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von Glinski M, Voigt M, Sogorski A, Wallner C, Dadras M, Behr B, Lehnhardt M, Goertz O. Influence of Remote Ischemic Conditioning and Nitrogen Monoxide on Angiogenesis and Microcirculation in a Mouse Ear Burn Model. J Surg Res 2024; 293:347-356. [PMID: 37806221 DOI: 10.1016/j.jss.2023.08.035] [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: 01/17/2022] [Revised: 07/25/2023] [Accepted: 08/28/2023] [Indexed: 10/10/2023]
Abstract
INTRODUCTION Remote ischemic conditioning (RIC) has been shown to improve tissue resilience against ischemia. The aim of this study was to investigate the influence of RIC and its key factor, nitrogen monoxide (NO), on angiogenesis in a burn wound. MATERIALS AND METHODS A unilateral burn injury on the ear of hairless mice (n = 48) was generated via a hot air jet in a contact-free manner. In four randomized groups, including the control (NoRIC group), RIC alone (RIConly group), RIC plus NO donor (ISDN group), and RIC plus NO synthase inhibitor (L-NAME group), the impact on angiogenesis, vessel diameter, blood flow, edema formation, and leukocyte-endothelial-cell interaction was evaluated over a 12-d period using intravital fluorescence microscopy. RESULTS Tissue perfusion was significantly improved by RIC (Day 3: ISDN group showed 182% and RIConly group showed 200% of baseline [BL], P < 0.001), while angiogenesis was not improved by RIC (nonperfused area on Day 12: mean 52% of BL in all groups, P >0.05). The application of ISDN did not further enhance the positive effect of RIC, whereas the application of L-NAME neutralized the effect of RIC. The most pronounced edema formation was observed in the RIConly group (mean 145% of BL, P ≤0.001), while the NoRIC group showed the least edema formation (Day 12: 117% of BL). CONCLUSIONS RIC led to increased tissue perfusion, which did not result in improved angiogenesis, which may have been due to increased edema formation after RIC performance. The results of the present study do not support the establishment of a causal therapy strategy for burn wounds, including RIC.
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Affiliation(s)
- Maxi von Glinski
- Department of Plastic and Hand Surgery, Burn Center, BG-University Hospital Bergmannsheil, Ruhr University Bochum, Bochum, Germany.
| | - Maria Voigt
- Department of Plastic and Hand Surgery, Burn Center, BG-University Hospital Bergmannsheil, Ruhr University Bochum, Bochum, Germany
| | - Alexander Sogorski
- Department of Plastic and Hand Surgery, Burn Center, BG-University Hospital Bergmannsheil, Ruhr University Bochum, Bochum, Germany
| | - Christoph Wallner
- Department of Plastic and Hand Surgery, Burn Center, BG-University Hospital Bergmannsheil, Ruhr University Bochum, Bochum, Germany
| | - Mehran Dadras
- Department of Plastic and Hand Surgery, Burn Center, BG-University Hospital Bergmannsheil, Ruhr University Bochum, Bochum, Germany
| | - Bjoern Behr
- Department of Plastic and Hand Surgery, Burn Center, BG-University Hospital Bergmannsheil, Ruhr University Bochum, Bochum, Germany
| | - Marcus Lehnhardt
- Department of Plastic and Hand Surgery, Burn Center, BG-University Hospital Bergmannsheil, Ruhr University Bochum, Bochum, Germany
| | - Ole Goertz
- Department of Plastic and Hand Surgery, Burn Center, BG-University Hospital Bergmannsheil, Ruhr University Bochum, Bochum, Germany; Department of Plastic, Reconstructive and Aesthetic Surgery, Hand Surgery, Martin-Luther Hospital, Berlin, Germany
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Wahlstrøm KL, Ekeloef S, Sidelmann JJ, Gögenur I, Münster AMB. Effect of remote ischemic preconditioning on fibrin formation and metabolism in patients undergoing hip fracture surgery: a randomized clinical trial. Blood Coagul Fibrinolysis 2022; 33:25-33. [PMID: 34561340 PMCID: PMC8728681 DOI: 10.1097/mbc.0000000000001090] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2021] [Revised: 09/03/2021] [Accepted: 09/07/2021] [Indexed: 11/30/2022]
Abstract
Remote ischemic preconditioning (RIPC) prior to surgery has recently been shown to reduce the risk of myocardial injury and myocardial infarction after hip fracture surgery. This study investigated whether RIPC initiated antithrombotic mechanisms in patients undergoing hip fracture surgery. This trial was a predefined sub-study of a multicentre randomized clinical trial. Adult patients with cardiovascular risk factors undergoing hip fracture surgery between September 2015 and September 2017 were randomized 1 : 1 to RIPC or control. RIPC was initiated before surgery with a tourniquet applied to the upper arm and it consisted of four cycles of 5 min of forearm ischemia followed by five minutes of reperfusion. The outcomes such as surgery-induced changes in thrombin generation, fibrinogen/fibrin turnover, tissue plasminogen activator, plasminogen activator inhibitor-1 and fibrin structure measurements were determined preoperatively (prior to RIPC) and 2 h postoperatively. One hundred and thirty-seven patients were randomized to RIPC (n = 65) or control (n = 72). There were no significant changes in thrombin generation, fibrinogen/fibrin turnover or fibrin structure measurements determined pre and postoperatively between patients in the RIPC and control groups. Subgroup analyses on patients not on anticoagulant therapy (n = 103), patients receiving warfarin (n = 17) and patients receiving direct oral anticoagulant therapy (n = 18) showed no significant changes between the RIPC-patients and controls. RIPC did not affect changes in thrombin generation, fibrin turnover or fibrin structure in adult patients undergoing hip fracture surgery suggesting that the cardiovascular effect of RIPC in hip fracture surgery is not related to alterations in fibrinogen/fibrin metabolism.
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Affiliation(s)
- Kirsten L. Wahlstrøm
- Centre for Surgical Science, Department of Surgery, Zealand University Hospital, Køge
| | - Sarah Ekeloef
- Centre for Surgical Science, Department of Surgery, Zealand University Hospital, Køge
| | - Johannes J. Sidelmann
- Unit for Thrombosis Research, Department of Regional Health Research, University of Southern Denmark and Department of Clinical Biochemistry, University Hospital of Southern Denmark
| | - Ismail Gögenur
- Centre for Surgical Science, Department of Surgery, Zealand University Hospital, Køge
| | - Anna-Marie B. Münster
- Unit for Thrombosis Research, Department of Regional Health Research, University of Southern Denmark and Department of Clinical Biochemistry, University Hospital of Southern Denmark
- Department of Clinical Biochemistry, Regional Hospital West Jutland, Holstebro, Denmark
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Kleinbongard P, Andreadou I, Vilahur G. The platelet paradox of injury versus protection in myocardial infarction-has it been overlooked? Basic Res Cardiol 2021; 116:37. [PMID: 34037862 PMCID: PMC8150149 DOI: 10.1007/s00395-021-00876-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/26/2021] [Accepted: 04/26/2021] [Indexed: 02/06/2023]
Affiliation(s)
- Petra Kleinbongard
- Institute for Pathophysiology, West German Heart and Vascular Center, University of Essen Medical School, University of Duisburg-Essen, Hufelandstr. 55, 45122, Essen, Germany.
| | - Ioanna Andreadou
- Laboratory of Pharmacology, Faculty of Pharmacy, National and Kapodistrian University of Athens, Athens, Greece
| | - Gemma Vilahur
- CIBERCV, Instituto Salud Carlos III, Madrid, Spain.,Cardiovascular Research Chair Autonomous University of Barcelona (UAB), Barcelona, Spain
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Baig S, Moyle B, Nair KPS, Redgrave J, Majid A, Ali A. Remote ischaemic conditioning for stroke: unanswered questions and future directions. Stroke Vasc Neurol 2021; 6:298-309. [PMID: 33903181 PMCID: PMC8258051 DOI: 10.1136/svn-2020-000722] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2020] [Revised: 01/13/2021] [Accepted: 01/31/2021] [Indexed: 11/07/2022] Open
Abstract
Remote ischaemic conditioning (RIC) refers to a process whereby periods of intermittent ischaemia, typically via the cyclical application of a blood pressure cuff to a limb at above systolic pressure, confers systemic protection against ischaemia in spatially distinct vascular territories. The mechanisms underlying this have not been characterised fully but have been shown to involve neural, hormonal and systemic inflammatory signalling cascades. Preclinical and early clinical studies have been promising and suggest beneficial effects of RIC in acute ischaemic stroke, symptomatic intracranial stenosis and vascular cognitive impairment. Through systematic searches of several clinical trials databases we identified 48 active clinical trials of RIC in ischaemic stroke, intracerebral haemorrhage and subarachnoid haemorrhage. We summarise the different RIC protocols and outcome measures studied in ongoing clinical trials and highlight which studies are most likely to elucidate the underlying biological mechanisms of RIC and characterise its efficacy in the near future. We discuss the uncertainties of RIC including the optimal frequency and duration of therapy, target patient groups, cost-effectiveness, the confounding impact of medications and the absence of a clinically meaningful biomarker of the conditioning response. With several large clinical trials of RIC expected to report their outcomes within the next 2 years, this review aims to highlight the most important studies and unanswered questions that will need to be addressed before this potentially widely accessible and low-cost intervention can be used in clinical practice.
