stresses is presented, particularly with respect to the differences produced between leaflet thicknesses of 0.20, 0.25 and 0.30 mm and for bioprosthetic and polymeric leaflet material models. RESULTS In all cases, peak stresses occurred close to the modelled suture lines joining the leaflets and the skirt and high stresses were also present along axially aligned folds in the leaflets. Stresses were lower for the polymeric leaflets. CONCLUSION Successful simulation of crimping requires a finely resolved skirt mesh. Leaflet stresses during crimping are dependent on leaflet thickness, material properties and the ratio of leaflet volume to the available volume inside the crimped valve.
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Affiliation(s)
- N. W. Bressloff
- grid.5491.90000 0004 1936 9297Faculty of Engineering & Physical Sciences, University of Southampton, Boldrewood Innovation Campus, Southampton, SO16 7QF UK
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Xuan Y, Dvir D, Wisneski AD, Wang Z, Ye J, Guccione JM, Ge L, Tseng EE. Impact of Transcatheter Aortic Valve Size on Leaflet Stresses: Implications for Durability and Optimal Grey Zone Sizing. ACTA ACUST UNITED AC 2021; 6:64-71. [PMID: 34708162 DOI: 10.4244/aij-d-19-00005] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Aims As indications for transcatheter aortic valve replacement (TAVR) continue to expand towards younger and lower-risk patients, durability becomes an increasingly important question. Durability decreases as leaflet stresses increase, but the impact of transcatheter heart valve (THV) size on stress is unknown. Patient annulus sizes can fall within "grey zones" between 2 TAVR sizes. Our aim was to examine the impact of balloon-expandable THV size on leaflet stresses. Methods and Results SapienXT 23mm, 26mm, and 29mm sizes (Edwards Lifesciences, Inc) underwent micro-computed tomography scanning to create THV computational models then loaded to systemic pressure using finite element software. THV leaflet maximum principal stresses were 1.69MPa (23mm), 1.70MPa (26mm), and 2.12MPa (29mm) at mean arterial pressure. For intermediate annulus sizes, undersizing the larger THV yielded lower leaflet stresses than oversizing the smaller THV. Conclusions Increasing THV size yielded greater leaflet maximum principal stresses, which could suggest a relationship between THV size and long-term durability.. For annulus "grey zones" sizes, undersizing the larger THV resulted in lower leaflet stresses than oversizing the smaller THV. These results may influence optimal device sizing, as THV durability remains an important, unanswered question.
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Affiliation(s)
- Yue Xuan
- Department of Surgery, University of California San Francisco and San Francisco VA Medical Centers, San Francisco, CA
| | - Danny Dvir
- Division of Cardiology, University of Washington, Seattle, WA
| | - Andrew D Wisneski
- Department of Surgery, University of California San Francisco and San Francisco VA Medical Centers, San Francisco, CA
| | - Zhongjie Wang
- Department of Surgery, University of California San Francisco and San Francisco VA Medical Centers, San Francisco, CA
| | - Jian Ye
- Division of Cardiovascular Surgery, St. Paul's Hospital and Vancouver General Hospital, Vancouver, BC, Canada
| | - Julius M Guccione
- Department of Surgery, University of California San Francisco and San Francisco VA Medical Centers, San Francisco, CA
| | - Liang Ge
- Department of Surgery, University of California San Francisco and San Francisco VA Medical Centers, San Francisco, CA
| | - Elaine E Tseng
- Department of Surgery, University of California San Francisco and San Francisco VA Medical Centers, San Francisco, CA
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Xuan Y, Dvir D, Wang Z, Ye J, Guccione JM, Ge L, Tseng EE. Stent and leaflet stresses across generations of balloon-expandable transcatheter aortic valves. Interact Cardiovasc Thorac Surg 2020; 30:879-886. [PMID: 32248231 PMCID: PMC7248644 DOI: 10.1093/icvts/ivaa037] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2019] [Revised: 01/10/2020] [Accepted: 02/04/2020] [Indexed: 12/23/2022] Open
Abstract
