Direct factor Xa inhibitors and the risk of cancer and cancer mortality: A Danish population-based cohort study.

BACKGROUND: Preclinical animal studies have suggested that myeloid cell-synthesized coagulation factor X dampens antitumor immunity and that rivaroxaban, a direct factor Xa inhibitor, can be used to promote tumor immunity. This study was aimed at assessing whether patients with atrial fibrillation taking direct factor Xa inhibitors have lower risk of cancer and cancer-related mortality than patients taking the direct thrombin inhibitor dabigatran. METHODS AND FINDINGS: This nationwide population-based cohort study in Denmark included adult patients with atrial fibrillation and without a history of cancer, who started taking a factor Xa inhibitor or dabigatran between 2011 and 2015. Data on medical history, outcomes, and drug use were acquired through Danish healthcare registries. The primary outcome was any cancer. Secondary outcomes were cancer-related mortality and all-cause mortality. Outcome events were assessed during 5 years of follow-up in an intention-to-treat analysis. The propensity score-based inverse probability of treatment weighting was used to compute cumulative incidence and subdistribution hazard ratios (SHRs) and corresponding 95% confidence intervals (CIs), with death as a competing event. Propensity scores were estimated using logistic regression and including in the model sex, age group at index date, comorbidities, and use of comedications. A total of 11,742 patients with atrial fibrillation starting a factor Xa inhibitor and 11,970 patients starting dabigatran were included. Mean age was 75.2 years (standard deviation [SD] 11.2) in the factor Xa cohort and 71.7 years (SD 11.1) in the dabigatran cohort. On the basis of the propensity score-weighted models, after 5 years of follow-up, no substantial difference in the cumulative incidence of cancer was observed between the factor Xa inhibitor (2,157/23,711; 9.11%, 95% CI [8.61%,9.63%]) and dabigatran (2,294/23,715; 9.68%, 95% CI [9.14%,10.25%]) groups (SHR 0.94, 95% CI [0.89,1.00], P value 0.0357). We observed no difference in cancer-related mortality (factor Xa inhibitors cohort 1,028/23,711; 4.33%, 95% CI [4.02%,4.68%]. Dabigatran cohort 1,001/23,715; 4.22%, 95% CI [3.83%,4.66%]; SHR 1.03, 95% CI [0.94,1.12]), but all-cause mortality was higher in the factor Xa inhibitor cohort (factor Xa inhibitors cohort 7,416/23,711; 31.31%, 95% CI [30.37%,32.29%]. Dabigatran cohort 6,531/23,715; 27.56%, 95% CI [26.69%,28.45%]; HR 1.17, 95% CI [1.13,1.21]). The main limitations of the study were the possibility of residual confounding and the short follow-up period. CONCLUSIONS: In this population based cohort study, factor Xa inhibitor use was not associated with an overall lower incidence of cancer or cancer-related mortality when compared to dabigatran. We did observe an increase in all-cause mortality in the factor Xa inhibitor cohort.

Recommendations on Monitoring and Replacement of Antithrombin, Fibrinogen, and Von Willebrand Factor in Pediatric Patients on Extracorporeal Membrane Oxygenation: The Pediatric Extracorporeal Membrane Oxygenation Anticoagulation CollaborativE Consensus Conference.

