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Frunt R, El Otmani H, Smits S, Clark CC, Maas C. Factor XII contact activation can be prevented by targeting 2 unique patches in its epidermal growth factor-like 1 domain with a nanobody. J Thromb Haemost 2024; 22:2562-2575. [PMID: 38897387 DOI: 10.1016/j.jtha.2024.06.005] [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: 01/22/2024] [Revised: 05/28/2024] [Accepted: 06/03/2024] [Indexed: 06/21/2024]
Abstract
BACKGROUND Factor (F)XII triggers contact activation by binding to foreign surfaces, with the epidermal growth factor-like 1 (EGF-1) domain being the primary binding site. Blocking FXII surface-binding might hold therapeutic value to prevent medical device-induced thrombosis. OBJECTIVES To unravel and prevent EGF-1-mediated FXII surface-binding with a variable domain of heavy chain-only antibody (VHH). METHODS FXII variants with glutamine substitutions of 2 positively charged amino acid patches within the EGF-1 domain were created. Their role in FXII contact activation was assessed using kaolin pull-down experiments, amidolytic activity assays, and clotting assays. FXII EGF-1 domain-specific VHHs were raised to inhibit EGF-1-mediated FXII contact activation while preserving quiescence. RESULTS Two unique, positively charged patches in the EGF-1 domain were identified (upstream, 73K74K76K78H81K82H; downstream, 87K113K). Neutralizing the charge of both patches led to a 99% reduction in FXII kaolin binding, subsequent decrease in autoactivation of 94%, and prolongation of clot formation in activated partial thromboplastin time assays from 36 (±2) to 223 (±13) seconds. Three FXII EGF-1-specific VHHs were developed that are capable of inhibiting kaolin binding and subsequent contact system activation in plasma. The most effective VHH "F2" binds the positively charged patches and thereby dose-dependently extends activated partial thromboplastin time clotting times from 29 (±2) to 43 (±3) seconds without disrupting FXII quiescence. CONCLUSION The 2 unique, positively charged patches in FXII EGF-1 cooperatively mediate FXII surface-binding, making both patches crucial for contact activation. Targeting these with FXII EGF-1-specific VHHs can exclusively decrease FXII surface-binding and subsequent contact activation, while preserving zymogen quiescence. These patches thus have potential as druggable targets in preventing medical device-induced thrombosis.
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Affiliation(s)
- Rowan Frunt
- Central Diagnostic Laboratory Research, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands.
| | - Hinde El Otmani
- Central Diagnostic Laboratory Research, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands
| | - Simone Smits
- Central Diagnostic Laboratory Research, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands
| | - Chantal C Clark
- Center for Benign Hematology, Thrombosis and Hemostasis - Van Creveldkliniek, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands
| | - Coen Maas
- Central Diagnostic Laboratory Research, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands
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Rajsic S, Breitkopf R, Treml B, Jadzic D, Innerhofer N, Eckhardt C, Oberleitner C, Nawabi F, Bukumiric Z. Anti-Xa-guided Anticoagulation With Unfractionated Heparin and Thrombosis During Extracorporeal Membrane Oxygenation Support: A Systematic Review and Meta-analysis. J Cardiothorac Vasc Anesth 2024; 38:1662-1672. [PMID: 38839489 DOI: 10.1053/j.jvca.2024.03.042] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/29/2024] [Revised: 03/27/2024] [Accepted: 03/29/2024] [Indexed: 06/07/2024]
Abstract
OBJECTIVE The initiation of extracorporeal membrane oxygenation (ECMO) triggers complex coagulation processes necessitating systemic anticoagulation. Therefore, anticoagulation monitoring is crucial to avoid adverse events such as thrombosis and hemorrhage. The main aim of this work was to analyze the association between anti-Xa levels and thrombosis occurrence during ECMO support. DESIGN Systematic literature review and meta-analysis (Scopus and PubMed, up to July 29, 2023). SETTING All retrospective and prospective studies. PARTICIPANTS Patients receiving ECMO support. INTERVENTION Anticoagulation monitoring during ECMO support. MEASUREMENTS AND MAIN RESULTS A total of 16 articles with 1,968 patients were included in the review and 7 studies in the meta-analysis (n = 374). Patients with thrombosis had significantly lower mean anti-Xa