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Sherwin J, Thompson E, Hill KD, Watt K, Lodge AJ, Gonzalez D, Hornik CP. Clinical pharmacology considerations for children supported with ventricular assist devices. Cardiol Young 2018; 28:1082-1090. [PMID: 29991374 PMCID: PMC6299825 DOI: 10.1017/s1047951118001075] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The ventricular assist device is being increasingly used as a "bridge-to-transplant" option in children with heart failure who have failed medical management. Care for this medically complex population must be optimised, including through concomitant pharmacotherapy. Pharmacokinetic/pharmacodynamic alterations affecting pharmacotherapy are increasingly discovered in children supported with extracorporeal membrane oxygenation, another form of mechanical circulatory support. Similarities between extracorporeal membrane oxygenation and ventricular assist devices support the hypothesis that similar alterations may exist in ventricular assist device-supported patients. We conducted a literature review to assess the current data available on pharmacokinetics/pharmacodynamics in children with ventricular assist devices. We found two adult and no paediatric pharmacokinetic/pharmacodynamic studies in ventricular assist device-supported patients. While mechanisms may be partially extrapolated from children supported with extracorporeal membrane oxygenation, dedicated investigation of the paediatric ventricular assist device population is crucial given the inherent differences between the two forms of mechanical circulatory support, and pathophysiology that is unique to these patients. Commonly used drugs such as anticoagulants and antibiotics have narrow therapeutic windows with devastating consequences if under-dosed or over-dosed. Clinical studies are urgently needed to improve outcomes and maximise the potential of ventricular assist devices in this vulnerable population.
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Affiliation(s)
- Jennifer Sherwin
- Department of Pediatrics, Duke University Hospital, Durham, NC, USA
| | | | - Kevin D. Hill
- Department of Pediatrics, Duke University Hospital, Durham, NC, USA
- Duke Clinical Research Institute, Duke University, Durham, NC, USA
| | - Kevin Watt
- Department of Pediatrics, Duke University Hospital, Durham, NC, USA
- Duke Clinical Research Institute, Duke University, Durham, NC, USA
| | - Andrew J. Lodge
- Department of Surgery, Duke University Hospital, Durham, NC, USA
| | - Daniel Gonzalez
- Division of Pharmacotherapy and Experimental Therapeutics, UNC Eshelman School of Pharmacy, The University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Christoph P. Hornik
- Department of Pediatrics, Duke University Hospital, Durham, NC, USA
- Duke Clinical Research Institute, Duke University, Durham, NC, USA
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Yamada T, Nishimura K, Akamatsu T, Tsukiya T, Park C, Kono S, Matsuda K, Ban T. In Vivo Testing of a Magnetically Suspended Centrifugal Pump Designed for Long-Term Use. Int J Artif Organs 2018. [DOI: 10.1177/039139889702001005] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The life of currently-available centrifugal pumps is limited to no more than three days. As a magnetically suspended centrifugal pump (MSCP) contains no shaft or seal, it could be expected to have a longer life expectancy. The MSCP was evaluated in a chronic animal model using eight adult sheep. Left ventricular assist with the MSCP was instituted between the left atrium and the descending aorta. The flow rates ranged from 2.5 to 6.0 L/min. The duration of the experiments ranged from 14 to 60 days. No mechanical failure occurred. The plasma free hemoglobin levels remained within an acceptable range (3-19 mg/dL). No reduction in the counts of red blood cells or platelets was observed. Thrombus formation within the MSCP was recognized in one pump. The main reason for termination was thromboembolism derived from the circuits. Three types of regulation methods (constant rotational speed, constant motor current, and controlled motor current) were also investigated. Regulation by a constant motor current mode altered the pressure-flow (P-Q) characteristics, and thereby, a steadier pump flow was obtained compared with regulation in the constant rotational speed mode. Moreover, the controlled motor current mode can change the P-Q relationship. These results demonstrate that the MSCP is a promising device for long-term use.