OBJECTIVES: To derive systematic review informed, modified Delphi consensus regarding monitoring and replacement of specific coagulation factors during pediatric extracorporeal membrane oxygenation (ECMO) support for the Pediatric ECMO Anticoagulation CollaborativE. DATA SOURCES: A structured literature search was performed using PubMed, Embase, and Cochrane Library (CENTRAL) databases from January 1988 to May 2020, with an update in May 2021. STUDY SELECTION: Included studies assessed monitoring and replacement of antithrombin, fibrinogen, and von Willebrand factor in pediatric ECMO support. DATA EXTRACTION: Two authors reviewed all citations independently, with conflicts resolved by a third reviewer if required. Twenty-nine references were used for data extraction and informed recommendations. Evidence tables were constructed using a standardized data extraction form. DATA SYNTHESIS: Risk of bias was assessed using the Quality in Prognosis Studies tool. The evidence was evaluated using the Grading of Recommendations Assessment, Development, and Evaluation system. A panel of 48 experts met over 2 years to develop evidence-based recommendations and, when evidence was lacking, expert-based consensus statements. A web-based modified Delphi process was used to build consensus via the Research And Development/University of California Appropriateness Method. Consensus was defined as greater than 80% agreement. We developed one weak recommendation and four expert consensus statements. CONCLUSIONS: There is insufficient evidence to formulate recommendations on monitoring and replacement of antithrombin, fibrinogen, and von Willebrand factor in pediatric patients on ECMO. Optimal monitoring and parameters for replacement of key hemostasis parameters is largely unknown.

Comparison of warfarin, rivaroxaban, and dabigatran for effectiveness and safety in atrial fibrillation patients with different CHA2DS2-VASc scores: a retrospective cohort study.

BACKGROUND: This retrospective cohort study aims to compare the effectiveness and safety of warfarin, rivaroxaban, and dabigatran in atrial fibrillation (AF) patients with different CHA2DS2-VASc scores in northern China. METHODS: A retrospective cohort study was performed to evaluate anticoagulation in AF patients at the second affiliated hospital of Harbin Medical University from September 2018 to August 2019. Patients included in this study (n = 806) received warfarin (n = 300), or rivaroxaban (n = 203), or dabigatran (n = 303). Baseline characteristics and follow-up data including adherence, bleeding events and ischemic stroke (IS) events were collected. RESULTS: Patients receiving rivaroxaban (73.9%) or dabigatran (73.6%) showed better adherence than those receiving warfarin (56.7%). Compared with warfarin-treated patients, dabigatran-treated patients had lower incidence of bleeding events (10.9% vs 19.3%, χ2 = 8.385, P = 0.004) and rivaroxaban-treated patients had lower incidence of major adverse cardiovascular events (7.4% vs 13.7%, χ2 = 4.822, P = 0.028). We classified patients into three groups based on CHA2DS2-VASc score (0-1, 2-3, ≥ 4). In dabigatran intervention, incidence of bleeding events was higher in patients with score 0-1 (20.0%) than those with score 2-3 (7.9%, χ2 = 5.772, P = 0.016) or score ≥ 4 (8.6%, χ2 = 4.682, P = 0.030). Patients with score 0-1 in warfarin or rivaroxaban therapy had a similar but not significant increase of bleeding compared with patients with score 2-3 or score ≥ 4, respectively. During the follow-up, 33 of 806 patients experienced IS and more than half (19, 57.6%) were patients with score ≥ 4. Comparing patients with score 0-1 and 2-3, the latter had an significant reduction of IS in patients prescribed warfarin and non-significant reduction in rivaroxaban and dabigatran therapy. CONCLUSION: Compared with warfarin therapy, patients with different CHA2DS2-VASc scores receiving either rivaroxaban or dabigatran were associated with higher persistence. AF patients with score ≥ 4 were more likely to experience IS events while hemorrhagic tendency preferred patients with low score 0-1.

Bivalirudin Monitoring in Pediatric Ventricular Assist Device and Extracorporeal Membrane Oxygenation: Analysis of Single-Center Retrospective Cohort Data 2018-2022.

