2022 international clinical practice guidelines for the treatment and prophylaxis of venous thromboembolism in patients with cancer, including patients with COVID-19.

The International Initiative on Thrombosis and Cancer is an independent academic working group of experts aimed at establishing global consensus for the treatment and prophylaxis of cancer-associated thrombosis. The 2013, 2016, and 2019 International Initiative on Thrombosis and Cancer clinical practice guidelines have been made available through a free, web-based mobile phone application. The 2022 clinical practice guidelines, which are based on a literature review up to Jan 1, 2022, include guidance for patients with cancer and with COVID-19. Key recommendations (grade 1A or 1B) include: (1) low-molecular-weight heparins (LMWHs) for the initial (first 10 days) treatment and maintenance treatment of cancer-associated thrombosis; (2) direct oral anticoagulants for the initial treatment and maintenance treatment of cancer-associated thrombosis in patients who are not at high risk of gastrointestinal or genitourinary bleeding, in the absence of strong drug-drug interactions or of gastrointestinal absorption impairment; (3) LMWHs or direct oral anticoagulants for a minimum of 6 months to treat cancer-associated thrombosis; (4) extended prophylaxis (4 weeks) with LMWHs to prevent postoperative venous thromboembolism after major abdominopelvic surgery in patients not at high risk of bleeding; and (5) primary prophylaxis of venous thromboembolism with LMWHs or direct oral anticoagulants (rivaroxaban or apixaban) in ambulatory patients with locally advanced or metastatic pancreatic cancer who are treated with anticancer therapy and have a low risk of bleeding.

Endothelial cell biomarkers in critically ill COVID-19 patients with encephalitis.

COVID-19 is associated with encephalitis in critically ill patients and endothelial dysfunction seems to contribute to this life-threatening complication. Our objective was to determine the hallmark of endothelial activation in COVID-19-related encephalitis. In an observational study in intensive care unit (ICU), we compared vascular biomarkers of critically ill COVID-19 patients with or without encephalitis. To be classified in the encephalitis group, patients had to have new onset of central neurologic symptom, and pathological findings on either brain magnetic resonance imaging (MRI) and/or electroencephalogram (EEG). Among the 32 critically ill COVID-19 consecutive patients, 21 were categorized in the control group and 11 in the encephalitis group. Encephalitis patients had a longer ICU stay than control patients (median length [25th-75th percentile] of 52 [16-79] vs. 20.5 [11-44] days, respectively, p = 0.04). Nine-month overall follow-up mortality reached 21% (7/32 patients), with mortality rates in the encephalitis group and the control group of 27% and 19%, respectively. Encephalitis was associated with significant higher release of soluble endothelial activation markers (sE-selectin, tumor necrosis factor-α (TNF-α), interleukin 6, placental growth factor, and thrombomodulin), but these increases were correlated with TNF-α plasmatic levels. The hypoxia-inducible protein angiopoietin-like 4 (ANGPTL4) was at significantly higher levels in encephalitis patients compared to control patients (p = 0.0099), and in contrary to the other increased factors, was not correlated with TNF-α levels (r = 0.2832, p = 0.1163). Our findings suggest that COVID-19-related encephalitis is a cytokine-associated acute brain dysfunction. ANGPTL4 was the only elevated marker found in encephalitis patients, which was not correlated with systemic inflammation, suggesting that ANGPTL4 might be a relevant factor to predict encephalitis in critically ill COVID-19 patients.

Emicizumab does not interfere with the activated clotting time.

