Search

Patients with cancer have an increased risk of thrombosis requiring anticoagulants and/or antiplatelet agents, and they can also encounter thrombocytopenia due to cancer itself or cancer therapies. They often undergo many procedures such as tissue or bone marrow biopsies, placement of central access lines, diagnostic or therapeutic draining procedures, lumbar puncture, and more. Management of antithrombotic agents or thrombocytopenia around the time of these procedures is highly variable. In this document, the Hemostasis and Malignancy Subcommittee of the International Society on Thrombosis and Haemostasis aims to provide useful practice guidance in the management of antithrombotic agents and thrombocytopenia around the time of common procedures in patients with cancer.

Aims Gene expression biosignatures may hold promise to individualize antiplatelet therapy in conjunction with current guidelines and risk scores. The Aspirin Response Signature (ARS) score is comprised of a weighted sum of correlated, pro-thrombotic gene transcripts measured in whole blood. In prior work where volunteers were exposed to aspirin 325 mg daily, higher ARS score was associated with lower platelet function; separately, in a clinical cohort of patients, higher ARS scores were associated with increased risk of adverse cardiovascular events. To better understand this apparent paradox, we measured ARS gene expression and score in volunteers to determine aspirin dose–response and ticagrelor relationships with ARS score and separately in patients to assess whether ARS is associated with incident bleeding. Methods and results Blood samples were collected from volunteers (N = 188) who were exposed to 4 weeks of daily aspirin 81 mg, daily aspirin 325 mg, and/or twice-daily ticagrelor 90 mg. ARS scores were calculated from whole blood RNA qPCR, and platelet function and protein expression were assessed in platelet-rich plasma. In mixed linear regression models, aspirin 81 mg exposure was not associated with changes in ARS gene expression or score. Aspirin 325 mg exposure resulted in a 6.0% increase in ARS gene expression (P = 7.5 × 10−9 vs. baseline, P = 2.1 × 10−4 vs. aspirin 81 mg) and an increase in expression of platelet proteins corresponding to ARS genes. Ticagrelor exposure resulted in a 30.7% increase in ARS gene expression (P < 1 × 10−10 vs. baseline and each aspirin dose) and ARS score (P = 7.0 × 10−7 vs. baseline, P = 3.6 × 10−6 and 5.59 × 10−4 vs. aspirin 81 and 325 mg, respectively). Increases in ARS gene expression or score were associated with the magnitude of platelet inhibition across agents. To assess the association between ARS scores and incident bleeding, ARS scores were calculated in patients undergoing cardiac catheterization (N = 1421), of whom 25.4% experienced bleeding events over a median 6.2 years of follow-up. In a Cox model adjusting for demographics and baseline antithrombotic medication use, patients with ARS scores above the median had a higher risk of incident bleeding [hazard ratio 1.26 (95% CI 1.01–1.56), P = 0.038]. Conclusions The ARS is an Antiplatelet Response Signature that increases in response to greater platelet inhibition due to antiplatelet therapy and may represent a homeostatic mechanism to prevent bleeding. ARS scores could inform future strategies to prevent bleeding while maintaining antiplatelet therapy’s benefit of ischaemic cardiovascular event protection.

Objective Stakeholders involved in developing recommendations need to have a common understanding of health outcomes and the perspective of affected individuals. In this paper we report on the development and application of health outcome descriptors (HODs) to inform decision-making by panels developing guideline recommendations. Study Design and Setting Ten American Society of Hematology guideline panels addressing the management of venous thromboembolism developed HODs, rated their importance and health utility, applied them to prioritize outcomes, and to balance potential benefits and harms to formulate recommendations. Results It was feasible to involve 18 panelists in developing 127 HODs. There was high agreement (82%) across the ten panels about outcomes perceived as critical or important for decision-making. Panelists’ utility ratings of the outcomes were strongly correlated with panelists’ outcome importance ratings (Pearson's r=-0.88). HODs were incorporated into Grading of Recommendations Assessment, Development and Evaluation (GRADE) evidence-to-decision (EtD) frameworks to support a shared understanding of health outcomes in panel deliberations. Conclusion HODs serve as a valuable tool to promote an explicit, common understanding of health outcomes during clinical guideline development and across different stakeholders. They are helpful across multiple steps of guideline development to facilitate panels’ judgements, aiming to avoid variable implicit interpretations of health outcomes.

Venous thromboembolism (VTE) is a serious complication of orthopedic surgery. Low molecular weight heparin (LMWH) has been the standard of care for thromboprophylaxis in this population. However, direct oral anticoagulants (DOACs) are increasingly being used as alternatives.To assess the efficacy and safety of DOACs versus LMWH for thromboprophylaxis in orthopedic surgery.We searched MEDLINE, Embase, and the Cochrane Collaboration Central Register of Controlled Trials from inception until April 2020, for randomized controlled trials (RCTs) comparing DOACs with LMWH for thromboprophylaxis in orthopedic surgery.Twenty-five RCTs met inclusion criteria, including 40,438 patients, with a mean age of 68 years and 50% were males. Compared to LMWH, DOACs were associated with a significant reduction of major VTE; defined as the composite events of proximal deep vein thrombosis (DVT), pulmonary embolism (PE), and VTE-related mortality (RR 0.33; 95% CI: 0.20-0.53; P0.01), and total DVT (RR: 0.59; 95% CI: 0.48-0.73; P0.01), but not PE (RR 0.81; 95% CI: 0.49-1.34; P=0.42). There was no statistically significant difference between both groups on the incidence of major bleeding (RR 0.99; 95% CI: 0.77-1.27; P=0.92), clinically relevant non-major bleeding (RR 1.04; 95% CI: 0.92-1.17; P=0.52), all-cause mortality (RR 1.06; 95% CI: 0.64-1.76; P=0.83), VTE-related mortality (RR 0.84; 95% CI: 0.40-1.74; P=0.64) and bleeding-related mortality (RR 1.24; 95% CI: 0.30-5.18; P=0.77).For patients undergoing orthopedic surgery, thromboprophylaxis with DOACs is associated with a significant reduction of major VTE and DVT, compared to LMWH. Safety outcomes were not significantly different between both treatment groups.