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Affiliation(s)
- Sheharyar Baig
- Cerebrovascular Medicine, The University of Sheffield Institute for Translational Neuroscience, Sheffield, UK
| | - Bethany Moyle
- Cerebrovascular Medicine, The University of Sheffield Institute for Translational Neuroscience, Sheffield, UK
| | | | - Jessica Redgrave
- Cerebrovascular Medicine, The University of Sheffield Institute for Translational Neuroscience, Sheffield, UK
| | - Arshad Majid
- Faculty of Medicine and Dentistry, University of Sheffield, Sheffield, UK
| | - Ali Ali
- Geriatrics and Stroke Medicine, Sheffield Teaching Hospitals NHS Foundation Trust, Sheffield, UK .,Sheffield NIHR Biomedical Research Centre, The University of Sheffield, Sheffield, UK
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Cho YJ, Nam K, Yoo SJ, Lee S, Bae J, Park JY, Kim HR, Kim TK, Jeon Y. Effects of remote ischemic preconditioning on platelet activation and reactivity in patients undergoing cardiac surgery using cardiopulmonary bypass: a randomized controlled trial. Platelets 2020; 33:123-131. [PMID: 33307907 DOI: 10.1080/09537104.2020.1856362] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
During cardiopulmonary bypass (CPB), platelet activation and dysfunction are associated with adverse outcomes. Remote ischemic preconditioning (RIPC) has been shown to attenuate platelet activation. We evaluated the effects of RIPC on platelet activation during CPB in patients undergoing cardiac surgery. Among 58 randomized patients, 26 in the RIPC group and 28 in the sham-RIPC group were analyzed. RIPC consisted of 4 cycles of 5-min ischemia induced by inflation of pneumatic cuff pressure to 200 mmHg, followed by 5-min reperfusion comprising deflation of the cuff on the upper arm. Platelet activation was assessed using flow cytometry analysis of platelet activation markers. The primary endpoint was the AUC of CD62P expression during the first 3 h after initiation of CPB. Secondary outcomes were the AUC of PAC-1 expression and monocyte-platelet aggregates (MPA) during 3 h of CPB. The AUCs of CD62P expression during 3 h after initiation of CPB were 219.4 ± 43.9 and 211.0 ± 41.2 MFI in the RIPC and sham-RIPC groups, respectively (mean difference, 8.42; 95% CI, -14.8 and 31.7 MFI; p =.471). The AUCs of PAC-1 expression and MPA did not differ between groups. RIPC did not alter platelet activation and reactivity during CPB in patients undergoing cardiac surgery.
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Affiliation(s)
- Youn Joung Cho
- Department of Anesthesiology and Pain Medicine, Seoul National University Hospital, Seoul National University College of Medicine, Seoul, Korea
| | - Karam Nam
- Department of Anesthesiology and Pain Medicine, Seoul National University Hospital, Seoul National University College of Medicine, Seoul, Korea
| | - Sol Ji Yoo
- Department of Anesthesiology and Pain Medicine, Seoul National University Hospital, Seoul National University College of Medicine, Seoul, Korea
| | - Seohee Lee
- Department of Anesthesiology and Pain Medicine, Seoul National University Hospital, Seoul National University College of Medicine, Seoul, Korea
| | - Jinyoung Bae
- Department of Anesthesiology and Pain Medicine, Seoul National University Hospital, Seoul National University College of Medicine, Seoul, Korea
| | - Ji-Young Park
- FACS Core Facility, Seoul National University College of Medicine, Seoul, Korea
| | - Hang-Rae Kim
- Department of Biomedical Sciences, BK21 FOUR Biomedical Science Project, Seoul National University College of Medicine, Seoul, Korea
| | - Tae Kyong Kim
- Department of Anesthesiology and Pain Medicine, Seoul National University Hospital, Seoul National University College of Medicine, Seoul, Korea.,Department of Anesthesiology and Pain Medicine, SMG-SNU Boramae Medical Center, Seoul National University College of Medicine, Seoul, Korea
| | - Yunseok Jeon
- Department of Anesthesiology and Pain Medicine, Seoul National University Hospital, Seoul National University College of Medicine, Seoul, Korea
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Gorog DA, Farag M, Spinthakis N, Yellon DM, Bøtker HE, Kharbanda RK, Hausenloy DJ. Effect of remote ischaemic conditioning on platelet reactivity and endogenous fibrinolysis in ST-elevation myocardial infarction: a substudy of the CONDI-2/ERIC-PPCI randomized controlled trial. Cardiovasc Res 2020; 117:623-634. [PMID: 32163139 DOI: 10.1093/cvr/cvaa061] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/09/2020] [Revised: 02/20/2020] [Accepted: 03/11/2020] [Indexed: 01/30/2023] Open
Abstract
AIMS Remote ischaemic conditioning (RIC) has been shown to reduce myocardial infarct size in animal models of myocardial infarction. Platelet thrombus formation is a critical determinant of outcome in ST-segment elevation myocardial infarction (STEMI). Whether the beneficial effects of RIC are related to thrombotic parameters is unclear. METHODS AND RESULTS In a substudy of the Effect of Remote Ischaemic Conditioning on clinical outcomes in STEMI patients undergoing Primary Percutaneous Coronary Intervention (ERIC-PPCI) trial, we assessed the effect of RIC on thrombotic status. Patients presenting with STEMI were randomized to immediate RIC consisting of an automated autoRIC™ cuff on the upper arm inflated to 200 mmHg for 5 min and deflated for 5 min for four cycles (n = 53) or sham (n = 47). Venous blood was tested at presentation, discharge (48 h) and 6-8 weeks, to assess platelet reactivity, coagulation, and endogenous fibrinolysis using the Global Thrombosis Test and thromboelastography. Baseline thrombotic status was similar in the two groups. At discharge, there was some evidence that the time to in vitro thrombotic occlusion under high shear stress was longer with RIC compared to sham (454 ± 105 s vs. 403 ± 105 s; mean difference 50.1 s; 95% confidence interval 93.7-6.4, P = 0.025), but this was no longer apparent at 6-8 weeks. There was no difference in clot formation or endogenous fibrinolysis between the study arms at any time point. CONCLUSION RIC may reduce platelet reactivity in the first 48 h post-STEMI. Further research is needed to delineate mechanisms through which RIC may reduce platelet reactivity, and whether it may improve outcomes in patients with persistent high on-treatment platelet reactivity.