values (standardized mean difference -0.36, 95% confidence interval [CI] -0.62 to -0.11, p < 0.01). Furthermore, a positive correlation was observed between unfractionated heparin infusion and anti-Xa levels (pooled estimate of correlation coefficients 0.31, 95% CI 0.19 to 0.43, p < 0.001). The most common adverse events were major bleeding (42%) and any kind of hemorrhage (36%), followed by thromboembolic events (30%) and circuit or oxygenator membrane thrombosis (19%). More than half of the patients did not survive to discharge (52%). CONCLUSIONS This work revealed significantly lower levels of anti-Xa in patients experiencing thromboembolic events and a positive correlation between anti-Xa and unfractionated heparin infusion. Considering the contemplative limitations of conventional monitoring tools, further research on the role of anti-Xa is warranted. New trials should be encouraged to confirm these findings and determine the most suitable monitoring strategy for patients receiving ECMO support.
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Affiliation(s)
- Sasa Rajsic
- Department of Anesthesiology and Intensive Care Medicine, Medical University Innsbruck, 6020, Innsbruck, Austria.
| | - Robert Breitkopf
- Department of Anesthesiology and Intensive Care Medicine, Medical University Innsbruck, 6020, Innsbruck, Austria
| | - Benedikt Treml
- Department of Anesthesiology and Intensive Care Medicine, Medical University Innsbruck, 6020, Innsbruck, Austria
| | - Dragana Jadzic
- Anesthesia and Intensive Care Department, Pain Therapy Service, Cagliari University, Cagliari, Italy
| | - Nicole Innerhofer
- Department of Anesthesiology and Intensive Care Medicine, Medical University Innsbruck, 6020, Innsbruck, Austria
| | - Christine Eckhardt
- Department of Anesthesiology and Intensive Care Medicine, Medical University Innsbruck, 6020, Innsbruck, Austria
| | - Christoph Oberleitner
- Department of Anesthesiology and Intensive Care Medicine, Medical University Innsbruck, 6020, Innsbruck, Austria
| | - Fariha Nawabi
- Department of Anesthesiology and Intensive Care Medicine, Medical University Innsbruck, 6020, Innsbruck, Austria
| | - Zoran Bukumiric
- Institute of Medical Statistics and Informatics, Faculty of Medicine, University of Belgrade, 11000, Belgrade, Serbia
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Rajsic S, Breitkopf R, Treml B, Jadzic D, Innerhofer N, Eckhardt C, Oberleitner C, Bukumiric Z. Association of anti-factor Xa-guided anticoagulation with hemorrhage during ECMO support: A systematic review and meta-analysis. Clin Cardiol 2024; 47:e24273. [PMID: 38693831 PMCID: PMC11063723 DOI: 10.1002/clc.24273] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/01/2024] [Revised: 04/08/2024] [Accepted: 04/15/2024] [Indexed: 05/03/2024] Open
Abstract
BACKGROUND The use of extracorporeal membrane oxygenation (ECMO) is associated with complex hemostatic changes. Systemic anticoagulation is initiated to prevent clotting in the ECMO system, but this comes with an increased risk of bleeding. Evidence on the use of anti-Xa-guided monitoring to prevent bleeding during ECMO support is limited. Therefore, we aimed to analyze the association between anti-factor Xa-guided anticoagulation and hemorrhage during ECMO. METHODS A systematic review and meta-analysis was performed (up to August 2023). PROSPERO CRD42023448888. RESULTS Twenty-six studies comprising 2293 patients were included in the analysis, with six works being part of the meta-analysis. The mean anti-Xa values did not show a significant difference between patients with and without hemorrhage (standardized mean difference -0.05; 95% confidence interval [CI]: -0.19; 0.28, p = .69). We found a positive correlation between anti-Xa levels and unfractionated heparin dose (UFH; pooled estimate of correlation coefficients 0.44; 95% CI: 0.33; 0.55, p < .001). The most frequent complications were any type of hemorrhage (pooled 36%) and thrombosis (33%). Nearly half of the critically ill patients did not survive to hospital discharge (47%). CONCLUSIONS The most appropriate tool for anticoagulation monitoring in ECMO patients is uncertain. Our analysis did not reveal a significant difference in anti-Xa levels in patients with and without hemorrhagic events. However, we found a moderate correlation between anti-Xa and the UFH dose, supporting its utilization in monitoring UFH anticoagulation. Given the limitations of time-guided monitoring methods, the role of anti-Xa is promising and further research is warranted.
