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Flieder T, Blaesen S, Schulte K, Blasberg J, Lauenroth V, Knabbe C, Schramm R, Morshuis M, Gummert J, Birschmann I. Aspirin resistance in patients with ventricular assist devices: A follow-up study. Artif Organs 2024; 48:781-788. [PMID: 38553978 DOI: 10.1111/aor.14742] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2023] [Revised: 02/07/2024] [Accepted: 02/26/2024] [Indexed: 06/12/2024]
Abstract
BACKGROUND Despite combined anticoagulation therapy consisting of a vitamin K antagonist and an antiplatelet agent, thromboembolic complications often occur in patients with a left ventricular assist device (LVAD). In addition, bleeding events are also common. Resistance to antiplatelet drugs is a well-known phenomenon; however, the utilization of laboratory chemistry testing for the presence of such resistance, and then switching therapy, is controversial. METHODS We tested 132 patients with LVAD (HeartWare n = 57, HeartMate II n = 22, HeartMate 3 n = 53) on acetylsalicylic acid (ASA) therapy for resistance and followed them for a maximum of 7 years regarding pump thrombosis. Light transmission aggregometry (LTA) and impedance aggregometry (IPA) were performed for testing platelet function. RESULTS We could show that patients with ASA resistance displayed an increased risk of pump thrombosis, regardless of the test used (LTA: OR = 6.20, CI [1.86-20.64], p = 0.003; IPA: OR = 12.14, CI [3.00-49.07], p < 0.001). In patients with a HeartMate 3, we could not detect any pump thrombosis associated with aspirin resistance. Furthermore, there was no significant difference in bleeding events between patients with ASA resistance and ASA responders. CONCLUSION Laboratory testing of ASA resistance seems to be a good tool to detect an increased risk of pump thrombosis, at least for patients with a HeartWare or HeartMate II. The extent to which these thromboses can be prevented with a change of medication has to be investigated in further studies. No pump thrombosis was detected in patients with a HeartMate 3, and the question should be asked as to what constellation of underlying and concomitant diseases must be present to justify ASA therapy for these patients.
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Affiliation(s)
- Tobias Flieder
- Herz- und Diabeteszentrum Nordrhein-Westfalen, Universitätsklinik der Ruhr-Universität Bochum, Institut für Laboratoriums- und Transfusionsmedizin, Bad Oeynhausen, Germany
| | - Sonja Blaesen
- Herz- und Diabeteszentrum Nordrhein-Westfalen, Universitätsklinik der Ruhr-Universität Bochum, Institut für Laboratoriums- und Transfusionsmedizin, Bad Oeynhausen, Germany
| | - Katrin Schulte
- Herz- und Diabeteszentrum Nordrhein-Westfalen, Universitätsklinik der Ruhr-Universität Bochum, Institut für Laboratoriums- und Transfusionsmedizin, Bad Oeynhausen, Germany
| | - Jost Blasberg
- Institut für Psychosoziale Medizin, Psychotherapie und Psychoonkologie, Universitätsklinikum Jena, Friedrich-Schiller-Universität, Jena, Germany
| | - Volker Lauenroth
- Herz- und Diabeteszentrum Nordrhein-Westfalen, Universitätsklinik der Ruhr-Universität Bochum, Klinik für Thorax- und Kardiovaskularchirurgie, Bad Oeynhausen, Germany
| | - Cornelius Knabbe
- Herz- und Diabeteszentrum Nordrhein-Westfalen, Universitätsklinik der Ruhr-Universität Bochum, Institut für Laboratoriums- und Transfusionsmedizin, Bad Oeynhausen, Germany
| | - René Schramm
- Herz- und Diabeteszentrum Nordrhein-Westfalen, Universitätsklinik der Ruhr-Universität Bochum, Klinik für Thorax- und Kardiovaskularchirurgie, Bad Oeynhausen, Germany
| | - Michiel Morshuis
- Herz- und Diabeteszentrum Nordrhein-Westfalen, Universitätsklinik der Ruhr-Universität Bochum, Klinik für Thorax- und Kardiovaskularchirurgie, Bad Oeynhausen, Germany
| | - Jan Gummert
- Herz- und Diabeteszentrum Nordrhein-Westfalen, Universitätsklinik der Ruhr-Universität Bochum, Klinik für Thorax- und Kardiovaskularchirurgie, Bad Oeynhausen, Germany
| | - Ingvild Birschmann
- Herz- und Diabeteszentrum Nordrhein-Westfalen, Universitätsklinik der Ruhr-Universität Bochum, Institut für Laboratoriums- und Transfusionsmedizin, Bad Oeynhausen, Germany