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Affiliation(s)
- Diana A Gorog
- National Heart and Lung Institute, Faculty of Medicine, Imperial College, Dovehouse Street, London SW3 6LR, UK.,Postgraduate Medical School, University of Hertfordshire, Hertfordshire, UK.,Department of Cardiology, East and North Hertfordshire NHS Trust, Hertfordshire, UK
| | - Mohamed Farag
- Postgraduate Medical School, University of Hertfordshire, Hertfordshire, UK.,Cardiology Department, Royal Papworth Hospital NHS Foundation Trust, Papworth Everard, Cambridge, UK
| | - Nikolaos Spinthakis
- Postgraduate Medical School, University of Hertfordshire, Hertfordshire, UK.,Department of Cardiology, East and North Hertfordshire NHS Trust, Hertfordshire, UK
| | - Derek M Yellon
- The Hatter Cardiovascular Institute, University College London, London, UK
| | - Hans Erik Bøtker
- Department of Cardiology, Aarhus University Hospital, Aarhus N, Denmark
| | - Rajesh K Kharbanda
- Cardiology Department, Oxford Heart Centre, Oxford University Hospitals NHS Trust, Oxford, UK.,Department of Cardiovascular Medicine, University of Oxford, Oxford, UK
| | - Derek J Hausenloy
- The Hatter Cardiovascular Institute, University College London, London, UK.,Cardiovascular & Metabolic Disorders Program, Duke-National University of Singapore Medical School, Singapore, Singapore.,Department of Cardiology, National Heart Research Institute Singapore, National Heart Centre, Singapore, Singapore.,Yong Loo Lin School of Medicine, National University Singapore, Singapore, Singapore.,Cardiovascular Research Center, College of Medical and Health Sciences, Asia University, Taichung City, Taiwan.,Tecnologico de Monterrey, Centro de Biotecnologia-FEMSA, Nuevo Leon, Mexico
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7
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Heinen A, Welke V, Behmenburg F, Stroethoff M, Stoldt V, Hoffmann T, Hollmann MW, Huhn R. Haemotherapy with Fibrinogen for Perioperative Bleeding Prevention-A View on Arterial Thrombogenesis and Myocardial Infarction in the Rat In Vivo. J Clin Med 2019; 8:jcm8060880. [PMID: 31248164 PMCID: PMC6617325 DOI: 10.3390/jcm8060880] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2019] [Revised: 06/13/2019] [Accepted: 06/17/2019] [Indexed: 01/05/2023] Open
Abstract
Major blood loss during cardiac surgery is associated with increased morbidity and mortality. Clinical pilot studies indicated that preoperative fibrinogen supplementation reduces postoperative blood loss without increasing thrombotic complications. However, an increase in fibrinogen concentration might rather aggravate pre-existing thrombosis than increase the incidence of thrombotic events. Therefore, we investigated, in the present study, whether fibrinogen supplementation influences (1) arterial thrombus formation, (2) the extent of myocardial infarction and (3) the cardioprotective effect of ischaemic preconditioning. Arterial thrombogenesis of the femoral artery was induced by topic FeCl3 treatment in anaesthetised Wistar rats after pretreatment with 60 mg/kg (Fiblow), 120 mg/kg (Fibhigh) or vehicle (Con). Vessel blood flow was monitored, and time to vessel occlusion was analysed as a marker for arterial thrombogenesis. In addition, regional myocardial I/R injury was induced by temporary left coronary artery occlusion in rats pretreated with or without fibrinogen supplementation. In additional groups, ischaemic preconditioning (IPC) was induced by 3 cycles of 5 min of ischaemia/reperfusion. In all groups, myocardial infarct size was determined by triphenyltetrazoliumchlorid staining. Arterial thrombogenesis was not affected by fibrinogen pretreatment. No differences in time until vessel occlusion between Con, Fiblow and Fibhigh groups were observed. In addition, fibrinogen supplementation in low and high concentrations had no effect on infarct size after regional myocardial ischaemia and reperfusion (Fiblow: 66 ± 10%, Fibhigh: 62 ± 9%; each ns vs. Con). IPC reduced infarct size from 62 ± 14% to 34 ± 12% (p < 0.05 vs. Con). Furthermore, both fibrinogen concentrations did not affect cardioprotection by ischaemic preconditioning (Fiblow + IPC: 34 ± 11%, Fibhigh + IPC: 31 ± 13%; each ns vs. IPC). Haemotherapy with fibrinogen did not affect arterial thrombogenesis, myocardial infarction and the cardioprotective effect of ischaemic preconditioning.
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Affiliation(s)
- André Heinen
- Institute of Cardiovascular Physiology, Heinrich-Heine-University Duesseldorf, Universitaetsstr. 1, 40225 Duesseldorf, Germany.
| | - Vera Welke
- Department of Anesthesiology, University Hospital Duesseldorf, Moorenstr. 5, 40225 Duesseldorf, Germany.
| | - Friederike Behmenburg
- Department of Anesthesiology, University Hospital Duesseldorf, Moorenstr. 5, 40225 Duesseldorf, Germany.
| | - Martin Stroethoff
- Department of Anesthesiology, University Hospital Duesseldorf, Moorenstr. 5, 40225 Duesseldorf, Germany.
| | - Volker Stoldt
- Department of General, Visceral and Pediatric Surgery, University Hospital Duesseldorf, Moorenstr. 5, 40225 Duesseldorf, Germany.
| | - Till Hoffmann
- Institute of Transplantation Diagnostics and Cell Therapeutics, University Hospital Duesseldorf, Moorenstr. 5, 40225 Duesseldorf, Germany.
| | - Markus W Hollmann
- Department of Anesthesiology, Amsterdam University Medical Center (AUMC), Location AMC, Meiberdreef 9, 1105 AZ Amsterdam, The Netherlands.
| | - Ragnar Huhn
- Department of Anesthesiology, University Hospital Duesseldorf, Moorenstr. 5, 40225 Duesseldorf, Germany.
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Ziegler M, Wang X, Peter K. Platelets in cardiac ischaemia/reperfusion injury: a promising therapeutic target. Cardiovasc Res 2019; 115:1178-1188. [PMID: 30906948 PMCID: PMC6529900 DOI: 10.1093/cvr/cvz070] [Citation(s) in RCA: 78] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/14/2018] [Revised: 02/01/2019] [Accepted: 03/21/2019] [Indexed: 12/21/2022] Open
Abstract
Acute myocardial infarction (AMI) is the single leading cause of mortality and morbidity worldwide. A key component of AMI therapy is the timely reopening of occluded vessels to prevent further ischaemic damage to the myocardium. However, reperfusion of the ischaemic myocardium can itself trigger reperfusion injury causing up to 50% of the overall infarct size. In recent years, considerable research has been devoted to understanding the pathogenesis of ischaemia/reperfusion (I/R) injury and platelets have emerged as a major contributing factor. This review summarizes the role of platelets in the pathogenesis of I/R injury and highlights the potential of platelet-directed therapeutics to minimize cardiac I/R injury. Activated platelets infiltrate specifically into the ischaemic/reperfused myocardium and contribute to I/R injury by the formation of microthrombi, enhanced platelet-leucocyte aggregation, and the release of potent vasoconstrictor and pro-inflammatory molecules. This review demonstrates the benefits of platelet inhibition beyond their well-described anti-thrombotic effect and highlights the direct cardioprotective role of anti-platelet drugs. In particular, the inhibition of COX, the P2Y12 receptor and the GPIIb/IIIa receptor has demonstrated the potential to attenuate I/R injury. Moreover, targeting of drug candidates or regenerative cells to the activated platelets accumulated within the ischaemic/reperfused myocardium shows remarkable potential to protect the myocardium from I/R injury. Overall, activated platelets play a key role in the pathogenesis of I/R injury. Their direct inhibition as well as their use as epitopes for site-directed therapy is a unique and promising therapeutic approach for the prevention of I/R injury and ultimately the preservation of cardiac function.
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Affiliation(s)
- Melanie Ziegler
- Atherothrombosis and Vascular Biology Laboratory, Baker Heart and Diabetes Institute, Commercial Road 75, Melbourne, Australia
| | - Xiaowei Wang
- Atherothrombosis and Vascular Biology Laboratory, Baker Heart and Diabetes Institute, Commercial Road 75, Melbourne, Australia
| | - Karlheinz Peter
- Atherothrombosis and Vascular Biology Laboratory, Baker Heart and Diabetes Institute, Commercial Road 75, Melbourne, Australia
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9
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Han R, Liu X, Zheng M, Zhao R, Liu X, Yin X, Liu X, Tian Y, Shi L, Sun K, Yang X. Effect of remote ischemic preconditioning on left atrial remodeling and prothrombotic response after radiofrequency catheter ablation for atrial fibrillation. PACING AND CLINICAL ELECTROPHYSIOLOGY: PACE 2018; 41:246-254. [PMID: 29315665 DOI: 10.1111/pace.13271] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/23/2016] [Revised: 11/30/2017] [Accepted: 12/04/2017] [Indexed: 11/30/2022]
Affiliation(s)
- Ruijuan Han
- Heart Center, Beijing Chao-Yang Hospital; Capital Medical University; Beijing 100020 China
- Translational Medicine Research Center; Baotou Central Hospital, Inner Mongolia; Baotou 014040 China
| | - Xiaoqing Liu
- Heart Center, Beijing Chao-Yang Hospital; Capital Medical University; Beijing 100020 China
| | - Meili Zheng
- Heart Center, Beijing Chao-Yang Hospital; Capital Medical University; Beijing 100020 China
| | - RuiPing Zhao
- Translational Medicine Research Center; Baotou Central Hospital, Inner Mongolia; Baotou 014040 China
| | - XiaoYan Liu
- Heart Center, Beijing Chao-Yang Hospital; Capital Medical University; Beijing 100020 China
| | - Xiandong Yin
- Heart Center, Beijing Chao-Yang Hospital; Capital Medical University; Beijing 100020 China
| | - Xingpeng Liu
- Heart Center, Beijing Chao-Yang Hospital; Capital Medical University; Beijing 100020 China
| | - Ying Tian
- Heart Center, Beijing Chao-Yang Hospital; Capital Medical University; Beijing 100020 China
| | - Liang Shi
- Heart Center, Beijing Chao-Yang Hospital; Capital Medical University; Beijing 100020 China
| | - Kai Sun
- Translational Medicine Research Center; Baotou Central Hospital, Inner Mongolia; Baotou 014040 China
- Department of Radiology, Cardiovascular Institute and Fu Wai Hospital, Chinese Academy of Medical Sciences; Peking Union Medical College, Xi-Cheng District; Beijing 100037 China
| | - Xinchun Yang
- Heart Center, Beijing Chao-Yang Hospital; Capital Medical University; Beijing 100020 China
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Przyklenk K, Whittaker P. Ischemic Conditioning Attenuates Platelet-Mediated Thrombosis. J Cardiovasc Pharmacol Ther 2017; 22:391-396. [DOI: 10.1177/1074248417724871] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Data obtained in both preclinical models and humans have revealed that the favorable cardiac consequences of ischemic conditioning extend beyond a direct effect on the cardiomyocyte. In the current review, we summarize our as-yet limited understanding of the complex relationships between ischemic conditioning, platelet activation–aggregation, and cardioprotection.
