Event rates and risk factors for venous thromboembolism and major bleeding in a population of hospitalized adult patients with acute medical illness receiving enoxaparin thromboprophylaxis.

BACKGROUND: We aimed to describe the event rates and risk-factors for symptomatic venous thromboembolism (VTE) and major bleeding in a population of hospitalized acutely ill medical patients. METHODS: Patients ≥40 years old and hospitalized for acute medical illness who initiated enoxaparin prophylaxis were selected from the US Optum research database. Rates of symptomatic VTE and major bleeding at 90-days were estimated via the Kaplan-Meier (KM) method. Risk factors were identified via the Cox proportional hazards model. RESULTS: A total of 123,022 patients met the selection criteria. The KM rates of VTE and major bleeding at 90-days were 3.5 % and 2.2 %, respectively. Among subgroups, the risk of VTE varied from 3.0 % in patients with ischemic stroke to 6.9 % in patients with a cancer-related hospitalization, and the risk of major bleeding varied from 1.9 % in patients with inflammatory conditions to 3.6 % in patients with ischemic stroke. Key risk factors for VTE were prior VTE (HR=4.15, 95 % confidence interval [CI] 3.80-4.53), cancer-related hospitalization (HR=2.35, 95 % CI 2.10-2.64), and thrombophilia (HR=1.64, 95 % CI 1.29-2.08). Key risk factors for major bleeding were history of major bleeding (HR=2.17, 95 % CI 1.72-2.74), history of non-major bleeding (HR=2.46, 95 % CI 2.24-2.70), and hospitalization for ischemic stroke (2.42, 95 % CI 2.11-2.78). CONCLUSION: There is substantial heterogeneity in the event rates for VTE and major bleeding in acute medically ill patients. History of VTE and cancer related hospitalization represent profiles with a high risk of VTE, where continued VTE prophylaxis may be warranted.

Serial D-dimers after anticoagulant cessation in unprovoked venous thromboembolism: Data from the REVERSE cohort study.

INTRODUCTION: While several risk stratification tools have been developed to predict the risk of recurrence in patients with an unprovoked venous thromboembolism (VTE), only 1 in 4 patients are categorized as low-risk. Rather than a one-time measure, serial D-dimer assessment holds promise to enhance the prediction of VTE recurrence after oral anticoagulant (OAC) cessation. METHODS: Using the REVERSE cohort, we compared VTE recurrence among patients with normal D-dimer levels (<490 ng/mL among males under age 70, <500 ng/mL in others) at OAC cessation and 1-month follow-up, to those with an elevated D-dimer level at either timepoint. We also evaluated VTE recurrence based on absolute increase in D-dimer levels between the two timepoints (e.g., ∆D-dimer) according to quartiles. RESULTS: Among 214 patients with serial D-dimer levels measured at OAC cessation and 1-month follow-up, an elevated D-dimer level at either timepoint was associated with a numerically higher risk of recurrent VTE than patients with normal D-dimer levels at both timepoints (6.9 % vs. 4.2 % per year, hazard ratio 1.6; 95 % CI 0.9-2.7). Among women with <2 HERDOO2 criteria, a normal D-dimer level at both timepoints predicted a very low risk of recurrent VTE during follow-up (0.8 % per year, 95 % CI 0.1-2.8). Irrespective of baseline value, recurrent VTE risk was only 3 % per year (95 % CI 1.4-5.6) among patients in the lowest ∆D-dimer quartile. CONCLUSION: Serial normal D-dimer levels have the potential to identify patients at a low risk of recurrent VTE. In addition, ∆D-dimer, irrespective of its elevation above cutoff threshold, may predict recurrent VTE.

Illustrated State-of-the-Art Capsules of the ISTH 2023 Congress.