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Straccia A, Chassagne F, Barbour MC, Beckman J, Li S, Mahr C, Aliseda A. A Computational Investigation of the Effects of Temporal Synchronization of Left Ventricular Assist Device Speed Modulation with the Cardiac Cycle on Intraventricular Hemodynamics. Ann Biomed Eng 2024; 52:1763-1778. [PMID: 38517620 DOI: 10.1007/s10439-024-03489-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2023] [Accepted: 03/07/2024] [Indexed: 03/24/2024]
Abstract
Patients with advanced heart failure are implanted with a left ventricular assist device (LVAD) as a bridge-to-transplantation or destination therapy. Despite advances in pump design, the risk of stroke remains high. LVAD implantation significantly alters intraventricular hemodynamics, where regions of stagnation or elevated shear stresses promote thrombus formation. Third generation pumps incorporate a pulsatility mode that modulates rotational speed of the pump to enhance in-pump washout. We investigated how the timing of the pulsatility mode with the cardiac cycle affects intraventricular hemodynamic factors linked to thrombus formation. Computational fluid dynamics simulations with Lagrangian particle tracking to model platelet behavior in a patient-specific left ventricle captured altered intraventricular hemodynamics due to LVAD implantation. HeartMate 3 incorporates a pulsatility mode that modulates the speed of the pump every two seconds. Four different timings of this pulsatility mode with respect to the cardiac cycle were investigated. A strong jet formed between the mitral valve and inflow cannula. Blood stagnated in the left ventricular outflow tract beneath a closed aortic valve, in the near-wall regions off-axis of the jet, and in a large counterrotating vortex near the anterior wall. Computational results showed good agreement with particle image velocimetry results. Synchronization of the pulsatility mode with peak systole decreased stasis, reflected in the intraventricular washout of virtual contrast and Lagrangian particles over time. Temporal synchronization of HeartMate 3 pulsatility with the cardiac cycle reduces intraventricular stasis and could be beneficial for decreasing thrombogenicity.
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Affiliation(s)
- Angela Straccia
- Department of Mechanical Engineering, University of Washington, Seattle, WA, USA.
| | | | - Michael C Barbour
- Department of Mechanical Engineering, University of Washington, Seattle, WA, USA
| | - Jennifer Beckman
- Division of Cardiology, University of Washington, Seattle, WA, USA
| | - Song Li
- Institute for Advanced Cardiac Care, Medical City Healthcare, Dallas, TX, USA
| | - Claudius Mahr
- Institute for Advanced Cardiac Care, Medical City Healthcare, Dallas, TX, USA
| | - Alberto Aliseda
- Department of Mechanical Engineering, University of Washington, Seattle, WA, USA
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3
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Lv S, He ZP, Liu GM, Hu SS. A multi-constituent model for assessing the effect of impeller shroud on the thrombosis potential of a centrifugal blood pump. Int J Artif Organs 2024; 47:269-279. [PMID: 38506302 DOI: 10.1177/03913988241239456] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/21/2024]
Abstract
Centrifugal blood pumps can be used for treating heart failure patients. However, pump thrombosis has remained one of the complications that trouble clinical treatment. This study analyzed the effect of impeller shroud on the thrombosis risk of the blood pump, and predicted areas prone to thrombosis. Multi-constituent transport equations were presented, considering mechanical activation and biochemical activation. It was found that activated platelets concentration can increase with shear stress and adenosine diphosphate(ADP) concentration increasing, and the highest risk of thrombosis inside the blood pump was under extracorporeal membrane oxygenation (ECMO) mode. Under the same condition, ADP concentration and thrombosis index of semi-shroud impeller can increase by 7.3% and 7.2% compared to the closed-shroud impeller. The main reason for the increase in thrombosis risk was owing to elevated scalar shear stress and more coagulation promoting factor-ADP released. The regions with higher thrombosis potential were in the center hole, top and bottom clearance. As a novelty, the findings revealed that impeller shroud can influence mechanical and biochemical activation factors. It is useful for identifying potential risk regions of thrombus formation based on relative comparisons.