Thrombotic storm is a rare clinical entity characterized by acute to subacute thrombosis developing at multiple sites over a few days to a few weeks. An 11-year-old boy presented with headache and facial nerve palsy. He was found to have cortical sinus venous thrombosis and was initiated on low molecular weight heparin, but rapidly progressed with thromboses involving the pulmonary arteries and deep veins of the legs. Thereafter managed on high-dose unfractionated heparin, he eventually stabilized after a hospital stay of 34 days. Genetic analysis showed potentially pathogenic variants in the factor V and stabilin-2 genes.

Commissioned and introduced by Associate Editors Irene Roberts and Thomas Ortel, this Review Series focuses on common areas in pediatric hematology practice, emphasizing new therapeutic and diagnostic developments. The specific challenges of managing hemostatic and thrombotic disorders in children are described by O’Brien and Zia. Distinguishing acquired immune diseases from inherited disorders of blood counts is a common problem for pediatric hematologists, and this is tackled in reviews by Grace and Lambert for thrombocytopenias and by Dokal et al for bone marrow failure. Finally, Gallagher provides a stepwise approach to the diagnosis and treatment of anemia in infancy and childhood, at both the individual patient level and the population level.

Structured AbstractImportanceTicagrelor inhibits platelet function, prevents myocardial infarction, and causes bleeding. A comprehensive analysis of the on- and off-target platelet effects of ticagrelor that underlie its clinical effects is lacking.ObjectiveTo test the hypothesis that platelet transcripts that change in response to ticagrelor exposure are associated with platelet function or bleeding.DesignA discovery cohort of healthy volunteers were sequentially exposed to aspirin, aspirin washout, and ticagrelor. Messenger RNA sequencing (mRNAseq) of purified platelets was performed pre/post each exposure. We defined the ticagrelor exposure signature (TES) as the ratio of mean expression of up-vs. down-regulated genes by ticagrelor that were prioritized based on lasso regression, weighted gene co-expression networks, and isoform level analyses. A separate healthy cohort was recruited to validate ticagrelor’s effects on TES genes measured using Nanostring. Platelet function was measured at baseline and in response to ticagrelor exposure in all participants. Self-reported bleeding was systematically queried during periods of ticagrelor exposure.SettingAn early phase, academic, clinical research unit.ParticipantsSelf-reported, healthy volunteers age > 30 and < 75, non-smoking, taking no daily prescribed medications.ExposuresTicagrelor (90 mg twice daily) and aspirin (81 mg/day and 325 mg/day) each for 4 weeks.Main outcomes and measuresExpression levels of platelet messenger RNA, platelet count, mean platelet volume, and 9 different measures of ex vivo platelet function (aggregated into a previously described platelet function score), and self-reported bleeding at baseline and after each exposure.ResultsIn the discovery cohort (n = 58, mean age 43, 39 female) platelet mRNAseq identified (FDR < 5%) 1820 up- and 1589 down-regulated genes associated with ticagrelor exposure. We prioritized 84 of these transcripts to calculate a TES score, which was increased by ticagrelor and unaffected by either dose of aspirin. In an independent cohort (n = 49, mean age 44, 24 female) we validated that ticagrelor exposure (beta = 0.48, SE = 0.08, p < 0.0001) increases TES scores. In combined analyses of discovery and validation cohorts, when TES levels were calculated using baseline platelet RNA, higher TES levels were associated with lower levels of baseline platelet function (meta-analysis beta = -0.60, standard error [SE] 0.29, P = 0.04) and self-reported bleeding during ticagrelor exposure (meta-analysis beta = 0.28, standard error [SE] = 0.14, P = 0.04). In contrast, we found no associations between bleeding with baseline platelet count, platelet volume, or platelet function.Conclusions and RelevanceTicagrelor exposure reproducibly and specifically changes a set of platelet transcripts, the baseline levels of which are a biomarker for platelet function and bleeding tendency on ticagrelor.Key PointsQuestionWhat are the global effects of ticagrelor exposure on platelets beyond platelet inhibition?FindingsIn an experimental human study of different antiplatelet therapies, we comprehensively characterized the effects of ticagrelor on platelet messenger RNA (mRNA). We found that 4 weeks of 90mg twice daily ticagrelor therapy specifically and reproducibly changes the levels of selected platelet mRNA. At baseline, volunteers with levels of platelet gene expression that mimic ticagrelor exposure had lower levels of platelet function and when exposed to ticagrelor a greater tendency for minor bleeding.MeaningBy using ticagrelor exposure as a molecular probe, we identified a platelet RNA biomarker that may identify patients at higher risk for ticagrelor-associated bleeding.

This guidance focuses on methodological aspects of lupus anticoagulant (LA) testing, as well as interpretation of results for clinicians. The main changes in how to test for LA compared with the International Society on Thrombosis and Haemostasis Scientific and Standardization Committee 2009 guidelines, in the preanalytical phase are more detailed recommendations on how to handle testing in anticoagulated patients, and the timing of testing. Also, routine coagulation tests are advised to obtain more information on the coagulation background of the patient, and when necessary, anti-Xa activity measurement for heparins or specific assays for direct oral anticoagulants should be performed. The three-step procedure with two test systems (diluted Russell's viper venom time and activated partial thromboplastin time [aPTT]) is essentially not changed. Silica remains the preferable activator in the aPTT assays, but ellagic acid is not excluded. We advise simultaneous performance of the mixing and confirmatory step, in each sample with a prolonged screening test. The confirmatory step can also be performed on a mixture of patient plasma and normal pooled plasma. Cutoff values should be established in-house on at least 120 normals, with transference of the manufacturer's cutoffs as an alternative. Reporting of results has not been changed, although more attention is focused on what clinicians should know. Patient selection for LA testing has been expanded.