INTRODUCTION: The activated clotting time (ACT) is a useful marker of unfractionated heparin (UFH) activity during cardiopulmonary bypass (CPB) or cardiac catheterization. Emicizumab, recently approved for bleeding prevention in haemophilia A patients, acts like FVIII but does not need prior activation; it therefore shortens coagulation times in assays using intrinsic pathway activators and so is expected to shorten the ACT. AIM: To evaluated emicizumab's impact on heparin-induced ACT (Hemochron®) prolongation. METHODS: We measured the high-range (HR) ACT in citrated blood samples from healthy donors (HDs) (n = 9), CPB patients (n = 3) and emicizumab-treated patients (n = 5) after spiking with UFH and/or emicizumab. The low range (LR) ACT was also measured in spiked-samples from HDs and emicizumab-treated patients. RESULTS: In HDs, the median [interquartile range] baseline HR-ACTs were similar with and without emicizumab (129 [123-138] and 136 [115-141] s for 50 µg/ml, respectively); whatever the concentration of emicizumab (10 to 50 µg/ml), increasing the UFH concentration (1-5 UI/ml) prolonged the HR-ACT. In blood from patients undergoing CPB, the HR-ACT prolongation observed during this procedure was not masked by emicizumab at any concentration. Likewise, the addition of increasing concentrations of UFH to blood from emicizumab-treated patients induced a concentration-dependent prolongation of HR-ACT. Baseline LR-ACT were prolonged in emicizumab-treated patients but as for HR-ACT, emicizumab does not prevent heparin-induced prolongation of LR-ACT. CONCLUSION: Emicizumab does not interfere with UFH-induced ACT prolongation. The hemochron® ACT can be used to monitor UFH in patients receiving emicizumab during CPB or cardiac catheterization.

Incidence, risk factors, and management of bleeding in patients receiving anticoagulants for the treatment of cancer-associated thrombosis.

Updated clinical practice guidelines recommend the long-term use of low-molecular-weight heparins or direct oral anticoagulants as the preferred option for the treatment of cancer-associated thrombosis (CAT), using a personalized approach matching the right drug to the right patient. In most cases, the benefit of anticoagulant therapy outweighs the risk. However, the long-term use of anticoagulants is associated with a non-negligible risk of bleeding, which constitutes a rare but serious adverse effect. Bleeding complications have been reported to be overall 2 to 3 times more frequent in cancer patients with CAT receiving anticoagulation than in non-cancer patients, with a reported incidence of major bleeding ranging from 2.4 to 16.0% in randomized controlled trials (RCT). In the absence of validated risk assessment model to predict the risk of bleeding in these patients, a careful evaluation of each individual profile, with adequate selection of the most appropriate anticoagulant for each individual patient, is warranted for overcoming management challenges, taking in account the numerous factors which may potentiate the overall bleeding risk in these complex patients, such as advanced or metastatic disease, older age, anemia, thrombocytopenia, renal impairment, liver dysfunction, and concomitant anticancer therapies. The purpose of this review is to call for awareness on bleeding complications as a major safety issue of CAT treatment and to summarize data from recent RCT and real-world studies on the incidence and risk factors for bleeding in this unique and challenging population to further help clinicians in decision-making.

Acquired factor V inhibitor: a nation-wide study of 38 patients.

Acquired factor V inhibitor (AFVI) is an extremely rare disorder that may cause severe bleeding. To identify factors associated with bleeding risk in AFVI patients, a national, multicentre, retrospective study was made including all AFVI patients followed in 21 centres in France between 1988 and 2015. All patients had an isolated factor V (FV) deficiency <50% associated with inhibitor activity. Patients with constitutional FV deficiency and other causes of acquired coagulation FV deficiencies were excluded. The primary outcome was incident bleeding and factors associated with the primary outcome were identified. Thirty-eight (74 [36-100] years, 42·1% females) patients with AFVI were analysed. Bleeding was reported in 18 (47·4%) patients at diagnosis and in three (7·9%) during follow-up (7 [0·2-48.7] months). At diagnosis, FV was <10% in 31 (81·6%) patients. Bleeding at diagnosis was associated with a prolonged prothrombin time that strongly correlated with the AFVI level measured in plasma {r = 0·63, 95% confidence interval (CI) [0·36-0·80], P < 0·05}. Bleeding onset during follow-up was associated with a slow AFVI clearance (P < 0·001). The corresponding receiver operating characteristics curve showed that AFVI clearance was predictive of bleeding onset with an AFVI clearance of seven months with a sensitivity of 100% (95% CI: 29-100) and a specificity of 86% (95% CI: 57-98, P = 0·02). Kaplan-Meier analysis showed that AFVI clearance >7 months increased the risk of bleeding by 8 (95% CI: [0·67-97], P = 0·075). Prothrombin time at diagnosis and time for clearance of FV inhibitor during follow-up are both associated with bleeding in patients with AFVI.

