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Palomares DE, Tran PL, Jerman C, Momayez M, Deymier P, Sheriff J, Bluestein D, Parthasarathy S, Slepian MJ. Vibro-Acoustic Platelet Activation: An Additive Mechanism of Prothrombosis with Applicability to Snoring and Obstructive Sleep Apnea. Bioengineering (Basel) 2023; 10:1414. [PMID: 38136005 PMCID: PMC10741028 DOI: 10.3390/bioengineering10121414] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2023] [Revised: 11/28/2023] [Accepted: 12/08/2023] [Indexed: 12/24/2023] Open
Abstract
Introduction: Obstructive sleep apnea (OSA) and loud snoring are conditions with increased cardiovascular risk and notably an association with stroke. Central in stroke are thrombosis and thromboembolism, all related to and initiaing with platelet activation. Platelet activation in OSA has been felt to be driven by biochemical and inflammatory means, including intermittent catecholamine exposure and transient hypoxia. We hypothesized that snore-associated acoustic vibration (SAAV) is an activator of platelets that synergizes with catecholamines and hypoxia to further amplify platelet activation. Methods: Gel-filtered human platelets were exposed to snoring utilizing a designed vibro-acoustic exposure device, varying the time and intensity of exposure and frequency content. Platelet activation was assessed via thrombin generation using the Platelet Activity State assay and scanning electron microscopy. Comparative activation induced by epinephrine and hypoxia were assessed individually as well as additively with SAAV, as well as the inhibitory effect of aspirin. Results: We demonstrate that snore-associated acoustic vibration is an independent activator of platelets, which is dependent upon the dose of exposure, i.e., intensity x time. In snoring, acoustic vibrations associated with low-frequency sound content (200 Hz) are more activating than those associated with high frequencies (900 Hz) (53.05% vs. 22.08%, p = 0.001). Furthermore, SAAV is additive to both catecholamines and hypoxia-mediated activation, inducing synergistic activation. Finally, aspirin, a known inhibitor of platelet activation, has no significant effect in limiting SAAV platelet activation. Conclusion: Snore-associated acoustic vibration is a mechanical means of platelet activation, which may drive prothrombosis and thrombotic risk clinically observed in loud snoring and OSA.
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Affiliation(s)
- Daniel E. Palomares
- Department of Biomedical Engineering, University of Arizona, Tucson, AZ 85724, USA;
- Arizona Center for Accelerated Biomedical Innovation, University of Arizona, Tucson, AZ 85724, USA; (P.L.T.); (M.M.); (P.D.); (S.P.)
| | - Phat L. Tran
- Arizona Center for Accelerated Biomedical Innovation, University of Arizona, Tucson, AZ 85724, USA; (P.L.T.); (M.M.); (P.D.); (S.P.)
- Department of Medicine, University of Arizona, Tucson, AZ 85724, USA;
| | - Catherine Jerman
- Department of Medicine, University of Arizona, Tucson, AZ 85724, USA;
| | - Moe Momayez
- Arizona Center for Accelerated Biomedical Innovation, University of Arizona, Tucson, AZ 85724, USA; (P.L.T.); (M.M.); (P.D.); (S.P.)
- Department of Mining & Geological Engineering, University of Arizona, Tucson, AZ 85724, USA
| | - Pierre Deymier
- Arizona Center for Accelerated Biomedical Innovation, University of Arizona, Tucson, AZ 85724, USA; (P.L.T.); (M.M.); (P.D.); (S.P.)
- Department of Materials Science & Engineering, University of Arizona, Tucson, AZ 85724, USA
| | - Jawaad Sheriff
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, NY 11794, USA; (J.S.); (D.B.)
| | - Danny Bluestein
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, NY 11794, USA; (J.S.); (D.B.)
| | - Sairam Parthasarathy
- Arizona Center for Accelerated Biomedical Innovation, University of Arizona, Tucson, AZ 85724, USA; (P.L.T.); (M.M.); (P.D.); (S.P.)
- Department of Medicine, University of Arizona, Tucson, AZ 85724, USA;
- Health Sciences Center for Sleep and Circadian Sciences, University of Arizona, Tucson, AZ 85724, USA
| | - Marvin J. Slepian
- Department of Biomedical Engineering, University of Arizona, Tucson, AZ 85724, USA;
- Arizona Center for Accelerated Biomedical Innovation, University of Arizona, Tucson, AZ 85724, USA; (P.L.T.); (M.M.); (P.D.); (S.P.)
- Department of Medicine, University of Arizona, Tucson, AZ 85724, USA;
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, NY 11794, USA; (J.S.); (D.B.)
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Device Thrombogenicity Emulation: An In Silico Predictor of In Vitro and In Vivo Ventricular Assist Device Thrombogenicity. Sci Rep 2019; 9:2946. [PMID: 30814674 PMCID: PMC6393420 DOI: 10.1038/s41598-019-39897-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2018] [Accepted: 02/04/2019] [Indexed: 12/02/2022] Open
Abstract
Ventricular assist devices (VAD), a mainstay of therapy for advanced and end-stage heart failure, remain plagued by device thrombogenicity. Combining advanced in silico and in vitro methods, Device Thrombogenicity Emulation (DTE) is a device design approach for enhancing VAD thromboresistance. Here we tested DTE efficacy in experimental VAD designs. DTE incorporates iterative design modifications with advanced CFD to compute the propensity of large populations of platelets to activate by flow-induced stresses (statistically representing the VAD ‘Thrombogenic Footprint’). The DTE approach was applied to a VAD (MINDTE) design with a favorable thromboresistance profile and compared against a design (MAXDTE) that generated an intentionally poor thromboresistance profile. DTE predictions were confirmed by testing physical prototypes in vitro by measuring VAD thrombogenicity using the modified prothrombinase assay. Chronic in vivo studies in VAD implanted calves, revealed MINDTE calf surviving well with low platelet activation, whereas the MAXDTE animal sustained thromboembolic strokes. DTE predictions were confirmed, correlating with in vitro and in vivo thrombogenicity, supporting utility in guiding device development, potentially reducing the need for animal studies.
