Impact of the VTE-PREDICT calculator on clinicians' decision making in fictional patients with venous thromboembolism: a randomized controlled trial.

Background: After 3 months of anticoagulation for venous thromboembolism (VTE), the decision needs to be made whether to stop anticoagulation or extend treatment indefinitely. The VTE-PREDICT calculator can be used to estimate individual risks of VTE recurrence and bleeding to guide this decision. Objectives: To evaluate the impact of predicted individual risks of recurrence and bleeding on clinicians' decisions on anticoagulation duration and to assess usefulness of the VTE-PREDICT calculator. Methods: A randomized controlled trial and within-subject study was conducted among clinicians treating VTE patients. The clinicians were asked to complete an online survey containing 6 fictional case vignettes. Group A proposed anticoagulant duration for each case without additional information first and subsequently after seeing calculator-predicted risks (within-subject analysis). Group B was directly provided with calculator risks and proposed treatment duration for each case vignette (for comparison with group A results in a randomized controlled trial analysis). Then, group B received questions on usefulness and credibility of the calculator. Results: Forty-five clinicians were assigned to group A and 48 to B. Overall, group A did not propose different anticoagulation durations than group B. However, individual clinicians in group A changed proposed duration in 35% of the cases after seeing the calculator risks. The calculator was considered useful and credible by most clinicians. Conclusion: Overall, use of the VTE-PREDICT calculator did not affect proposed anticoagulation duration. However, individual clinicians frequently changed their proposed duration after using the calculator, especially for patients with high bleeding risk.

Drug Interactions between Androgen Receptor Axis-Targeted Therapies and Antithrombotic Therapies in Prostate Cancer: Delphi Consensus.

Background/Objectives: Abiraterone acetate, apalutamide, darolutamide, and enzalutamide, which make up the androgen receptor axis-targeted therapies (ARATs) drug class, are commonly used in the management of prostate cancer. Many patients on ARATs also receive oral antithrombotic therapy (i.e., anticoagulants or antiplatelets). The concomitant use of ARATs and antithrombotic therapies creates the potential for clinically relevant drug-drug interactions, but the literature regarding the actual consequences of these interactions, and guidance for co-prescribing, is limited. We assembled a multidisciplinary panel of experts and provided them with clinical information derived from a comprehensive literature review regarding the drug-drug interactions between ARATs and antithrombotic therapies. Methods: A three-stage modified electronic Delphi process was used to gather and consolidate opinions from the panel. Each stage consisted of up to three rounds of voting to achieve consensus on which ARAT/antithrombotic therapy drug pairs warrant attention, the possible clinical consequences of drug-drug interactions, and suggested actions for management. Results: The panel achieved consensus to avoid 11 ARAT/antithrombotic therapy drug pairs and modify therapy for eight pairs. Assessments relied heavily on pharmacokinetic data and extrapolation from drug-drug interaction studies of similarly metabolized drugs. Conclusions: This e-Delphi process highlights the need for further research into the clinical impact of ARAT/antithrombotic drug interactions. Nonetheless, the suggested actions aim to provide clinicians with a practical framework for therapeutic decision making.

Prothrombin complex concentrate for direct factor Xa inhibitor-associated bleeding or before urgent surgery.

INTRODUCTION: Factor Xa inhibitor (FXaI)-associated bleeding events are common and associated with substantial morbidity. Systematic evaluation of widely available, effective, and affordable FXaI bleed management strategies is needed. MATERIALS AND METHODS: We conducted a single-center retrospective cohort study of FXaI-treated patients presenting to a tertiary academic medical center from January 2018 to May 2019 who received 25-50 IU/kg 4F-PCC for either FXaI-associated major bleeding or urgent surgery. The primary outcome was hemostatic efficacy, and the safety outcome was the 30-day risk of thromboembolism. RESULTS: PCC was used to treat FXaI-associated bleeding in 83 cases (79.1 %) and was given before urgent surgery in 22 cases (20.9 %). Sixty-six patients were on apixaban, 38 were on rivaroxaban and one patient was on edoxaban. Intracranial hemorrhage (ICH) and gastrointestinal bleeding accounted for most bleeds (74.7 %). Median interval between last DOAC intake and presentation to triage was 9 h [IQR 5.3-14.8] and median PCC dosing was 40.0 IU/kg [IQR 28.5-46.6]. Forty-two patients (40.0 %) had pre-PCC FXaI levels drawn with median FXaI levels of 114.5 ng/mL [IQR 70.0-175.0]. Effective hemostasis occurred in 66.7 % [95%CI 55.4-76.3] of patients receiving PCC for bleeding and surgical hemostasis was rated as normal in 95.5 % (95%CI 76.5-100.0) for patients having urgent surgery. The 30-day risk of thromboembolism was 7.6 % [95%CI 3.7-14.5] and 22.9 % [95%CI 15.8-31.8] of patients died. CONCLUSIONS: PCC for FXaI-associated bleeding was associated with hemostatic efficacy in two-thirds of patients and thromboembolic events were uncommon. PCC represents a promising treatment strategy for FXaI-associated bleeding.