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Affiliation(s)
- Karin Przyklenk
- Cardiovascular Research Institute, Wayne State University School of Medicine, Detroit, MI, USA
- Department of Emergency Medicine, Wayne State University School of Medicine, Detroit, MI, USA
- Department of Physiology, Wayne State University School of Medicine, Detroit, MI, USA
| | - Peter Whittaker
- Cardiovascular Research Institute, Wayne State University School of Medicine, Detroit, MI, USA
- Department of Emergency Medicine, Wayne State University School of Medicine, Detroit, MI, USA
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11
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Kwong W, Parker JD. The Effect of Clopidogrel on the Response to Ischemia Reperfusion. J Cardiovasc Pharmacol Ther 2016; 22:368-373. [DOI: 10.1177/1074248416683047] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Reperfusion in the setting of acute ischemia is essential in limiting tissue necrosis. However, reperfusion itself is associated with significant adverse effects. There is animal evidence that platelets play a role in the adverse effects of ischemia and reperfusion (IR) injury. We examined whether clopidogrel would have favorable effects on endothelial dysfunction induced by an episode of IR. Using a parallel design, we administered clopidogrel 600 mg or matching placebo to normal volunteers (n = 20) 24 hours before an episode of IR. Flow-mediated dilatation (FMD, radial artery) was assessed before and after 20 minutes of upper arm ischemia. Following IR, there was a highly significant decrease in FMD in the placebo group (7.6% ± 1.3% vs 3.4% ± 0.1%; P < .001). In the clopidogrel group, there was no change in FMD post-IR (8.3% ± 0.8% vs 7.1% ± 1.2%; P = not significant). Following IR, FMD in the placebo group was significantly smaller than that observed in the clopidogrel group ( P < .01). Ischemia and reperfusion caused no change in plasma levels of biomarkers of inflammation (intercellular adhesion molecule 1, chemokine ligand 5, and interleukin 6) in either group. Therefore, a single dose of clopidogrel given 24 hours prior to an episode of IR had protective effects, limiting the adverse effects of ischemia on endothelial function.
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Affiliation(s)
- Wilson Kwong
- Division of Cardiology, Mount Sinai and University Health Network Hospitals, Toronto, Ontario, Canada
- Department of Pharmacology and Toxicology, University of Toronto, Toronto, Ontario, Canada
| | - John D. Parker
- Division of Cardiology, Mount Sinai and University Health Network Hospitals, Toronto, Ontario, Canada
- Department of Pharmacology and Toxicology, University of Toronto, Toronto, Ontario, Canada
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12
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Leunissen TC, Gijsberts CM, Wisman PP, Huisman A, Berg MT, Asselbergs FW, Hoefer IE, Pasterkamp G, Moll FL, de Borst GJ, Roest M. Lower Platelet Reactivity Is Associated with Presentation of Unstable Coronary Artery Disease. Int J Angiol 2016; 25:210-218. [PMID: 27867285 DOI: 10.1055/s-0036-1593823] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
In patients with acute coronary syndrome, high platelet reactivity (PR) is associated with an increased risk of secondary thrombotic events. However, in patients undergoing elective percutaneous coronary intervention (PCI), no association between high PR and outcome has been demonstrated. At present, the relation of PR and clinical symptoms is unknown. To examine the association of PR with clinical indication for diagnostic angiography (stable or unstable coronary artery disease [CAD]), taking into account the influence of P2Y12 inhibitors. A platelet function score (PFS) was determined in 195 patients by quantifying fibrinogen binding and P-selectin expression with flow cytometry. We evaluated the PFS with clinical presentation of stable or unstable CAD, angiographic severity of CAD, and the incidence of cardiovascular events during 2 years of follow-up. All data were analyzed stratified by P2Y12 inhibitor use (long-term and preprocedural versus none). Surprisingly, among non-P2Y12 inhibitor users, the PFS was lower in patients with unstable CAD compared with stable CAD (5.6 ± 1.8 vs. 7.4 ± 1.6; p = 0.001). Angiographic CAD severity showed no relation with PFS. The SYNTAX score tended to be inversely related with PFS: low PFS, 13.2 (IQR, 11.9-19.1); median PFS, 10.0 (IQR, 5.0-14.0); and high PFS, 8.0 (IQR, 5.0-13.0), without significance (p = 0.304). Patients with low PFSs required more re-PCIs than those with median and high PFSs (11.1 vs. 4.7 vs. 0.0%, p = 0.004). This association was modified for patients using P2Y12 inhibitors. Among patients without P2Y12 inhibitors undergoing coronary angiography, presentation of unstable CAD is independently associated with lower PR.
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Affiliation(s)
- Tesse C Leunissen
- Department of Clinical Chemistry and Hematology, University Medical Center Utrecht, Utrecht, The Netherlands; Department of Vascular Surgery, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Crystel M Gijsberts
- Department of Experimental Cardiology, University Medical Center Utrecht, Utrecht, The Netherlands; Department of Cardiology, ICIN-The Netherlands Heart Institute, Utrecht, The Netherlands
| | - Peter Paul Wisman
- Department of Clinical Chemistry and Hematology, University Medical Center Utrecht, Utrecht, The Netherlands; Department of Vascular Surgery, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Albert Huisman
- Department of Clinical Chemistry and Hematology, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Maarten Ten Berg
- Department of Clinical Chemistry and Hematology, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Folkert W Asselbergs
- Department of Cardiology, University Medical Centre Utrecht, Utrecht, The Netherlands; Durrer Center for Cardiogenetic Research, ICIN-The Netherlands Heart Institute, Utrecht, The Netherlands; Institute of Cardiovascular Science, University College London, London, United Kingdom
| | - Imo E Hoefer
- Department of Clinical Chemistry and Hematology, University Medical Center Utrecht, Utrecht, The Netherlands; Department of Experimental Cardiology, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Gerard Pasterkamp
- Department of Clinical Chemistry and Hematology, University Medical Center Utrecht, Utrecht, The Netherlands; Department of Experimental Cardiology, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Frans L Moll
- Department of Vascular Surgery, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Gert Jan de Borst
- Department of Vascular Surgery, University Medical Center Utrecht, Utrecht, The Netherlands
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Lanza GA, Stazi A, Villano A, Torrini F, Milo M, Laurito M, Flego D, Aurigemma C, Liuzzo G, Crea F. Effect of Remote Ischemic Preconditioning on Platelet Activation Induced by Coronary Procedures. Am J Cardiol 2016; 117:359-65. [PMID: 26739396 DOI: 10.1016/j.amjcard.2015.10.056] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/06/2015] [Revised: 10/30/2015] [Accepted: 10/30/2015] [Indexed: 10/22/2022]
Abstract
In this study, we aim to assess whether remote ischemic preconditioning (RIPC) reduces platelet activation during coronary angiography (CA) and/or percutaneous coronary interventions. We studied 30 patients who underwent CA because of a suspect of stable angina. Patients were randomized to RIPC (3 short episodes of forearm ischemia) or sham RIPC (controls) before the procedure. Blood samples were collected at baseline, at the end of the procedure, and 24 hours later. Monocyte-platelet aggregate (MPA) formation and platelet CD41 in the MPA gate and CD41 and CD62 expression in the platelet gate were assessed by flow cytometry, in the absence and in the presence of adenosine diphosphate (ADP) stimulation. A significant increase in platelet activation occurred during the invasive procedure in controls, which persisted at 24 hours. However, compared with controls, RIPC group showed no or a lower increase in platelet variables, including MPA formation (p <0.0001) and CD41 (p = 0.002) in the MPA gate and CD41 (p <0.0001) and CD62 (p = 0.002) in the platelet gate. ADP increased platelet activation at baseline, but did not further increase platelet reactivity during the invasive procedure in either groups. Percutaneous coronary interventions, performed in 10 patients (6 in the RIPC group and 4 in controls), did not have any further significant effect on platelet activation and reactivity compared with CA alone. In conclusion, RIPC reduces platelet activation occurring during CA. In contrast, no effects were observed on platelet response to ADP stimulation, probably related to the administration of an ADP antagonist in all patients.