Incidence of Venous Thromboembolism in Patients With Newly Diagnosed Pancreatic Cancer and Factors Associated With Outcomes.

BACKGROUND & AIMS: Pancreatic ductal adenocarcinoma (PDAC) is associated with the highest incidence of venous thromboembolism (VTE) of any cancer type. However, little is known about risk factors for VTE or its outcomes in patients with PDAC. METHODS: We collected data from a prospective, observational study performed at multiple centers in France from May 2014 through November 2018 (the Base Clinico-Biologique de l'Adénocarcinome Pancréatique [BACAP] study) linked to a database of patients with a new diagnosis of PDAC of any stage. Data were collected from 731 patients at baseline and during clinical follow-up or in the event of symptoms. The primary endpoint was the onset of VTE during follow-up. The secondary endpoints were progression-free survival (PFS) and overall survival (OS) times. RESULTS: During a median follow-up of 19.3 months, 152 patients (20.79%) developed a VTE. The median time from PDAC diagnosis to the onset of VTE was 4.49 months. Cumulative incidence values of VTE were 8.07% (95% confidence interval [CI], 6.31-10.29) at 3 months and 19.21% (95% CI, 16.27-22.62) at 12 months. In multivariate analysis, PDAC primary tumor location (isthmus vs head: hazard ratio [HR], 2.06; 95% CI, 1.09-3.91; P = .027) and stage (locally advanced vs resectable or borderline: HR, 1.66; 95% CI, 1.10-2.51, P = .016; metastatic vs resectable or borderline: HR, 2.50; 95% CI, 1.64-3.79; P < .001) were independent risk factors for the onset of VTE. Patients who developed VTE during follow-up had shorter times of PFS (HR, 1.74; 95% CI, 1.19-2.54; P = .004) and OS (HR, 2.02; 95% CI, 1.57-2.60; P < .001). CONCLUSION: In an analysis of data from the BACAP study, we found that frequent and early onsets of VTE after diagnoses of PDAC are associated with significant decreases in times of PFS and OS. Studies are needed to determine whether primary prophylaxis of VTE in patients with PDAC will improve morbidity and mortality related to VTE. (ClinicalTrials.gov, Number: clinicaltrials.gov as number NCT02818829).

Heparin-induced thrombocytopenia in COVID-19 patients with severe acute respiratory distress syndrome requiring extracorporeal membrane oxygenation: two case reports.

Veno-venous (VV) extracorporeal membrane oxygenation (ECMO) is increasingly used in Coronavirus disease-19 (COVID-19) patients with the most severe forms of acute respiratory distress syndrome (ARDS). Its use is associated with a significant hemostatic challenge, especially in COVID- 19 patients who have been demonstrated to otherwise present a COVID-19-associated coagulopathy. The systematic use of unfractionated heparin therapy to prevent circuit thrombosis is warranted during ECMO support. The clinical presentation and management of heparin-induced thrombocytopenia, which is a rare but life-threatening complication of heparin therapy, has not been described in those patients yet. We report herein two cases of laboratory-confirmed HIT in COVID-19 patients with severe ARDS admitted to our intensive care unit for VV-ECMO support and the successful use of argatroban as an alternative therapy. We also provide a brief literature review of best evidence for managing such patients. The diagnosis and management of HIT is particularly challenging in COVID-19 patients receiving ECMO support. An increased awareness is warranted in those patients who already present a procoagulant state leading to higher rates of thrombotic events which can confuse the issues. Argatroban seems to be an appropriate and safe therapeutic option in COVID-19 patients with HIT while on VV-ECMO.

2019 international clinical practice guidelines for the treatment and prophylaxis of venous thromboembolism in patients with cancer.

