Anticoagulation for Stroke Prevention in Atrial Fibrillation and Treatment of Venous Thromboembolism and Portal Vein Thrombosis in Cirrhosis: Guidance from the SSC of the ISTH.

Whilst advanced liver disease was previously considered to be an acquired bleeding disorder, there is increasing recognition of an associated prothrombotic state with patients being at higher risk of atrial fibrillation (AF) and stroke and venous thromboembolism including portal vein thrombosis (PVT). We review the available literature on epidemiology, pathophysiology and risk factors and provide guidance on anticoagulant management of these conditions in adults with cirrhosis. In patients with Child-Pugh A or B cirrhosis and AF, we recommend anticoagulation with standard dose direct oral anticoagulants (DOACs) in accordance with cardiology guideline recommendations for patients without liver disease. In those with Child-Pugh C cirrhosis, there is inadequate evidence with respect to the benefit and risk of anticoagulation for AF. For patients with cirrhosis and acute deep vein thrombosis or pulmonary embolism, we recommend anticoagulation and suggest use of either a DOAC or low molecular weight heparin/vitamin K antagonist. We recommend anticoagulation for patients with cirrhosis and symptomatic PVT. We suggest anticoagulation for those with asymptomatic, progressing PVT and recommend continuing extended anticoagulation for liver transplant candidates with PVT.

Cost-effectiveness of sutimlimab in cold agglutinin disease.

Primary cold agglutinin disease (CAD) is a rare autoimmune hemolytic anemia caused by cold-reactive antibodies that bind to red blood cells and lead to complement-mediated hemolysis. Patients with primary CAD experience the burden of increased health resource utilization and reduced quality of life. The standard-of-care (SOC) in patients with primary CAD has included cold avoidance, transfusion support, and chemoimmunotherapy. The use of sutimlimab, a humanized monoclonal antibody that selectively inhibits C1-mediated hemolysis, was shown to reduce transfusion-dependence and improve quality of life across two pivotal phase 3 studies, further supported by 2-year extension data. Using data from the transfusion-dependent patient population that led to sutimlimab's initial FDA approval, we performed the first-ever cost-effectiveness analysis in primary CAD. The projected incremental cost-effectiveness ratio (ICER) in our Markov model was $2 340 000/QALY, significantly above an upper-end conventional US willingness-to-pay threshold of $150 000/QALY. These results are consistent across scenarios of higher body weight and a pan-refractory SOC patient phenotype (i.e., treated sequentially with bendamustine-rituximab, bortezomib, ibrutinib, and eculizumab). No parameter variations in deterministic sensitivity analyses changed our conclusion. In probabilistic sensitivity analysis, SOC was favored over sutimlimab in 100% of 10 000 iterations. Exploratory threshold analyses showed that significant price reduction (>80%) or time-limited treatment (<18 months) followed by lifelong clinical remission off sutimlimab would allow sutimlimab to become cost-effective. The impact of sutimlimab on health system costs with longer term follow-up data merits future study and consideration through a distributional cost-effectiveness framework.

Distinguishing ASH Clinical Practice Guidelines from Other Forms of ASH Clinical Advice.

The American Society of Hematology (ASH) develops a variety of resources that provide guidance to clinicians on the diagnosis and management of blood diseases. These resources include clinical practice guidelines (CPGs) and other forms of clinical advice. While both ASH CPGs and other forms of clinical advice provide recommendations, they differ with respect to the methods underpinning their development, the principal type of recommendations they offer, their transparency and concordance with published evidence, and the time and resources required for their development. It is crucial that end users be aware of the differences between CPGs and other forms of clinical advice and that producers and publishers of these resources use clear and unambiguous terminology to facilitate their distinction. The objective of this article is to highlight similarities and differences between ASH CPGs and other forms of ASH clinical advice and to discuss the implications of these differences for end users.

Cost-effectiveness of prophylaxis with recombinant vs plasma-derived VWF in severe von Willebrand disease in the United States.

ABSTRACT: We evaluated the cost-effectiveness of prophylaxis with recombinant von Willebrand factor (rVWF) vs with plasma-derived von Willebrand factor (pdVWF) for patients with severe Von Willebrand disease. We found that rVWF is a cost-saving factor replacement compared with pdVWF across all willingness-to-pay thresholds in the United States.