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Affiliation(s)
- Shen Lv
- Shenzhen Key Laboratory of Cardiovascular Disease, Fuwai Hospital Chinese Academy of Medical Sciences, Shenzhen, Shenzhen, Guangdong Province, China
| | - Zhi-Peng He
- Shenzhen Key Laboratory of Cardiovascular Disease, Fuwai Hospital Chinese Academy of Medical Sciences, Shenzhen, Shenzhen, Guangdong Province, China
| | - Guang-Mao Liu
- Shenzhen Key Laboratory of Cardiovascular Disease, Fuwai Hospital Chinese Academy of Medical Sciences, Shenzhen, Shenzhen, Guangdong Province, China
- State Key Laboratory of Cardiovascular Disease, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Sheng-Shou Hu
- Shenzhen Key Laboratory of Cardiovascular Disease, Fuwai Hospital Chinese Academy of Medical Sciences, Shenzhen, Shenzhen, Guangdong Province, China
- State Key Laboratory of Cardiovascular Disease, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
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4
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Martinez J, Smegner K, Tomoda M, Motomura T, Chivukula VK. Encouraging Regular Aortic Valve Opening for EVAHEART 2 LVAD Support Using Virtual Patient Hemodynamic Speed Modulation Analysis. ASAIO J 2024; 70:207-216. [PMID: 38029749 DOI: 10.1097/mat.0000000000002093] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2023] Open
Abstract
This study focuses on investigating the EVAHEART 2 left ventricular assist device (LVAD) toward designing optimal pump speed modulation (PSM) algorithms for encouraging aortic valve (AV) flow. A custom-designed virtual patient hemodynamic model incorporating the EVAHEART 2 pressure-flow curves, cardiac chambers, and the systemic and pulmonary circulations was developed and used in this study. Several PSM waveforms were tested to evaluate their influence on the mean arterial pressure (MAP), cardiac output (CO), and AV flow for representative heart failure patients. Baseline speeds were varied from 1,600 to 2,000 rpm. For each baseline speed, the following parameters were analyzed: 1) PSM ratio (reduced speed/baseline speed), 2) PSM duration (3-7 seconds), 3) native ventricle contractility, and 4) patient MAP of 70 and 80 mm Hg. More than 2,000 rpm virtual patient scenarios were explored. A lower baseline speed (1,600 and 1,700 rpm) produced more opportunities for AV opening and more AV flow. Higher baseline speeds (1,800 and 2,000 rpm) had lower or nonexistent AV flow. When analyzing PSM ratios, a larger reduction in speed (25%) over a longer PSM (5+ seconds) duration produced the most AV flow. Lower patient MAP and increased native ventricle contractility also contributed to improving AV opening frequency and flow. This study of the EVAHEART 2 LVAD is the first to focus on leveraging PSM to enhance pulsatility and encourage AV flow. Increased AV opening frequency can benefit aortic root hemodynamics, thereby improving patient outcomes.
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Affiliation(s)
- Jasmine Martinez
- From the Department of Biomedical Engineering and Science, Florida Institute of Technology, Melbourne, Florida
| | | | | | | | - Venkat Keshav Chivukula
- From the Department of Biomedical Engineering and Science, Florida Institute of Technology, Melbourne, Florida
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5
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Schlöglhofer T, Gross C, Abart T, Schaefer AK, Marko C, Röhrich M, Widhalm G, Kaufmann F, Weigel I, Al Asadi H, Karner B, Riebandt J, Wiedemann D, Laufer G, Schima H, Zimpfer D. HeartMate 3 Snoopy: Noninvasive cardiovascular diagnosis of patients with fully magnetically levitated blood pumps during echocardiographic speed ramp tests and Valsalva maneuvers. J Heart Lung Transplant 2024; 43:251-260. [PMID: 37769887 DOI: 10.1016/j.healun.2023.09.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2023] [Revised: 08/30/2023] [Accepted: 09/18/2023] [Indexed: 10/03/2023] Open
Abstract
PURPOSE The HeartMate 3 (HM3) left ventricular assist device (LVAD) has demonstrated excellent clinical outcomes; however, pump speed optimization is challenging with the available HM3 monitoring. Therefore, this study reports on clinical HM3 parameters collected with a noninvasive HM3 monitoring system (HM3 Snoopy) during echocardiographic speed ramp tests and Valsalva maneuvers. METHODS In this prospective, single-center study, the HM3 data communication between the controller and pump was recorded with a novel data acquisition system. Twelve pump parameters sampled every second (1 Hz) and clinical assessments (echocardiography, electrocardiogram (ECG), and blood pressure measurement) during speed ramp tests were analyzed using Pearson's correlation (r, median [IQR]). The cause for the occurrence of pulsatility index (PI)-events during ramp speed tests and valsalva maneuvers