Venous thromboembolism (VTE) is the second leading cause of death in patients with cancer. These patients are at a high risk of VTE recurrence and bleeding during anticoagulant therapy. The International Initiative on Thrombosis and Cancer is an independent academic working group aimed at establishing a global consensus for the treatment and prophylaxis of VTE in patients with cancer. The International Initiative on Thrombosis and Cancer last updated its evidence-based clinical practice guidelines in 2016 with a free, web-based mobile phone application, which was subsequently endorsed by the International Society on Thrombosis and Haemostasis. The 2019 International Initiative on Thrombosis and Cancer clinical practice guidelines, which are based on a systematic review of the literature published up to December, 2018, are presented along with a Grading of Recommendations Assessment Development and Evaluation scale methods, with the support of the French National Cancer Institute. These guidelines were reviewed by an expanded international advisory committee and endorsed by the International Society on Thrombosis and Haemostasis. Results from head-to-head clinical trials that compared direct oral anticoagulant with low-molecular-weight heparin are also summarised, along with new evidence for the treatment and prophylaxis of VTE in patients with cancer.

Antithrombotic efficacy of bivalirudin compared to unfractionated heparin during percutaneous coronary intervention for acute coronary syndrome.

Bivalirudin is associated with an increased risk of acute stent thrombosis (AST) compared to unfractionated heparin (UFH) in acute coronary syndrome patients (ACS) during short-duration percutaneous coronary intervention (PCI). The mechanisms involved are unknown. We aimed to investigate the antithrombotic efficacy of bivalirudin compared to UFH during PCI. In a monocenter study, we prospectively enrolled 30 patients undergoing PCI for a non-ST elevation ACS. They were randomly assigned to a single intravenous (IV) bolus of UFH (70 IU/kg) or an IV bolus of bivalirudin 0.75 mg/kg followed by a 1.75 mg/kg/h infusion during PCI. All patients received a loading dose (LD) of 180 mg of ticagrelor at the time of PCI. The VASP index and activated partial thromboplastin time (aPTT) were used to assess the course of platelet reactivity (PR) and antithrombotic activity. The two groups were similar regarding baseline, angiographic, and interventional characteristics. There was no difference between the two groups in the course of PR following ticagrelor LD. An optimal PR inhibition was obtained 4 h after the LD of ticagrelor. The level of antithrombotic activity was significantly lower in the bivalirudin group compared to the UFH group (p < 0.001) during PCI but similar at 2 and 4 h post-PCI. We observed that, in ACS undergoing PCI, the antithrombotic efficacy of an IV bolus of bivalirudin is significantly lower than that of a 70-IU/kg UFH bolus. This could contribute to the excess in thrombotic acute events observed during short-duration PCI.

Lean body weight is the best scale for venous thromboprophylaxis algorithm in severely obese patients undergoing bariatric surgery.

Severely obese patients undergoing bariatric surgery (BS) are at increased risk for venous thromboembolism (VTE). How standard low molecular weight heparin (LMWH) regimen should be adapted to provide both sufficient efficacy and safety in this setting is unclear. We aimed to compare the influence of four body size descriptors (BSD) on peak anti-Xa levels in BS obese patients receiving LMWH fixed doses to identify which one had the greatest impact. One hundred and thirteen BS obese patients [median body mass index (BMI), 43.3 kg/m2 (IQR, 40.6-48.7 kg/m2)] receiving subcutaneous dalteparin 5000 IU twice daily were included in this prospective monocenter study. Peak steady-state anti-Xa levels were measured peri-operatively following thromboprophylaxis initiation. Only 48% of patients achieved target anti-Xa levels (0.2-0.5 IU/ml). In univariate analysis, age, gender, total body-weight (TBW), lean body-weight (LBW), ideal body-weight (IBW), BMI and estimated glomerural filtration rate (eGFR) were associated with anti-Xa levels. The strongest negative association was observed with LBW (r = -0.56, p < .0001). Receiver operating characteristic curves indicated that among BSD, LBW (cut-off >55.8 kg) had the highest sensitivity (73%) and specificity (69%) to predict sub-prophylactic anti-Xa levels. In multivariate analysis, LBW and eGFR remained associated with anti-Xa levels (ß = -0.47 ±â€¯0.08, p < .0001 and ß = -0.19 ±â€¯0.08; p = .02, respectively). In BS morbidly obese patients receiving LMWH for thromboprophylaxis after BS, LBW and eGFR are the main determinants of anti-Xa level, and could be proposed in LMWH-based thromboprophylaxis dosing algorithms. The efficacy of a LBW-scale based dosing algorithm for optimal VTE prevention deserves further prospective randomized trials.