Optimizing antithrombotic therapy in patients with coexisting cardiovascular and gastrointestinal disease.

Balancing the safety and efficacy of antithrombotic agents in patients with gastrointestinal disorders is challenging because of the potential for interference with the absorption of antithrombotic drugs and for an increased risk of bleeding. In this Review, we address considerations for enteral antithrombotic therapy in patients with cardiovascular disease and gastrointestinal comorbidities. For those with gastrointestinal bleeding (GIB), we summarize a general scheme for risk stratification and clinical evidence on risk reduction approaches, such as limiting the use of concomitant medications that increase the risk of GIB and the potential utility of gastrointestinal protection strategies (such as proton pump inhibitors or histamine type 2 receptor antagonists). Furthermore, we summarize the best available evidence and potential gaps in our knowledge on tailoring antithrombotic therapy in patients with active or recent GIB and in those at high risk of GIB but without active or recent GIB. Finally, we review the recommendations provided by major medical societies, highlighting the crucial role of teamwork and multidisciplinary discussions to customize the antithrombotic regimen in patients with coexisting cardiovascular and gastrointestinal diseases.

Cost-effectiveness of rapid vs in-house vs send-out ADAMTS13 testing for immune thrombotic thrombocytopenic purpura.

ABSTRACT: While awaiting confirmatory results, empiric therapy for patients suspected to have immune thrombotic thrombocytopenic purpura (iTTP) provides benefits and also accrues risks and costs. Rapid assays for ADAMTS13 may be able to avoid the cost and risk exposure associated with empiric treatment. We conducted, to our knowledge, the first cost-effectiveness evaluation of testing strategies with rapid vs traditional ADAMTS13 assays in patients with intermediate- to high-risk PLASMIC scores, with and without caplacizumab use. We built a Markov cohort simulation with 4 clinical base-case analyses: (1) intermediate-risk PLASMIC score with caplacizumab; (2) intermediate-risk PLASMIC score without caplacizumab; (3) high-risk PLASMIC score with caplacizumab; and (4) high-risk PLASMIC score without caplacizumab. Each of these evaluated 3 testing strategies: (1) rapid assay (<1-hour turnaround); (2) in-house fluorescence resonance energy transfer (FRET)-based assay (24-hour turnaround); and (3) send-out FRET-based assay (72-hour turnaround). The primary outcome was the incremental net monetary benefit reported over a 3-day time horizon and across accepted willingness-to-pay thresholds in US dollars per quality-adjusted life-year (QALY). While accruing the same amount of QALYs, the rapid assay strategy saved up to $46 820 (95% CI, $41 961-$52 486) per patient tested. No parameter variation changed the outcome. In probabilistic sensitivity analyses, the rapid assay strategy was favored in 100% (3 base cases and scenario analyses) and 99% (1 base-case and scenario analysis) across 100 000 Monte Carlo iterations within each. Rapid ADAMTS13 testing for patients with intermediate- or high-risk PLASMIC scores yields significant per patient cost savings, achieved by reducing the costs associated with unnecessary therapeutic plasma exchange and caplacizumab therapy in patients without iTTP.

Algorithm for Rapid Exclusion of Clinically Relevant Plasma Levels of Direct Oral Anticoagulants in Patients Using the DOAC Dipstick: An Expert Consensus Paper.

BACKGROUND: With the widespread use of direct oral anticoagulants (DOACs), there is an urgent need for a rapid assay to exclude clinically relevant plasma levels. Accurate and rapid determination of DOAC levels would guide medical decision-making to (1) determine the potential contribution of the DOAC to spontaneous or trauma-induced hemorrhage; (2) identify appropriate candidates for reversal, or (3) optimize the timing of urgent surgery or intervention. METHODS AND RESULTS: The DOAC Dipstick test uses a disposable strip to identify factor Xa- or thrombin inhibitors in a urine sample. Based on the results of a systematic literature search followed by an analysis of a simple pooling of five retrieved clinical studies, the test strip has a high sensitivity and an acceptably high negative predictive value when compared with levels measured with liquid chromatography tandem mass spectrometry or calibrated chromogenic assays to reliably exclude plasma DOAC concentrations ≥30 ng/mL. CONCLUSION: Based on these data, a simple algorithm is proposed to enhance medical decision-making in acute care indications useful primarily in hospitals not having readily available quantitative tests and 24/7. This algorithm not only determines DOAC exposure but also differentiates between factor Xa and thrombin inhibitors to better guide clinical management.