was investigated. RESULTS In 24 patients (age: 58.9 ± 8.8 years, body mass index: 28.1 ± 5.1 kg/m2, female: 20.8%), 35 speed ramp tests were performed with speed changes in the range of ±1000 rpm from a baseline speed of 5443 ± 244 rpm. Eight HM3 pump parameters from estimated flow, motor current, and LVAD speed together with blood pressure showed positive collinearities (r = 0.9 [0.1]). Negative collinearities were observed for pump flow pulsatility, pulsatility index, rotor noise, and left ventricular diameters (r = -0.8 [0.1]), whereas rotor displacement and heartrate showed absence of collinearities (r = -0.1 [0.08]). CONCLUSIONS In this study, the HM3 Snoopy was successfully used to acquire more parameters from the HM3 at a higher sampling rate. Analysis of HM3 per-second data provide additional clinical diagnostic information on heart-pump interactions and cause of PI-events.
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Affiliation(s)
- Thomas Schlöglhofer
- Department of Cardiac Surgery, Medical University of Vienna, Vienna, Austria; Ludwig Boltzmann Institute for Cardiovascular Research, Vienna, Austria; Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria.
| | - Christoph Gross
- Department of Cardiac Surgery, Medical University of Vienna, Vienna, Austria
| | - Theodor Abart
- Department of Cardiac Surgery, Medical University of Vienna, Vienna, Austria
| | | | - Christiane Marko
- Department of Cardiac Surgery, Medical University of Vienna, Vienna, Austria
| | - Michael Röhrich
- Department of Anesthesia, Intensive Care Medicine and Pain Medicine, Medical University of Vienna, Vienna, Austria
| | - Gregor Widhalm
- Department of Cardiac Surgery, Medical University of Vienna, Vienna, Austria
| | - Friedrich Kaufmann
- Deutsches Herzzentrum der Charité (DHZC), Department of Cardiothoracic and Vascular Surgery, Berlin, Germany
| | - Ingo Weigel
- Department of Cardiac Surgery, Medical University of Vienna, Vienna, Austria
| | - Hebe Al Asadi
- Department of Cardiac Surgery, Medical University of Vienna, Vienna, Austria
| | - Barbara Karner
- Department of Cardiac Surgery, Medical University of Vienna, Vienna, Austria
| | - Julia Riebandt
- Department of Cardiac Surgery, Medical University of Vienna, Vienna, Austria
| | - Dominik Wiedemann
- Department of Cardiac Surgery, Medical University of Vienna, Vienna, Austria
| | - Günther Laufer
- Department of Cardiac Surgery, Medical University of Vienna, Vienna, Austria
| | - Heinrich Schima
- Department of Cardiac Surgery, Medical University of Vienna, Vienna, Austria; Ludwig Boltzmann Institute for Cardiovascular Research, Vienna, Austria; Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria
| | - Daniel Zimpfer
- Department of Cardiac Surgery, Medical University of Vienna, Vienna, Austria; Ludwig Boltzmann Institute for Cardiovascular Research, Vienna, Austria
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6
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Khalili O, Asgari M. Fluid-structure interaction and structural simulation of high acceleration effects on surgical repaired human mitral valve biomechanics. Proc Inst Mech Eng H 2023; 237:1248-1260. [PMID: 37846647 DOI: 10.1177/09544119231200367] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2023]
Abstract
Mitral valve dynamics depend on force stability in the mitral leaflets, the mitral annulus, the chordae tendineae, and the papillary muscles. In chordal rupture conditions, the proper function of the valve disrupts, causing mitral regurgitation, the most prevalent valvular disease. In this study, Structural and FSI frameworks were employed to study valve dynamics in healthy, pathologic, and repaired states. Anisotropic, non-linear, hyper-elastic material properties applied to tissues of the valve while the first-order Ogden model reflected the best compatibility with the empirical data. Hemodynamic blood pressure of the cardiovascular system is applied on the leaflets as uniform loads varying by time, and exposure to high acceleration loads imposed on models. Immersed boundary method used for simulation of fluid in a cardiac cycle. In comparison between healthy and pathologic models, stress values and chordal tensions are increased, by nearly threefold and twofold, respectively. Stress concentration on leaflets is reduced by 75% after performing a successful surgical repair on the pathological model. Crash acceleration loads led to more significant stress and chordae tension on models, by 27% and 23%, respectively. It is concluded that a more sophisticated model could lead to a better understanding of human heart valve biomechanics in various conditions. If a preoperative plan is developed based on these modeling methods, the requirement for multiple successive repairs would be eliminated, operative times are shortened, and patient outcomes are improved.