This year's Congress of the International Society of Thrombosis and Haemostasis (ISTH) took place in person in Montréal, Canada, from June 24-28, 2023. The conference, held annually, highlighted cutting-edge advances in basic, translational, population and clinical sciences relevant to the Society. As for all ISTH congresses, we offered a special, congress-specific scientific theme; this year, the special theme was immunothrombosis. Certainly, over the last few years, COVID-19 infection and its related thrombotic and other complications have renewed interest in the concepts of thromboinflammation and immunothrombosis; namely, the relationship between inflammation, infection and clotting. Other main scientific themes of the Congress included Arterial Thromboembolism, Coagulation and Natural Anticoagulants, Diagnostics and Omics, Fibrinolysis and Proteolysis, Hemophilia and Rare Bleeding Disorders, Hemostatic System in Cancer, Inflammation and Immunity, Pediatrics, Platelet Disorders, von Willebrand Disease and Thrombotic Microangiopathies, Platelets and Megakaryocytes, Vascular Biology, Venous Thromboembolism and Women's Health. Among other sessions, the program included 28 State-of-the-Art (SOA) sessions with a total of 84 talks given by internationally recognized leaders in the field. SOA speakers were invited to prepare brief illustrated reviews of their talks that were peer reviewed and are included in this article. These illustrated capsules highlight the major scientific advances with potential to impact clinical practice. Readers are invited to take advantage of the excellent educational resource provided by these illustrated capsules. They are also encouraged to use the image in social media to draw attention to the high quality and impact of the science presented at the Congress.

Research Consensus Panel Follow-up: 8-Year Update on Submassive Pulmonary Embolism.

The 2015 Research Consensus Panel (RCP) on submassive pulmonary embolism (PE) set priorities for research in submassive PE and identified a rigorous randomized trial of catheter-directed therapy plus anticoagulation versus anticoagulation alone as the highest research priority. This update, written 8 years after the RCP was convened, describes the current state of endovascular PE practice and the Pulmonary Embolism-Thrombus Removal with Catheter-Directed Therapy trial, the main output from the RCP.

Accuracy and interrater agreement of death event adjudications by physician trainees: validation of the ISTH definition of pulmonary embolism-related death in an autopsy cohort.

BACKGROUND: We previously determined good agreement and high specificity of the International Society on Thrombosis and Haemostasis (ISTH) definition of pulmonary embolism (PE)-related death among an expert central adjudication committee (CAC). CACs are often composed of experts in the corresponding research field. Involving physician trainees in CACs would allow investigators to divide the workload and foster trainees' research experience. OBJECTIVE: To evaluate the accuracy of the ISTH definition of PE-related death for PE- versus non-PE-related deaths as confirmed by autopsy and its interrater agreement among physician trainees. METHODS: This retrospective autopsy cohort included all patients with PE-related deaths between January 2010 and July 2019 as well as patients who died in 2018 from a cause other than PE at the New York-Presbyterian Hospital. Based on premortem clinical summaries, two physician trainees independently determined the cause of death using the ISTH definition of PE-related death. We calculated the sensitivity and specificity of the ISTH definition to identify autopsy-confirmed PE-related death and its interrater agreement. RESULTS: Overall, 126 death events were adjudicated (median age, 68 years; 60 [48%] women), of which 29 (23%) were due to PE, as confirmed by autopsy. Sensitivity and specificity of the ISTH definition for autopsy-confirmed PE-related death was 48% (95% CI, 29-67) and 100% (95% CI, 96-100), respectively. Interrater reliability for PE-related death was good (percentage agreement, 93%; 95% CI, 87-96, Cohen's Kappa, 0.67; 95% CI, 44-85). CONCLUSION: Our findings are consistent with our previous validation study. They further support the use of the ISTH definition of PE-related death and revealed high agreement between adjudicators with varied experience.

Safety and efficacy of direct oral anticoagulants in patients with chronic thromboembolic pulmonary hypertension.

INTRODUCTION: Chronic thromboembolic pulmonary hypertension (CTEPH) remains an underdiagnosed disease. Anticoagulation is essential in its therapy to prevent recurrent venous thromboembolism (VTE). According to some international guidelines, vitamin K antagonists (VKA) remain the gold standard. Nevertheless, direct oral anticoagulants (DOAC) are widely used, partly because of numerous advantages. The objective of this study was to determine if DOAC is an effective and safe alternative to VKA in CTEPH patients. MATERIALS AND METHODS: A retrospective observational study was conducted between 2001 and 2021 in a CTEPH Clinic of a tertiary care hospital. We recorded demographic characteristics, anticoagulant therapies and pulmonary hypertension treatments received. Safety outcomes were bleeding events and deaths while efficacy outcomes were recurrent VTE events. RESULTS: Among the study population (N = 205), the distribution of anticoagulant used transitioned from majority on VKA to majority on DOAC. In 2020, 23 (19 %) were on VKA and 97 (78 %) on DOAC. Among 11 VTE events occurring during follow-up, 7 were in the VKA group (1.10 %/person-year) and 1 in the DOAC group (0.32 %/person-year). Rates of VTE recurrence were not significantly different in those treated with DOAC compared to VKA (P = 0.21). Total bleeding rate on VKA (2.52 %/person-year) and DOAC (2.52 %/person-year) were the same (P = 1.00). Among 27 patients who died, no deaths occurred as a consequence of bleeding or VTE events. CONCLUSION: Bleeding and VTE events were not higher in CTEPH patients receiving DOAC compared to VKA which adds confidence to considering DOAC as an effective and safe alternative for long term anticoagulation in CTEPH patients.