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Apostoli A, Bianchi V, Bono N, Dimasi A, Ammann KR, Moiia YR, Montisci A, Sheriff J, Bluestein D, Fiore GB, Pappalardo F, Candiani G, Redaelli A, Slepian MJ, Consolo F. Prothrombotic activity of cytokine-activated endothelial cells and shear-activated platelets in the setting of ventricular assist device support. J Heart Lung Transplant 2019; 38:658-667. [PMID: 30846234 DOI: 10.1016/j.healun.2019.02.009] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2018] [Revised: 02/11/2019] [Accepted: 02/13/2019] [Indexed: 12/17/2022] Open
Abstract
BACKGROUND We systematically analyzed the synergistic effect of: (i) cytokine-mediated inflammatory activation of endothelial cells (ECs) with and (ii) shear-mediated platelet activation (SMPA) as a potential contributory mechanism to intraventricular thrombus formation in the setting of left ventricular assist device (LVAD) support. METHODS Intact and shear-activated human platelets were exposed to non-activated and cytokine-activated ECs. To modulate the level of LVAD-related shear activation, platelets were exposed to shear stress patterns of varying magnitude (30, 50, and 70 dynes/cm2, 10 minutes) via a hemodynamic shearing device. ECs were activated via exposure to inflammatory tumor necrosis factor-α (TNF-α 10 and 100 ng/ml, 24 hours), consistent with inflammatory activation recorded in patients on LVAD circulatory support. RESULTS Adhesivity of shear-activated platelets to ECs was significantly higher than that of intact/unactivated platelets, regardless of the initial activation level (70 dynes/cm2 shear-activated platelets vs intact platelets: +80%, p < 0.001). Importantly, inflammatory activation of ECs amplified platelet prothrombinase activity progressively with increasing shear stress magnitude and TNF-α concentration: thrombin generation of 70 dynes/cm2 shear-activated platelets was 2.6-fold higher after exposure and adhesion to 100 ng/ml TNF-α‒activated ECs (p < 0.0001). CONCLUSIONS We demonstrated synergistic effect of SMPA and cytokine-mediated EC inflammatory activation to enhance EC‒platelet adhesion and platelet prothrombotic function. These mechanisms may contribute to intraventricular thrombosis in the setting of mechanical circulatory support.
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Affiliation(s)
- Alice Apostoli
- Department of Electronics, Information and Bioengineering, Politecnico di Milano, Milano, Italy
| | - Valentina Bianchi
- Department of Electronics, Information and Bioengineering, Politecnico di Milano, Milano, Italy
| | - Nina Bono
- Politecnico di Milano Research Unit, National Interuniversity Consortium of Materials Science and Technology, Milano, Italy
| | - Annalisa Dimasi
- Department of Electronics, Information and Bioengineering, Politecnico di Milano, Milano, Italy
| | - Kaitlyn R Ammann
- Department of Biomedical Engineering, University of Arizona, Tucson, Arizona, USA
| | - Yana Roka Moiia
- Department of Biomedical Engineering, University of Arizona, Tucson, Arizona, USA
| | - Andrea Montisci
- Anesthesia and Intensive Care, Sant'Ambrogio Cardiothoracic Center, Milano, Italy
| | - Jawaad Sheriff
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, New York, USA
| | - Danny Bluestein
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, New York, USA
| | - Gianfranco B Fiore
- Department of Electronics, Information and Bioengineering, Politecnico di Milano, Milano, Italy
| | - Federico Pappalardo
- Advanced Heart Failure and Mechanical Circulatory Support Program, San Raffaele Scientific Institute, Milano, Italy; Università Vita Salute San Raffaele, Milano, Italy
| | - Gabriele Candiani
- Biocompatibility and Cell Culture Laboratory "BioCell," Department of Chemistry, Materials and Chemical Engineering "Giulio Natta," Politecnico di Milano, Milano, Italy
| | - Alberto Redaelli
- Department of Electronics, Information and Bioengineering, Politecnico di Milano, Milano, Italy
| | - Marvin J Slepian
- Department of Biomedical Engineering, University of Arizona, Tucson, Arizona, USA
| | - Filippo Consolo
- Department of Electronics, Information and Bioengineering, Politecnico di Milano, Milano, Italy; Advanced Heart Failure and Mechanical Circulatory Support Program, San Raffaele Scientific Institute, Milano, Italy; Università Vita Salute San Raffaele, Milano, Italy.
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Rotman OM, Bianchi M, Ghosh RP, Kovarovic B, Bluestein D. Principles of TAVR valve design, modelling, and testing. Expert Rev Med Devices 2018; 15:771-791. [PMID: 30318937 PMCID: PMC6417919 DOI: 10.1080/17434440.2018.1536427] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
INTRODUCTION Transcatheter aortic valve replacement (TAVR) has emerged as an effective minimally-invasive alternative to surgical valve replacement in medium- to high-risk, elderly patients with calcific aortic valve disease and severe aortic stenosis. The rapid growth of the TAVR devices market has led to a high variety of designs, each aiming to address persistent complications associated with TAVR valves that may hamper the anticipated expansion of TAVR utility. AREAS COVERED Here we outline the challenges and the technical demands that TAVR devices need to address for achieving the desired expansion, and review design aspects of selected, latest generation, TAVR valves of both clinically-used and investigational devices. We further review in detail some of the up-to-date modeling and testing approaches for TAVR, both computationally and experimentally, and additionally discuss those as complementary approaches to the ISO 5840-3 standard. A comprehensive survey of the prior and up-to-date literature was conducted to cover the most pertaining issues and challenges that TAVR technology faces. EXPERT COMMENTARY The expansion of TAVR over SAVR and to new indications seems more promising than ever. With new challenges to come, new TAV design approaches, and materials used, are expected to emerge, and novel testing/modeling methods to be developed.