Déjà vu all over again: a recurrent flaw in anticoagulant study design.

The availability of direct oral anticoagulants (DOACs) rapidly changed the landscape of anticoagulation between 2010-present. Randomized controlled trials demonstrating efficacy with similar or superior safety compared to warfarin led to widespread use of DOACs in male and female patients of all ages. Years later, post-marketing data demonstrated a markedly increased rate of heavy menstrual bleeding (HMB) with rivaroxaban that had gone undetected in registry trials. Factor XI (FXI) inhibitors are currently being investigated as another alternative to available anticoagulation agents. While generally mild, the phenotype of inherited FXI deficiency includes bleeding in tissues with enhanced fibninolysis, including HMB. Thus, we aimed to perform a systematic review of published studies on FXI inhibitors in order to estimate rates of HMB. However, we found that few studies included menstruating individuals and even fewer specifically reported on uterine bleeding, highlighting once again a flaw in our approach to conducting trials of new anticoagulants.

Management and outcomes in patients with tumor thrombus: a retrospective cohort study.

BACKGROUND: Tumor thrombus can be associated with an increased risk of venous thromboembolism (VTE) and poor prognosis. The risks and benefits of anticoagulation remain unclear. OBJECTIVES: To evaluate the role of anticoagulation and associated outcomes in patients with tumor thrombus. METHODS: We conducted a single-center retrospective cohort study in patients with tumor thrombus from 2019 to 2022. All patients were followed for 12 months from the diagnosis of tumor thrombus or until death if death occurred earlier. The primary outcome was the percentage of patients prescribed any dose of anticoagulation for tumor thrombus (or concurrent bland thrombus/VTE). The secondary outcomes included new thrombosis, major bleeding, clinically relevant nonmajor bleeding, and mortality. We calculated the 6- and 12-month cumulative incidence of outcomes with 95% CI and compared those given anticoagulation vs not, considering death as a competing risk. RESULTS: We included 211 patients, among whom 106 (50.2%; 95% CI, 47.9%-52.6%) were given anticoagulation for tumor thrombus or concurrent VTE (present in 21.8%). The most common type of cancer was hepatocellular carcinoma (28%). Splanchnic veins were the most commonly involved (49.3%). Anticoagulation was more likely used if tumor thrombus involved the inferior vena cava and/or the heart, with concurrent VTE, or if thrombosis service was consulted. The overall 12-month incidence of new VTE was 11.4% (95% CI, 7.3%-16.5%), that of major bleeding + clinically relevant nonmajor bleeding was 36.6% (95% CI, 29.6%-43.5%), and mortality of 52.5% (95% CI, 44.8%-59.6%), with no significant differences among groups given anticoagulation or not. CONCLUSION: Patients with tumor thrombus carry high risks of VTE, bleeding, and mortality. The impact of anticoagulation remains unclear.

Impact of limited language proficiency on participation in venous thromboembolism research: a retrospective analysis.