Antiphospholipid syndrome (APS), an acquired autoimmune thrombophilia, is characterised by thrombosis and/or pregnancy morbidity in association with persistent antiphospholipid antibodies. The 16th International Congress on Antiphospholipid Antibodies Task Force on APS Treatment Trends reviewed the current status with regard to existing and novel treatment trends for APS, which is the focus of this Task Force report. The report addresses current treatments and developments since the last report, on the use of direct oral anticoagulants in patients with APS, antiplatelet agents, adjunctive therapies (hydroxychloroquine, statins and vitamin D), targeted treatment including rituximab, belimumab, and anti-TNF agents, complement inhibition and drugs based on peptides of beta-2-glycoprotein I. In addition, the report summarises potential new players, including coenzyme Q10, adenosine receptor agonists and adenosine potentiation. In each case, the report provides recommendations for clinicians, based on the current state of the art, and suggests a clinical research agenda. The initiation and development of appropriate clinical studies requires a focus on devising suitable outcome measures, including a disease activity index, an optimal damage index, and a specific quality of life index.

Hypercoagulability is an increasingly recognized complication of SARS‐CoV‐2 infection. As such, anticoagulation has become part and parcel of comprehensive COVID‐19 management. However, several uncertainties exist in this area including the appropriate type and dose of heparin. In addition, special patient populations, including those with high body mass index and renal impairment, require special consideration. Although the current evidence is still insufficient, we provide a pragmatic approach to anticoagulation in COVID‐19, but stress the need for further trials in this area.

BACKGROUND Patients with antiphospholipid antibodies (aPL) and thromboembolism (TE) are at risk for recurrent TE. Few studies, however, distinguish patients based on the initial event. OBJECTIVES We performed a systematic review and meta-analysis to investigate patients with aPL and venous TE (VTE), provoked or unprovoked, and patients with arterial TE (ATE). PATIENTS/METHODS We conducted searches in PubMed, CINAHL, Cochrane, and EMBASE. Inclusion criteria were prospective trials or cohort studies investigating patients with aPL and ATE or VTE. Excluded studies did not provide estimated recurrence rates, did not specify whether the incident event was ATE or VTE, included patients with multiple events, or included

Objective: To report the utilization of emicizumab in a patient with severe hemophilia A with inducible inhibitors and the reduction of drug costs related to decreased on-demand recombinant factor VIIa use. Case Summary: A 65-year-old African American man with established hemophilia A with an inducible factor VIII inhibitor presented with a bleeding hematoma from the right posterior thigh. The patient was historically managed on frequent administration of recombinant factor VIIa to achieve hemostasis and was started on every 2-hour dosing during this admission. Emicizumab, a new therapy for hemophilia A, became available during this admission, and the patient discontinued recombinant factor VIIa and transitioned to weekly emicizumab injections. The patient did not require any recombinant factor VIIa during the following 12 months resulting in substantial drug cost savings. Discussion: After initiation of emicizumab therapy, the patient no longer required on-demand treatment with recombinant factor VIIa for bleeds. Through this reduction in recombinant factor VIIa, there was a large decrease in inpatient drug costs and inpatient admissions for bleeding events. Conclusion: The potential reduction in drug costs and inpatient admissions should be considered when determining if emicizumab therapy is appropriate for hemophilia A patients with inhibitors. Further research is needed to confirm that continued long-term use of emicizumab remains associated with a reduction in on-demand treatment.

Increasing evidence supports the safety and effectiveness of managing low-risk deep vein thrombosis (DVT) or pulmonary embolism (PE) in outpatient settings. We performed a systematic review to assess safety and effectiveness of managing patients with DVT or PE at home compared with the hospital. Medline, Embase, and Cochrane databases were searched up to July 2019 for relevant randomized clinical trials (RCTs), and prospective cohort studies. Two investigators independently screened titles and abstracts of identified citations and extracted data from relevant full-text papers. Risk ratios (RRs) were calculated, and certainty of evidence was assessed using Grading of Recommendations Assessment, Development and Evaluation (GRADE). Seven RCTs (1922 patients) were included in meta-analyses on managing patients with DVT. Pooled estimates indicated decreased risk of PE (RR = 0.64; 95% confidence interval [CI], 0.44-0.93) and recurrent DVT (RR = 0.61; 95% CI, 0.42-0.90) for home management, both with moderate certainty of the evidence. Reductions in mortality and major bleeding were not significant, both with low certainty of the evidence. Two RCTs (445 patients) were included in meta-analyses on home management of low-risk patients with PE. Pooled estimates indicated no significant difference in all-cause mortality, recurrent PE, and major bleeding, all with low certainty of the evidence. Results of pooled estimates from 3 prospective cohort studies (234 patients) on home management of PE showed similar results. Our findings indicate that low-risk DVT patients had similar or lower risk of patient-important outcomes with home treatment compared with hospital treatment. In patients with low-risk PE, there was important uncertainty about a difference between home and hospital treatment.