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Affiliation(s)
- Oren M. Rotman
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, NY 11794, USA
| | - Matteo Bianchi
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, NY 11794, USA
| | - Ram P. Ghosh
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, NY 11794, USA
| | - Brandon Kovarovic
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, NY 11794, USA
| | - Danny Bluestein
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, NY 11794, USA
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Dimasi A, Roka-Moiia Y, Consolo F, Rasponi M, Fiore GB, Slepian MJ, Redaelli A. Microfluidic flow-based platforms for induction and analysis of dynamic shear-mediated platelet activation-Initial validation versus the standardized hemodynamic shearing device. BIOMICROFLUIDICS 2018; 12:042208. [PMID: 29861819 PMCID: PMC5963949 DOI: 10.1063/1.5024500] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2018] [Accepted: 05/07/2018] [Indexed: 06/08/2023]
Abstract
A microfluidic flow-based platform (μFP), able to stimulate platelets via exposure of shear stress patterns pertinent to cardiovascular devices and prostheses, was compared to the Hemodynamic Shearing Device (HSD)-a state-of-the-art bench-top system for exposure of platelets to defined levels and patterns of shear. Platelets were exposed to time-varying shear stress patterns in the two systems; in detail, platelets were recirculated in the μFP or stimulated in the HSD to replicate comparable exposure time. Shear-mediated platelet activation was evaluated via (i) the platelet activity state assay, allowing the measurement of platelet-mediated thrombin generation and associated prothrombotic tendencies, (ii) scanning electron microscopy to evaluate morphological changes of sheared platelets, and (iii) flow cytometry for the determination of platelet phosphatidylserine exposure as a marker of shear activation. The results revealed good matching and comparability between the two systems, with similar trends of platelet activation, formation of microaggregates, and analogous trends of activation marker exposure for both the HSD and microfluidic-stimulated samples. These findings support future translation of the microfluidic platform as a Point-of-Care facsimile system for the diagnosis of thrombotic risk in patients implanted with cardiovascular devices.
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Affiliation(s)
- Annalisa Dimasi
- Department of Electronics, Information and Bioengineering, Politecnico di Milano, Via Golgi 39, 20133 Milano, Italy
| | - Yana Roka-Moiia
- Department of Medicine and Biomedical Engineering, Sarver Heart Center, University of Arizona, 1501 N Campbell Ave, Tucson, Arizona 85724, USA
| | | | - Marco Rasponi
- Department of Electronics, Information and Bioengineering, Politecnico di Milano, Via Golgi 39, 20133 Milano, Italy
| | - Gianfranco B. Fiore
- Department of Electronics, Information and Bioengineering, Politecnico di Milano, Via Golgi 39, 20133 Milano, Italy
| | - Marvin J Slepian
- Department of Medicine and Biomedical Engineering, Sarver Heart Center, University of Arizona, 1501 N Campbell Ave, Tucson, Arizona 85724, USA
| | - Alberto Redaelli
- Department of Electronics, Information and Bioengineering, Politecnico di Milano, Via Golgi 39, 20133 Milano, Italy
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Ventricular Assist Device Implantation Configurations Impact Overall Mechanical Circulatory Support System Thrombogenic Potential. ASAIO J 2018; 63:285-292. [PMID: 27922885 DOI: 10.1097/mat.0000000000000488] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Ventricular assist devices (VADs) became in recent years the standard of care therapy for advanced heart failure with hemodynamic compromise. With the steadily growing population of device recipients, various postimplant complications have been reported, mostly associated with the hypershear generated by VADs that enhance their thrombogenicity by activating platelets. Although VAD design optimization can significantly improve its thromboresistance, the implanted VAD need to be evaluated as part of a system. Several clinical studies indicated that variability in implantation configurations may contribute to the overall system thrombogenicity. Numerical simulations were conducted in the HeartAssist 5 (HA5) and HeartMate II (HMII) VADs in the following implantation configurations: 1) inflow cannula angles: 115° and 140° (HA5); 2) three VAD circumferential orientations: 0°, 30°, and 60° (HA5 and HMII); and 3) 60° and 90° outflow graft anastomotic angles with respect to the ascending aorta (HA5). The stress accumulation of the platelets was calculated along flow trajectories and collapsed into a probability density function, representing the "thrombogenic footprint" of each configuration-a proxy to its thrombogenic potential (TP). The 140° HA5 cannula generated lower TP independent of the circumferential orientation of the VAD. Sixty-degree orientation generated the lowest TP for the HA5 versus 0° for the HMII. An anastomotic angle of 60° resulted in lower TP for HA5. These results demonstrate that optimizing the implantation configuration reduces the overall system TP. Thromboresistance can be enhanced by combining VAD design optimization with the surgical implantation configurations for achieving better clinical outcomes of implanted VADs.