Assessment of platelet function on the routine coagulation analyzer Sysmex CS-2000i.

BACKGROUND: Light transmission aggregometry (LTA) is considered as the gold standard for testing platelet function in the setting of both platelet disorders suspicion and response to antiplatelet therapy evaluation. LTA requires however specialized equipment, substantial blood sample volumes, is technically challenging and time-consuming. AIM: To evaluate an automated platelet aggregation method performed on a routine coagulation analyzer Sysmex CS-2000i. METHODS: 46 patients presenting a bleeding syndrome and 62 patients with acute coronary syndrome receiving dual antiplatelet therapy were studied in total. Platelet aggregations were performed on CS-2000i equipped with a dedicated software and on APACT-4004 (Elitech, France) as the reference instrument. Aggregation was measured by monitoring the changes in light absorbance occurring in response to ADP 2.5, 5 and 10µM, collagen 3.3 µg/mL, epinephrin 10µM, ristocetin 1.25 mg/mL and arachidonic acid 0.5 mg/mL in platelet rich plasma (PRP). PRP were tested simultaneously on both CS-2000i and APACT-4004 devices. Platelet stirred speed were 800 rpm for both instruments. RESULTS: Significant correlations were observed between CS-2000i and LTA after all stimulations (p< 0.001). Patients presenting a bleeding syndrome had similar aggregation profiles with both methods. A single patient presented a severe platelet disorder (Glanzmann Thrombasthenia) and its PRP showed defective aggregation in response to all agonists except ristocetin with both instruments. Finally, the inter-agreement rates for CS-2000i and APACT-4004 to detect low responders to thienopyridines or aspirine were strong (weighted kappa> 0.70). CONCLUSION: Platelet aggregation on the routine coagulation analyzer CS-2000i is an easily accessible, handy, reliable, standardized, and rapid tool to assess platelet function which allows to skirt most of the LTA limitations.

A meta-analysis of genome-wide association studies identifies ORM1 as a novel gene controlling thrombin generation potential.

Thrombin, the major enzyme of the hemostatic system, is involved in biological processes associated with several human diseases. The capacity of a given individual to generate thrombin, called the thrombin generation potential (TGP), can be robustly measured in plasma and was shown to associate with thrombotic disorders. To investigate the genetic architecture underlying the interindividual TGP variability, we conducted a genome-wide association study in 2 discovery samples (N = 1967) phenotyped for 3 TGP biomarkers, the endogenous thrombin potential, the peak height, and the lag time, and replicated the main findings in 2 independent studies (N = 1254). We identified the ORM1 gene, coding for orosomucoid, as a novel locus associated with lag time variability, reflecting the initiation process of thrombin generation with a combined P value of P = 7.1 × 10(-15) for the lead single nucleotide polymorphism (SNP) (rs150611042). This SNP was also observed to associate with ORM1 expression in monocytes (P = 8.7 × 10(-10)) and macrophages (P = 3.2 × 10(-3)). In vitro functional experiments further demonstrated that supplementing normal plasma with increasing orosomucoid concentrations was associated with impaired thrombin generation. These results pave the way for novel mechanistic pathways and therapeutic perspectives in the etiology of thrombin-related disorders.

COMparison of Platelet reactivity following prAsugrel and ticagrelor loading dose in ST-Segment elevation myocardial infarctION patients: The COMPASSION study.

Prasugrel and ticagrelor are potent P2Y12-ADP receptor antagonists which are superior to clopidogrel in acute coronary syndromes. To date no clinical trial directly compared these two drugs. Platelet reactivity correlates with ischemic and bleeding events in patients undergoing percutaneous coronary intervention. Recent pharmacological studies have observed a delayed onset of action of these two drugs in ST-segment elevation myocardial infarction (STEMI). We provide the first adequately powered pharmacological study comparing PR following ticagrelor and prasugrel loading dose (LD) in STEMI patients when the maximal biological effect is reached. In the present study, ticagrelor was associated with a lower rate of high on-treatment PR compared to prasugrel.