Using the Vaccine Adverse Event Reporting System, the number and demographic characteristics of cases of thrombosis with thrombocytopenia syndrome occurring after receipt of COVID-19 vaccines in the United States were determined., Visual Abstract. Thrombosis With Thrombocytopenia Syndrome After COVID-19 Vaccination. Using the Vaccine Adverse Event Reporting System, the number and demographic characteristics of cases of thrombosis with thrombocytopenia syndrome occurring after receipt of COVID-19 vaccines in the United States were determined. Visual Abstract. Thrombosis With Thrombocytopenia Syndrome After COVID-19 Vaccination. Using the Vaccine Adverse Event Reporting System, the number and demographic characteristics of cases of thrombosis with thrombocytopenia syndrome occurring after receipt of COVID-19 vaccines in the United States were determined., Background: Thrombosis with thrombocytopenia syndrome (TTS) is a potentially life-threatening condition associated with adenoviral-vectored COVID-19 vaccination. It presents similarly to spontaneous heparin-induced thrombocytopenia. Twelve cases of cerebral venous sinus thrombosis after vaccination with the Ad26.COV2.S COVID-19 vaccine (Janssen/Johnson & Johnson) have previously been described. Objective: To describe surveillance data and reporting rates of all reported TTS cases after COVID-19 vaccination in the United States. Design: Case series. Setting: United States. Patients: Case patients receiving a COVID-19 vaccine from 14 December 2020 through 31 August 2021 with thrombocytopenia and thrombosis (excluding isolated ischemic stroke or myocardial infarction) reported to the Vaccine Adverse Event Reporting System. If thrombosis was only in an extremity vein or pulmonary embolism, a positive enzyme-linked immunosorbent assay for antiplatelet factor 4 antibodies or functional heparin-induced thrombocytopenia platelet test result was required. Measurements: Reporting rates (cases per million vaccine doses) and descriptive epidemiology. Results: A total of 57 TTS cases were confirmed after vaccination with Ad26.COV2.S (n = 54) or a messenger RNA (mRNA)–based COVID-19 vaccine (n = 3). Reporting rates for TTS were 3.83 per million vaccine doses (Ad26.COV2.S) and 0.00855 per million vaccine doses (mRNA-based COVID-19 vaccines). The median age of patients with TTS after Ad26.COV2.S vaccination was 44.5 years (range, 18 to 70 years), and 69% of patients were women. Of the TTS cases after mRNA-based COVID-19 vaccination, 2 occurred in men older than 50 years and 1 in a woman aged 50 to 59 years. All cases after Ad26.COV2.S vaccination involved hospitalization, including 36 (67%) with intensive care unit admission. Outcomes of hospitalizations after Ad26.COV2.S vaccination included death (15%), discharge to postacute care (17%), and discharge home (68%). Limitations: Underreporting and incomplete case follow-up. Conclusion: Thrombosis with thrombocytopenia syndrome is a rare but serious adverse event associated with Ad26.COV2.S vaccination. The different demographic characteristics of the 3 cases reported after mRNA-based COVID-19 vaccines and the much lower reporting rate suggest that these cases represent a background rate. Primary Funding Source: Centers for Disease Control and Prevention.

Antiphospholipid syndrome (APS) is a thrombo-inflammatory disease propelled by circulating autoantibodies that recognize cell surface phospholipids and phospholipid binding proteins. The result is an increased risk of thrombotic events, pregnancy morbidity, and various other autoimmune and inflammatory complications. Although antiphospholipid syndrome was first recognized in patients with lupus, the stand alone presentation of antiphospholipid syndrome is at least equally common. Overall, the diagnosis appears to affect at least one in 2000 people. Studies of antiphospholipid syndrome pathogenesis have long focused on logical candidates such as coagulation factors, endothelial cells, and platelets. Recent work has shed light on additional potential therapeutic targets within the innate immune system, including the complement system and neutrophil extracellular traps. Vitamin K antagonists remain the mainstay of treatment for most patients with thrombotic antiphospholipid syndrome and, based on current data, appear superior to the more targeted direct oral anticoagulants. The potential role of immunomodulatory treatments in antiphospholipid syndrome management is receiving increased attention. As for many systemic autoimmune diseases, the most important future direction is to more precisely identify mechanistic drivers of disease heterogeneity in pursuit of unlocking personalized and proactive treatments for patients.

Since the COVID-19 pandemic began over 2 years ago, its global impact has been enormous. Our growing understanding of the pathophysiology of this disease has particular links to hematology. Introduced by Ortel and Berliner, this Review Series provides up-to-date overviews of the many areas in which COVID-19 has implications for hematology practice.

BackgroundThrombosis with thrombocytopenia syndrome (TTS) is a potentially life-threatening condition associated with adenoviral-vectored COVID-19 vaccination. TTS presents similarly to autoimmune heparin-induced thrombocytopenia. Twelve cases of cerebral venous sinus thrombosis following Janssen/Johnson & Johnson (Ad26.COV2.S) COVID-19 vaccination have been described.ObjectiveDescribe surveillance data and reporting rates of TTS cases following COVID-19 vaccination.DesignCase series.SettingUnited StatesPatientsCase-patients reported to the Vaccine Adverse Event Reporting System (VAERS) receiving COVID-19 vaccine from December 14, 2020 through August 31, 2021, with thrombocytopenia and thrombosis (excluding isolated ischemic stroke or myocardial infarction). If thrombosis was only in an extremity vein or pulmonary embolism, a positive enzyme-linked immunosorbent assay for anti-platelet factor 4 antibody was required.MeasurementsReporting rates (cases/million vaccine doses) and descriptive epidemiology.Results52 TTS cases were confirmed following Ad26.COV2.S (n=50) or mRNA-based COVID-19 (n=2) vaccination. TTS reporting rates were 3.55 per million (Ad26.COV2.S) and 0.0057 per million (mRNA-based COVID-19 vaccines). Median age of patients with TTS following Ad26.COV2.S vaccination was 43.5 years (range: 18–70); 70% were female. Both TTS cases following mRNA-based COVID-19 vaccination occurred in males aged >50 years. All cases following Ad26.COV2.S vaccination involved hospitalization including 32 (64%) with intensive care unit admission. Outcomes of hospitalizations following Ad26.COV2.S vaccination included death (12%), discharge to post-acute care (16%), and discharge home (72%).LimitationsUnder-reporting and incomplete case follow-up.ConclusionTTS is a rare but serious adverse event associated with Ad26.COV2.S vaccination. The different demographic characteristics of the two cases reported after mRNA-based COVID-19 vaccines and the much lower reporting rate suggest that these cases represent a background rate.Funding SourceCDC

Venous thromboembolism (VTE) affects approximately 1-2 individuals per 1000 annually and is associated with an increased risk for pulmonary hypertension, postthrombotic syndrome, and recurrent VTE.To determine risk factors, incidence, treatments, and outcomes of VTE through a 2-year surveillance program initiated in Durham County, North Carolina (population approximately 280,000 at time of study).We performed a retrospective analysis of data actively collected from three hospitals in Durham County during the surveillance period.A total of 987 patients were diagnosed with VTE, for an annual rate of 1.76 per 1000 individuals. Hospital-associated VTE occurred in 167 hospitalized patients (16.9%) and 271 outpatients who were hospitalized within 90 days of diagnosis (27.5%). Annual incidence was 1.98 per 1000 Black individuals compared to 1.25 per 1000 White individuals (Ongoing surveillance provides an effective strategy to identify patients with VTE and monitor treatment and outcomes. We demonstrated that hospital-associated VTE continues to be a major contributor to the burden of VTE and confirmed the higher incidence of VTE in Black compared to White individuals.

NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines) for Cancer-Associated Venous Thromboembolic Disease focus on the prevention, diagnosis, and treatment of patients with cancer who have developed or who are at risk for developing venous thromboembolism (VTE). VTE is a significant concern among cancer patients, who are at heightened risks for developing as well as dying from the disease. The management of patients with cancer with VTE often requires multidisciplinary efforts at treating institutions. The NCCN panel comprises specialists from various fields: cardiology, hematology/hematologic oncology, internal medicine, interventional radiology, medical oncology, pharmacology/pharmacy, and surgery/surgical oncology. This article focuses on VTE prophylaxis for medical and surgical oncology inpatients and outpatients, and discusses risk factors for VTE development, risk assessment tools, as well as management methods, including pharmacological and mechanical prophylactics. Contraindications to therapeutic interventions and special dosing, when required, are also discussed.

Background: Venous thromboembolism (VTE), which includes deep vein thrombosis (DVT) and pulmonary embolism (PE), occurs in ∼1 to 2 individuals per 1000 each year, corresponding to ∼300 000 to 600 000 events in the United States annually. Objective: These evidence-based guidelines from the American Society of Hematology (ASH) intend to support patients, clinicians, and others in decisions about treatment of VTE. Methods: ASH formed a multidisciplinary guideline panel balanced to minimize potential bias from conflicts of interest. The McMaster University GRADE Centre supported the guideline development process, including updating or performing systematic evidence reviews. The panel prioritized clinical questions and outcomes according to their importance for clinicians and adult patients. The Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach was used to assess evidence and make recommendations, which were subject to public comment. Results: The panel agreed on 28 recommendations for the initial management of VTE, primary treatment, secondary prevention, and treatment of recurrent VTE events. Conclusions: Strong recommendations include the use of thrombolytic therapy for patients with PE and hemodynamic compromise, use of an international normalized ratio (INR) range of 2.0 to 3.0 over a lower INR range for patients with VTE who use a vitamin K antagonist (VKA) for secondary prevention, and use of indefinite anticoagulation for patients with recurrent unprovoked VTE. Conditional recommendations include the preference for home treatment over hospital-based treatment for uncomplicated DVT and PE at low risk for complications and a preference for direct oral anticoagulants over VKA for primary treatment of VTE.

Highlights • COVID-19 patients are at increased risk of thromboembolic complications. • Escalated-dose thromboprophylaxis may help reduce the rate of thromboembolic events. • The bleeding risk is highest for patients treated with therapeutic anticoagulation.

The development of vaccines to fight COVID-19 has been a remarkable medical achievement. However, this global immunization effort has been complicated by a rare vaccine-related outcome characterized by thrombocytopenia and thrombosis in association with platelet-activating anti–platelet factor 4 antibodies. In this Spotlight, we will discuss the recently described complication of vaccine-induced immune thrombotic thrombocytopenia (VITT) occurring in response to certain COVID-19 vaccines. Although information about this clinical condition is rapidly evolving, we will summarize our current understanding of VITT.

Background Systematic surveillance for venous thromboembolism (VTE) in the United States has been recommended by several organizations. Despite adoption of electronic medical records (EMRs) by most health care providers and facilities, however, systematic surveillance for VTE is not available. Objectives This article develops a comprehensive, population-based surveillance strategy for VTE in a defined geographical region. Methods The primary surveillance strategy combined computerized searches of the EMR with a manual review of imaging data at the Duke University Health System in Durham County, North Carolina, United States. Different strategies of searching the EMR were explored. Consolidation of results with autopsy reports (nonsearchable in the EMR) and with results from the Durham Veterans' Administration Medical Center was performed to provide a comprehensive report of new VTE from the defined region over a 2-year timeframe. Results Monthly searches of the primary EMR missed a significant number of patients with new VTE who were identified by a separate manual search of radiology records, apparently related to delays in data entry and coding into the EMR. Comprehensive searches incorporating a location-restricted strategy were incomplete due to the assigned residence reflecting the current address and not the address at the time of event. The most comprehensive strategy omitted the geographic restriction step and identified all patients with VTE followed by manual review of individual records to remove incorrect entries (e.g., outside the surveillance time period or geographic location; no evidence for VTE). Consolidation of results from the EMR searches with results from autopsy reports and the separate facility identified additional patients not diagnosed within the Duke system. Conclusion We identified several challenges with implementing a comprehensive VTE surveillance program that could limit accuracy of the results. Improved electronic strategies are needed to cross-reference patients across multiple health systems and to minimize the need for manual review and confirmation of results.

Introduction Heparin‐induced thrombocytopenia (HIT) is a potentially life‐threatening adverse reaction of heparin. Laboratory evaluation of HIT is often not available within a reasonable time. We evaluated the HemosIL® HIT‐Ab(PF4‐H) (Instrumentation Laboratory), a rapid, on‐demand, fully automated, latex immunoturbidimetric assay (LIA). Materials and methods Following determination of the LIA's reference interval and cutoff values, a multicenter study was conducted between March 2013 and June 2015. Plasma samples of HIT‐suspected patients (n = 632) were collected and evaluated by LIA on the ACL TOP® Family systems (Instrumentation Laboratory), enzyme‐linked immunosorbent assays (EIA), and serotonin release assay (SRA). Patient characteristics, medical conditions, comorbidities, laboratory results, and medications were collected via medical chart review. The pretest clinical probability of HIT was also calculated for each patient. Results Based on the 95% reference interval for healthy donors and HIT‐negative patients, a LIA value ≥1.0 U/mL was interpreted positive. The overall agreement of LIA versus EIA and SRA results were 90% (95% CI 88%‐92%) and 79% (95% CI 75%‐82%), respectively. The negative predictive value for LIA and EIA was comparable (87%) with SRA. The positive and negative percent agreements with the clinical probability were 89% (95% CI 69%‐97%) and 86% (95% CI 83%‐89%), respectively, with a negative predictive value of 99.6% (95% CI 98%‐100%). Discussion Overall, the LIA results were comparable to those of EIA and SRA. This fully automated assay with a remarkable short analytical turnaround time of