OBJECTIVES: The activated partial thromboplastin time (aPTT) is the most frequently used monitoring assay for bivalirudin in children and young adults on mechanical circulatory support including ventricular assist devices (VADs) and extracorporeal membrane oxygenation (ECMO). However, intrinsic variability of the aPTT complicates management and risks bleeding or thrombotic complications. We evaluated the utility and reliability of a bivalirudin-calibrated dilute thrombin time (Bival dTT) assay for bivalirudin monitoring in this population. DESIGN: Retrospective analysis of clinical data (including aPTT, dilute thrombin time [dTT]) and results of residual plasma samples from VAD patients were assessed in two drug-calibrated experimental assays. One assay (Bival dTT) was validated for clinical use in VAD patients, and subsequently used by clinicians in ECMO patients. Pearson correlation and simple linear regression were used to determine R2 correlation coefficients between the different laboratory parameters using Statistical Package for Social Sciences (Armonk, NY). SETTING: ICUs at Cincinnati Children's Hospital Medical Center. SUBJECTS: Children on VAD or ECMO support anticoagulated with bivalirudin. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: One hundred fifteen plasma samples from 11 VAD patients were analyzed. Both drug-calibrated experimental assays (anti-IIa and Bival dTT) showed excellent correlation with each other ( R2 = 0.94) and with the dTT ( R2 = 0.87), but poor correlation with aPTT ( R2 = 0.1). Bival dTT was selected for validation in VAD patients. Subsequently, clinically ordered results (105) from 11 ECMO patients demonstrated excellent correlation between the Bival dTT and the standard dTT ( R2 = 0.86) but very poor correlation with aPTT ( R2 = 0.004). CONCLUSIONS: APTT is unreliable and correlates poorly with bivalirudin's anticoagulant effect in ECMO and VAD patients. A drug-calibrated Bival dTT offers superior reliability and opportunity to standardize results across institutions. Additional studies are needed to determine an appropriate therapeutic range and correlation with clinical outcomes.

The role of inflammation and antithrombin supplementation on thromboelastographic parameters during veno-venous ECMO for respiratory failure.

INTRODUCTION: Extracorporeal membrane oxygenation (ECMO) may act as a driver or propagator of systemic inflammation. In turn, cytokine release can modify thromboelastographic (TEG) tests which are commonly used for anticoagulation monitoring. In this context, antithrombin (AT) supplementation might further modify TEG. METHODS: This is a pre-specified sub-study of the "Randomized Controlled Trial of Antithrombin Supplementation During Extracorporeal Membrane Oxygenation" study (investigator-initiated, randomized, single-blind, two-arm trial) conducted in two Italian ECMO referral ICUs. Adult patients requiring vv-ECMO for respiratory failure and undergoing unfractioned heparin (UFH) administration were enrolled and randomized whether to receive AT supplementation. Plasma samples for cytokine assay (IL-8, IL-10, IL-6, IL-1ß, TNF-α and Pro-ADM) and heparinase TEG were collected from every patient before ECMO start, 24 h and 72 h after ECMO start, before ECMO removal, and 7 days after ECMO removal or upon ICU discharge whichever happened first. AT concentration, coagulation and clinical data were collected before ECMO start and at pre-fixed time points. RESULTS: Thirty-nine patients were enrolled (21 treatments, 18 controls). TEG-R had a weak-to-moderate positive correlation with IL-8, IL-6, IL-10 and TNF-α and a moderate positive correlation with Pro-ADM. TEG-ANG showed a weak negative correlation with IL-8, IL-6 and TNF-α, while TEG-MA negatively correlated with IL-8, TNF-α and Pro-ADM. AT supplementation seemed to modify the association between TEG-MA and IL-8, IL-10 and Pro-ADM; conversely, AT did not affect the relationship among TEG-R or TEG-ANG and the studied cytokines. CONCLUSIONS: High concentrations of systemic cytokines correlated with longer reaction times and decreased angle and amplitude at TEG, suggesting that an increase in inflammation is related with hypocoagulability as revealed by thromboelastography.

Bivalirudin as a substitute for heparin in neurointervention for patients with heparin-induced thrombocytopenia.