OBJECTIVES Transcatheter aortic valve replacement (TAVR) is established therapy for severe aortic stenosis patients with intermediate-, high- and prohibitive-risk for surgery. A significant challenge when expanding TAVR to low-risk and younger patients is the unknown long-term durability. High leaflet stresses have been associated with surgical bioprosthetic valve degeneration. In this study, we examined the impact of changes in valve design across 3 generations of same-sized TAVR devices on stent and leaflet stresses. METHODS The 26-mm Edwards SAPIEN, 23, 26 and 29 mm SAPIEN XT (XT) and 26 mm SAPIEN 3 (S3) (n = 1 each) underwent micro-computed tomography (micro-CT) scanning. Dynamic finite element computational simulations of 23-26 mm SAPIEN, 23-29 mm XT and 23-29 mm S3 were performed with physiological loading and micro-CT or scaled geometries. RESULTS Peak stresses were concentrated in the commissure area and along the bottom of the suture, representing areas most likely to develop structural valve degeneration across TAVR generations. Latest-generation S3 showed greatest 99th percentile principal stress on commissural leaflets for 26 and 29 mm, and increased stresses over XT for 23 mm. Percentage of higher stress areas within the leaflets steadily increased across generations, 3.8%, 3.9% and 5.7%, respectively, for 26 mm SAPIEN, XT and S3 with similar trend for 29-mm valves. CONCLUSIONS Using computational simulations based on high-fidelity modelling of balloon-expandable TAVRs, our study demonstrated that maximum stress areas existed in similar leaflet locations across SAPIEN generations, while the latest model S3 had the highest magnitude for both 26- and 29-mm valves. S3 also had the largest area of higher stresses than other generations, which would be prone to degeneration. Our study coupled with future long-term clinical outcomes >10 years will provide insight on biomechanics of TAVR degeneration.
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Affiliation(s)
- Yue Xuan
- Division of Cardiothoracic Surgery, University of California San Francisco and San Francisco VA Medical Center, San Francisco, CA, USA
| | - Danny Dvir
- Division of Cardiology, University of Washington, Seattle, WA, USA
| | - Zhongjie Wang
- Division of Cardiothoracic Surgery, University of California San Francisco and San Francisco VA Medical Center, San Francisco, CA, USA
| | - Jian Ye
- Department of Surgery, St Paul’s Hospital, Vancouver, BC, Canada
| | - Julius M Guccione
- Division of Cardiothoracic Surgery, University of California San Francisco and San Francisco VA Medical Center, San Francisco, CA, USA
| | - Liang Ge
- Division of Cardiothoracic Surgery, University of California San Francisco and San Francisco VA Medical Center, San Francisco, CA, USA
| | - Elaine E Tseng
- Division of Cardiothoracic Surgery, University of California San Francisco and San Francisco VA Medical Center, San Francisco, CA, USA
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Luraghi G, Migliavacca F, García-González A, Chiastra C, Rossi A, Cao D, Stefanini G, Rodriguez Matas JF. On the Modeling of Patient-Specific Transcatheter Aortic Valve Replacement: A Fluid-Structure Interaction Approach. Cardiovasc Eng Technol 2019; 10:437-455. [PMID: 31309527 DOI: 10.1007/s13239-019-00427-0] [Citation(s) in RCA: 62] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/14/2019] [Accepted: 07/04/2019] [Indexed: 12/14/2022]
Abstract
PURPOSE Transcatheter aortic valve replacement (TAVR) is a minimally invasive treatment for high-risk patients with aortic diseases. Despite its increasing use, many influential factors are still to be understood and require continuous investigation. The best numerical approach capable of reproducing both the valves mechanics and the hemodynamics is the fluid-structure interaction (FSI) modeling. The aim of this work is the development of a patient-specific FSI methodology able to model the implantation phase as well as the valve working conditions during cardiac cycles. METHODS The patient-specific domain, which included the aortic root, native valve and calcifications, was reconstructed from CT images, while the CAD model of the device, metallic frame and pericardium, was drawn from literature data. Ventricular and aortic pressure waveforms, derived from the patient's data, were used as boundary conditions. The proposed method was applied to two real clinical cases, which presented different outcomes in terms of paravalvular leakage (PVL), the main complication after TAVR. RESULTS The results confirmed the clinical prognosis of mild and moderate PVL with coherent values of regurgitant volume and effective regurgitant orifice area. Moreover, the final release configuration of the device and the velocity field were compared with postoperative CT scans and Doppler traces showing a good qualitative and quantitative matching. CONCLUSION In conclusion, the development of realistic and accurate FSI patient-specific models can be used as a support for clinical decisions before the implantation.