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Affiliation(s)
- T. Yamada
- Department of Cardiovascular Surgery, Faculty of Medicine, Kyoto University, Kyoto - Japan
| | - K. Nishimura
- Department of Cardiovascular Surgery, Faculty of Medicine, Kyoto University, Kyoto - Japan
| | - T. Akamatsu
- Department of Mechanical Engineering, Faculty of Engineering, Kyoto University, Kyoto - Japan
| | - T. Tsukiya
- Department of Mechanical Engineering, Faculty of Engineering, Kyoto University, Kyoto - Japan
| | - C.H. Park
- Department of Cardiovascular Surgery, Faculty of Medicine, Kyoto University, Kyoto - Japan
| | - S. Kono
- Department of Cardiovascular Surgery, Faculty of Medicine, Kyoto University, Kyoto - Japan
| | - K. Matsuda
- Department of Cardiovascular Surgery, Faculty of Medicine, Kyoto University, Kyoto - Japan
| | - T. Ban
- Department of Cardiovascular Surgery, Faculty of Medicine, Kyoto University, Kyoto - Japan
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Slaughter MS. Long-term continuous flow left ventricular assist device support and end-organ function: prospects for destination therapy. J Card Surg 2011; 25:490-4. [PMID: 20642766 DOI: 10.1111/j.1540-8191.2010.01075.x] [Citation(s) in RCA: 74] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Pulsatile flow left ventricular assist devices (PF-LVADs) have successfully supported patients with severe heart failure for bridge-to-transplant (BTT) and destination therapy (DT). End-organ dysfunction is often reversed, optimizing the patient's condition to enhance survival, and quality of life. Questions have been raised regarding the potential for continuous flow LVADs (CF-LVADs) to provide the same quality of circulatory support. Prior research showing that PF is superior to continuous, non-PF does not appear to be relevant with CF-LVADs for BTT and DT. Under most clinical conditions, arterial pulsatility is present during CF-LVAD support, and this type of support should not be termed "nonpulsatile." Clinical studies have shown that renal, hepatic, and neurocognitive function is either maintained within a normal range, or is significantly improved, during CF-LVAD support for durations up to 15 months. Results of the randomized clinical trial between the CF HeartMate II and the pulsatile HeartMate XVE (both by Thoratec Corp, Pleasanton, CA, USA) are pending final US Food and Drug Administration (FDA) review and are not yet published. Studies of microcirculation during CF-LVAD support indicate that capillary blood flow is adequate to support cellular function. There are anecdotal cases of patients being supported with a CF-LVAD for over seven years with preserved end-organ function. Presently, there are no clinical reports indicating that end-organ function is not well maintained. Current clinical evidence indicates that end-organ perfusion and function can be well maintained for extended durations of support with a CF-LVAD.
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Affiliation(s)
- Mark S Slaughter
- Division of Thoracic and Cardiovascular Surgery, University of Louisville, Louisville, Kentucky 40202, USA.
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Affiliation(s)
- Deborah J Kozik
- Division of Cardiothoracic Surgery, Department of Surgery, University of Kentucky College of Medicine, Lexington, KY, USA
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Drakos SG, Charitos CE, Ntalianis A, Terrovitis JV, Siafakas KX, Dolou P, Pierrakos C, Charitos E, Karelas J, Nanas JN. Comparison of pulsatile with nonpulsatile mechanical support in a porcine model of profound cardiogenic shock. ASAIO J 2005; 51:26-9. [PMID: 15745130 DOI: 10.1097/01.mat.0000150323.62708.35] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
The aim of this study was to examine whether pulsatility by intraaortic balloon counterpulsation (IABP) is an important adjunct to the treatment of profound cardiogenic shock (CS) with a widely used, nonpulsatile centrifugal pump (CP). In each of 18 anesthetized, open chest pigs, the outflow cannula of the CP was inserted in the aortic arch through the right external carotid artery, and the inflow cannula of the CP was placed in the left atrium. A 40 cc IABP was subsequently placed in the descending aorta through the left external carotid artery. CS was induced by occlusion of coronary arteries and the infusion of propranolol and crystalloid fluid. Mean aortic pressure, pulse pressure, aortic end diastolic pressure, left ventricular end diastolic pressure, right atrial pressure, and heart rate were monitored. Cardiac output and left anterior descending artery flow were measured with a transit time ultrasound flowmeter. During profound CS, life sustaining hemodynamics were maintained only with the support of the assist devices. Hemodynamic support with the CP was associated with a nearly nonpulsatile flow and a pulse pressure of 7 +/- 4 mm Hg, which increased to 33 +/- 10 mm Hg (p = 0.000) after combining the CP with the IABP. Compared with the hemodynamic support offered by the CP alone, addition of the IABP increased mean aortic pressure from 40 +/- 15 to 50 +/- 16 mm Hg (p = 0.000), cardiac output from 810 +/- 194 to 1,200 +/- 234 ml/min (p = 0.003), and left anterior descending artery flow from 26 +/- 10 to 39 +/- 14 ml/min (p = 0.001). In profound CS, mechanical support provided by a continuous flow CP is enhanced by the added pulsatility of the IABP.