OBJECTIVES: Heparin-induced thrombocytopenia is a known complication of heparin exposure with potentially life-threatening sequelae. Direct thrombin inhibitors can be substituted for heparin in patients with heparin-induced thrombocytopenia that require anticoagulation. However, the use of direct thrombin inhibitors as a substitute for heparin has not been widely reported in the neuroendovascular literature. MATERIALS AND METHODS: Here we report the first use of the direct thrombin inhibitor bivalirudin in a neuroendovascular procedure as a substitute for heparin in a patient with a ruptured pseudoaneurysm and heparin-induced thrombocytopenia, and review the literature on the use of bivalirudin and argatroban for such patients. RESULTS: Bivalirudin was safely and effectively used in the case reported, with no thrombotic or hemorrhagic complications. Our literature review revealed a paucity of studies on the use of heparin alternatives, including bivalirudin, in neuroendovascular procedures in patients with heparin-induced thrombocytopenia. CONCLUSIONS: Heparin-induced thrombocytopenia is an important iatrogenic disease process in patients undergoing neuroendovascular procedures, and developing protocols to diagnose and manage heparin-induced thrombocytopenia is important for healthcare systems. While further research needs to be done to establish the full range of anticoagulation options to substitute for heparin, our case indicates bivalirudin as a potential candidate.

Efficacy and safety of dabigatran and rivaroxaban in atrial fibrillation patients with impaired liver function: a multicenter retrospective cohort study.

BACKGROUND: The efficacy and safety of direct oral anticoagulants (DOACs) in atrial fibrillation (AF) patients with impaired liver function (ILF) have not been sufficiently studied. The aim of this study was to evaluate the efficacy and safety of DOACs for stroke prevention in patients with AF and ILF. METHOD: This study was based on data from 15 centers in China, including 4,982 AF patients. The patients were divided into 2 subgroups based on their liver function status: patients with normal liver function (NLF)(n = 4213) and patients with ILF (n = 769). Logistic regression analysis was used to investigate the risk of total bleeding, major bleeding, thromboembolism, and all-cause deaths in AF patients with NLF and ILF after taking dabigatran or rivaroxaban, respectively. RESULTS: Among AF patients treated with dabigatran or rivaroxaban, patients with ILF were associated with significantly higher major bleeding, compared with NLF patients (aOR: 4.797; 95% CI: 2.224-10.256; P < 0.001). In patients with NLF, dabigatran (n = 2011) had considerably lower risk of total bleeding than rivaroxaban (n = 2202) (aOR: 1.23; 95% CI: 1.002-1.513; P = 0.049). In patients with ILF, dabigatran (n = 321) significantly favored lower risks of major bleeding compared with rivaroxaban(n = 448) (aOR: 5.484; 95% CI: 1.508-35.269; P = 0.026). CONCLUSION: After using dabigatran or rivaroxaban, patients with ILF had remarkably increased risk of major bleeding compared with patients with NLF. In AF patients with NLF, dabigatran had the distinct strength of significantly reduced risk of total bleeding compared with rivaroxaban. In patients with AF and ILF, dabigatran use was associated with lower risk for major bleeding compared with rivaroxaban.

A systematic review and meta-analysis of the effectiveness of primary thromboprophylaxis in acute lymphoblastic leukemia during early-phase therapy including asparaginase or its prolonged form.