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Affiliation(s)
- Sasa Rajsic
- Department of Anaesthesiology and Intensive Care MedicineMedical University InnsbruckInnsbruckAustria
| | - Robert Breitkopf
- Department of Anaesthesiology and Intensive Care MedicineMedical University InnsbruckInnsbruckAustria
| | - Benedikt Treml
- Department of Anaesthesiology and Intensive Care MedicineMedical University InnsbruckInnsbruckAustria
| | - Dragana Jadzic
- Anesthesia and Intensive Care Department, Pain Therapy ServiceCagliari UniversityCagliariItaly
| | - Nicole Innerhofer
- Department of Anaesthesiology and Intensive Care MedicineMedical University InnsbruckInnsbruckAustria
| | - Christine Eckhardt
- Department of Anaesthesiology and Intensive Care MedicineMedical University InnsbruckInnsbruckAustria
| | - Christoph Oberleitner
- Department of Anaesthesiology and Intensive Care MedicineMedical University InnsbruckInnsbruckAustria
| | - Zoran Bukumiric
- Institute of Medical Statistics and Informatics, Faculty of MedicineUniversity of BelgradeBelgradeSerbia
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Mayerhöfer T, Joannidis M, Peer A, Perschinka F, Fries D, Mair P, Gasteiger L, Bachler M, Kilo J, Herkner H, Schwameis M, Schellongowski P, Nagler B, Kornfehl A, Staudinger T, Buchtele N. Anticoagulation with argatroban using hemoclot™ targets is safe and effective in CARDS patients receiving venovenous extracorporeal membrane oxygenation: An exploratory bi-centric cohort study. Thromb Res 2024; 236:161-166. [PMID: 38452448 DOI: 10.1016/j.thromres.2024.02.026] [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: 12/13/2023] [Revised: 02/19/2024] [Accepted: 02/24/2024] [Indexed: 03/09/2024]
Abstract
Direct thrombin inhibitors, including argatroban, are increasingly used for anticoagulation during venovenous extracorporeal membrane oxygenation (VV ECMO). In many centers activated partial thromboplastin time (aPTT) is used for monitoring, but it can be affected by several confounders. The aim of this study was to evaluate the safety and efficacy of anticoagulation with argatroban titrated according to diluted thrombin time targets (hemoclot™ assay) compared to anti-Xa guided anticoagulation with unfractionated heparin (UFH). METHODS This cohort study included adults at two tertiary care centers who required VV ECMO for severe COVID-19-related acute respiratory distress syndrome (CARDS). Patients received center-dependent argatroban or UFH for anticoagulation during ECMO. Argatroban was guided following a hemoclot™ target range of 0.4-0.6 μg/ml. UFH was guided by anti-factor Xa (antiXa) levels (0.2-0.3 IU/ml). The primary outcome was safety of argatroban compared to UFH, assessed by time to first clinically relevant bleeding event or death during ECMO. Secondary outcomes included efficacy (time to thromboembolism) and feasibility (proportion of anticoagulation targets within range). RESULTS From 2019 to 2021 57 patients were included in the study with 27 patients (47 %) receiving argatroban and 30 patients (53 %) receiving UFH. The time to the first clinically relevant bleeding or death during ECMO was similar between groups (HR (argatroban vs. UFH): 1.012, 95 % CI 0.44-2.35, p = 0.978). Argatroban was associated with a decreased risk for thromboembolism compared to UFH (HR 0.494 (95 % CI 0.26-0.95; p = 0.034)). The overall proportion of anticoagulation within target ranges was not different between groups (46 % (23-54 %) vs. 46 % (37 %-57 %), p = 0.45). CONCLUSION Anticoagulation with argatroban according to hemoclot™ targets (0.4-0.6 μg/ml) compared to antiXa guided UFH (0.2-0.3 IU/ml) is safe and may prolong thromboembolism-free time in patients with severe ARDS requiring VV ECMO.