Sex differences in thromboprophylaxis of the critically ill: a secondary analysis of a randomized trial.

PURPOSE: Venous thromboembolism (VTE) is a common complication of critical illness. Sex- or gender-based analyses are rarely conducted and their effect on outcomes is unknown. We assessed for an effect modification of thromboprophylaxis (dalteparin or unfractionated heparin [UFH]) by sex on thrombotic (deep venous thrombosis [DVT], pulmonary embolism [PE], VTE) and mortality outcomes in a secondary analysis of the Prophylaxis for Thromboembolism in Critical Care Trial (PROTECT). METHODS: We conducted unadjusted analyses using Cox proportional hazards analysis, stratified by centre and admission diagnostic category, including sex, treatment, and an interaction term. Additionally, we performed adjusted analyses and assessed the credibility of our findings. RESULTS: Critically ill female (n = 1,614) and male (n = 2,113) participants experienced similar rates of DVT, proximal DVT, PE, any VTE, ICU death, and hospital death. In unadjusted analyses, we did not find significant differences in treatment effect favouring males (vs females) treated with dalteparin (vs UFH) for proximal leg DVT, any DVT, or any PE, but found a statistically significant effect (moderate certainty) favouring dalteparin in males for any VTE (males: hazard ratio [HR], 0.71; 95% confidence interval [CI], 0.52 to 0.96 vs females: HR, 1.16; 95% CI, 0.81 to 1.68; P = 0.04). This effect remained after adjustment for baseline characteristics (males: HR, 0.70; 95% CI, 0.52 to 0.96 vs females: HR, 1.17; 95% CI, 0.81 to 1.68; P = 0.04) and weight (males: HR, 0.70; 95% CI, 0.52 to 0.96 vs females: HR, 1.20; 95% CI, 0.83 to 1.73; P = 0.03). We did not identify a significant effect modification by sex on mortality. CONCLUSIONS: We found an effect modification by sex of thromboprophylaxis on VTE in critically ill patients that requires confirmation. Our findings highlight the need for sex- and gender-based analyses in acute care research.

RéSUMé: OBJECTIF: La maladie thromboembolique veineuse (MTEV) est une complication fréquente au cours des maladies critiques. Des analyses basées sur le sexe ou le genre sont rarement effectuées et leur effet sur les critères d'évaluation est inconnu. Nous avons évalué une modification de l'effet de la thromboprophylaxie (daltéparine ou héparine non fractionnée [HNF]) selon le sexe sur la maladie thrombotique (thrombose veineuse profonde [TVP], embolie pulmonaire [EP], MTEV) et sur les critères de mortalité au cours d'une analyse secondaire de l'étude PROTECT (essai de prophylaxie de la thromboembolie en soins critiques). MéTHODE: Nous avons réalisé des analyses non ajustées au moyen d'une analyse des risques proportionnels de Cox, stratifiées par site et catégorie diagnostique à l'admission, incluant le sexe, le traitement et un terme d'interaction. Nous avons aussi réalisé des analyses ajustées et avons évalué la crédibilité de nos constatations. RéSULTATS: Les participant·es dans un état critique de sexe féminin (n = 1 614) et masculin (n = 2 113) ont présenté des taux semblables de TVP, EP, et MTEV de tout type, de décès en soins intensifs et de décès en milieu hospitalier. Nous n'avons pas trouvé de différences significatives dans les analyses non ajustées en faveur des hommes (par rapport aux femmes) traités par la daltéparine (par rapport à l'HNF) pour la TVP de la cuisse, la TVP de tout type, ou tout type d'EP; en revanche, nous avons trouvé un effet statistiquement significatif (certitude modérée) en faveur de la daltéparine pour la MTEV de tout type (hommes : rapport de risque [RR], 0,71; intervalle de confiance [IC] à 95 %, 0,52 à 0,96 par rapport aux femmes : RR, 1,16; IC 95 %, 0,81 à 1,68; P = 0,04). Cet effet a persisté après ajustement pour les caractéristiques à l'inclusion (hommes : RR, 0,70; IC 95 %, 0,52 à 0,96 par rapport aux femmes : RR, 1,17; IC 95 %, 0,81 à 1,68; P = 0,04) et le poids (hommes : RR, 0,70; IC 95 %, 0,52 à 0,96 par rapport aux femmes : RR, 1,20; IC 95 %, 0,83 à 1,73; P = 0,03). Nous n'avons pas identifié de modification significative de l'effet en fonction du sexe sur la mortalité. CONCLUSION: Nous avons trouvé une modification de l'effet en fonction du sexe sur la thromboprophylaxie sur la MTEV chez les patient·es en état critique; cette constatation nécessite une confirmation. Nos constatations soulignent le besoin d'analyses en fonction du sexe et du genre dans la recherche sur les soins aigus.