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14
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Hepponstall M, Ignjatovic V, Binos S, Attard C, Karlaftis V, d'Udekem Y, Monagle P, Konstantinov IE. Remote ischemic preconditioning (RIPC) modifies the plasma proteome in children undergoing repair of tetralogy of fallot: a randomized controlled trial. PLoS One 2015; 10:e0122778. [PMID: 25826479 PMCID: PMC4380409 DOI: 10.1371/journal.pone.0122778] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2014] [Accepted: 02/11/2015] [Indexed: 12/22/2022] Open
Abstract
BACKGROUND Remote ischemic preconditioning (RIPC) has been applied in paediatric cardiac surgery. We have demonstrated that RIPC induces a proteomic response in plasma of healthy volunteers. We tested the hypothesis that RIPC modifies the proteomic response in children undergoing Tetralogy of Fallot (TOF) repair. METHODS AND RESULTS Children (n=40) were randomized to RIPC and control groups. Blood was sampled at baseline, after cardiopulmonary bypass (CPB) and 6, 12 and 24h post-CPB. Plasma was analysed by liquid chromatography mass spectrometry (LC-MS) in an untargeted approach. Peptides demonstrating differential expression (p<0.01) were subjected to tandem LC-MS/MS and protein identification. Corresponding proteins were identified using the NCBI protein database. There was no difference in age (7.3±3.5vs6.8±3.6 months)(p=0.89), weight (7.7±1.8vs7.5±1.9 kg)(p=0.71), CPB time (104±7vs94±7 min)(p=0.98) or aortic cross-clamp time (83±22vs75±20 min)(p=0.36). No peptides were differentially expressed at baseline or immediately after CPB. There were 48 peptides with higher expression in the RIPC group 6h post-CPB. This was no longer evident at 12 or 24h, with one peptide down-regulated in the RIPC group. The proteins identified were: inter-alpha globulin inhibitor (42.0±11.8 vs 820.8±181.1, p=0.006), fibrinogen preproprotein (59.3±11.2 vs 1192.6±278.3, p=0.007), complement-C3 precursor (391.2±160.9 vs 5385.1±689.4, p=0.0005), complement C4B (151.5±17.8 vs 4587.8±799.2, p=0.003), apolipoprotein B100 (53.4±8.3 vs 1364.5±278.2, p=0.005) and urinary proteinase inhibitor (358.6±74.9 vs 5758.1±1343.1, p=0.009). These proteins are involved in metabolism, haemostasis, immunity and inflammation. CONCLUSIONS We provided the first comprehensive analysis of RIPC-induced proteomic changes in children undergoing surgery. The proteomic changes peak 6h post-CPB and return to baseline within 24h of surgery. TRIAL REGISTRATION ACTR.org.au ACTRN12610000496011.
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Affiliation(s)
- Michele Hepponstall
- Murdoch Childrens Research Institute, Melbourne, Australia; Cardiac Surgery Unit and Cardiology, Royal Children's Hospital, Melbourne, Australia; Department of Paediatrics, The University of Melbourne, Melbourne, Australia; Department of Environment and Primary Industries, Bioscience Research Division, Melbourne, Australia
| | - Vera Ignjatovic
- Murdoch Childrens Research Institute, Melbourne, Australia; Department of Paediatrics, The University of Melbourne, Melbourne, Australia
| | - Steve Binos
- Department of Environment and Primary Industries, Bioscience Research Division, Melbourne, Australia
| | - Chantal Attard
- Murdoch Childrens Research Institute, Melbourne, Australia
| | | | - Yves d'Udekem
- Murdoch Childrens Research Institute, Melbourne, Australia; Cardiac Surgery Unit and Cardiology, Royal Children's Hospital, Melbourne, Australia
| | - Paul Monagle
- Murdoch Childrens Research Institute, Melbourne, Australia; Department of Paediatrics, The University of Melbourne, Melbourne, Australia
| | - Igor E Konstantinov
- Murdoch Childrens Research Institute, Melbourne, Australia; Cardiac Surgery Unit and Cardiology, Royal Children's Hospital, Melbourne, Australia; Department of Paediatrics, The University of Melbourne, Melbourne, Australia
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Heusch G, Bøtker HE, Przyklenk K, Redington A, Yellon D. Remote ischemic conditioning. J Am Coll Cardiol 2015; 65:177-95. [PMID: 25593060 PMCID: PMC4297315 DOI: 10.1016/j.jacc.2014.10.031] [Citation(s) in RCA: 470] [Impact Index Per Article: 52.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/25/2014] [Revised: 10/16/2014] [Accepted: 10/22/2014] [Indexed: 12/12/2022]
Abstract
In remote ischemic conditioning (RIC), brief, reversible episodes of ischemia with reperfusion in one vascular bed, tissue, or organ confer a global protective phenotype and render remote tissues and organs resistant to ischemia/reperfusion injury. The peripheral stimulus can be chemical, mechanical, or electrical and involves activation of peripheral sensory nerves. The signal transfer to the heart or other organs is through neuronal and humoral communications. Protection can be transferred, even across species, with plasma-derived dialysate and involves nitric oxide, stromal derived factor-1α, microribonucleic acid-144, but also other, not yet identified factors. Intracardiac signal transduction involves: adenosine, bradykinin, cytokines, and chemokines, which activate specific receptors; intracellular kinases; and mitochondrial function. RIC by repeated brief inflation/deflation of a blood pressure cuff protects against endothelial dysfunction and myocardial injury in percutaneous coronary interventions, coronary artery bypass grafting, and reperfused acute myocardial infarction. RIC is safe and effective, noninvasive, easily feasible, and inexpensive.
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Affiliation(s)
- Gerd Heusch
- Institute for Pathophysiology, West German Heart and Vascular Centre Essen, University of Essen Medical School, Essen, Germany.
| | - Hans Erik Bøtker
- Department of Cardiology, Aarhus University Hospital Skejby, Aarhus, Denmark
| | - Karin Przyklenk
- Cardiovascular Research Institute, Wayne State University School of Medicine, Detroit, Michigan
| | - Andrew Redington
- Hospital for Sick Children and University of Toronto, Toronto, Ontario, Canada
| | - Derek Yellon
- The Hatter Cardiovascular Institute, University College London, London, United Kingdom
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Tang YH, Vital S, Russell J, Seifert H, Senchenkova E, Granger DN. Transient ischemia elicits a sustained enhancement of thrombus development in the cerebral microvasculature: effects of anti-thrombotic therapy. Exp Neurol 2014; 261:417-23. [PMID: 25058045 DOI: 10.1016/j.expneurol.2014.07.004] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2014] [Revised: 06/26/2014] [Accepted: 07/10/2014] [Indexed: 12/22/2022]
Abstract
OBJECTIVE While transient ischemic attack (TIA) is a well-known harbinger of ischemic stroke, the mechanisms that link TIA to subsequent strokes remain poorly understood. The overall aim of this study was to determine whether: 1) brief periods of transient cerebral ischemia render this tissue more vulnerable to thrombus development and 2) antiplatelet agents used in TIA patients alter ischemia-induced thrombogenesis. APPROACH & RESULTS The middle cerebral artery of C57BL/6 mice was occluded for 2.5-10min, followed by reperfusion periods of 1-28days. Intravital microscopy was used to monitor thrombus development in cerebral microvessels induced by light/dye photoactivation. Thrombosis was quantified as the time to platelet aggregation on the vessel wall and the time for complete blood flow cessation. While brief periods of cerebral ischemia were not associated with neurological deficits or brain infarction (evaluated after 1day), it yielded a pronounced and prolonged (up to 28days) acceleration of thrombus formation, compared to control (sham) mice. This prothrombotic phenotype was not altered by pre- and/or post-treatment of mice with either aspirin (A), clopidogrel (C), dipyridamole (D), or atorvastatin (S), or with A+D+S. CONCLUSIONS The increased vulnerability of the cerebral vasculature to thrombus development after a brief period of transient ischemia can be recapitulated in a murine model. Antiplatelet or antithrombotic agents used in patients with TIA show no benefit in this mouse model of brief transient ischemia.