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Affiliation(s)
- Timo Mayerhöfer
- Division of Intensive Care and Emergency Medicine, Department of Internal Medicine, Medical University Innsbruck, Austria
| | - Michael Joannidis
- Division of Intensive Care and Emergency Medicine, Department of Internal Medicine, Medical University Innsbruck, Austria
| | - Andreas Peer
- Division of Intensive Care and Emergency Medicine, Department of Internal Medicine, Medical University Innsbruck, Austria
| | - Fabian Perschinka
- Division of Intensive Care and Emergency Medicine, Department of Internal Medicine, Medical University Innsbruck, Austria
| | - Dietmar Fries
- Department of Anaesthesiology and Intensive Care Medicine, Medical University Innsbruck, Innsbruck, Austria
| | - Peter Mair
- Department of Anaesthesiology and Intensive Care Medicine, Medical University Innsbruck, Innsbruck, Austria
| | - Lukas Gasteiger
- Department of Anaesthesiology and Intensive Care Medicine, Medical University Innsbruck, Innsbruck, Austria
| | - Mirjam Bachler
- Institute for Sports Medicine, Alpine Medicine and Health Tourism (ISAG), UMIT - Private University for Health Sciences and Health Technology, Hall i.T., Austria
| | - Juliane Kilo
- Department of Cardiac Surgery, Innsbruck Medical University, Innsbruck, Austria
| | - Harald Herkner
- Department of Emergency Medicine, Medical University of Vienna, Austria
| | - Michael Schwameis
- Department of Emergency Medicine, Medical University of Vienna, Austria
| | - Peter Schellongowski
- Department of Medicine I, Intensive Care Unit 13i2, Medical University of Vienna, Austria
| | - Bernhard Nagler
- Department of Medicine I, Intensive Care Unit 13i2, Medical University of Vienna, Austria
| | - Andrea Kornfehl
- Department of Medicine I, Intensive Care Unit 13i2, Medical University of Vienna, Austria
| | - Thomas Staudinger
- Department of Medicine I, Intensive Care Unit 13i2, Medical University of Vienna, Austria
| | - Nina Buchtele
- Department of Medicine I, Intensive Care Unit 13i2, Medical University of Vienna, Austria.