BACKGROUND/OBJECTIVES Prothrombin complex concentrates (PCC) are increasingly administered off-label in the United States to treat bleeding in cardiovascular surgical patients and carry the potential risk for acquired thromboembolic side-effects after surgery. Therefore, we hypothesized that the use of low-dose 3-factor (3F) PCC (20-30 IU/kg), as part of a transfusion algorithm, reduces bleeding without increasing postoperative thrombotic/thromboembolic complications. MATERIALS/METHODS After IRB approval, we retrospectively analysed 114 consecutive, complex cardiovascular surgical patients (age > 18 years), between February 2014 and June 2015, that received low-dose 3F-PCC (Profilnine® ), of which seven patients met established exclusion criteria. PCC was dosed according to an institutional perioperative algorithm. Allogeneic transfusions were recorded before and after PCC administration (n = 107). The incidence of postoperative thromboembolic events was determined within 30 days of surgery, and Factor II levels were measured in a subset of patients (n = 20) as a quality control measure to avoid excessive PCC dosing. RESULTS Total allogeneic blood product transfusion reached a mean of 12·4 ± 9·9 units before PCC and 5·0 ± 6·3 units after PCC administration (P

Limited data exists regarding the clinical outcomes of andexanet alfa and four factor prothrombin complex concentrate (4F-PCC) for reversal of apixaban or rivaroxaban in the setting of intracranial hemorrhage (ICH). The objective of this study was to evaluate clinical outcomes of 4F-PCC and andexanet alfa for reversal of ICH associated with oral factor Xa inhibitors. This was a retrospective, single-center, case series evaluating hemostatic efficacy of patients receiving andexanet alfa) or 4F-PCC for reversal of apixaban or rivaroxaban after ICH. Secondary endpoints included in-hospital mortality, thrombotic complications, timing of reversal agents, intensive care unit and hospital length of stay, patient disposition, and 30-day readmission rate. During the study period, 21 patients received andexanet alfa and 35 received 4F-PCC. Hemostatic efficacy occurred in 64.7% of patients receiving andexanet alfa and 54.8% of receiving 4F-PCC. Thirty-day all-cause mortality was 45.2% for 4F-PCC and 30% for andexanet alfa. Thrombotic events were higher with 4F-PCC (31.4%) compared to andexanet alfa (14.3%). Median time from presentation to administration of reversal agent was 2.67 [1.75-4.13] hours with andexanet alfa and 1.73 [1.21-3.55] hours with 4F-PCC. Discharge to skilled nursing facilities and 30-day readmission were similar between groups. In this cohort, reversal with andexanet alfa and 4F-PCC differed in terms ofhemostatic efficacy and thrombotic events after ICH in patients anticoagulated with apixaban or rivaroxaban.

Key Points The proposed guideline manuscript template is the first detailed template for transparent and complete reporting of guidelines.Consistent application of the template may simplify preparing an evidence-based guideline manuscript and facilitate its use., Visual Abstract, Trustworthy health guidelines should provide recommendations, document the development process, and highlight implementation information. Our objective was to develop a guideline manuscript template to help authors write a complete and useful report. The McMaster Grading of Recommendations Assessment, Development and Evaluation Centre collaborated with the American Society of Hematology (ASH) to develop guidelines for the management of venous thromboembolism. A template for reporting the guidelines was developed based on prior approaches and refined using input from other key stakeholders. The proposed guideline manuscript template includes: (1) title for guideline identification, (2) abstract, including a summary of key recommendations, (3) overview of all recommendations (executive summary), and (4) the main text, providing sufficient detail about the entire process, including objectives, background, and methodological decisions from panel selection and conflict-of-interest management to criteria for updating, as well as supporting information, such as links to online (interactive) tables. The template further allows for tailoring to the specific topic, using examples. Initial experience with the ASH guideline manuscript template was positive, and challenges included drafting descriptions of recommendations involving multiple management pathways, tailoring the template for a specific guideline, and choosing key recommendations to highlight. Feedback from a larger group of guideline authors and users will be needed to evaluate its usefulness and refine. The proposed guideline manuscript template is the first detailed template for transparent and complete reporting of guidelines. Consistent application of the template may simplify the preparation of an evidence-based guideline manuscript and facilitate its use.

Background Venous thromboembolism (VTE) is a well-known complication associated with surgical procedures. The implementation of thromboprophylaxis in this population has become a vital aspect of perioperative care to decrease VTE-associated morbidity and mortality risk. However, data assessing the role of thromboprophylaxis for patients undergoing vascular surgery are sparse. Assessing the role of thromboprophylaxis by low-molecular-weight heparin or unfractionated heparin in vascular surgery. Methods We searched MEDLINE, Embase, and the Cochrane Collaboration Central Register of Controlled Trials from inception until December 2020, for randomized controlled trials assessing the role of thromboprophylaxis in vascular surgery. Results Eight randomized controlled trials met inclusion criteria, including 3130 patients, with a mean age of 55.35 years and 45% were females. Compared with placebo, anticoagulant use was associated with a decrease in deep venous thrombosis (DVT) (risk ratio [RR], 0.34; 95% confidence interval [CI], 0.11-1.05; P = .06; I2 = 68%) and pulmonary embolism (PE) (RR, 0.17; 95% CI, 0.02-1.22; P = .08; I2 = 41%), but this trend did not attain statistical significance. There was no difference for bleeding outcomes between anticoagulants and placebo (RR, 0.90; 95% CI, 0.05-15.01; P = .94; I2 = 76%). There was no significant difference in outcomes when low-molecular-weight heparin was compared directly with unfractionated heparin. In a sensitivity analysis, anticoagulant use was associated with a significant decrease in DVT or PE in patients undergoing venous surgeries, but was not associated with a significant decrease in DVT or PE in patients undergoing arterial surgeries, although this analysis was limited by the small number of studies in each group. Conclusions Among patients undergoing vascular surgery, thromboprophylaxis with anticoagulants showed a trend toward a lesser incidence of VTE when compared with placebo, although this difference was not statistically significant. Bleeding outcomes were comparable between both treatment groups.