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Affiliation(s)
- Stavros G Drakos
- University of Athens School of Medicine, Department of Clinical Therapeutics, "Alexandra" Hospital, Athens, Greece
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Affiliation(s)
- J J Magner
- Department of Anaesthesia and Intensive Care Medicine, Royal Brompton and Harefield NHS Trust, Harefield Hospital, Harefield, Middlesex, UB9 6JH, UK
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Affiliation(s)
- Paul L DiGiorgi
- Department of Surgery, Columbia University, New York, New York 10032, USA
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Litwak KN, Kihara S, Kameneva MV, Litwak P, Uryash A, Wu Z, Griffith BP. Effects of continuous flow left ventricular assist device support on skin tissue microcirculation and aortic hemodynamics. ASAIO J 2003; 49:103-7. [PMID: 12558315 DOI: 10.1097/00002480-200301000-00016] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Continuous flow ventricular assist devices (CFVADs) are thought to be the next generation of circulatory assist devices. With many now in various stages of development or clinical trial, it is important that the physiologic aspects of these pumps be critically analyzed. In this study, 15 calves were divided into two groups. One group received a CFVAD, and the other a sham implant. Two additional animals were used in an acute study to examine aortic blood flow patterns from a CFVAD. Tissue perfusion was measured on all animals before surgery and then weekly thereafter. Before surgery, there was no difference in hemodynamics or tissue perfusion between studied animals. Postoperatively, CFVAD animals had statistically significant increased diastolic pressure. Significantly decreased pulse pressure, pulse index, and tissue perfusion were also observed in CFVAD animals. Results from the flow pattern studies suggested that at moderate levels of pump support (40-75%), the amount of blood flow distal to the outflow graft anastomosis decreased approximately 25% because of increased regurgitant blood flow in the aorta. These results suggest that the diminished tissue perfusion is likely due to changes in aortic hemodynamics and provide some insight into the distribution of flow from CFVADs.
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Affiliation(s)
- Kenneth N Litwak
- Department of Surgery, University of Pittsburgh, 215 McGowan Institute, 3025 E. Carson St., Pittsburgh, PA 15203, USA
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Abstract
Heart transplantation remains the treatment of choice for end-stage heart failure despite limited donor availability and allograft durability. Artificial heart technology was initially developed as a replacement for transplantation but the initial experience with these technologies was disappointing. The quest for a total artificial heart has largely been abandoned in favor of ventricular assist devices (VADs). VADs have gained widespread acceptance as bridge to transplant and bridge to recovery therapy. After more than a decade of clinical use, several FDA approved device designs have proved effective in treating patients with various causes of heart failure. This review describes the current, clinically available ventricular replacement and assist devices and defines the adult patient populations in which they are useful. The next generation of these devices will soon become available and their clinical utility will likely shape the future direction of heart failure therapy. Ultimately the concept of a long-term total artificial heart may be revisited.
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Affiliation(s)
- D A D'Alessandro
- Department of Surgery, Columbia University, New York, New York, USA
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Williams M, Oz M, Mancini D. Cardiac assist devices for end-stage heart failure. HEART DISEASE (HAGERSTOWN, MD.) 2001; 3:109-15. [PMID: 11975779 DOI: 10.1097/00132580-200103000-00008] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Cardiac assist devices have become an important therapy for patients with end-stage cardiac failure. These devices continue to evolve. Most current devices provide temporary, left-sided support for patients with cardiogenic shock from postcardiotomy syndrome or for patients awaiting cardiac transplantation. The two most frequently used left ventricular assist devices as a bridge to transplant are the Thermocardiosystems (HeartMate I) and the Novacor devices. The selection criteria for the use of these devices and treatment of these patients will be reviewed. Additionally, other currently available devices and future devices are also presented and discussed.