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Affiliation(s)
- Omid Khalili
- Faculty of Mechanical Engineering, K. N. Toosi University of Technology, Tehran, Iran
| | - Masoud Asgari
- Faculty of Mechanical Engineering, K. N. Toosi University of Technology, Tehran, Iran
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7
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Consolo F, Pieri M, Pazzanese V, Scandroglio AM, Pappalardo F. Longitudinal analysis of pump parameters over long-term support with the HeartMate 3 left ventricular assist device. J Cardiovasc Med (Hagerstown) 2023; 24:771-775. [PMID: 37409664 DOI: 10.2459/jcm.0000000000001522] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/07/2023]
Abstract
AIMS Recurrence of heart failure emerged as the main cause of long-term mortality in patients implanted with the HeartMate 3 (HM3) left ventricular assist device (LVAD). We aimed at deriving a possible mechanistic rationale of clinical outcomes and analyzed longitudinal changes in pump parameters over prolonged HM3 support to investigate long-term effects of pump settings on left ventricular mechanics. METHODS Data on pump parameters (i.e. pump speed, estimated flow, and pulsatility index) were prospectively recorded in consecutive HM3 patients following postoperative rehabilitation (baseline) and then at 6, 12, 24, 36, 48, and 60 months of support. RESULTS Data of 43 consecutive patients were analyzed. Pump parameters were set according to regular patients' follow-up, including clinical and echocardiographic assessment. We recorded a significant progressive increase in pump speed over the course of support: from 5200 (5050-5300) rpm at baseline to 5400 (5300-5600) rpm at 60 months of support ( P = 0.0007). Consistently with the increase in pump speed, a significant increase in pump flow ( P = 0.007) and a decrease in pulsatility index ( P = 0.005) were also recorded. CONCLUSION Our results reveal unique features of the HM3 on left ventricular activity. The need for progressive increase in pump support suggests indeed a lack of recovery and worsening of left ventricular function, which emerge as a possible mechanistic rationale of heart failure related mortality in HM3 patients. New algorithms to optimize pump settings should be envisioned to further improve LVAD-LV interaction and, ultimately, clinical outcomes in the HM3 population. CLINICAL TRIAL REGISTRATION https://clinicaltrials.gov/ct2/show/NCT03255928. CLINICALTRIALSGOV IDENTIFIER NCT03255928.