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Consolo F, Sferrazza G, Motolone G, Contri R, Valerio L, Lembo R, Pozzi L, Della Valle P, De Bonis M, Zangrillo A, Fiore GB, Redaelli A, Slepian MJ, Pappalardo F. Platelet activation is a preoperative risk factor for the development of thromboembolic complications in patients with continuous-flow left ventricular assist device. Eur J Heart Fail 2017; 20:792-800. [DOI: 10.1002/ejhf.1113] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/08/2017] [Revised: 10/23/2017] [Accepted: 11/20/2017] [Indexed: 12/13/2022] Open
Affiliation(s)
- Filippo Consolo
- Università Vita Salute San Raffaele; Milan Italy
- Department of Electronics; Information and Bioengineering, Politecnico di Milano; Milan Italy
| | - Giulia Sferrazza
- Department of Electronics; Information and Bioengineering, Politecnico di Milano; Milan Italy
- Anesthesia and Cardiothoracic Intensive Care; San Raffaele Scientific Institute; Milan Italy
| | - Giulia Motolone
- Department of Electronics; Information and Bioengineering, Politecnico di Milano; Milan Italy
- Anesthesia and Cardiothoracic Intensive Care; San Raffaele Scientific Institute; Milan Italy
| | - Rachele Contri
- Anesthesia and Cardiothoracic Intensive Care; San Raffaele Scientific Institute; Milan Italy
| | - Lorenzo Valerio
- Department of Electronics; Information and Bioengineering, Politecnico di Milano; Milan Italy
- Anesthesia and Cardiothoracic Intensive Care; San Raffaele Scientific Institute; Milan Italy
| | - Rosalba Lembo
- Anesthesia and Cardiothoracic Intensive Care; San Raffaele Scientific Institute; Milan Italy
| | - Loris Pozzi
- Coagulation Service and Thrombosis Research Unit; San Raffaele Scientific Institute; Milan Italy
| | - Patrizia Della Valle
- Coagulation Service and Thrombosis Research Unit; San Raffaele Scientific Institute; Milan Italy
| | | | - Alberto Zangrillo
- Università Vita Salute San Raffaele; Milan Italy
- Anesthesia and Cardiothoracic Intensive Care; San Raffaele Scientific Institute; Milan Italy
| | - Gianfranco B. Fiore
- Department of Electronics; Information and Bioengineering, Politecnico di Milano; Milan Italy
| | - Alberto Redaelli
- Department of Electronics; Information and Bioengineering, Politecnico di Milano; Milan Italy
| | - Marvin J. Slepian
- Department of Medicine and Biomedical Engineering, Sarver Heart Center; The University of Arizona; Tucson AZ USA
| | - Federico Pappalardo
- Università Vita Salute San Raffaele; Milan Italy
- Anesthesia and Cardiothoracic Intensive Care; San Raffaele Scientific Institute; Milan Italy
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Valerio L, Sheriff J, Tran PL, Brengle W, Redaelli A, Fiore GB, Pappalardo F, Bluestein D, Slepian MJ. Routine clinical anti-platelet agents have limited efficacy in modulating hypershear-mediated platelet activation associated with mechanical circulatory support. Thromb Res 2017; 163:162-171. [PMID: 29428715 DOI: 10.1016/j.thromres.2017.12.001] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2017] [Revised: 11/03/2017] [Accepted: 12/02/2017] [Indexed: 11/25/2022]
Abstract
INTRODUCTION Continuous flow ventricular assist devices (cfVADs) continue to be limited by thrombotic complications associated with disruptive flow patterns and supraphysiologic shear stresses. Patients are prescribed complex antiplatelet therapies, which do not fully prevent recurrent thromboembolic events. This is partially due to limited data on antiplatelet efficacy under cfVAD-associated shear conditions. MATERIALS AND METHODS We investigated the efficacy of antiplatelet drugs directly acting on three pathways: (1) cyclooxygenase (aspirin), (2) phosphodiesterase (dipyridamole, pentoxifylline, cilostazol), and (3) glycoprotein IIb-IIIa (eptifibatide). Gel-filtered platelets treated with these drugs were exposed for 10min to either constant shear stresses (30dyne/cm2 and 70dyne/cm2) or dynamic shear stress profiles extracted from simulated platelet trajectories through a cfVAD (Micromed DeBakey). Platelet activation state (PAS) was measured using a modified prothrombinase-based assay, with drug efficacy quantified based on PAS reduction compared to untreated controls. RESULTS AND CONCLUSIONS Significant PAS reduction was observed for all drugs after exposure to 30dyne/cm2 constant shear stress, and all drugs but dipyridamole after exposure to the 30th percentile shear stress waveform of the cfVAD. However, only cilostazol was significantly effective after 70dyne/cm2 constant shear stress exposure, though no significant reduction was observed upon exposure to median shear stress conditions in the cfVAD. These results, coupled with the persistence of reported clinical thrombotic complication, suggest the need for the development of new classes of drugs that are especially designed to mitigate thrombosis in cfVAD patients, while reducing or eliminating the risk of bleeding.
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Affiliation(s)
- Lorenzo Valerio
- Department of Electronics, Information, and Bioengineering, Politecnico di Milano, Milan, Italy; Department of Cardiothoracic Anesthesia and Intensive Care, Istituto Scientifico San Raffaele, Milan, Italy
| | - Jawaad Sheriff
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, NY, USA
| | - Phat L Tran
- Department of Biomedical Engineering, Sarver Heart Center, University of Arizona, Tucson, AZ, USA
| | - William Brengle
- Department of Biomedical Engineering, Sarver Heart Center, University of Arizona, Tucson, AZ, USA
| | - Alberto Redaelli
- Department of Electronics, Information, and Bioengineering, Politecnico di Milano, Milan, Italy
| | - Gianfranco B Fiore
- Department of Electronics, Information, and Bioengineering, Politecnico di Milano, Milan, Italy
| | - Federico Pappalardo
- Department of Cardiothoracic Anesthesia and Intensive Care, Istituto Scientifico San Raffaele, Milan, Italy
| | - Danny Bluestein
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, NY, USA
| | - Marvin J Slepian
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, NY, USA; Department of Biomedical Engineering, Sarver Heart Center, University of Arizona, Tucson, AZ, USA; Department of Medicine, Sarver Heart Center, University of Arizona, Tucson, AZ, USA.