Asparaginase is essential in the initial management of acute lymphoblastic leukemia (ALL) but frequently leads to venous thromboembolism (VTE). Using anticoagulants for primary VTE prevention has been studied with no consensus. We conducted a systematic literature search in PubMed, Scopus, and Web of science and performed random-effect meta-analysis using Mantel-Haenszel method in RevMan 5.4 to analyze primary pharmacological thromboprophylaxis during asparaginase treatment in early-phase (induction, consolidation, or intensification phase) therapy in patients with ALL with all ages and followed with subgroup analysis by age. Meta-analysis of 13 articles describing the effect of antithrombin supplementation in 1375 patients showed that antithrombin prophylaxis decreases the risk of VTE by 43% (RR, 0.57; 95% CI, 0.38 - 0.83; p=0.004), with mild heterogeneity (I2=35%, p=0.10) and moderate certainty by GRADE. 8 articles included for meta-analysis of low-molecular weight heparin (LMWH) treatment in 612 patients showed that it decreased the risk of VTE by nearly 40% (RR, 0.61; 95% CI, 0.45 - 0.81; p=0.00081), with minimal heterogeneity (I2=14%, p=0.31) but low certainty. Subgroup analysis showed that only prophylaxis with antithrombin supplementation significantly decreased the VTE rate in adult patients with moderate certainty. In pediatric patients, one nonrandomized prospective study showed that LMWH combined with antithrombin has a better thromboprophylaxis effect than antithrombin alone. In the PREVAPIX-ALL trial, prophylaxis with direct factor Xa inhibitor Apixaban did not benefit children younger than 18 years except for cases of obesity. We concluded that thromboprophylaxis with antithrombin is effective in ALL patients older than 18 years during the early phase of therapy, and LMWH combined with antithrombin supplementation might be effective for pediatric patients with ALL. Apixaban is effective in pediatric ALL patients with obesity and needs further study in other high-risk patients.

Differential Use of Glycoprotein IIb/IIIa Inhibitors with Bivalirudin in Patients with STEMI Undergoing PCI: A Systematic Review and Meta-Analysis.

AIM: The efficacy and safety of bivalirudin when used concurrently with glycoprotein IIb/IIIa inhibitors (GPI) is uncertain. In this systematic review and meta-analysis, we aimed to evaluate the efficacy and safety of bivalirudin versus heparin in patients with ST-segment elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (PCI) and to explore the impact of differential use (greater and balanced) of GPI. METHODS: Online databases were queried from inception to March 2023 to identify eight randomized controlled trials (n = 22,483) for inclusion. The primary outcomes included all-cause mortality, major bleeding, major adverse cardiovascular events (MACE), and net adverse clinical events (NACE). Secondary efficacy endpoints included cardiac death, reinfarction, stent thrombosis (ST), and stroke. Data were pooled using a random-effects model to derive risk ratios (RRs) and 95% confidence intervals (CIs). RESULTS: When compared to heparin, bivalirudin was associated with a significant reduction in all-cause mortality (RR 0.83; 95% CI 0.72-0.97; P = 0.02), major bleeding (RR 0.73; 95% CI 0.57-0.93; P = 0.01), cardiac death (RR 0.79; 95% CI 0.66-0.94; P = 0.01), and NACE (RR 0.80; 95% CI 0.72-0.89; P < 0.0001). However, while the bivalirudin arm showed an increased likelihood of ST in the greater GPI subgroup (RR 1.70; 95% CI 1.13-2.56; P = 0.01), it was associated with a decreased likelihood of ST in the balanced GPI subgroup (RR 0.40; 95% CI 0.24-0.65; P = 0.0003). CONCLUSION: Overall, our findings suggest that bivalirudin may be a more efficacious intervention than heparin for reducing certain adverse events in patients with STEMI undergoing primary PCI.

Exploring antithrombin: insights into its physiological features, clinical implications and analytical techniques.

Antithrombin is an essential protein that acts as a natural anticoagulant in the human body. It is synthesized by the liver and belongs to the serine protease inhibitors, which are commonly referred to as the SERPINS superfamily. The antithrombin molecule comprises 432 amino acids and has a molecular weight of approximately 58 200 D. It consists of three domains, including an amino-terminal domain, a carbohydrate-rich domain, and a carboxyl-terminal domain. The amino-terminal domain binds with heparin, whereas the carboxyl-terminal domain binds with serine protease. Antithrombin is a crucial natural anticoagulant that contributes approximately 60-80% of plasma anticoagulant activities in the human body. Moreover, antithrombin has anti-inflammatory effects that can be divided into coagulation-dependent and coagulation-independent effects. Furthermore, it exhibits antitumor activity and possesses a broad range of antiviral properties. Inherited type I antithrombin deficiency is a quantitative disorder that is characterized by low antithrombin activity due to low plasma levels. On the other hand, inherited type II antithrombin deficiency is a qualitative disorder that is characterized by defects in the antithrombin molecule. Acquired antithrombin deficiencies are more common than hereditary deficiencies and are associated with various clinical conditions due to reduced synthesis, increased loss, or enhanced consumption. The purpose of this review was to provide an update on the structure, functions, clinical implications, and methods of detection of antithrombin.