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Brock R, Kornfehl A, Staudinger T, Schellongowski P, Quehenberger P, Schwameis M, Buchtele N. Prevalence of FXII-Deficiency and Its Relevance to Monitoring Anticoagulation in Adults Receiving Extracorporeal Membrane Oxygenation. ASAIO J 2024; 70:217-223. [PMID: 37875022 DOI: 10.1097/mat.0000000000002085] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2023] Open
Abstract
During extracorporeal membrane oxygenation (ECMO) blood is exposed to artificial surfaces, resulting in contact activation of the intrinsic coagulation pathway initiated by coagulation factor XII (FXII). Little is known about the prevalence of acquired FXII-deficiency, especially during ECMO. The primary outcome was the prevalence of acquired FXII-deficiency (FXII activity <60%) during ECMO. Secondary outcomes included differences in hemorrhagic/thromboembolic complications, doses of unfractionated heparin administered, and time points of anticoagulation within target ranges between patients with and without FXII-deficiency. Of 193 adults receiving ECMO therapy between 2013 and 2021, FXII testing was performed in 64 (33%) patients. Of these, 89% ( n = 57) had an acquired FXII-deficiency. Median complication-free intervals were not different between patients with and without acquired FXII-deficiency (bleeding: 28 days [6-145] vs. 12 days [11-not available], p = 0.85; thromboembolism: 16 days [8-54] vs. 13 days [3-15], p = 0.053). Patients with acquired FXII-deficiency received less heparin (16,554 IU/day vs. 25,839 IU/day; p = 0.009) and were less likely to be within aPTT-target ranges (23.1% [14.3%-36.4%] vs. 37.8% [33.7%-58.3%], p = 0.005). Acquired FXII-deficiency is common during ECMO and may affect monitoring of anticoagulation. The impact of FXII-activity on complications needs to be determined in future studies.
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Meyer AD, Thorpe CR, Fraker T, Cancio T, Rocha J, Willis RP, Cap AP, Gailani D, Shatzel JJ, Tucker EI, McCarty OJ. Factor XI Inhibition With Heparin Reduces Clot Formation in Simulated Pediatric Extracorporeal Membrane Oxygenation. ASAIO J 2023; 69:1074-1082. [PMID: 37801726 PMCID: PMC10841048 DOI: 10.1097/mat.0000000000002048] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/08/2023] Open
Abstract
Extracorporeal membrane oxygenation (ECMO) supplies circulatory support and gas exchange to critically ill patients. Despite the use of systemic anticoagulation, blood exposure to ECMO surfaces causes thromboembolism complications. Inhibition of biomaterial surface-mediated activation of coagulation factor XI (FXI) may prevent device-associated thrombosis. Blood was collected from healthy volunteers (n = 13) following the U.S. Army Institute of Surgical Research standard operating procedure for testing in an ex vivo ECMO circuit. A roller-pump circuit circulated either 0.5 U/ml of unfractionated heparin alone or in combination with the anti-FXI immunoglobulin G (IgG) (AB023) for 6 hours or until clot formation caused device failure. Coagulation factor activity, platelet counts, time to thrombin generation, peak thrombin, and endogenous thrombin potential were quantified. AB023 in addition to heparin sustained circuit patency in all tested circuits (5/5) after 6 hours, while 60% of circuits treated with heparin alone occluded (3/8), log-rank p < 0.03. AB023 significantly prolonged the time to clot formation as compared to heparin alone (15.5 vs . 3.3 minutes; p < 0.01) at the 3-hour time point. AB023 plus heparin significantly reduced peak thrombin compared to heparin alone (123 vs . 217 nM; p < 0.01). Inhibition of contact pathway activation of FXI may be an effective adjunct to anticoagulation in extracorporeal life support.