Background: Health guideline development requires sequential prioritization of the guideline topic, questions, and health outcomes. In this paper we report on new approaches for prioritizing questions and outcomes in guidelines. Methods: Ten guideline panels on venous thromboembolism rated potential guideline questions on a 9-point scale according to their overall importance and 6 criteria: common in practice, uncertainty in practice, variation in practice, new evidence available, cost consequences, not previously addressed. We randomized panelists to rate one potential question with and without the 6 criteria. Panelists rated importance of outcomes, defined with health outcome descriptors (HODs), using a 9-point scale, and health utility of outcomes on a visual analogue scale. Results: Of 469 potential questions identified, 72.5% were rated as important but not of high priority, and 25.4% as high priority. Each criterion was significantly associated with the overall importance rating. The overall importance rating means were 5.96 (SD 2.38) and 6.53 (SD 2.45) ( P = 0.25) for those randomized to rate questions with and without the criteria, respectively. The mean importance rating for 121 outcomes was 6.01 (SD 1.25), with 35.5% rated as critical for decision-making. Panelists provided health utility ratings for 127 outcomes, with a minimum mean rating of 0.12 (SD 0.10) and maximum of 0.91 (SD 0.15). Conclusion: Our structured process provided information to help explain perspectives of question importance, to facilitate panels' outcome prioritization, and to facilitate decision-making in guideline development. (c) 2021 Published by Elsevier Inc.

BACKGROUND: Platelet gene polymorphisms are associated with variable on-treatment platelet reactivity and vary by race. Whether differences in platelet reactivity and aspirin or ticagrelor exist between African-American and European-Americans remains poorly understood. METHODS: Biological samples from three prior prospective antiplatelet challenge studies at the Duke Clinical Research Unit were used to compare platelet reactivity between African-American and European-American subjects. Platelet reactivity at baseline, on-aspirin, on-ticagrelor, and the treatment effect of aspirin or ticagrelor were compared between groups using an adjusted mixed effects model. RESULTS: Compared with European-Americans (n=282; 50% female; mean±standard deviation age, 50±16), African-Americans (n=209; 67% female; age 48±12) had lower baseline platelet reactivity with platelet function analyzer-100 (PFA-100) (p

This guidance focuses on methodological aspects of lupus anticoagulant (LA) testing, as well as interpretation of results for clinicians. The main changes in how to test for LA compared with the International Society on Thrombosis and Haemostasis Scientific and Standardization Committee 2009 guidelines, in the preanalytical phase are more detailed recommendations on how to handle testing in anticoagulated patients, and the timing of testing. Also, routine coagulation tests are advised to obtain more information on the coagulation background of the patient, and when necessary, anti-Xa activity measurement for heparins or specific assays for direct oral anticoagulants should be performed. The three-step procedure with two test systems (diluted Russell's viper venom time and activated partial thromboplastin time [aPTT]) is essentially not changed. Silica remains the preferable activator in the aPTT assays, but ellagic acid is not excluded. We advise simultaneous performance of the mixing and confirmatory step, in each sample with a prolonged screening test. The confirmatory step can also be performed on a mixture of patient plasma and normal pooled plasma. Cutoff values should be established in-house on at least 120 normals, with transference of the manufacturer's cutoffs as an alternative. Reporting of results has not been changed, although more attention is focused on what clinicians should know. Patient selection for LA testing has been expanded.

Background:Methods for the development of clinical guidelines have advanced dramatically over the past 2 decades to strive for trustworthiness, transparency, user-friendliness, and rigor. The American Society of Hematology (ASH) guidelines on venous thromboembolism (VTE) have followed these advances, together with application of methodological innovations.Objective:In this article, we describe methods and methodological innovations as a model to inform future guideline enterprises by ASH and others to achieve guideline standards. Methodological innovations introduced in the development of the guidelines aim to address current challenges in guideline development.Methods:We followed ASH policy for guideline development, which is based on the Guideline International Network (GIN)-McMaster Guideline Development Checklist and current best practices. Central coordination, specialist working groups, and expert panels were established for the development of 10 VTE guidelines. Methodological guidance resources were developed to guide the process across guidelines panels. A methods advisory group guided the development and implementation of methodological innovations to address emerging challenges and needs.Results:The complete set of VTE guidelines will include >250 recommendations. Methodological innovations include the use of health-outcome descriptors, online voting with guideline development software, modeling of pathways for diagnostic questions, application of expert evidence, and a template manuscript for publication of ASH guidelines. These methods advance guideline development standards and have already informed other ASH guideline projects.Conclusions:The development of the ASH VTE guidelines followed rigorous methods and introduced methodological innovations during guideline development, striving for the highest possible level of trustworthiness, transparency, user-friendliness, and rigor.

In this Review Series, introduced by Associate Editor Thomas L. Ortel, experts contribute 6 seminal reviews that focus on the treatment of venous thromboembolism (VTE) in adults and children, the management of VTE developing in unusual locations and in the setting of thrombophilia, and new targets and antithrombotic therapies in development.

After completing anticoagulation therapy for acute venous thromboembolism (VTE), patients with unprovoked VTE are at increased risk of recurrent thrombotic events. Recent studies suggest a risk of nearly 10% in the first year after stopping anticoagulants and 30% at 8 years. Therefore, it is important to consider extended anticoagulation for secondary prevention in these high‐risk patients. While several oral anticoagulants are available for this purpose, there is limited information available regarding the optimal agent to minimize bleeding risks and maximize efficacy at VTE prevention. This review article summarizes the evidence available for Vitamin‐K antagonists (VKAs) and direct oral anticoagulants (DOACs) for extended treatment of VTE. We also introduce the COVET trial, the first head‐to‐head comparison of VKAs to DOACs, rivaroxaban and apixaban, for extended management of unprovoked VTE.