Tissue factor-positive neutrophils bind to injured endothelial wall and initiate thrombus formation.

For a long time, blood coagulation and innate immunity have been viewed as interrelated responses. Recently, the presence of leukocytes at the sites of vessel injury has been described. Here we analyzed interaction of neutrophils, monocytes, and platelets in thrombus formation after a laser-induced injury in vivo. Neutrophils immediately adhered to injured vessels, preceding platelets, by binding to the activated endothelium via leukocyte function antigen-1-ICAM-1 interactions. Monocytes rolled on a thrombus 3 to 5 minutes postinjury. The kinetics of thrombus formation and fibrin generation were drastically reduced in low tissue factor (TF) mice whereas the absence of factor XII had no effect. In vitro, TF was detected in neutrophils. In vivo, the inhibition of neutrophil binding to the vessel wall reduced the presence of TF and diminished the generation of fibrin and platelet accumulation. Injection of wild-type neutrophils into low TF mice partially restored the activation of the blood coagulation cascade and accumulation of platelets. Our results show that the interaction of neutrophils with endothelial cells is a critical step preceding platelet accumulation for initiating arterial thrombosis in injured vessels. Targeting neutrophils interacting with endothelial cells may constitute an efficient strategy to reduce thrombosis.

Management of venous thromboembolic disease in patients with malignant brain tumours.

This article addresses the management of venous thromboembolism in patients with malignant brain tumours, including both primary and secondary (metastatic) tumours. The available data on patients on venous thromboembolism recurrence and bleeding risks in patients with brain tumours is limited, since these patients have been excluded from most randomised, interventional, head-to-head, clinical trials comparing low molecular weight heparins to vitamin K antagonists or to direct oral Factor Xa inhibitors. More information is available from retrospective observational studies, which however were generally small, and carried a high risk of confounding. Their findings suggest that direct Factor Xa inhibitor use is associated with lower rates of intracranial haemorrhage compared with low molecular weight heparins. Overall, the safety profile of direct oral Factor Xa inhibitors when used to prevent venous thromboembolism recurrence in patients with either primary or secondary brain tumours appears to be favourable. The available data are in favour of using an anticoagulant at a full therapeutic dose in patients with primary and secondary brain tumours experiencing a venous thromboembolism, although they are not yet sufficiently robust to permit recommending a direct Factor Xa inhibitor over low-molecular weight heparin.

Management of cancer-associated thromboembolism in vulnerable population.

Although all patients with cancer-associated thrombosis (CAT) have a high morbidity and mortality risk, certain groups of patients are particularly vulnerable. This may expose the patient to an increased risk of thrombotic recurrence or bleeding (or both), as the benefit-risk ratio of anticoagulant treatment may be modified. Treatment thus needs to be chosen with care. Such vulnerable groups include older patients, patients with renal impairment or thrombocytopenia, and underweight and obese patients. However, these patient groups are poorly represented in clinical trials, limiting the available data, on which treatment decisions can be based. Meta-analysis of data from randomised clinical trials suggests that the relative treatment effect of direct oral factor Xa inhibitors (DXIs) and low molecular weight heparin (LMWH) with respect to major bleeding could be affected by advanced age. No evidence was obtained for a change in the relative risk-benefit profile of DXIs compared to LMWH in patients with renal impairment or of low body weight. The available, albeit limited, data do not support restricting the use of DXIs in patients with CAT on the basis of renal impairment or low body weight. In older patients, age is not itself a critical factor for choice of treatment, but frailty is such a factor. Patients over 70 years of age with CAT should undergo a systematic frailty evaluation before choosing treatment and modifiable bleeding risk factors should be addressed. In patients with renal impairment, creatine clearance should be assessed and monitored regularly thereafter. In patients with an eGFR<30mL/min/1.72m2, the anticoagulant treatment may need to be adapted. Similarly, platelet count should be assessed prior to treatment and monitored regularly. In patients with grade 3-4, thrombocytopenia (<50,000 platelets/µL) treatment with a LMWH at a reduced dose should be considered. For patients with CAT and low body weight, standard anticoagulant treatment recommendations are appropriate, whereas in obese patients, apixaban may be preferred.