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Affiliation(s)
- Ya Hui Tang
- Department of Molecular and Cellular Physiology, Louisiana State University Health Sciences Center, Shreveport, LA, USA
| | - Shantel Vital
- Department of Molecular and Cellular Physiology, Louisiana State University Health Sciences Center, Shreveport, LA, USA
| | - Janice Russell
- Department of Molecular and Cellular Physiology, Louisiana State University Health Sciences Center, Shreveport, LA, USA
| | - Hilary Seifert
- Department of Molecular and Cellular Physiology, Louisiana State University Health Sciences Center, Shreveport, LA, USA
| | - Elena Senchenkova
- Department of Molecular and Cellular Physiology, Louisiana State University Health Sciences Center, Shreveport, LA, USA
| | - D Neil Granger
- Department of Molecular and Cellular Physiology, Louisiana State University Health Sciences Center, Shreveport, LA, USA.
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Transcutaneous electrical nerve stimulation as a novel method of remote preconditioning: in vitro validation in an animal model and first human observations. Basic Res Cardiol 2014; 109:406. [DOI: 10.1007/s00395-014-0406-0] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/12/2013] [Revised: 02/16/2014] [Accepted: 02/21/2014] [Indexed: 10/25/2022]
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18
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Effect of Remote Ischemic Preconditioning on Platelet Activation and Reactivity Induced by Ablation for Atrial Fibrillation. Circulation 2014; 129:11-7. [DOI: 10.1161/circulationaha.113.005336] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Background—
Radiofrequency ablation of atrial fibrillation has been associated with some risk of thromboembolic events. Previous studies showed that preventive short episodes of forearm ischemia (remote ischemic preconditioning [IPC]) reduce exercise-induced platelet reactivity. In this study, we assessed whether remote IPC has any effect on platelet activation induced by radiofrequency ablation of atrial fibrillation.
Methods and Results—
We randomized 19 patients (age, 54.7±11 years; 17 male) undergoing radiofrequency catheter ablation of paroxysmal atrial fibrillation to receive remote IPC or sham intermittent forearm ischemia (control subjects) before the procedure. Blood venous samples were collected before and after remote IPC/sham ischemia, at the end of the ablation procedure, and 24 hours later. Platelet activation and reactivity were assessed by flow cytometry by measuring monocyte-platelet aggregate formation, platelet CD41 in the monocyte-platelet aggregate gate, and platelet CD41 and CD62 in the platelet gate in the absence and presence of ADP stimulation. At baseline, there were no differences between groups in platelet variables. Radiofrequency ablation induced platelet activation in both groups, which persisted after 24 hours. However, compared with control subjects, remote IPC patients showed a lower increase in all platelet variables, including monocyte-platelet aggregate formation (
P
<0.0001), CD41 in the monocyte-platelet aggregate gate (
P
=0.002), and CD41 (
P
<0.0001) and CD62 (
P
=0.002) in the platelet gate. Compared with control subjects, remote IPC was also associated with a significantly lower ADP-induced increase in all platelet markers.
Conclusions—
Our data show that remote IPC before radiofrequency catheter ablation for paroxysmal atrial fibrillation significantly reduces the increased platelet activation and reactivity associated with the procedure.
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20
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Sels JWEM, Rutten B, van Holten TC, Hillaert MAK, Waltenberger J, Pijls NHJ, Pasterkamp G, de Groot PG, Roest M. The relationship between fractional flow reserve, platelet reactivity and platelet leukocyte complexes in stable coronary artery disease. PLoS One 2013; 8:e83198. [PMID: 24391745 PMCID: PMC3877034 DOI: 10.1371/journal.pone.0083198] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2013] [Accepted: 11/10/2013] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND The presence of stenoses that significantly impair blood flow and cause myocardial ischemia negatively affects prognosis of patients with stable coronary artery disease. Altered platelet reactivity has been associated with impaired prognosis of stable coronary artery disease. Platelets are activated and form complexes with leukocytes in response to microshear gradients caused by friction forces on the arterial wall or flow separation. We hypothesized that the presence of significantly flow-limiting stenoses is associated with altered platelet reactivity and formation of platelet-leukocyte complexes. METHODS One hundred patients with stable angina were studied. Hemodynamic significance of all coronary stenoses was assessed with Fractional Flow Reserve (FFR). Patients were classified FFR-positive (at least one lesion with FFR≤0.75) or FFR-negative (all lesions FFR>0.80). Whole blood samples were stimulated with increasing concentrations of ADP, TRAP, CRP and Iloprost with substimulatory ADP. Expression of P-selectin as platelet activation marker and platelet-leukocyte complexes were measured by flowcytometry. Patients were stratified on clopidogrel use. FFR positive and negative patient groups were compared on platelet reactivity and platelet-leukocyte complexes. RESULTS Platelet reactivity between FFR-positive patients and FFR-negative patients did not differ. A significantly lower percentage of circulating platelet-neutrophil complexes in FFR-positive patients and a similar non-significant decrease in percentage of circulating platelet-monocyte complexes in FFR-positive patients was observed. CONCLUSION The presence of hemodynamically significant coronary stenoses does not alter platelet reactivity but is associated with reduced platelet-neutrophil complexes in peripheral blood of patients with stable coronary artery disease.
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Affiliation(s)
- Jan-Willem E. M. Sels
- Department of Cardiology, Catharina Hospital Eindhoven, Eindhoven, The Netherlands
- Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, The Netherlands
| | - Bert Rutten
- Department of Clinical Chemistry and Hematology, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Thijs C. van Holten
- Department of Clinical Chemistry and Hematology, University Medical Center Utrecht, Utrecht, The Netherlands
| | | | - Johannes Waltenberger
- Department of Cardiology, Maastricht University Medical Center, Maastricht. The Netherlands
- Department of Cardiovascular Medicine, University of Muenster, Muenster, Germany
| | - Nico H. J. Pijls
- Department of Cardiology, Catharina Hospital Eindhoven, Eindhoven, The Netherlands
- Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, The Netherlands
| | - Gerard Pasterkamp
- Laboratory of Experimental Cardiology, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Philip G. de Groot
- Department of Clinical Chemistry and Hematology, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Mark Roest
- Department of Clinical Chemistry and Hematology, University Medical Center Utrecht, Utrecht, The Netherlands
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Scalone G, Aurigemma C, Tomai F, Corvo P, Battipaglia I, Lanza GA, Crea F. Effect of pre-infarction angina on platelet reactivity in acute myocardial infarction. Int J Cardiol 2013; 167:51-6. [DOI: 10.1016/j.ijcard.2011.11.085] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/09/2011] [Revised: 11/06/2011] [Accepted: 11/27/2011] [Indexed: 10/14/2022]
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Mosawy S, Jackson DE, Woodman OL, Linden MD. Inhibition of platelet-mediated arterial thrombosis and platelet granule exocytosis by 3',4'-dihydroxyflavonol and quercetin. Platelets 2012; 24:594-604. [PMID: 23249183 DOI: 10.3109/09537104.2012.749396] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Flavonols are polyphenolic compounds with broad-spectrum kinase inhibitory, as well as potent anti-oxidant and anti-inflammatory properties. Anti-platelet potential of quercetin (Que) and several related flavonoids have been reported; however, few studies have assessed the ability of flavonols to inhibit exocytosis of different platelet granules or to inhibit thrombus formation in vivo. 3',4'-Dihydroxyflavonol (DiOHF) is a flavonol which is structurally related to Que and has been shown to have greater anti-oxidant capacity and to improve the endothelial function in the context of diabetes and ischaemia/reperfusion injury. While the structural similarity to Que suggests DiOHF may have a potential to inhibit platelet function, no studies have assessed the anti-platelet potential of DiOHF. We therefore investigated platelet granule inhibition and potential to delay arterial thrombosis by Que and DiOHF. Both Que and DiOHF showed inhibition of collagen, adenosine diphosphate and arachidonic acid stimulated platelet aggregation, agonist-induced GPIIb/IIIa activation as demonstrated by PAC-1 and fibrinogen binding. While both flavonols inhibited agonist-induced granule exocytosis, greater inhibition of dense granule exocytosis occurred with DiOHF as measured by both ATP release and flow cytometry. In contrast, while Que inhibited agonist-induced P-selectin expression, as measured by both platelet surface P-selectin expression and upregulation of surface GPIIIa expression, inhibition by DiOHF was not significant for either parameter. C57BL/6 mice treated with 6 mg kg(-1) IV Que or DiOHF maintained greater blood flow following FeCl3-induced carotid artery injury when compared to the vehicle control. We provide evidence that Que and DiOHF improve blood flow following arterial injury in part by attenuating platelet granule exocytosis.