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Affiliation(s)
- Giulia Luraghi
- Laboratory of Biological Structure Mechanics (LaBS), Department of Chemistry, Materials and Chemical Engineering "Giulio Natta", Piazza L. da Vinci 32, 20133, Milan, Italy.
| | - Francesco Migliavacca
- Laboratory of Biological Structure Mechanics (LaBS), Department of Chemistry, Materials and Chemical Engineering "Giulio Natta", Piazza L. da Vinci 32, 20133, Milan, Italy
| | - Alberto García-González
- Laboratori de Càlcul Numèric (LaCàN), E.T.S. de Ingenieros de Caminos, Canales y Puertos, Universitat Politècnica de Catalunya (UPC), Jordi Girona 1-3, 08034, Barcelona, Spain
| | - Claudio Chiastra
- Laboratory of Biological Structure Mechanics (LaBS), Department of Chemistry, Materials and Chemical Engineering "Giulio Natta", Piazza L. da Vinci 32, 20133, Milan, Italy.,PoliToBIOMed Lab, Department of Mechanical and Aerospace Engineering, Politecnico di Torino, Corso Duca degli Abruzzi 24, 10129, Turin, Italy
| | - Alexia Rossi
- Department of Biomedical Sciences, Humanitas University, via Rita Levi Montalcini 4, 20090, Pieve Emanuele, MI, Italy
| | - Davide Cao
- Department of Biomedical Sciences, Humanitas University, via Rita Levi Montalcini 4, 20090, Pieve Emanuele, MI, Italy
| | - Giulio Stefanini
- Department of Biomedical Sciences, Humanitas University, via Rita Levi Montalcini 4, 20090, Pieve Emanuele, MI, Italy
| | - Jose Felix Rodriguez Matas
- Laboratory of Biological Structure Mechanics (LaBS), Department of Chemistry, Materials and Chemical Engineering "Giulio Natta", Piazza L. da Vinci 32, 20133, Milan, Italy
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Navarese EP, Andreotti F, Kołodziejczak M, Wanha W, Lauten A, Veulemans V, Frediani L, Kubica J, de Cillis E, Wojakowski W, Ochala A, Zeus T, Bortone A, Buffon A, Jung C, Pestrichella V, Gurbel PA. Age-Related 2-Year Mortality After Transcatheter Aortic Valve Replacement: the YOUNG TAVR Registry. Mayo Clin Proc 2019; 94:1457-1466. [PMID: 30824280 DOI: 10.1016/j.mayocp.2019.01.008] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/25/2018] [Revised: 12/21/2018] [Accepted: 01/02/2019] [Indexed: 10/27/2022]
Abstract
OBJECTIVE To comparatively assess the natural history of patients of different ages undergoing transcatheter aortic valve replacement (TAVR). PATIENTS AND METHODS For this study, we used the YOUNG TAVR, an international, multicenter registry investigating mortality trends up to 2 years in patients with aortic valve stenosis treated by TAVR, classified according to 3 prespecified age groups: 75 years or younger (n=179), 76 to 86 years (n=602), and older than 86 years (n=221). A total of 1002 patients undergoing TAVR were included. Demographic, clinical, and outcome data in the youngest group were compared with those of patients 76 to 86 years and older than 86 years. Patients were followed up for up to 2 years. RESULTS Compared with patients 75 years or younger (reference group), patients aged 76 to 86 years and older than 86 years had nonsignificantly different 30-day mortality (odds ratio, 0.76; 95% CI, 0.41-1.38; P=.37 and odds ratio, 1.27; 95% CI, 0.62-2.60; P=.51, respectively) and 1-year mortality (hazard ratio (HR), 0.72; 95% CI, 0.48-1.09; P=.12 and HR, 1.11; 95% CI, 0.88-1.40; P=.34, respectively). Mortality at 2 years was significantly lower among patients aged 76 to 86 years (HR, 0.62; 95% CI, 0.42-0.90; P=.01) but not among the older group (HR, 1.06; 95% CI, 0.68-1.67; P=.79). The Society of Thoracic Surgeons 30-day mortality score was lower in younger patients who, however, had a significantly higher prevalence of chronic obstructive pulmonary disease (P=.005 vs the intermediate group and P=.02 vs the older group) and bicuspid aortic valves (P=.02 vs both older groups), larger left ventricles, and lower ejection fractions. CONCLUSION In the present registry, mortality at 2 years after TAVR among patients 75 years or younger was higher compared with that of patients aged 75 to 86 years and was not markedly different from that of patients older than 86 years. The findings are attributable at least in part to a greater burden of comorbidities in the younger age group that are not entirely captured by current risk assessment tools.