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Design and numerical evaluation of an axial partial-assist blood pump for Chinese and other heart failure patients. Int J Artif Organs 2017; 40:489-497. [PMID: 28777391 DOI: 10.5301/ijao.5000616] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/01/2017] [Indexed: 11/20/2022]
Abstract
A fully implantable axial left ventricular assist device LAP31 was developed for Chinese or other heart failure patients who need partial support. Based on the 5-Lpm total cardiac blood output of Chinese without heart failure disease, the design point of LAP31 was set to a flow rate of 3 Lpm with 100-mmHg pressure head. To achieve the required pressure head and good hemolytic performance, a structure that includes a spindly rotor hub and a diffuser with splitter and cantilevered main blades was developed. Computational fluid dynamics (CFD) was used to analyze the hydraulic and hemodynamic performance of LAP31. Then in vitro hydraulics experiments were conducted. The numerical simulation results show that LAP31 could generate a 1 to 8 Lpm flow rate with a 60.9 to 182.7 mmHg pressure head when the pump was rotating between 9,000 and 12,000 rpm. The average scalar shear stress of the blood pump was 21.7 Pa, and the average exposure time was 71.0 milliseconds. The mean hemolysis index of LAP31 obtained using Heuser's hemolysis model and Giersiepen's model was 0.220% and 3.89 × 10-5% respectively. After adding the splitter blades, the flow separation at the suction surface of the diffuser was reduced. The cantilever structure reduced the tangential velocity from 6.1 to 4.7-1.4 m/s within the blade gap by changing the blade gap from shroud to hub. Subsequently, the blood damage caused by shear stress was reduced. In conclusion, the hydraulic and hemolytic characteristics of the LAP31 are acceptable for partial support.
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Liu G, Zhou J, Sun H, Zhang Y, Chen H, Hu S. Effects of Cone-Shaped Bend Inlet Cannulas of an Axial Blood Pump on Thrombus Formation: An Experiment and Simulation Study. Med Sci Monit 2017; 23:1655-1661. [PMID: 28379938 PMCID: PMC5389533 DOI: 10.12659/msm.903421] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Background Cannula shape and connection style influence the risk of thrombus formation in the blood pump by varying the blood flow characteristics inside the pump. Inlet cannulas should be designed based on the need for anatomical fit and reducing the risk of thrombus generation in the blood pump. The effects on thrombus formation of the cone-shaped bend inlet cannulas of axial blood pumps should be studied. Material/Methods The cannulas were designed as cone-shaped, with 1 bent section connecting 2 straight sections. Both the silicone tube and novel cone-shaped cannula were simulated for comparison. The flow fields of a blood pump with inlet cannula were simulated by computational fluid dynamics (CFD) at flows of 2.0, 2.5, and 3.0 liters per minute (lpm), with pump rotational speeds of 7500, 8000, and 8500 rpm, respectively. Then, 6 two-dimensional (2D) particle image velocimetry (PIV) tests were conducted and the velocity distributions were analyzed. Results A low-velocity region was located inside the pump entrance when a soft silicone tube was used. At 8500 rpm and 3.0 lpm working condition, the minimum velocity inside the pump with cone-shaped cannulas was 2.5×10−1 m/s. The cone-shaped cannulas eliminated the low-velocity region inside the pump. Both CFD and PIV results showed that the low-velocity region did not spread to the entrance of the blood pump within the flow range from 2.0 lpm to 7.0 lpm. Conclusions The designed cone-shaped bent cannulas can eliminate the low-velocity region inside the blood pump and reduce the risk of thrombus formation in the blood pump.