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Affiliation(s)
- Sapha Mosawy
- Health Innovations Research Institute, RMIT University , Melbourne , Australia
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Røpcke DM, Hjortdal VE, Toft GE, Jensen MO, Kristensen SD. Remote ischemic preconditioning reduces thrombus formation in the rat. J Thromb Haemost 2012; 10:2405-6. [PMID: 22947090 DOI: 10.1111/j.1538-7836.2012.04914.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
- D M Røpcke
- Department of Cardiothoracic and Vascular Surgery, Aarhus University Hospital - Skejby Department of Experimental and Clinical Research, Aarhus University Hospital - Skejby Department of Plastic Surgery, Aarhus University Hospital - NBG Department of Engineering, University of Aarhus Department of Cardiology, Aarhus University Hospital - Skejby, Denmark
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Whittaker P, Przyklenk K. Remote-conditioning ischemia provides a potential approach to mitigate contrast medium-induced reduction in kidney function: a retrospective observational cohort study. Cardiology 2011; 119:145-50. [PMID: 21952203 DOI: 10.1159/000330930] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/08/2011] [Accepted: 07/12/2011] [Indexed: 11/19/2022]
Abstract
Contrast medium administration during imaging and therapeutic procedures can cause renal injury, partly due to ischemia. Therefore, we hypothesized that brief ischemia and reperfusion episodes applied at a distant site - multiple balloon inflations and deflations during angioplasty - may serve as a remote-conditioning (RC) stimulus and thereby protect against contrast-induced kidney injury. To test this hypothesis, we (1) utilized cases from a prior study in which patients undergoing emergent angioplasty for ST segment elevation myocardial infarction received either 1-3 balloon inflations (controls) or were 'conditioned' with multiple (≥4) inflations, and (2) assessed renal function for 3 days in patients with an estimated glomerular filtration rate (eGFR) of <90 ml/min/1.73 m(2) prior to revascularization (mild kidney disease). Both groups displayed increased eGFR at day 1 after angioplasty versus baseline; attributed to in-hospital hydration (control: 77 ± 14 vs. 68 ± 12 ml/min/1.73 m(2); p < 0.01; RC: 81 ± 21 vs. 69 ± 12 ml/min/1.73 m(2); p < 0.01). In controls, this improvement was transient: eGFR subsequently decreased to 70 ± 14 ml/min/1.73 m(2) at day 3 (p < 0.05). In contrast, the RC group (despite receiving 25% more contrast volume) showed no functional decline at day 3 (80 ± 14 ml/min/1.73 m(2)). These results are consistent with remote ischemic conditioning providing a novel potential approach to attenuate contrast-associated renal injury.
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Affiliation(s)
- Peter Whittaker
- Department of Emergency Medicine, Wayne State University, Detroit, Mich., USA.
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Pedersen CM, Cruden NL, Schmidt MR, Lau C, Bøtker HE, Kharbanda RK, Newby DE. Remote ischemic preconditioning prevents systemic platelet activation associated with ischemia-reperfusion injury in humans. J Thromb Haemost 2011; 9:404-7. [PMID: 21083644 DOI: 10.1111/j.1538-7836.2010.04142.x] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
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Przyklenk K, Frelinger AL, Linden MD, Whittaker P, Li Y, Barnard MR, Adams J, Morgan M, Al-Shamma H, Michelson AD. Targeted inhibition of the serotonin 5HT2A receptor improves coronary patency in an in vivo model of recurrent thrombosis. J Thromb Haemost 2010; 8:331-40. [PMID: 19922435 PMCID: PMC2916638 DOI: 10.1111/j.1538-7836.2009.03693.x] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
BACKGROUND Release of serotonin and activation of serotonin 5HT2A receptors on platelet surfaces is a potent augmentative stimulus for platelet aggregation. However, earlier-generation serotonin receptor antagonists were not successfully exploited as antiplatelet agents, possibly owing to their lack of specificity for the 5HT2A receptor subtype. OBJECTIVE To assess whether targeted inhibition of the serotonin 5HT2A receptor attenuates recurrent thrombosis and improves coronary patency in an in vivo canine model mimicking unstable angina. METHODS In protocol 1, anesthetized dogs were pretreated with a novel, selective inverse agonist of the 5HT2A receptor (APD791) or saline. Recurrent coronary thrombosis was then initiated by coronary artery injury+stenosis, and coronary patency was monitored for 3 h. Protocol 2 was similar, except that: (i) treatment with APD791 or saline was begun 1 h after the onset of recurrent thrombosis; (ii) template bleeding time was measured; and (iii) blood samples were obtained for in vitro flow cytometric assessment of platelet responsiveness to serotonin. RESULTS APD791 attenuated recurrent thrombosis, irrespective of the time of treatment: in both protocols, flow-time area (index of coronary patency; normalized to baseline coronary flow) averaged 58-59% (P<0.01) following administration of APD791 vs. 21-28% in saline controls. Moreover, the in vivo antithrombotic effect of APD791 was not accompanied by increased bleeding, but was associated with significant and selective inhibition of serotonin-mediated platelet activation. CONCLUSION 5HT2A receptor inhibition with APD791, even when initiated after the onset of recurrent thrombosis, improves coronary patency in the in vivo canine model.
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Affiliation(s)
- K Przyklenk
- Center for Platelet Function Studies, Department of Emergency Medicine, University of Massachusetts Medical School, Worcester, MA, USA.
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Hoole SP, Heck PM, Sharples L, Khan SN, Duehmke R, Densem CG, Clarke SC, Shapiro LM, Schofield PM, O'Sullivan M, Dutka DP. Cardiac Remote Ischemic Preconditioning in Coronary Stenting (CRISP Stent) Study: a prospective, randomized control trial. Circulation 2009; 119:820-7. [PMID: 19188504 DOI: 10.1161/circulationaha.108.809723] [Citation(s) in RCA: 338] [Impact Index Per Article: 22.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
BACKGROUND Myocyte necrosis as a result of elective percutaneous coronary intervention (PCI) occurs in approximately one third of cases and is associated with subsequent cardiovascular events. This study assessed the ability of remote ischemic preconditioning (IPC) to attenuate cardiac troponin I (cTnI) release after elective PCI. METHODS AND RESULTS Two hundred forty-two consecutive patients undergoing elective PCI with undetectable preprocedural cTnI were recruited. Subjects were randomized to receive remote IPC (induced by three 5-minute inflations of a blood pressure cuff to 200 mm Hg around the upper arm, followed by 5-minute intervals of reperfusion) or control (an uninflated cuff around the arm) before arrival in the catheter laboratory. The primary outcome was cTnI at 24 hours after PCI. Secondary outcomes included renal dysfunction and major adverse cardiac and cerebral event rate at 6 months. The median cTnI at 24 hours after PCI was lower in the remote IPC compared with the control group (0.06 versus 0.16 ng/mL; P=0.040). After remote IPC, cTnI was <0.04 ng/mL in 44 patients (42%) compared with 24 in the control group (24%; P=0.01). Subjects who received remote IPC experienced less chest discomfort (P=0.0006) and ECG ST-segment deviation (P=0.005) than control subjects. At 6 months, the major adverse cardiac and cerebral event rate was lower in the remote IPC group (4 versus 13 events; P=0.018). CONCLUSIONS Remote IPC reduces ischemic chest discomfort during PCI, attenuates procedure-related cTnI release, and appears to reduce subsequent cardiovascular events.