BACKGROUND: Limited language proficiency is an established barrier to research participation among racialized populations. While prior studies have highlighted the underrepresentation of racialized populations in venous thromboembolism (VTE) research, the impact of limited language proficiency as a reason for nonconsent among eligible patients is unknown. OBJECTIVES: To determine the impact of language barrier as the primary reason for VTE research non-participation. METHODS: We reviewed all prospective VTE studies conducted at a research-intensive academic thrombosis research program in Canada between 2014 and 2024. Studies with screening logs that systematically and consecutively captured eligibility assessment and reasons for nonconsent were included. Primary outcome was nonconsent of a screen-eligible patient due to limited language proficiency as the reported reason. We derived pooled estimates of nonconsent due to limited language proficiency as a proportion of consented participants and determined subgroup rates by phase of VTE management, associated medical conditions, and recruitment settings. RESULTS: Screening logs of 28 studies with 22 057 screening events, 8317 screen-eligible patients, and 3320 consented participants were included. For every 100 consented participants, 3.2 (95% CI, 2.0-5.3) screen-eligible individuals were unable to provide consent due to limited language proficiency. Rates of nonconsent were highest in studies involving cancer (5.6 per 100 participants; 95% CI, 2.9-10.4) and in studies recruiting patients from ambulatory settings outside of the thrombosis clinic (10.8 per 100 participants; 95% CI, 4.8-22.6). CONCLUSION: Language proficiency is a key barrier to VTE research participation. Urgent implementation of targeted interventions aimed at mitigating linguistic barriers is essential to ensure equitable opportunities for VTE research participation for racialized patients disproportionately affected by language proficiency.

The risk of venous thromboembolism in primary central nervous system lymphoma: a systematic review and meta-analysis.

Primary central nervous system lymphoma (PCNSL) is a rare extranodal lymphoma localized to the central nervous system. Small single-center studies have suggested that patients with PCNSL may be at high risk of venous thromboembolism (VTE). This systematic review aimed to estimate the risk of VTE in patients with PCNSL. A systematic review was conducted using Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. MEDLINE, Embase, and CINAHL were searched from 1990 to 2022. Prospective and retrospective observational studies as well as clinical trials were included. The primary efficacy outcome was VTE, and the primary safety outcome was major bleeding as defined by the individual studies. After screening 883 studies, 46 studies (3688 patients) with PCNSL were included. Mean age was 62.4 years. Five studies explored the use of thromboprophylaxis (acetyl salicylic acid or anticoagulation [n = 1]) and low-molecular-weight heparin (n = 4). Overall, 420 patients developed VTE (11.4%), including 17 fatal events (4% of all VTE). Two studies that reported on VTE prophylaxis representing 77 patients identified 8 breakthrough VTE events (10.4%). Most studies (n = 34; 74.5%) did not report major bleeding complications. Among studies reporting on bleeding, 174 major bleeding (7.4%) events were reported out of 2361 patients, 3 of which were attributed to thromboprophylaxis. Patients with PCNSL seem to be at high risk of both VTE and bleeding complications. Future clinical trials in this population should routinely collect data on incidence of VTE and bleeding to help clinicians assess the risk-to-benefit ratio of thromboprophylaxis in this high-risk patient population.

Anticoagulation for the Prevention of Arterial Thromboembolism in Cancer Patients by Primary Tumor Site: A Systematic Review and Meta-Analysis of Randomized Trials.

AIMS: Incidence of arterial thromboembolism (ATE) among ambulatory cancer patients varies by primary tumor site. However, it is unclear whether this alters the benefit-to-harm profile of prophylactic anticoagulation for ATE prevention. Therefore, we systematically evaluated the efficacy and safety of anticoagulants for ATE prevention among ambulatory cancer patients according to the primary tumor site. METHODS AND RESULTS: We conducted a systematic review using Medline, Embase, SCOPUS, and CENTRAL, and included randomized trials comparing prophylactic anticoagulation to no anticoagulation among ambulatory cancer patients who initiated tumor-directed systemic therapy. Incidence of symptomatic ATE (acute ischemic stroke, acute myocardial infarction or peripheral artery occlusion) and major bleeding, as well as risk differences (RDs) attributable to anticoagulation were meta-analyzed by primary tumor site using random-effects modeling. We included 10 randomized controlled trials with 9,875 patients with follow-up ranging from 3.3 to 68 (median 6.6) months. While prophylactic anticoagulation did not reduce ATE risks overall (RD -0.49%; 95% CI -0.49% to 0.01%; I2=0%), it conferred a protective effect among pancreatic cancer patients (RD -3.2%; 95%CI -5.7% to -0.8%; I2=0%) without a detectable increase in major bleeding (RD -1.4%; 95% CI -4.6% to 1.8%; I2=0%). Prophylactic anticoagulation was not associated with ATE risk reduction in other tumor sites. CONCLUSION: Based on available evidence, prophylactic anticoagulation did not reduce ATE risk among ambulatory cancer patients overall. However, we observed lower incidence of ATE among pancreatic cancer patients randomized to receive anticoagulation. Prophylactic anticoagulant use to reduce ATEs in pancreatic cancer should be evaluated in future research.