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Affiliation(s)
- Andrew D. Meyer
- Division of Pediatric Critical Care, Department of Pediatrics, University of Texas Health Science Center, San Antonio, TX
- Organ Support & Automation Technologies, U.S. Army Institute of Surgical Research (USAISR), Ft. Sam Houston, TX
| | | | - Tamara Fraker
- The Geneva Foundation, San Antonio Military Medical Center, Ft. Sam Houston, TX
| | | | | | | | - Andrew P. Cap
- Organ Support & Automation Technologies, U.S. Army Institute of Surgical Research (USAISR), Ft. Sam Houston, TX
| | - David Gailani
- Department of Pathology, Microbiology and Immunology, Vanderbilt University School of Medicine, Nashville, TN
| | - Joseph J. Shatzel
- Department of Biomedical Engineering, Oregon Health & Science University, Portland, OR
- Division of Hematology & Medical Oncology, Oregon Health & Science University, Portland, OR
| | - Erik I. Tucker
- Department of Biomedical Engineering, Oregon Health & Science University, Portland, OR
- Aronora, Inc., Portland, OR
| | - Owen J.T. McCarty
- Department of Biomedical Engineering, Oregon Health & Science University, Portland, OR
- Aronora, Inc., Portland, OR
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Levy JH, Staudinger T, Steiner ME. How to manage anticoagulation during extracorporeal membrane oxygenation. Intensive Care Med 2022; 48:1076-1079. [PMID: 35689697 PMCID: PMC9187844 DOI: 10.1007/s00134-022-06723-z] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2022] [Accepted: 04/29/2022] [Indexed: 11/28/2022]
Affiliation(s)
- Jerrold H Levy
- Departments of Anesthesiology, Critical Care, and Surgery, Duke University School of Medicine, Duke University Medical Center, 2301 Erwin Rd., 5691H HAFS, Box 3094, Durham, NC, 27710, USA.
| | - Thomas Staudinger
- Department of Medicine I, Medical University of Vienna, Vienna, Austria
| | - Marie E Steiner
- Divisions of Critical Care and Hematology/Oncology, Department of Pediatrics, University of Minnesota, Minneapolis, MN, USA
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Monitoring of Unfractionated Heparin Therapy in the Intensive Care Unit Using a Point-of-Care aPTT: A Comparative, Longitudinal Observational Study with Laboratory-Based aPTT and Anti-Xa Activity Measurement. J Clin Med 2022; 11:jcm11051338. [PMID: 35268436 PMCID: PMC8911237 DOI: 10.3390/jcm11051338] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2022] [Revised: 02/20/2022] [Accepted: 02/26/2022] [Indexed: 12/18/2022] Open
Abstract
Continuous intravenous unfractionated heparin (UFH) is administered routinely in the intensive care unit (ICU) for the anticoagulation of patients, and monitoring is performed by the activated partial thromboplastin time (APTT) or anti-Xa activity. However, these strategies are associated with potentially large time intervals before dose adjustments, which could be detrimental to the patient. The aim of the study was to compare a point-of-care (POCT) version of the APTT to (i) laboratory-based APTT and (ii) measurements of anti-Xa activity in terms of correlation, agreement and turnaround time (TAT). Thirty-five ICU patients requiring UFH therapy were prospectively included and followed longitudinally for a maximum duration of 15 days. UFH was administered according to a local adaptation of Raschke and Amanzadeh’s aPTT nomograms. Simultaneous measurements of POCT-APTT (CoaguCheck® aPTT Test, Roche Diagnostics) on a drop of fresh whole blood, laboratory-based APTT (C.K. Prest®, Stago) and anti-Xa activity (STA®Liquid anti-Xa, Stago) were systematically performed two to six times a day. Antithrombin, C-reactive protein, fibrinogen, factor VIII and lupus anticoagulant were measured. The time tracking of sampling and analysis was recorded. The overall correlation between POCT-APTT and laboratory APTT (n = 795 pairs) was strongly positive (rs = 0.77, p < 0.0001), and between POCT-APTT and anti-Xa activity (n = 729 pairs) was weakly positive (rs = 0.46, p < 0.0001). Inter-method agreement (Cohen’s kappa (k)) between POCT and laboratory APTT was 0.27, and between POCT and anti-Xa activity was 0.30. The median TATs from sample collection to the lab delivery of results for lab-APTT and anti-Xa were 50.9 min (interquartile range (IQR), 38.4−69.1) and 66.3 min (IQR, 49.0−91.8), respectively, while the POCT delivered results in less than 5 min (p < 0.0001). Although the use of the POCT-APTT device significantly reduced the time to results, the results obtained were poorly consistent with those obtained by lab-APTT or anti-Xa activity, and therefore it should not be used with the nomograms developed for lab-APTT.
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