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Affiliation(s)
- Guangmao Liu
- State Key Laboratory of Cardiovascular Disease, Fuwai Hospital, Beijing, China (mainland)
| | - Jianye Zhou
- State Key Laboratory of Cardiovascular Disease, Fuwai Hospital, Beijing, China (mainland)
| | - Hansong Sun
- State Key Laboratory of Cardiovascular Disease, Fuwai Hospital, Beijing, China (mainland)
| | - Yan Zhang
- State Key Laboratory of Cardiovascular Disease, Fuwai Hospital, Beijing, China (mainland)
| | - Haibo Chen
- State Key Laboratory of Cardiovascular Disease, Fuwai Hospital, Beijing, China (mainland)
| | - Shengshou Hu
- State Key Laboratory of Cardiovascular Disease, Fuwai Hospital, Beijing, China (mainland)
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The effectiveness of platelet supplementation for the reversal of ticagrelor-induced inhibition of platelet aggregation: An in-vitro study. Eur J Anaesthesiol 2017; 33:361-7. [PMID: 26351831 DOI: 10.1097/eja.0000000000000348] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND Management of ticagrelor-induced bleeding is challenging, as no antidote is currently available. Platelet transfusion, usually proposed to reverse antiplatelet drugs, has been suggested to be ineffective but few data are available. OBJECTIVE To assess the efficacy of platelet supplementation to restore platelet aggregation inhibited by ticagrelor. DESIGN In vitro study. SETTING Blood samples were obtained from the French Blood Bank Institute. PARTICIPANTS Healthy blood donors. INTERVENTIONS Whole blood from healthy donors was spiked with ticagrelor or aspirin (used as a positive control). MAIN OUTCOME MEASURES Platelet aggregation was investigated with impedance aggregometry on whole blood [expressed in ohms (V)] and light transmission aggregometry (expressed in %) on platelet-rich plasma using ADP or arachidonic acid as agonists for ticagrelor or aspirin, respectively. Platelet supplementation was defined as the addition of washed platelet suspension increasing at least 60% of whole blood platelet count. RESULTS Ticagrelor (3.25 mM) inhibited ADP-induced platelet aggregation compared with control either in whole blood (2 vs. 13 V, P < 0.05) or in platelet-rich plasma (15 vs. 75% P < 0.05). Aspirin (25 mM) inhibited arachidonic acid-induced aggregation (1 vs. 7.5 V, P < 0.05 in whole blood and 5 vs. 77.5%, P = 0.01 in platelet-rich plasma). Platelet supplementation completely restored arachidonic acid-induced platelet aggregation in whole blood (10 vs. 1 V, P = 0.008) and platelet-rich plasma (73 vs. 5%, P < 0.01) in aspirin-treated samples, whereas it failed to correct ADP-induced aggregation (2 vs. 2 V in whole blood and 13.5 vs. 15% in platelet-rich plasma, P > 0.05) in ticagrelor-treated samples. We also report a case of a ticagrelor-treated patient in whom platelet transfusion failed to restore ADP-induced platelet aggregation. CONCLUSION Platelet supplementation restored platelet aggregation in aspirin-spiked but not in ticagrelor-spiked samples. These results do not support the use of platelet transfusion to reverse the effects of ticagrelor.
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Slepian MJ, Sheriff J, Hutchinson M, Tran P, Bajaj N, Garcia JGN, Scott Saavedra S, Bluestein D. Shear-mediated platelet activation in the free flow: Perspectives on the emerging spectrum of cell mechanobiological mechanisms mediating cardiovascular implant thrombosis. J Biomech 2016; 50:20-25. [PMID: 27887727 DOI: 10.1016/j.jbiomech.2016.11.016] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2016] [Accepted: 11/02/2016] [Indexed: 12/13/2022]
Abstract
Shear-mediated platelet activation (SMPA) is central in thrombosis of implantable cardiovascular therapeutic devices. Despite the morbidity and mortality associated with thrombosis of these devices, our understanding of mechanisms operative in SMPA, particularly in free flowing blood, remains limited. Herein we present and discuss a range of emerging mechanisms for consideration for "free flow" activation under supraphysiologic shear. Further definition and manipulation of these mechanisms will afford opportunities for novel pharmacologic and mechanical strategies to limit SMPA and enhance overall implant device safety.
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Affiliation(s)
- Marvin J Slepian
- Departments of Medicine and Biomedical Engineering, University of Arizona, Tucson, AZ 85721, United States; Department of Biomedical Engineering, Stony Brook University, NY 11794, United States.
| | - Jawaad Sheriff
- Department of Biomedical Engineering, Stony Brook University, NY 11794, United States
| | - Marcus Hutchinson
- Departments of Medicine and Biomedical Engineering, University of Arizona, Tucson, AZ 85721, United States
| | - Phat Tran
- Departments of Medicine and Biomedical Engineering, University of Arizona, Tucson, AZ 85721, United States
| | - Naing Bajaj
- Departments of Medicine and Biomedical Engineering, University of Arizona, Tucson, AZ 85721, United States
| | - Joe G N Garcia
- Departments of Medicine and Biomedical Engineering, University of Arizona, Tucson, AZ 85721, United States
| | - S Scott Saavedra
- Departments of Chemistry and Biochemistry, University of Arizona, Tucson, AZ 85721, United States
| | - Danny Bluestein
- Department of Biomedical Engineering, Stony Brook University, NY 11794, United States
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Microfluidic approaches for the assessment of blood cell trauma: a focus on thrombotic risk in mechanical circulatory support devices. Int J Artif Organs 2016; 39:184-93. [PMID: 27034318 DOI: 10.5301/ijao.5000485] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/03/2016] [Indexed: 11/20/2022]
Abstract
INTRODUCTION Mechanical circulatory support devices (MCSDs) are emerging as a valuable therapeutic option for the management of end-stage heart failure. However, although recipients are routinely administered with anti-thrombotic (AT) drugs, thrombosis persists as a severe post-implant complication. Conventional clinical assays and coagulation markers demonstrate partial ability in preventing the onset of thrombosis. Through years, different laboratory techniques have been proposed as potential tools for the evaluation of platelets' hemostatic response in MCSD recipients. Most rely on platelet aggregation tests; they are performed in static or low shear conditions, neglecting the prominent contribution of MCSD shear-induced mechanical load in enhancing platelet activation (PA). On the other hand, those tests able to account for shear-induced PA have limited possibility of effective clinical translation. AIMS AND METHODS Advances on this side have been addressed by microfluidic technology. Microfluidic devices have been developed for AT drug monitoring under flow, able to replicate physiological and/or constant shear flow conditions in vitro. In this paper, we present a newly developed microfluidic platform able to expose platelets to MCSD-specific dynamic shear stress patterns. We performed in vitro tests circulating human platelets in the microfluidic platform and quantifying the dynamics of PA by means of the Platelet Activity State (PAS) assay. RESULTS Our results prove the feasibility of using microfluidics for the diagnosis of MCSD-related thrombotic risk. This study paves the way for the development of a miniaturized point-of-care device for monitoring AT drug regimen. Such a system may have significant impact on limiting the incidence of thrombosis in MCSD recipients.