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Affiliation(s)
| | - Marina Pieri
- Università Vita Salute San Raffaele, Milano
- Department of Anesthesia and Intensive Care, Cardiothoracic Intensive Care Unit, IRCCS San Raffaele Scientific Institute, Milan
| | - Vittorio Pazzanese
- Cardiac Intensive Care Unit, IRCCS San Raffaele Scientific Institute, Milan
| | - Anna Mara Scandroglio
- Department of Anesthesia and Intensive Care, Cardiothoracic Intensive Care Unit, IRCCS San Raffaele Scientific Institute, Milan
| | - Federico Pappalardo
- Cardiothoracic and Vascular Anesthesia and Intensive Care, AO SS. Antonio e Biagio e Cesare Arrigo, Alessandria, Italy
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8
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Bornoff J, Najar A, Fresiello L, Finocchiaro T, Perkins IL, Gill H, Cookson AN, Fraser KH. Fluid-structure interaction modelling of a positive-displacement Total Artificial Heart. Sci Rep 2023; 13:5734. [PMID: 37059748 PMCID: PMC10104863 DOI: 10.1038/s41598-023-32141-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2022] [Accepted: 03/23/2023] [Indexed: 04/16/2023] Open
Abstract
For those suffering from end-stage biventricular heart failure, and where a heart transplantation is not a viable option, a Total Artificial Heart (TAH) can be used as a bridge to transplant device. The Realheart TAH is a four-chamber artificial heart that uses a positive-displacement pumping technique mimicking the native heart to produce pulsatile flow governed by a pair of bileaflet mechanical heart valves. The aim of this work was to create a method for simulating haemodynamics in positive-displacement blood pumps, using computational fluid dynamics with fluid-structure interaction to eliminate the need for pre-existing in vitro valve motion data, and then use it to investigate the performance of the Realheart TAH across a range of operating conditions. The device was simulated in Ansys Fluent for five cycles at pumping rates of 60, 80, 100 and 120 bpm and at stroke lengths of 19, 21, 23 and 25 mm. The moving components of the device were discretised using an overset meshing approach, a novel blended weak-strong coupling algorithm was used between fluid and structural solvers, and a custom variable time stepping scheme was used to maximise computational efficiency and accuracy. A two-element Windkessel model approximated a physiological pressure response at the outlet. The transient outflow volume flow rate and pressure results were compared against in vitro experiments using a hybrid cardiovascular simulator and showed good agreement, with maximum root mean square errors of 15% and 5% for the flow rates and pressures respectively. Ventricular washout was simulated and showed an increase as cardiac output increased, with a maximum value of 89% after four cycles at 120 bpm 25 mm. Shear stress distribution over time was also measured, showing that no more than [Formula: see text]% of the total volume exceeded 150 Pa at a cardiac output of 7 L/min. This study showed this model to be both accurate and robust across a wide range of operating points, and will enable fast and effective future studies to be undertaken on current and future generations of the Realheart TAH.
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Affiliation(s)
- Joseph Bornoff
- Department of Mechanical Engineering, University of Bath, Bath, UK
| | - Azad Najar
- Scandinavian Real Heart AB, Västerås, Sweden
| | - Libera Fresiello
- Faculty of Science and Technology, University of Twente, Twente, The Netherlands
| | | | | | - Harinderjit Gill
- Department of Mechanical Engineering, University of Bath, Bath, UK
- Centre for Therapeutic Innovation, University of Bath, Bath, UK
| | - Andrew N Cookson
- Department of Mechanical Engineering, University of Bath, Bath, UK
- Centre for Therapeutic Innovation, University of Bath, Bath, UK
| | - Katharine H Fraser
- Department of Mechanical Engineering, University of Bath, Bath, UK.
- Centre for Therapeutic Innovation, University of Bath, Bath, UK.
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Ravenberg KK, Gabriel MM, Leotescu A, Tran AT, Grosse GM, Schuppner R, Ernst J, Lichtinghagen R, Tiede A, Werwitzke S, Bara CL, Schmitto JD, Weissenborn K, Hanke JS, Worthmann H. Microembolic signal monitoring in patients with HeartMate 3 and HeartWare left ventricular assist devices: Association with antithrombotic treatment and cerebrovascular events. Artif Organs 2023; 47:370-379. [PMID: 36114791 DOI: 10.1111/aor.14409] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2022] [Revised: 08/07/2022] [Accepted: 09/06/2022] [Indexed: 02/03/2023]
Abstract
BACKGROUND In patients with left ventricular assist devices (LVADs), ischemic and hemorrhagic stroke are dreaded complications. Predictive markers for these events are lacking. This study aimed to investigate the prevalence and predictive value of microembolic signals (MES) for stroke, detected by Transcranial Doppler sonography (TCD) in patients with HeartMate 3 (HM 3) or HeartWare (HW). METHODS A thirty-minute bilateral TCD monitoring of the middle cerebral artery (MCA) was performed in 62 outpatients with LVAD (HM 3 N = 31, HW N = 31) and 31 healthy controls. Prevalence and quantity of MES were investigated regarding clinical and laboratory parameters. Cerebrovascular events (CVE) were recorded on follow-up at 90 and 180 days. RESULTS MES were detected in six patients with HM 3, three patients with HW, and three controls. Within the LVAD groups, patients on monotherapy with vitamin-K-antagonist (VKA) without antiplatelet therapy were at risk for a higher count of MES (negative binomial regression: VKA: 1; VKA + ASA: Exp(B) = 0.005, 95%CI 0.001-0.044; VKA + clopidogrel: Exp(B) = 0.012, 95%CI 0.002-0.056). There was no association between the presence of MES and CVE or death on follow-up (p > 0.05). CONCLUSION For the first time, the prevalence of MES was prospectively investigated in a notable outpatient cohort of patients with HM 3 and HW. Despite optimized properties of the latest LVAD, MES remain detectable depending on antithrombotic therapy. No association between MES and CVE could be detected.