Effectiveness and safety of prophylactic anticoagulation among hospitalized patients with inflammatory bowel disease.

ABSTRACT: Hospitalized patients with inflammatory bowel disease (IBD) are at increased risk of venous thromboembolism (VTE). We aimed to evaluate the effectiveness and safety of prophylactic anticoagulation compared with no anticoagulation in hospitalized patients with IBD. We conducted a retrospective cohort study using a hospital-based database. We included patients with IBD who had a length of hospital stay ≥2 days between 1 January 2016 and 31 December 2019. We excluded patients who had other indications for anticoagulation, users of direct oral anticoagulants, warfarin, therapeutic-intensity heparin, and patients admitted for surgery. We defined exposure to prophylactic anticoagulation using charge codes. The primary effectiveness outcome was VTE. The primary safety outcome was bleeding. We used propensity score matching to reduce potential differences between users and nonusers of anticoagulants and Cox proportional-hazards regression to estimate adjusted hazard ratios (HRs) and 95% confidence intervals (CIs). The analysis included 56 194 matched patients with IBD (users of anticoagulants, n = 28 097; nonusers, n = 28 097). In the matched sample, prophylactic use of anticoagulants (vs no use) was associated with a lower rate of VTE (HR, 0.62; 95% CI, 0.41-0.94) and with no difference in the rate of bleeding (HR, 1.05; 95% CI, 0.87-1.26). In this study of hospitalized patients with IBD, prophylactic use of heparin was associated with a lower rate of VTE without increasing bleeding risk compared with no anticoagulation. Our results suggest potential benefits of prophylactic anticoagulation to reduce the burden of VTE in hospitalized patients with IBD.

Improving methods of clinical practice guidelines: From guidelines to pathways to fast-and-frugal trees and decision analysis to develop individualised patient care.

BACKGROUND: Current methods for developing clinical practice guidelines have several limitations: they are characterised by the "black box" operation-a process with defined inputs and outputs but an incomplete understanding of its internal workings; they have "the integration problem"-a lack of framework for explicitly integrating factors such as patient preferences and trade-offs between benefits and harms; they generate one recommendation at a time that typically are not connected in a coherent analytical framework; and they apply to "average" patients, while clinicians and their patients seek advice tailored to individual circumstances. METHODS: We propose augmenting the current guideline development method by converting evidence-based pathways into fast-and-frugal decision trees (FFTs) and integrating them with generalised decision curve analysis to formulate clear, individualised management recommendations. RESULTS: We illustrate the process by developing recommendations for the management of heparin-induced thrombocytopenia (HIT). We converted evidence-based pathways for HIT, developed by the American Society of Hematology, into an FFT. Here, we consider only thrombotic complications and major bleeding. We leveraged the predictive potential of FFTs to compare the effects of argatroban, bivalirudin, fondaparinux, and direct oral anticoagulants (DOACs) using generalised decision curve analysis. We found that DOACs were superior to other treatments if the FFT-predicted probability of HIT exceeded 3%. CONCLUSIONS: The proposed analytical framework connects guidelines, pathways, FFTs, and decision analysis, offering risk-tailored personalised recommendations and addressing current guideline development critiques.

Confidence score: a data-driven measure for inclusive systematic reviews considering unpublished preprints.

OBJECTIVES: COVID-19, since its emergence in December 2019, has globally impacted research. Over 360 000 COVID-19-related manuscripts have been published on PubMed and preprint servers like medRxiv and bioRxiv, with preprints comprising about 15% of all manuscripts. Yet, the role and impact of preprints on COVID-19 research and evidence synthesis remain uncertain. MATERIALS AND METHODS: We propose a novel data-driven method for assigning weights to individual preprints in systematic reviews and meta-analyses. This weight termed the "confidence score" is obtained using the survival cure model, also known as the survival mixture model, which takes into account the time elapsed between posting and publication of a preprint, as well as metadata such as the number of first 2-week citations, sample size, and study type. RESULTS: Using 146 preprints on COVID-19 therapeutics posted from the beginning of the pandemic through April 30, 2021, we validated the confidence scores, showing an area under the curve of 0.95 (95% CI, 0.92-0.98). Through a use case on the effectiveness of hydroxychloroquine, we demonstrated how these scores can be incorporated practically into meta-analyses to properly weigh preprints. DISCUSSION: It is important to note that our method does not aim to replace existing measures of study quality but rather serves as a supplementary measure that overcomes some limitations of current approaches. CONCLUSION: Our proposed confidence score has the potential to improve systematic reviews of evidence related to COVID-19 and other clinical conditions by providing a data-driven approach to including unpublished manuscripts.