Treatments and outcomes of neonatal disseminated intravascular coagulation with and without neonatal asphyxia: A retrospective study using nationwide data in Japan.

BACKGROUND: Although neonatal disseminated intravascular coagulation (DIC) is associated with high mortality and severe complications, few studies have reported its clinical course. We aimed to describe the characteristics, treatments, and outcomes of neonatal DIC by using a national inpatient database. METHODS: Using the Japanese Diagnosis Procedure Combination database, we identified 5533 patients with neonatal DIC who were admitted to neonatal intensive care units between July 2010 and March 2020. We categorized the patients into those with asphyxia (n = 2911) and those without asphyxia (n = 2622). We investigated the patient characteristics, treatments, and outcomes. We further categorized neonates with asphyxia according to its severity. RESULTS: The gestational age of neonates with asphyxia was significantly lower than that of neonates without asphyxia (P < 0.001). Antithrombin was most commonly used for DIC (40%). Neonates with asphyxia were more likely to receive antithrombin (43% vs. 38%; P < 0.001), recombinant human soluble thrombomodulin (28% vs. 20%; P < 0.001), and fresh frozen plasma transfusion (68% vs. 51%; P < 0.001) than those without asphyxia. Neonates with asphyxia had higher in-hospital mortality (17% vs. 10%; P < 0.001), severe bleeding (11% vs. 6.8%; P < 0.001), and hospitalization costs than those without asphyxia. Additionally, neonates with severe asphyxia were more likely to receive several DIC therapies (such as recombinant human soluble thrombomodulin [30% vs. 24%]) and had higher in-hospital mortality (19% vs. 11%) and hospitalization costs than those with mild asphyxia. CONCLUSIONS: In this large retrospective study of neonatal DIC, patients with asphyxia received several treatments and demonstrated unfavorable outcomes when compared to those without asphyxia.

Anti-thrombotic Effects Mediated by a Novel Dual-Target Peptide Inhibiting Both Platelet Aggregation and Thrombin Activity without Causing Bleeding.

BACKGROUND: Classical anticoagulants and antiplatelets are associated with high frequencies of bleeding complications or treatment failure when used as single agents. Thrombin plays an important role in the blood coagulation system. GP IIb/IIIa is the central receptor of platelets, which can recognize the Arg-Gly-Asp (RGD) sequence and activate platelets. MATERIAL AND METHODS: Molecular simulation and homology modeling were performed to design a novel dual-target anticoagulant short peptide (PTIP ). The activities of PTIP on coagulation and platelet in vitro were analyzed. The antithrombotic activity of PTIP was determined by pulmonary thromboembolism model, ferric chloride injury model and arteriovenous bypass thrombosis model. Bleeding effect and toxicity of PTIP were evaluated. RESULTS: We have constructed a novel dual-target peptide (PTIP) based on the direct thrombin inhibitor peptide (DTIP). PTIP was expressed at high levels in Pichia pastoris. PTIP interfered with thrombin-mediated coagulation and ADP-induced platelet aggregation in vitro. When injected intravenously or subcutaneously, PTIP showed potent and dose-dependent extension of aPTT and PT which were similar to DTIP; but only PTIP was capable of inhibiting platelet aggregation. PTIP (1.0 mg/kg) decelerated thrombosis formation in venous and arterial vessels induced by FeCl3 injury. PTIP (1.0 mg/kg) also prevented deep venous thrombosis and increased the survival rate associated with pulmonary thromboembolism. And PTIP effectively reduced thrombus length in arteriovenous bypass thrombosis model. Moreover, the antithrombotic dose of PTIP could not induce bleeding. CONCLUSION: These data establish that PTIP represents a novel antithrombotic agent whose effects involve both inhibition of platelet activation and reduction of fibrin generation. And PTIP not only can be used in venous thrombosis and arterial thrombosis, it can also replace the combined treatment of antiplatelet and anticoagulant drugs in thrombotic diseases.