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Affiliation(s)
- M Williams
- Department of Medicine, Columbia-Presbyterian Medical Center, New York, New York, USA
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Savage EB, Clark RE, Griffin WP, Davis SA, Hughson S, Conway CJ, Magovern GJ. The AB-180 circulatory support system: summary of development and plans for phase I clinical trial. Ann Thorac Surg 1999; 68:768-74. [PMID: 10475486 DOI: 10.1016/s0003-4975(99)00579-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
BACKGROUND The AB-180 circulatory support system is a small, durable, efficient centrifugal pump with low thrombogenic potential. The device was designed to provide a fully implantable, left ventricular assist system for short-term support to address the issues of systemic anticoagulation, thrombus formation, infection, and cost. METHODS Extensive bench and animal studies were performed to validate the mechanical integrity of the device and its functionality as an implant. RESULTS These studies demonstrated anticoagulation requirements, established operating guidelines, incorporated safety systems, and demonstrated safety and efficacy. CONCLUSIONS The AB-180 fulfills the stated goals on initial evaluation. A phase I human trial is underway.
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Affiliation(s)
- E B Savage
- Allegheny General Hospital, Allegheny-Singer Research Institute, Pittsburgh, Pennsylvania, USA
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Shum-Tim D, Duncan BW, Hraska V, Friehs I, Shin'oka T, Jonas RA. Evaluation of a pulsatile pediatric ventricular assist device in an acute right heart failure model. Ann Thorac Surg 1997; 64:1374-80. [PMID: 9386707 DOI: 10.1016/s0003-4975(97)00901-6] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
BACKGROUND The development of pulsatile ventricular assist devices for children has been limited mainly by size constraints. The purpose of this study was to evaluate the MEDOS trileaflet-valved, pulsatile, pediatric right ventricular assist device (stroke volume = 9 mL) in a neonatal lamb model of acute right ventricular failure. METHODS Right ventricular failure was induced in ten 3-week-old lambs (8.6 kg) by right ventriculotomy and disruption of the tricuspid valve. Control group 1 (n = 5) had no mechanical support whereas experimental group 2 (n = 5) had right ventricular assist device support for 6 hours. The following hemodynamic parameters were measured in all animals: heart rate and right atrial, pulmonary arterial, left atrial, and systemic arterial pressures. Cardiac output was measured by an electromagnetic flow probe placed on the pulmonary artery. RESULTS All results are expressed as mean +/- standard deviation and analyzed by Student's t test. A p value less than 0.05 was considered statistically significant. Base-line measurements were not significantly different between groups and included systemic arterial pressure, 80.6 +/- 12.7 mm Hg; right atrial pressure, 4.6 +/- 1.6 mm Hg; mean pulmonary arterial pressure, 15.6 +/- 4.2 mm Hg; left atrial pressure, 4.8 +/- 0.8 mm Hg; and cardiac output, 1.4 +/- 0.2 L/min. Right ventricular injury produced hemodynamics compatible with right ventricular failure in both groups: mean systemic arterial pressure, 38.8 +/- 10.4 mm Hg; right atrial pressure, 16.8 +/- 2.3 mm Hg; left atrial pressure, 1.4 +/- 0.5 mm Hg; and cardiac output, 0.6 +/- 0.1 L/min. All group 1 animals died at a mean of 71.4 +/- 9.4 minutes after the operation. All group 2 animals survived the duration of study. Hemodynamic parameters were recorded at 2, 4, and 6 hours on and off pump, and were significantly improved at all time points: mean systemic arterial pressure, 68.0 +/- 13.0 mm Hg; right atrial pressure, 8.2 +/- 2.3 mm Hg; left atrial pressure, 6.4 +/- 2.1 mm Hg; and cardiac output, 1.0 +/- 0.2 L/min. CONCLUSIONS The results demonstrate the successful creation of a right ventricular failure model and its salvage by a miniaturized, pulsatile right ventricular assist device. The small size of this device makes its use possible even in small neonates.
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Affiliation(s)
- D Shum-Tim
- Department of Cardiovascular Surgery, Children's Hospital, Boston, Massachusetts 02115, USA
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