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Affiliation(s)
- Eliano P Navarese
- Interventional Cardiology and Cardiovascular Medicine Research, Mater Dei Hospital, and SIRIO MEDICINE network, Bari, Italy; Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Canada; Cardiovascular Institute, Ludwik Rydygier Collegium Medicum, Nicolaus Copernicus University, Bydgoszcz, Poland.
| | - Felicita Andreotti
- Institute of Cardiology, Fondazione Policlinico Universitario Agostino Gemelli, IRCCS, Catholic University Medical School, Rome, Italy
| | - Michalina Kołodziejczak
- Cardiovascular Institute, Ludwik Rydygier Collegium Medicum, Nicolaus Copernicus University, Bydgoszcz, Poland
| | - Wojciech Wanha
- Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Canada; Division of Cardiology and Structural Heart Diseases, Medical University of Silesia, Katowice, Poland
| | - Alexander Lauten
- Division of Cardiology and Structural Heart Diseases, Medical University of Silesia, Katowice, Poland; Department of Cardiology, Charité-Universitätsmedizin Berlin, German Centre for Cardiovascular Research (DZHK), University Heart Center, Berlin, Germany
| | - Verena Veulemans
- Department of Cardiology, Pulmonology and Vascular Medicine, Heinrich-Heine University, Düsseldorf, Germany
| | - Lara Frediani
- Department of Cardiology, Azienda Usl Toscana Nord-Ovest Cardiologia UTIC ed Emodinamica-Ospedali Riuniti di Livorno, Italy
| | - Jacek Kubica
- Cardiovascular Institute, Ludwik Rydygier Collegium Medicum, Nicolaus Copernicus University, Bydgoszcz, Poland
| | - Emanuela de Cillis
- Department of Emergency and Organ Transplantation, Section of Cardiovascular Diseases, School of Medicine, University of Bari, Italy
| | - Wojciech Wojakowski
- Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Canada; Division of Cardiology and Structural Heart Diseases, Medical University of Silesia, Katowice, Poland
| | - Andrzej Ochala
- Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Canada; Division of Cardiology and Structural Heart Diseases, Medical University of Silesia, Katowice, Poland
| | - Tobias Zeus
- Department of Cardiology, Pulmonology and Vascular Medicine, Heinrich-Heine University, Düsseldorf, Germany
| | - Alessandro Bortone
- Department of Emergency and Organ Transplantation, Section of Cardiovascular Diseases, School of Medicine, University of Bari, Italy
| | - Antonio Buffon
- Institute of Cardiology, Fondazione Policlinico Universitario Agostino Gemelli, IRCCS, Catholic University Medical School, Rome, Italy
| | - Christian Jung
- Department of Cardiology, Pulmonology and Vascular Medicine, Heinrich-Heine University, Düsseldorf, Germany
| | - Vincenzo Pestrichella
- Interventional Cardiology and Cardiovascular Medicine Research, Mater Dei Hospital, and SIRIO MEDICINE network, Bari, Italy
| | - Paul A Gurbel
- INOVA Heart and Vascular Institute, Fairfax, VA; Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Canada
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9
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Study on the Accuracy of Structural and FSI Heart Valves Simulations. Cardiovasc Eng Technol 2018; 9:723-738. [DOI: 10.1007/s13239-018-00373-3] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/08/2018] [Accepted: 08/11/2018] [Indexed: 12/29/2022]