Combining Super Learner with high-dimensional propensity score to improve confounding adjustment: A real-world application in chronic lymphocytic leukemia.

PURPOSE: High-dimensional propensity score (hdPS) is a semiautomated method that leverages a vast number of covariates available in healthcare databases to improve confounding adjustment. A novel combined Super Learner (SL)-hdPS approach was proposed to assist with selecting the number of covariates for propensity score inclusion, and was found in plasmode simulation studies to improve bias reduction and precision compared to hdPS alone. However, the approach has not been examined in the applied setting. METHODS: We compared SL-hdPS's performance with that of several hdPS models, each with prespecified covariates and a different number of empirically-identified covariates, using a cohort study comparing real-world bleeding rates between ibrutinib- and bendamustine-rituximab (BR)-treated individuals with chronic lymphocytic leukemia in Optum's de-identified Clinformatics® Data Mart commercial claims database (2013-2020). We used inverse probability of treatment weighting for confounding adjustment and Cox proportional hazards regression to estimate hazard ratios (HRs) for bleeding outcomes. Parameters of interest included prespecified and empirically-identified covariate balance (absolute standardized difference [ASD] thresholds of <0.10 and <0.05) and outcome HR precision (95% confidence intervals). RESULTS: We identified 2423 ibrutinib- and 1102 BR-treated individuals. Including >200 empirically-identified covariates in the hdPS model compromised covariate balance at both ASD thresholds. SL-hdPS balanced more covariates than all individual hdPS models at both ASD thresholds. The bleeding HR 95% confidence intervals were generally narrower with SL-hdPS than with individual hdPS models. CONCLUSION: In a real-world application, hdPS was sensitive to the number of covariates included, while use of SL for covariate selection resulted in improved covariate balance and possibly improved precision.

Defining a metrologically traceable and sustainable calibration hierarchy of international normalized ratio for monitoring of vitamin K antagonist treatment in accordance with International Organization for Standardization (ISO) 17511:2020 standard: communication from the International Federation of Clinical Chemistry and Laboratory Medicine-SSC/ISTH working group on prothrombin time/international normalized ratio standardization.

Calibration of prothrombin time (PT) in terms of international normalized ratio (INR) has been outlined in "Guidelines for thromboplastins and plasmas used to control oral anticoagulant therapy" (World Health Organization, 2013). The international standard ISO 17511:2020 presents requirements for manufacturers of in vitro diagnostic (IVD) medical devices (MDs) for documenting the calibration hierarchy for a measured quantity in human samples using a specified IVD MD. The objective of this article is to define an unequivocal, metrologically traceable calibration hierarchy for the INR measured in plasma as well as in whole blood samples. Calibration of PT and INR for IVD MDs according to World Health Organization guidelines is similar to that in cases where there is a reference measurement procedure that defines the measurand for value assignment as described in ISO 17511:2020. We conclude that, for PT/INR standardization, the optimal calibration hierarchy includes a primary process to prepare an international reference reagent and measurement procedure that defines the measurand by a value assignment protocol conforming to clause 5.3 of ISO 17511:2020. A panel of freshly prepared human plasma samples from healthy adult individuals and patients on vitamin K antagonists is used as a commutable secondary calibrator as described in ISO 17511:2020. A sustainable metrologically traceable calibration hierarchy for INR should be based on an international protocol for value assignment with a single primary reference thromboplastin and the harmonized manual tilt tube technique for clotting time determination. The primary international reference thromboplastin reagent should be used only for calibration of successive batches of the secondary reference thromboplastin reagent.

Heparin-induced thrombocytopenia: An illustrated review.