Preventative and curative treatment of venous thromboembolic disease in cancer patients.

Cancer-associated venous thromboembolism (CAT) is common in patients with cancer and associated with significant morbidity and mortality. The incidence of CAT continues to rise, complicating patient care and burdening healthcare systems. Patients with cancer experiencing VTE face poorer prognoses, making prevention and effective management imperative. This narrative review synthesizes evidence on thromboprophylaxis in ambulatory patients with cancer receiving systemic therapy and acute treatment strategies for CAT. Risk assessment models (e.g., Khorana score) aid in identifying high-risk patients who may benefit from thromboprophylaxis. Pharmacological thromboprophylaxis with low molecular weight heparins (LMWHs) and direct oral anticoagulants (DOACs) has been shown to reduce the risk of CAT without significantly increasing the risk of bleeding complications. However, implementation of risk-based strategies remains limited in clinical practice. For acute CAT management, LMWHs have been the standard of care, but DOACs are increasingly favored due to their convenience and efficacy. However, challenges persist, including bleeding risks and drug interactions. Emerging therapies targeting Factor XI inhibitors present promising alternatives, potentially addressing current limitations in anticoagulation management for CAT.

Examining postpartum anticoagulation practices: An international survey of healthcare providers.

BACKGROUND: The risk of venous thromboembolism (VTE) is 15 to 35-fold higher in the postpartum period compared to non-pregnant individuals. Clinical practice guidelines recommend the use of postpartum thromboprophylaxis with low molecular weight heparin (LMWH) for 6 weeks in individuals at high risk of developing VTE. However, a marked reduction in the risk of VTE risk occurs beyond the third week of the postpartum period. OBJECTIVE: We sought to characterize practice patterns of clinicians who manage postpartum individuals at high risk of VTE. METHODS: We conducted a cross-sectional study using a self-administered electronic questionnaire. The survey explored the use of postpartum thromboprophylaxis in high-risk individuals. Descriptive statistics were used to summarize survey responses. RESULTS: Of the 113 participants that responded to the initial invitation, 78 completed the survey (Europe (53.9 %); North America (23.2 %); Australia and New Zealand (19.0 %)). For individuals with a prior unprovoked or provoked deep venous thrombosis or pulmonary embolism, cerebral vein thrombosis and splanchnic vein thrombosis, 97.4 %, 93.5 %, 91.0 % and 88.5 % of the respondents recommended six weeks of postpartum thromboprophylaxis using LMWH, respectively. The recommendation for 6 weeks of thromboprophylaxis in patients with sickle cell disease and obstetric APS was comparatively lower (70.5 and 78.2 % respectively). Respondents with higher practice volumes and more years of experience in clinical practice were more likely to recommend a shorter duration of thromboprophylaxis. CONCLUSION: Our study highlights the variability in clinician recommendations and the acceptability of treatment durations for postpartum thromboprophylaxis in high-risk conditions. Prospective studies are needed to determine optimal duration and establish evidence-based management.

Testing of a risk-stratified patient decision aid to facilitate shared decision-making for extended postoperative thromboprophylaxis after major abdominal surgery for cancer.

BACKGROUND: Use of extended pharmacologic thromboprophylaxis after major abdominopelvic cancer surgery should depend on best-available scientific evidence and patients' informed preferences. We developed a risk-stratified patient decision aid to facilitate shared decision-making and sought to evaluate its effect on decision-making quality regarding use of extended thromboprophylaxis. METHODS: We enrolled patients undergoing major abdominopelvic cancer surgery at an academic tertiary care centre in this pre-post study. We evaluated change in decisional conflict, readiness to decide, decision-making confidence, and change in patient knowledge. Participants were provided the appropriate risk-stratified decision aid (according to their Caprini score) in either the preoperative or postoperative setting. A sample size calculation determined that we required 17 patients to demonstrate whether the decision aid meaningfully reduced decisional conflict. We used the Wilcoxon matched-pairs signed ranks test for interval scaled measures. RESULTS: We included 17 participants. The decision aid significantly reduced decisional conflict (median decisional conflict score 2.37 [range 1.00-3.81] v. 1.3 [range 1.00-3.25], p < 0.01). With the decision aid, participants had high confidence (median 86.4 [range 15.91-100]) and felt highly prepared to make a decision (median 90 [range 55-100]). Median knowledge scores increased from 50% (range 0%-100%) to 75% (range 25%-100%). CONCLUSION: Our risk-stratified, evidence-based decision aid on extended thromboprophylaxis after major abdominopelvic surgery significantly improved decision-making quality. Further research is needed to evaluate the usability and feasibility of this decision aid in the perioperative setting.