Investigation of real-world heparin resistance and anticoagulation management prior to cardiopulmonary bypass: report from a nationwide survey by the Japanese Association for Thoracic Surgery heparin resistance working group.

OBJECTIVE: Heparin resistance is often encountered during cardiopulmonary bypass. Heparin dose and activated clotting time target values for the initiation of cardiopulmonary bypass are not yet universally standardized; further no consensus exists on the management of heparin resistance. This study aimed to investigate the current real-world practice on heparin management and anticoagulant treatment for heparin resistance in Japan. METHODS: A questionnaire survey was conducted at medical institutions nationwide with which The Japanese Society of Extra-Corporeal Technology in Medicine members are affiliated, targeting surgical cases with cardiopulmonary bypass performed from January 2019 through December 2019. RESULTS: Among 69% (230/332) of the participating institutions, the criterion for heparin resistance was defined as "the target activated clotting time value not reached even with an additional dose of heparin administration". Cases of heparin resistance were reported in 89.8% (202/225) of the responded institutions. Of note, 75% (106/141) of the responded institutions reported heparin resistance associated with antithrombin activity ≥ 80%. Antithrombin concentrate was used in 38.4% (238/619 responses) or third dose of heparin in 37.8% (234/619 responses) for advanced heparin resistance treatment. Antithrombin concentrate was found to be effective in resolving heparin resistance in patients having normal, as well as lower antithrombin activity. CONCLUSION: Heparin resistance has occurred in many cardiovascular centers, even among patients with normal antithrombin activities. Interestingly, the administration of antithrombin concentrate resolved heparin resistance, regardless of the baseline antithrombin activity value.

Argatroban Use in Pediatric Patients Supported by Paracorporeal Ventricular Assist Devices.

Direct thrombin inhibitor (DTI) use has been associated with decreased stroke and death rates in children on ventricular assist devices (VADs). Most information about DTI use for children on VADs has focused on bivalirudin with limited data on argatroban. We hypothesized that, compared to unfractionated heparin (UFH), argatroban would be associated with decreased bleeding, stroke, and death rates in children on VADs. We retrospectively collected data from patients <18 years old on paracorporeal VADs at Children's Wisconsin between January 1, 2010 and July 1, 2021. We divided patients into cohorts based on anticoagulation strategy with heparin or argatroban. Definitions of bleeding and neurologic events were the same as in other published reports on this population. We compared categorical variables with the χ 2 or Fisher's exact test, and continuous variables with the Mann-Whitney U test. Nineteen children were anticoagulated with argatroban, and 16 with heparin. Demographics between groups were not significantly different. Stroke, bleeding, and death rates did not differ between patients treated with UFH versus argatroban. The study population was complex with a high rate of extracorporeal membrane oxygenation (ECMO) use before VAD support, which likely impacted our findings. Our study does not support argatroban as a superior alternative anticoagulant compared to UFH in children requiring VADs.

Monitoring of Argatroban in Critically Ill Patients: A Prospective Study Comparing Activated Partial Thromboplastin Time, Point-of-Care Viscoelastic Testing with Ecarin Clotting Time and Diluted Thrombin Time to Mass Spectrometry.