Heparin-induced thrombocytopenia (HIT) is an immune-mediated adverse drug effect from unfractionated or low-molecular-weight heparin that results in thrombocytopenia and potentially catastrophic thrombosis. HIT occurs due to the development of platelet-activating antibodies against multimolecular complexes of platelet factor 4 and heparin. Given the frequency of thrombocytopenia and heparin use among hospitalized patients, calculation of the 4Ts Score is recommended to identify patients at increased likelihood of HIT and direct further evaluation. In patients with an intermediate or high probability 4Ts Score, an immunoassay and functional assay are recommended to confirm or refute the diagnosis of HIT. Heparin avoidance and initiation of nonheparin anticoagulation are the mainstays of acute HIT management. In this illustrated review, we provide visual summaries of the diagnosis and management of HIT, highlighting connections between pathophysiology and clinical care as well as summarizing efforts in quality improvement in the field. We further emphasize common pitfalls and pearls in diagnosis and management to encourage evidence-based care. We include graphical representation of the unique challenges of HIT with cardiopulmonary bypass and also delineate autoimmune HIT and its subtypes.

Real-world safety and effectiveness of recombinant porcine sequence factor VIII in acquired haemophilia A: A non-interventional, post-authorization safety study.

INTRODUCTION: Recombinant porcine factor VIII (rpFVIII, susoctocog alfa) is indicated for the treatment of bleeding episodes in adults with acquired haemophilia A (AHA). AIM: To provide long-term real-world safety and effectiveness data for rpFVIII in the management of AHA bleeding episodes. METHODS: US PASS (NCT02610127) was a multicentre, uncontrolled, open-label, post-marketing safety surveillance study conducted in adults with AHA. Data were collected retrospectively or prospectively for 180 days after rpFVIII treatment. The primary outcome was the incidence of treatment-related serious adverse events (SAEs). Secondary outcomes included haemostatic effectiveness of rpFVIII and rpFVIII utilization. RESULTS: Fifty-three patients were enrolled from December 2015 to June 2019 (prospective, n = 30; retrospective, n = 23). Six patients experienced seven treatment-related SAEs (incidence 12.0%). The most common treatment-related SAE was FVIII inhibition (inhibiting antibodies to rpFVIII; incidence 8.0%, 95% CI: 2.2-19.2). Five patients reported seven thromboembolic events; one was an SAE and possibly related to rpFVIII. Of bleeding events treated with rpFVIII, 80.3% (57/71) of bleeds resolved with rpFVIII. The median (range) dose of rpFVIII per infusion was 50 (10-300) units/kg, with a median (range) of 6.0 (1-140) infusions and a median (range) time from bleed onset to bleed resolution of 14.0 (2.0-132.7) days. CONCLUSION: In this real-world study of rpFVIII for AHA, no new safety signals were identified compared with previous clinical trial findings. Eighty percent of bleeds resolved with rpFVIII treatment.

Early initiation of second-line therapy in primary immune thrombocytopenia: insights from real-world evidence.

To compare patients with primary immune thrombocytopenia (ITP) prescribed early (within 3 months of initial ITP treatment) second-line treatment (eltrombopag, romiplostim, rituximab, immunosuppressive agents, splenectomy) with or without concomitant first-line therapy to those who received only first-line therapy. This real-world retrospective cohort study of 8268 patients with primary ITP from a large US-based database (Optum® de-identified Electronic Health Record [EHR] dataset) combined electronic claims and EHR data. Outcomes included platelet count, bleeding events, and corticosteroid exposure 3 to 6 months after initial treatment. Baseline platelet counts were lower in patients receiving early second-line therapy (10‒28 × 109/L) versus those who did not (67 × 109/L). Counts improved and bleeding events decreased from baseline in all treatment groups 3 to 6 months after the start of therapy. Among the very few patients for whom follow-up treatment data were available (n = 94), corticosteroid use was reduced during the 3- to 6-month follow-up period in patients who received early second-line therapy versus those who did not (39% vs 87%, p < 0.001). Early second-line treatment was prescribed for more severe cases of ITP and appeared to be associated with improved platelet counts and bleeding outcomes 3 to 6 months after initial therapy. Early second-line therapy also appeared to reduce corticosteroid use after 3 months, although the small number of patients with follow-up data on treatment precludes any substantive conclusions. Further research is needed to determine whether early second-line therapy has an effect on the long-term course of ITP.