Objective Venous thromboembolism (VTE) prophylaxis is an important consideration for hospitalized older adults, and the Padua Prediction Score (PPS) is a risk prediction tool used to prioritize patient selection. We developed an automated PPS (APPS) algorithm using electronic health record (EHR) data. This study examines the accuracy of APPS and its individual components versus manual data extraction. Methods This is a retrospective cohort study of hospitalized general internal medicine patients, aged 70 and over. Fourteen clinical variables were collected to determine their PPS; APPS used EHR data exports from health system databases, and a trained abstractor performed manual chart abstractions. We calculated sensitivity and specificity of the APPS, using manual PPS as the gold standard for classifying risk category (low vs. high). We also examined performance characteristics of the APPS for individual variables. Results PPS was calculated by both methods on 311 individuals. The mean PPS was 3.6 (standard deviation, 1.8) for manual abstraction and 2.8 (1.4) for APPS. In detecting patients at high risk for VTE, the sensitivity and specificity of the APPS algorithm were 46 and 94%, respectively. The sensitivity for APPS was poor (range: 6–34%) for detecting acute conditions (i.e., acute myocardial infarction), moderate (range: 52–74%) for chronic conditions (i.e., heart failure), and excellent (range: 94–98%) for conditions of obesity and restricted mobility. Specificity of the automated extraction method for each PPS variable was > 87%. Conclusion APPS as a stand-alone tool was suboptimal for classifying risk of VTE occurrence. The APPS accurately identified high risk patients (true positives), but lower scores were considered indeterminate.

Introduction Limited data are available describing indications for and outcomes of therapeutic plasma exchange (TPE) in cardiac transplantation. Methods In a retrospective study of patients who underwent cardiac transplantation at Duke University Medical Center from 2010 to 2014, we reviewed 3 TPE treatment patterns: a Single TPE procedure within 24 h of transplant; Multiple TPE procedures initiated within 24 h of transplant; and 1 or more TPE procedures beginning >24 h post-transplant. Primary and secondary outcomes were overall survival (OS) and TPE survival (TS), respectively. Results Of 313 patients meeting study criteria, 109 (35%) underwent TPE. TPE was initiated in 82 patients within 24 h, 40 (37%) receiving a single procedure (Single TPE), and 42 (38%) multiple procedures (Multiple TPE). Twenty-seven (25%) began TPE >24 h after transplant (Delayed TPE). The most common TPE indication was elevated/positive panel reactive or human leukocyte antigen antibodies (32%). With a median follow-up of 49 months, the non-TPE treated and Single TPE cohorts had similar OS (HR 1.08 [CI, 0.54, 2.14], P = .84), while the Multiple and Delayed TPE cohorts had worse OS (HR 2.62 [CI, 1.53, 4.49] and HR 1.98 [CI, 1.02, 3.83], respectively). The Multiple and Delayed TPE cohorts also had worse TS (HR 2.59 [CI, 1.31, 5.14] and HR 3.18 [CI, 1.56, 6.50], respectively). Infection rates did not differ between groups but was independently associated with OS (HR 2.31 [CI, 1.50, 3.54]). Conclusions TPE is an important therapeutic modality in cardiac transplant patients. Prospective studies are needed to better define TPE's different roles in this patient population.

IMPORTANCE: Hospitalized patients with COVID-19 are at risk for venous and arterial thromboembolism and death. Optimal thromboprophylaxis dosing in high-risk patients is unknown. OBJECTIVE: To evaluate the effects of therapeutic-dose low-molecular-weight heparin (LMWH) vs institutional standard prophylactic or intermediate-dose heparins for thromboprophylaxis in high-risk hospitalized patients with COVID-19. DESIGN, SETTING, AND PARTICIPANTS: The HEP-COVID multicenter randomized clinical trial recruited hospitalized adult patients with COVID-19 with D-dimer levels more than 4 times the upper limit of normal or sepsis-induced coagulopathy score of 4 or greater from May 8, 2020, through May 14, 2021, at 12 academic centers in the US. INTERVENTIONS: Patients were randomized to institutional standard prophylactic or intermediate-dose LMWH or unfractionated heparin vs therapeutic-dose enoxaparin, 1 mg/kg subcutaneous, twice daily if creatinine clearance was 30 mL/min/1.73 m(2) or greater (0.5 mg/kg twice daily if creatinine clearance was 15-29 mL/min/1.73 m(2)) throughout hospitalization. Patients were stratified at the time of randomization based on intensive care unit (ICU) or non-ICU status. MAIN OUTCOMES AND MEASURES: The primary efficacy outcome was venous thromboembolism (VTE), arterial thromboembolism (ATE), or death from any cause, and the principal safety outcome was major bleeding at 30 ± 2 days. Data were collected and adjudicated locally by blinded investigators via imaging, laboratory, and health record data. RESULTS: Of 257 patients randomized, 253 were included in the analysis (mean [SD] age, 66.7 [14.0] years; men, 136 [53.8%]; women, 117 [46.2%]); 249 patients (98.4%) met inclusion criteria based on D-dimer elevation and 83 patients (32.8%) were stratified as ICU-level care. There were 124 patients (49%) in the standard-dose vs 129 patients (51%) in the therapeutic-dose group. The primary efficacy outcome was met in 52 of 124 patients (41.9%) (28.2% VTE, 3.2% ATE, 25.0% death) with standard-dose heparins vs 37 of 129 patients (28.7%) (11.7% VTE, 3.2% ATE, 19.4% death) with therapeutic-dose LMWH (relative risk [RR], 0.68; 95% CI, 0.49-0.96; P = .03), including a reduction in thromboembolism (29.0% vs 10.9%; RR, 0.37; 95% CI, 0.21-0.66; P

James L. Januzzi, Jr, MD, FACC, Chair Luis C. Afonso, MBBS, FACC Brendan Everett, MD, FACC Jonathan Halperin, MD, FACC Adrian Hernandez, MD, FACC William Hucker, MD Hani Jneid, MD, FACC Dharam Kumbhani, MD, SM, FACC Eva M. Lonn, MD, FACC Joseph Marine, MD, FACC James K. Min, MD, FACC