Provision and evaluation of explanations within an automated planning-based approach to solving the multimorbidity problem.

The multimorbidity problem involves the identification and mitigation of adverse interactions that occur when multiple computer interpretable guidelines are applied concurrently to develop a treatment plan for a patient diagnosed with multiple diseases. Solving this problem requires decision support approaches which are difficult to comprehend for physicians. As such, the rationale for treatment plans generated by these approaches needs to be provided. OBJECTIVE: To develop an explainability component for an automated planning-based approach to the multimorbidity problem, and to assess the fidelity and interpretability of generated explanations using a clinical case study. METHODS: The explainability component leverages the task-network model for representing computer interpretable guidelines. It generates post-hoc explanations composed of three aspects that answer why specific clinical actions are in a treatment plan, why specific revisions were applied, and how factors like medication cost, patient's adherence, etc. influence the selection of specific actions. The explainability component is implemented as part of MitPlan, where we revised our planning-based approach to support explainability. We developed an evaluation instrument based on the system causability scale and other vetted surveys to evaluate the fidelity and interpretability of its explanations using a two dimensional comparison study design. RESULTS: The explainability component was implemented for MitPlan and tested in the context of a clinical case study. The fidelity and interpretability of the generated explanations were assessed using a physician-focused evaluation study involving 21 participants from two different specialties and two levels of experience. Results show that explanations provided by the explainability component in MitPlan are of acceptable fidelity and interpretability, and that the clinical justification of the actions in a treatment plan is important to physicians. CONCLUSION: We created an explainability component that enriches an automated planning-based approach to solving the multimorbidity problem with meaningful explanations for actions in a treatment plan. This component relies on the task-network model to represent computer interpretable guidelines and as such can be ported to other approaches that also use the task-network model representation. Our evaluation study demonstrated that explanations that support a physician's understanding of the clinical reasons for the actions in a treatment plan are useful and important.

Heparin Dose Intensity and Organ Support-Free Days in Patients Hospitalized for COVID-19.

Background: Clinical trials suggest that therapeutic-dose heparin may prevent critical illness and vascular complications due to COVID-19, but knowledge gaps exist regarding the efficacy of therapeutic heparin including its comparative effect relative to intermediate-dose anticoagulation. Objectives: The authors performed 2 complementary secondary analyses of a completed randomized clinical trial: 1) a prespecified per-protocol analysis; and 2) an exploratory dose-based analysis to compare the effect of therapeutic-dose heparin with low- and intermediate-dose heparin. Methods: Patients who received initial anticoagulation dosed consistently with randomization were included. The primary outcome was organ support-free days (OSFDs), a combination of in-hospital death and days free of organ support through day 21. Results: Among 2,860 participants, 1,761 (92.8%) noncritically ill and 857 (89.1%) critically ill patients were treated per-protocol. Among noncritically ill per-protocol patients, the posterior probability that therapeutic-dose heparin improved OSFDs as compared with usual care was 99.3% (median adjusted OR: 1.36; 95% credible interval [CrI]: 1.07-1.74). Therapeutic heparin had a high posterior probability of efficacy relative to both low- (94.6%; adjusted OR: 1.26; 95% CrI: 0.95-1.64) and intermediate- (99.8%; adjusted OR: 1.80; 95% CrI: 1.22-2.62) dose thromboprophylaxis. Among critically ill per-protocol patients, the posterior probability that therapeutic heparin improved outcomes was low. Conclusions: Among noncritically ill patients hospitalized for COVID-19 who were randomized to and initially received therapeutic-dose anticoagulation, heparin, compared with usual care, was associated with improved OSFDs, a combination of in-hospital death and days free of organ support. Therapeutic heparin appeared superior to both low- and intermediate-dose thromboprophylaxis.