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Affiliation(s)
- Stephen P Hoole
- Department of Cardiology, Papworth Hospital, Papworth Everard, UK
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Whittaker P, Przyklenk K. Fibrin architecture in clots: a quantitative polarized light microscopy analysis. Blood Cells Mol Dis 2008; 42:51-6. [PMID: 19054699 DOI: 10.1016/j.bcmd.2008.10.014] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2008] [Accepted: 10/01/2008] [Indexed: 12/26/2022]
Abstract
Fibrin plays a vital structural role in thrombus integrity. Thus, the ability to assess fibrin architecture has a potential to provide insight into thrombosis and thrombolysis. Fibrin has an anisotropic molecular structure, which enables it to be seen with polarized light. Therefore, we aimed to determine if automated polarized light microscopy methods of quantifying two structural parameters; fibrin fiber bundle orientation and fibrin's optical retardation (OR: a measure of molecular anisotropy) could be used to assess thrombi. To compare fibrin fiber bundle orientation we analyzed picrosirius red-stained sections obtained from clots formed: (A) in vitro, (B) in injured and stenotic coronary arteries, and (C) in surgically created aortic aneurysms (n=6 for each group). To assess potential changes in OR, we examined fibrin in picrosirius red-stained clots formed after ischemic preconditioning (10 min ischemia+10 min reflow; a circumstance shown to enhance lysability) and in control clots (n=8 each group). The degree of fibrin organization differed significantly according to the location of clot formation; fibrin was most aligned in the aneurysms and least aligned in vitro whereas fibrin in the coronary clots had an intermediate organization. The OR of fibrin in the clots formed after ischemic preconditioning was lower than that in controls (2.9+/-0.5 nm versus 5.4+/-1.0 nm, P<0.05). The automated polarized light analysis methods not only enabled fibrin architecture to be assessed, but also revealed structural differences in clots formed under different circumstances.
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Affiliation(s)
- Peter Whittaker
- Cardiovascular Research Institute, Department of Emergency Medicine, Wayne State University, School of Medicine, Detroit, MI 48201, USA.
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Delayed inhibition of agonist-induced granulocyte-platelet aggregation after low-dose sevoflurane inhalation in humans. Anesth Analg 2008; 106:1749-58. [PMID: 18499605 DOI: 10.1213/ane.0b013e318172f9e9] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
BACKGROUND Sevoflurane can be used as sedative-analgesic drug with endothelial protective properties. We tested whether low-dose sevoflurane inhalation provides sustained inhibition of detrimental granulocyte-platelet aggregation in humans. METHODS Ten healthy male volunteers were enrolled in this crossover study. Each subject inhaled sevoflurane for 1 h at 0.5-1 vol % end-tidal concentration in oxygen (50 vol %). Inhaling oxygen (50 vol %) alone served as control. Venous blood samples were collected at baseline before inhalation, immediately after inhalation, and 24 h thereafter, and were used for flow cytometry to determine platelet surface marker (CD41, CD42b, CD62P/P-selectin, and PAC-1) on platelets and granulocytes and for kaolin-induced clot formation, as assessed by thromboelastography. In flow cytometry experiments, platelets were stimulated with arachidonic acid (AA, 30 microM), adenosine diphosphate (ADP, 1 microM), and thrombin receptor agonist peptide-6 (TRAP-6, 6 microM). RESULTS AA, ADP, and TRAP-6 markedly increased the expression of CD62P on platelets, whereas CD42b (shedding) and PAC-1 (heterotypic conjugates) expression decreased. The amount of granulocyte-platelet aggregates increased upon agonist stimulation. Low-dose sevoflurane inhalation reduced ADP-induced CD62P expression on platelets 24 h after inhalation, and inhibited the formation of granulocyte-platelet aggregates under stimulation with AA and ADP after 1 and 24 h, and with TRAP-6 after 24 h compared with control. Inhibition of granulocyte-platelet aggregates was accompanied by reduced clot firmness 24 h after sevoflurane inhalation compared with control. CONCLUSIONS We demonstrated for the first time that inhaling low-dose sevoflurane (<1 vol % end-tidal) inhibits agonist-induced granulocyte-platelet interactions 24 h after administration and thus counteracts thromboinflammatory processes.
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Tarnow I, Kristensen AT, Krogh AKR, Frelinger AL, Barnard MR, Michelson AD. Effects of physiologic agonists on canine whole blood flow cytometry assays of leukocyte-platelet aggregation and platelet activation. Vet Immunol Immunopathol 2008; 123:345-52. [PMID: 18405981 DOI: 10.1016/j.vetimm.2008.02.016] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2007] [Revised: 01/30/2008] [Accepted: 02/20/2008] [Indexed: 01/09/2023]
Abstract
Platelets play a role in both the innate and adaptive immune systems. Methods for detecting activated platelets and leukocyte-platelet aggregates (LPAs) are useful for basic and applied research concerning the role of platelets in inflammation and immune disorders. The aim of the study was to develop flow cytometric assays for detection of platelets binding to monocytes and neutrophils and for activated platelets in canine whole blood and to investigate the effect of physiologic agonists. Citrate anticoagulated whole blood was incubated with monoclonal antibodies against CD14 and CD61 for detection of LPAs, and the effect of various agonists was investigated. For detection of activated platelets, whole blood was incubated with monoclonal antibodies against CD62P and against a receptor-induced binding site on fibrinogen (CAP1) with CD61 as a platelet identifier. Isotype controls were prepared in parallel. The individual physiologic agonists ADP, collagen and epinephrine increased LPAs, CD62P and CAP1 binding only modestly. However, combinations of agonists gave more substantial increases. A dose-response relationship was seen using alpha- and gamma-thrombin, and ADP as agonists. In conclusion, we have developed flow cytometry assays to measure LPAs and platelet activation in canine whole blood, and have explored the effect of various physiologic agonists at different concentrations.
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Affiliation(s)
- Inge Tarnow
- Department of Basic Animal and Veterinary Sciences, Faculty of Life Sciences, University of Copenhagen, 7-Grønnegaardsvej, DK-1870 Frederiksberg C, Denmark
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Linden MD, Barnard MR, Frelinger A, Michelson AD, Przyklenk K. Effect of adenosine A2 receptor stimulation on platelet activation-aggregation: differences between canine and human models. Thromb Res 2007; 121:689-98. [PMID: 17727923 PMCID: PMC2346597 DOI: 10.1016/j.thromres.2007.07.002] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2006] [Revised: 06/11/2007] [Accepted: 07/01/2007] [Indexed: 12/26/2022]
Abstract
INTRODUCTION Adenosine A(2) agonists improve arterial patency in experimental models of recurrent thrombosis, an effect purportedly triggered by stimulation of platelet A(2) receptors and subsequent down-regulation of platelet function. However: (i) there is no direct evidence to substantiate this premise; and (ii) given the recognized differences among species in platelet signaling, it is possible that the mechanisms of A(2) receptor stimulation may be model-dependent. Accordingly, we applied an integrated in vivo and in vitro approach, using both canine and human models, to test the hypothesis that the anti-thrombotic effects of A(2) agonist treatment are due in part to inhibition of platelet activation. METHODS In Protocol 1, recurrent coronary thrombosis was triggered in anesthetized dogs by application of a stenosis at a site of arterial injury. Coronary patency and flow cytometric indices of platelet activation (P-selectin expression; formation of heterotypic aggregates) were compared in dogs pre-treated with the A(2) agonist CGS 21680 versus controls. In Protocols 2 and 3, blood samples were obtained from dogs and human volunteers. In vitro aggregation and platelet activation (assessed by impedance aggregometry and flow cytometry, respectively) were quantified in paired aliquots pre-incubated with CGS versus vehicle. RESULTS In the canine models, CGS improved in vivo coronary patency and attenuated in vitro aggregation but, contrary to our hypothesis, did not evoke a down-regulation in platelet activation. In contrast, in human blood samples, CGS attenuated both in vitro aggregation and flow cytometric markers of platelet activation-aggregation. CONCLUSION The mechanisms contributing to the anti-thrombotic effect of A(2) agonist treatment are species-dependent: adenosine A(2) receptor stimulation inhibits platelet activation in human, but not canine, models.
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Affiliation(s)
- Matthew D. Linden
- Center for Platelet Function Studies, University of Massachusetts Medical School, Worcester MA
- Department of Pediatrics, University of Massachusetts Medical School, Worcester MA
| | - Marc R. Barnard
- Center for Platelet Function Studies, University of Massachusetts Medical School, Worcester MA
| | - A.L. Frelinger
- Center for Platelet Function Studies, University of Massachusetts Medical School, Worcester MA
- Department of Pediatrics, University of Massachusetts Medical School, Worcester MA
| | - Alan D. Michelson
- Center for Platelet Function Studies, University of Massachusetts Medical School, Worcester MA
- Department of Pediatrics, University of Massachusetts Medical School, Worcester MA
| | - Karin Przyklenk
- Center for Platelet Function Studies, University of Massachusetts Medical School, Worcester MA
- Department of Emergency Medicine, University of Massachusetts Medical School, Worcester MA
- Department of Anesthesiology, University of Massachusetts Medical School, Worcester MA
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