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10
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Xuan Y, Dvir D, Wang Z, Mizoguchi T, Ye J, Guccione JM, Ge L, Tseng EE. Stent and leaflet stresses in 26-mm, third-generation, balloon-expandable transcatheter aortic valve. J Thorac Cardiovasc Surg 2018; 157:528-536. [PMID: 30041923 DOI: 10.1016/j.jtcvs.2018.04.115] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/28/2017] [Revised: 04/12/2018] [Accepted: 04/23/2018] [Indexed: 10/14/2022]
Abstract
OBJECTIVES Transcatheter aortic valve replacement has proven successful in treating intermediate-risk, high-risk, and inoperable patients with severe aortic stenosis. Third-generation, balloon-expandable transcatheter aortic valves were developed with an outer sealing skirt to reduce paravalvular leakage. As transcatheter aortic valve replacement use expands, long-term durability questions remain. Valve design influences durability, where regions of increased leaflet stress are vulnerable to early degeneration. However, third-generation transcatheter aortic valve stresses are unknown. Our goals were to determine the stent and leaflet stresses of third-generation, balloon-expandable transcatheter aortic valves. METHODS The commercial 26-mm Edwards SAPIEN 3 valve (Edwards Lifesciences, Inc, Irvine, Calif) underwent high-resolution micro-computed tomography scanning to develop a precise 3-dimensional geometric mesh of the stent and valve. Leaflet material properties were obtained from surgical bioprostheses, and stent material properties were based on cobalt-chromium. Simulations of systemic pressure loading were performed, and stress was calculated using finite element analyses. RESULTS At diastole, maximum and minimum principal stresses on transcatheter aortic valve leaflets were 2.7 MPa and -0.47 MPa, respectively. Peak leaflet stresses were observed at upper leaflet commissures, at their connection to the stent. Maximum and minimum principal stresses for the stent were 38.2 MPa and -44.4 MPa, respectively, at 80 mm Hg and were located just below the commissural stent. CONCLUSIONS Stress analysis of the 26-mm SAPIEN 3 valve using exact geometry from high-resolution scans demonstrated that peak stresses for both transcatheter aortic valve stent and leaflets were present at commissural tips where leaflets were attached. These regions would be most likely to initiate degeneration. The Dacron skirt had minimal effect on stresses on leaflets and stent.
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Affiliation(s)
- Yue Xuan
- Department of Surgery, University of California San Francisco and San Francisco VA Medical Centers, San Francisco, Calif
| | - Danny Dvir
- Division of Cardiology, University of Washington, Seattle, Wash
| | - Zhongjie Wang
- Department of Surgery, University of California San Francisco and San Francisco VA Medical Centers, San Francisco, Calif
| | - Trek Mizoguchi
- Department of Surgery, University of California San Francisco and San Francisco VA Medical Centers, San Francisco, Calif
| | - Jian Ye
- Division of Cardiovascular Surgery, St Paul's Hospital and Vancouver General Hospital, Vancouver, British Columbia, Canada
| | - Julius M Guccione
- Department of Surgery, University of California San Francisco and San Francisco VA Medical Centers, San Francisco, Calif
| | - Liang Ge
- Department of Surgery, University of California San Francisco and San Francisco VA Medical Centers, San Francisco, Calif
| | - Elaine E Tseng
- Department of Surgery, University of California San Francisco and San Francisco VA Medical Centers, San Francisco, Calif.
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