BACKGROUND: The direct thrombin inhibitor argatroban is indicated for the treatment of heparin-induced thrombocytopenia II, but it is also used off-label to treat critically ill patients presenting with heparin resistance, severe antithrombin deficiency, or hypercoagulability. Direct drug monitoring is not routinely available, and argatroban dosing is mainly based on global coagulation assays such as activated partial thromboplastin time (PTT) or diluted thrombin time (TT), both of which have limitations in patients with hypercoagulability. METHODS: Blood samples were obtained from critically ill patients treated with argatroban. Activated PTT and diluted TT were measured with a STA R Max3 analyzer (STAGO Deutschland GmbH, Germany) using an argatroban-calibrated kit. Ecarin clotting time was measured using a point-of-care viscoelastic test device. Liquid chromatography with tandem mass spectrometry was performed using a reversed-phase column, a solvent gradient, and an API4000 mass spectrometer with electrospray. Correlation was described using Pearson correlation coefficient r and Bayesian multilevel regression to estimate relationships between outcomes and covariates. RESULTS: From June 2021 to March 2022, 205 blood samples from 22 patients were analyzed, allowing for 195 activated PTT-liquid chromatography with tandem mass spectrometry comparisons, 153 ecarin clotting time-liquid chromatography with tandem mass spectrometry comparison, and 105 diluted TT-liquid chromatography with tandem mass spectrometry comparisons. Compared to liquid chromatography with tandem mass spectrometry, performance of argatroban quantification was best for diluted TT (r = 0.91), followed by ecarin clotting time (r = 0.58) and activated PTT (r = 0.48). Regression analysis revealed that patients with sepsis were more prone to argatroban overdosing (coefficient, 4.194; 95% credible interval, 2.220 to 6.792). CONCLUSIONS: Although activated PTT monitoring of argatroban is the most commonly used test, in critically ill patients, diluted TT provides more precise measurements. Alternately, point-of-care viscoelastic ecarin clotting time also provides guidance for argatroban dosing to identify overdosing if available. The data also suggested that patients with sepsis are at greater risk for argatroban overdosing.

Direct thrombin inhibitors fail to reverse the negative effects of heparin on lung growth and function after murine left pneumonectomy.

Neonates with congenital diaphragmatic hernia (CDH) frequently require cardiopulmonary bypass and systemic anticoagulation. We previously demonstrated that even subtherapeutic heparin impairs lung growth and function in a murine model of compensatory lung growth (CLG). The direct thrombin inhibitors (DTIs) bivalirudin and argatroban preserved growth in this model. Although DTIs are increasingly used for systemic anticoagulation clinically, patients with CDH may still receive heparin. In this experiment, lung endothelial cell proliferation was assessed following treatment with heparin-alone or mixed with increasing concentrations of bivalirudin or argatroban. The effects of subtherapeutic heparin with or without DTIs in the CLG model were also investigated. C57BL/6J mice underwent left pneumonectomy and subcutaneous implantation of osmotic pumps. Pumps were preloaded with normal saline, bivalirudin, or argatroban; treated animals received daily intraperitoneal low-dose heparin. In vitro, heparin-alone decreased endothelial cell proliferation and increased apoptosis. The effect of heparin on proliferation, but not apoptosis, was reversed by the addition of bivalirudin and argatroban. In vivo, low-dose heparin decreased lung volume compared with saline-treated controls. All three groups that received heparin demonstrated decreased lung function on pulmonary function testing and impaired exercise performance on treadmill tolerance testing. These findings correlated with decreases in alveolarization, vascularization, angiogenic signaling, and gene expression in the heparin-exposed groups. Together, these data suggest that bivalirudin and argatroban fail to reverse the inhibitory effects of subtherapeutic heparin on lung growth and function. Clinical studies on the impact of low-dose heparin with DTIs on CDH outcomes are warranted.NEW & NOTEWORTHY Infants with pulmonary hypoplasia frequently require cardiopulmonary bypass and systemic anticoagulation. We investigate the effects of simultaneous exposure to heparin and direct thrombin inhibitors (DTIs) on lung growth and pulmonary function in a murine model of compensatory lung growth (CGL). Our data suggest that DTIs fail to reverse the inhibitory effects of subtherapeutic heparin on lung growth and function. Clinical studies on the impact of heparin with DTIs on clinical outcomes are thus warranted.