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Valerio L, Tran PL, Sheriff J, Brengle W, Ghosh R, Chiu WC, Redaelli A, Fiore GB, Pappalardo F, Bluestein D, Slepian MJ. Aspirin has limited ability to modulate shear-mediated platelet activation associated with elevated shear stress of ventricular assist devices. Thromb Res 2016; 140:110-117. [PMID: 26938158 DOI: 10.1016/j.thromres.2016.01.026] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2015] [Revised: 01/25/2016] [Accepted: 01/31/2016] [Indexed: 10/22/2022]
Abstract
Continuous flow ventricular assist devices (cfVADs) while effective in advanced heart failure, remain plagued by thrombosis related to abnormal flows and elevated shear stress. To limit cfVAD thrombosis, patients utilize complex anti-thrombotic regimens built upon a foundation of aspirin (ASA). While much data exists on ASA as a modulator of biochemically-mediated platelet activation, limited data exists as to the efficacy of ASA as a means of limiting shear-mediated platelet activation, particularly under elevated shear stress common within cfVADs. We investigated the ability of ASA (20, 25 and 125 μM) to limit shear-mediated platelet activation under conditions of: 1) constant shear stress (30 dynes/cm(2) and 70 dynes/cm(2)); 2) dynamic shear stress, and 3) initial high shear exposure (70 dynes/cm(2)) followed by low shear exposure - i.e. a platelet sensitization protocol, utilizing a hemodynamic shearing device providing uniform shear stress in vitro. The efficacy of ASA to limit platelet activation mediated via passage through a clinical cfVAD system (DeBakey Micromed) in vitro was also studied. ASA reduced platelet activation only under conditions of low shear stress (38% reduction compared to control, n=10, p<0.004), with minimal protection at higher shear stress and under dynamic conditions (n=10, p>0.5) with no limitation of platelet sensitization. ASA had limited ability (25.6% reduction in platelet activation rate) to modulate shear-mediated platelet activation induced via cfVAD passage. These findings, while performed under "deconstructed" non-clinical conditions by utilizing purified platelets alone in vitro, provide a potential contributory mechanistic explanation for the persistent thrombosis rates experienced clinically in cfVAD patients despite ASA therapy. An opportunity exists to develop enhanced pharmacologic strategies to limit shear-mediated platelet activation at elevated shear levels associated with mechanical circulatory support devices.
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Affiliation(s)
- Lorenzo Valerio
- Department of Electronics, Information, and Bioengineering, Politecnico di Milano, Milan, Italy; Department of Cardiothoracic Anesthesia and Intensive Care, Istituto Scientifico San Raffaele, Milan, Italy.
| | - Phat L Tran
- Department of Biomedical Engineering, University of Arizona, Tucson, AZ, USA
| | - Jawaad Sheriff
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, NY, USA
| | - William Brengle
- Department of Biomedical Engineering, University of Arizona, Tucson, AZ, USA
| | - Ram Ghosh
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, NY, USA
| | - Wei-Che Chiu
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, NY, USA
| | - Alberto Redaelli
- Department of Electronics, Information, and Bioengineering, Politecnico di Milano, Milan, Italy
| | - Gianfranco B Fiore
- Department of Electronics, Information, and Bioengineering, Politecnico di Milano, Milan, Italy
| | - Federico Pappalardo
- Department of Cardiothoracic Anesthesia and Intensive Care, Istituto Scientifico San Raffaele, Milan, Italy
| | - Danny Bluestein
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, NY, USA
| | - Marvin J Slepian
- Department of Biomedical Engineering, University of Arizona, Tucson, AZ, USA; Department of Medicine, Sarver Heart Center, University of Arizona, Tucson, AZ, USA; Department of Biomedical Engineering, Stony Brook University, Stony Brook, NY, USA
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Consolo F, Valerio L, Brizzola S, Rota P, Marazzato G, Vincoli V, Reggiani S, Redaelli A, Fiore G. On the Use of the Platelet Activity State Assay for the In Vitro Quantification of Platelet Activation in Blood Recirculating Devices for Extracorporeal Circulation. Artif Organs 2016; 40:971-980. [DOI: 10.1111/aor.12672] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Affiliation(s)
- Filippo Consolo
- Dipartimento di Elettronica, Informazione e Bioingegneria; Politecnico di Milano; Milano Italy
| | - Lorenzo Valerio
- Dipartimento di Elettronica, Informazione e Bioingegneria; Politecnico di Milano; Milano Italy
| | - Stefano Brizzola
- Dipartimento di Scienze Veterinarie per la Salute, la Produzione Animale e la Sicurezza Alimentare, Facoltà di Medicina Veterinaria; Università di Milano; Milano Italy
| | - Paolo Rota
- Dipartimento di Elettronica, Informazione e Bioingegneria; Politecnico di Milano; Milano Italy
| | - Giulia Marazzato
- Dipartimento di Elettronica, Informazione e Bioingegneria; Politecnico di Milano; Milano Italy
| | - Valentina Vincoli
- Dipartimento di Elettronica, Informazione e Bioingegneria; Politecnico di Milano; Milano Italy
| | | | - Alberto Redaelli
- Dipartimento di Elettronica, Informazione e Bioingegneria; Politecnico di Milano; Milano Italy
| | - Gianfranco Fiore
- Dipartimento di Elettronica, Informazione e Bioingegneria; Politecnico di Milano; Milano Italy
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Management of anticoagulation and antiplatelet therapy in patients with left ventricular assist devices. J Thromb Thrombolysis 2015; 39:337-44. [PMID: 25549823 DOI: 10.1007/s11239-014-1162-6] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Left ventricular assist devices (LVADs) have increased the survival of patients with advanced heart failure fourfold. Despite these advances, significant bleeding and thrombotic complications occur. Hemorrhage requiring surgery has been reported in up to 30% of adults and 50% of children after LVAD placement. LVAD thrombosis and embolic stroke lead to significant long-term morbidity. Adults are treated with antithrombotic therapy to prevent thrombotic complications, but the amount and intensity of treatment differs between institutions. The goal international normalized ratio for warfarin therapy varies from 1.5 to 3.0. Some physicians manage adult LVAD patients without antiplatelet medication, whereas other adults are treated with aspirin as a single agent or combined with dipyridamole. In contrast, physicians typically manage children with LVADs using the Edmonton Anticoagulation and Platelet Inhibition Protocol, a detailed algorithm for anticoagulation and antiplatelet treatment modified based on thromboelastography results. LVAD implantation causes consumption of coagulation proteins, activation of fibrinolysis, and loss of high molecular weight von Willebrand protein multimers. How these changes in the coagulation system influence the risk of hemorrhage and initiation of thrombosis is unknown. Prospective, controlled studies are needed to determine the antithrombotic regimen that most effectively balances bleeding and thrombosis in LVAD patients.