Risk of developing post thrombotic syndrome after deep vein thrombosis with different anticoagulant regimens: A systematic review and pooled analysis.

BACKGROUND: Post-thrombotic syndrome (PTS) is common in patients with deep vein thrombosis (DVT). It is unclear if different types of anticoagulant therapies (e.g. vitamin K antagonists (VKA), direct oral anticoagulants (DOACs) or low molecular weight heparin (LMWH)) are associated with different risks of PTS. We sought to assess the incidence rates of PTS development following a proximal DVT of the lower extremity managed with different types of anticoagulation regimens. METHODS: A systematic search of MEDLINE, EMBASE and PubMed, from inception to June 2023 was performed. The primary outcome was development of PTS. The secondary outcomes included severe PTS, venous ulcers, and major bleeding. Incidence rates were pooled using the random effects model and expressed as event per 100 patient-years with its associated 95 % confidence intervals (CI) using R software. RESULTS: A total of 21 (4342 patients) articles were included in the analysis. The adjusted pooled incidence of PTS was 15.1 (95 % CI: 8.7 to 26.1), 18.2 (95 % CI: 9.4 to 35.1) and 24.6 (95 % CI: 9.2 to 65.5) per 100 patient-years patients managed with VKA, DOAC and LMWH, respectively. The adjusted pooled incidence of severe PTS was 5.1 (95 % CI: 2.6 to 10.0) and 0.2 (95 % CI: 0.01 to 2.7) per 100 patient-years for VKAs and DOACs, respectively. CONCLUSIONS: The development of PTS is common in patients with proximal lower extremity DVT. The incidence rates of PTS seem to be similar across the different anticoagulation regimens, but severe PTS may be lower among patients receiving a DOAC.

Arterial Thrombosis in Patients with Cancer.

Patients with cancer are at increased risk of arterial thromboembolic disease due to the presence of risk factors common to both the development of cancer and arterial thrombosis, the cancer itself, and the treatments provided to treat cancer. We review here the epidemiology and pathophysiology of arterial thromboembolic disease in cancer, along with its prevention and treatment strategies. We also propose a generalized approach for the management of arterial thromboembolic disease in this patient population.

Risk assessment tools for bleeding in patients with unprovoked venous thromboembolism: an analysis of the PLATO-VTE study.

BACKGROUND: Guidelines suggest indefinite anticoagulation after unprovoked venous thromboembolism (VTE) unless the bleeding risk is high, yet there is no consistent guidance on assessing bleeding risk. OBJECTIVES: This study aimed to evaluate the performance of 5 bleeding risk tools (RIETE, VTE-BLEED, CHAP, VTE-PREDICT, and ABC-Bleeding). METHODS: PLATO-VTE, a prospective cohort study, included patients aged ≥40 years with a first unprovoked VTE. Risk estimates were calculated at VTE diagnosis and after 3 months of treatment. Primary outcome was clinically relevant bleeding, as per International Society on Thrombosis and Haemostasis criteria, during 24-month follow-up. Discrimination was assessed by the area under the receiver operating characteristic curve (AUROC). Patients were classified as having a "high risk" and "non-high risk" of bleeding according to predefined thresholds; bleeding risk in both groups was compared by hazard ratios (HRs). RESULTS: Of 514 patients, 38 (7.4%) had an on-treatment bleeding. AUROCs were 0.58 (95% CI, 0.48-0.68) for ABC-Bleeding, 0.56 (95% CI, 0.46-0.66) for RIETE, 0.53 (95% CI, 0.43-0.64) for CHAP, 0.50 (95% CI, 0.41-0.59) for VTE-BLEED, and 0.50 (95% CI, 0.40-0.60) for VTE-PREDICT. The proportion of high-risk patients ranged from 1.4% with RIETE to 36.9% with VTE-BLEED. The bleeding incidence in the high-risk groups ranged from 0% with RIETE to 13.0% with ABC-Bleeding, and in the non-high-risk groups, it varied from 7.7% with ABC-Bleeding to 9.6% with RIETE. HRs ranged from 0.93 (95% CI, 0.46-1.9) for VTE-BLEED to 1.67 (95% CI, 0.86-3.2) for ABC-Bleeding. Recalibration at 3-month follow-up did not alter the results. CONCLUSION: In this cohort, discrimination of currently available bleeding risk tools was poor. These data do not support their use in patients with unprovoked VTE.