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Affiliation(s)
| | | | - Andrei Leotescu
- Department of Neurology, Hannover Medical School, Hannover, Germany
| | - Anh Thu Tran
- Department of Neurology, Hannover Medical School, Hannover, Germany
| | | | - Ramona Schuppner
- Department of Neurology, Hannover Medical School, Hannover, Germany
| | - Johanna Ernst
- Department of Neurology, Hannover Medical School, Hannover, Germany
| | - Ralf Lichtinghagen
- Institute of Clinical Chemistry, Hannover Medical School, Hannover, Germany
| | - Andreas Tiede
- Department of Hematology, Hemostasis, Oncology, and Stem Cell Transplantation, Hannover Medical School, Hannover, Germany
| | - Sonja Werwitzke
- Department of Hematology, Hemostasis, Oncology, and Stem Cell Transplantation, Hannover Medical School, Hannover, Germany
| | - Christoph Leon Bara
- Department of Cardiac, Thoracic, Transplantation and Vascular Surgery, Hannover Medical School, Hannover, Germany
| | - Jan Dieter Schmitto
- Department of Cardiac, Thoracic, Transplantation and Vascular Surgery, Hannover Medical School, Hannover, Germany
| | | | - Jasmin Sarah Hanke
- Department of Cardiac, Thoracic, Transplantation and Vascular Surgery, Hannover Medical School, Hannover, Germany
| | - Hans Worthmann
- Department of Neurology, Hannover Medical School, Hannover, Germany
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10
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Fang P, Yang Y, Wei X, Yu S. Preclinical evaluation of the fluid dynamics and hemocompatibility of the Corheart 6 left ventricular assist device. Artif Organs 2023. [PMID: 36625490 DOI: 10.1111/aor.14498] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2022] [Revised: 11/24/2022] [Accepted: 01/04/2023] [Indexed: 01/11/2023]
Abstract
BACKGROUND Corheart 6 (Corheart) is a newly developed magnetically levitated continuous-flow left ventricular assist device currently undergoing multicenter clinical trials in China. Featuring a small size, minimal weight, and low power consumption, the Corheart aims to improve pump hemocompatibility, reduce adverse events, and enhance the quality of life of heart failure patients. METHODS Computational simulations assessed flow field, shear stress, and washout, while in vitro and in vivo experiments were performed to further demonstrate hemocompatibility. RESULTS Numerical results show that the flow path in the Corheart blood pump is well designed. There is no significantly high shear stress in the majority of the flow domain. Short secondary flow paths and small pump size (small priming volume) provide good washing (0.049 and 0.165 s to remove 55% and 95% old blood, respectively), allowing low hemolysis levels both in computational and in vitro hemolysis tests (in vitro hemolysis index ranges from 0.00092 ± 0.00006 g/100 L to 0.00134 ± 0.00019 g/100 L). Good hemocompatibility was further evidenced by ten 60-day sheep implants tested with relatively low flow rates of 2.0 ± 0.2 L/min; the results showed no hemolysis or thrombosis. CONCLUSIONS Numerical and experimental results shed light on the fluid dynamics characteristics and hemocompatibility of the Corheart. It is believed that the Corheart will provide more promising possibilities for minimally invasive implantation techniques and for those patients with a small body surface area.
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Affiliation(s)
- Peng Fang
- School of Mechanical Engineering and Automation, Harbin Institute of Technology, Shenzhen, China
| | - Yuzhuo Yang
- Shenzhen Core Medical Technology Co, Ltd, Shenzhen, China
| | - Xufeng Wei
- Department of Cardiac Surgery, Wuxi Mingci Cardiovascular Hospital, Wuxi, China
| | - Shunzhou Yu
- Shenzhen Core Medical Technology Co, Ltd, Shenzhen, China
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