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Sheriff J, Claiborne TE, Tran PL, Kothadia R, George S, Kato YP, Pinchuk L, Slepian MJ, Bluestein D. Physical Characterization and Platelet Interactions under Shear Flows of a Novel Thermoset Polyisobutylene-based Co-polymer. ACS APPLIED MATERIALS & INTERFACES 2015; 7:22058-22066. [PMID: 26398588 PMCID: PMC4608843 DOI: 10.1021/acsami.5b07254] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Over the years, several polymers have been developed for use in prosthetic heart valves as alternatives to xenografts. However, most of these materials are beset with a variety of issues, including low material strength, biodegradation, high dynamic creep, calcification, and poor hemocompatibility. We studied the mechanical, surface, and flow-mediated thrombogenic response of poly(styrene-coblock-4-vinylbenzocyclobutene)-polyisobutylene-poly(styrene-coblock-4-vinylbenzocylcobutene) (xSIBS), a thermoset version of the thermoplastic elastomeric polyolefin poly(styrene-block-isobutylene-block-styrene) (SIBS), which has been shown to be resistant to in vivo hydrolysis, oxidation, and enzymolysis. Uniaxial tensile testing yielded an ultimate tensile strength of 35 MPa, 24.5 times greater than that of SIBS. Surface analysis yielded a mean contact angle of 82.05° and surface roughness of 144 nm, which was greater than for poly(ε-caprolactone) (PCL) and poly(methyl methacrylate) (PMMA). However, the change in platelet activation state, a predictor of thrombogenicity, was not significantly different from PCL and PMMA after fluid exposure to 1 dyn/cm(2) and 20 dyn/cm(2). In addition, the number of adherent platelets after 10 dyn/cm(2) flow exposure was on the same order of magnitude as PCL and PMMA. The mechanical strength and low thrombogenicity of xSIBS therefore suggest it as a viable polymeric substrate for fabrication of prosthetic heart valves and other cardiovascular devices.
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Affiliation(s)
- Jawaad Sheriff
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, NY 11794-8151, USA
| | - Thomas E. Claiborne
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, NY 11794-8151, USA
| | - Phat L. Tran
- Department of Biomedical Engineering, University of Arizona, Tucson, AZ 85721, USA
| | - Roshni Kothadia
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, NY 11794-8151, USA
| | - Sheela George
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, NY 11794-8151, USA
| | | | | | - Marvin J. Slepian
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, NY 11794-8151, USA
- Department of Biomedical Engineering, University of Arizona, Tucson, AZ 85721, USA
- Sarver Heart Center, University of Arizona, Tucson, AZ 85721, USA
| | - Danny Bluestein
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, NY 11794-8151, USA
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Valerio L, Consolo F, Bluestein D, Tran P, Slepian M, Redaelli A, Pappalardo F. Shear-mediated platelet activation in patients implanted with continuous flow LVADs: A preliminary study utilizing the platelet activity state (PAS) assay. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2015; 2015:1255-1258. [PMID: 26736495 DOI: 10.1109/embc.2015.7318595] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Left ventricular assist devices (LVADs) have emerged as vital life-saving therapeutic systems for patients with advanced and end-stage heart failure (HF). Despite their efficacy, VAD systems remain limited by post-implantation thrombotic complications. Shear-mediated platelet activation is the major driver of such complications in these devices. Nowadays few platelet function assays are routinely utilized in assessing the degree of platelet activation in VAD implanted patients. No assays exist that specifically target shear-mediated platelet activation. The platelet activity state (PAS) is a novel assay that has been well validated in vitro, measuring thrombin release as a surrogate for shear-mediated platelet activation. To date limited data exist as to the utility of this assay in the clinical setting. In the present study we evaluated eight LVAD patients' platelet activation level using the PAS assay. Simultaneous measurements of conventional prothrombotic and hemolysis markers, - i.e. fibrinogen and lactate dehydrogenase (LDH) - were also performed. Trends as to alteration from baseline were studied. We observed that the PAS assay allowed detection of an abnormal level of platelet activation in one patient in our series who suffered from an overt thrombosis. Interestingly in the same patient no signal of major abnormality in fibrinogen or LDH was detected. Further for 7/8 patients who were free of thrombosis, no significant level of platelet activation was detected via PAS assay, while elevation in fibrinogen and LDH were observed. As such, from our observational series it appears that the PAS assay is a sensitive and specific indicator of shear-mediated platelet activation. Further patients' experience will help elucidate the role of this promising assay in the management of LVAD implanted patients.
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