Exploring the Villalta scale to capture postthrombotic syndrome using alternative approaches: A subanalysis of the ATTRACT trial.

Background: Clinical trials that evaluated interventions to prevent postthrombotic syndrome (PTS) used the Villalta scale (VS) to define PTS, but there is a lack of consistency in its use. Objectives: This study aimed to improve the ability to identify patients with clinically meaningful PTS after DVT in participants of the ATTRACT trial. Methods: We conducted a post hoc exploratory analysis of 691 patients from the ATTRACT study, a randomized trial evaluating the effectiveness of pharmacomechanical thrombolysis to prevent PTS in proximal deep vein thrombosis. We compared 8 VS approaches to classify patients with or without PTS in terms of their ability to discriminate between those with poorer vs better venous disease-specific quality of life (Venous Insufficiency Epidemiological and Economic Study Quality of Life [VEINES-QOL]) between 6- and 24-months follow-up. The difference in the average area under the fitted curve of VEINES-QOL scores between PTS and no PTS ( Δ A U C ¯ ) were compared among approaches. Results: For any PTS (a single VS score ≥5), approaches 1 to 3 had similar Δ A U C ¯ (-21.2, -23.7, -22.0, respectively). Adjusting the VS for contralateral chronic venous insufficiency (CVI) or restricting to patients without baseline CVI (approaches 7 and 8) did not improve Δ A U C ¯ (-13.6, -19.9, respectively; P >.01). For moderate-to-severe PTS (a single VS score ≥10), approaches 5 and 6 requiring 2 positive assessments had greater but not statistically significant Δ A U C ¯ than approach 4, using one single positive assessment (-31.7, -31.0, -25.5, respectively; P >.01). Conclusion: A single VS score of ≥ 5 reliably distinguishes patients with clinically meaningful PTS as assessed by impact on QOL and is preferred because of greater convenience (only one assessment needed). Alternative methods to define PTS (ie, adjusting for CVI) do not improve the scale's ability to identify clinically meaningful PTS.

Performance and Head-to-Head Comparison of Three Clinical Models to Predict Occurrence of Postthrombotic Syndrome: A Validation Study.

OBJECTIVE: The SOX-PTS, Amin, and Méan models are three different clinical prediction scores stratifying the risk for postthrombotic syndrome (PTS) development in patients with acute deep vein thrombosis (DVT) of the lower limbs. Herein, we aimed to assess and compare these scores in the same cohort of patients. METHODS: We retrospectively applied the three scores in a cohort of 181 patients (196 limbs) who participated in the SAVER pilot trial for an acute DVT. Patients were stratified into PTS risk groups using positivity thresholds for high-risk patients as proposed in the derivation studies. All patients were assessed for PTS 6 months after index DVT using the Villalta scale. We calculated the predictive accuracy for PTS and area under receiver operating characteristic (AUROC) curve for each model. RESULTS: The Méan model was the most sensitive (sensitivity 87.7%; 95% confidence interval [CI]: 77.2-94.5) with the highest negative predictive value (87.5%; 95% CI: 76.8-94.4) for PTS. The SOX-PTS was the most specific score (specificity 97.5%; 95% CI: 92.7-99.5) with the highest positive predictive value (72.7%; 95% CI: 39.0-94.0). The SOX-PTS and Méan models performed well for PTS prediction (AUROC: 0.72; 95% CI: 0.65-0.80 and 0.74; 95% CI: 0.67-0.82), whereas the Amin model did not (AUROC: 0.58; 95% CI: 0.49-0.67). CONCLUSION: Our data support that the SOX-PTS and Méan models have good accuracy to stratify the risk for PTS.

The risk of major bleeding in patients with factor V Leiden or prothrombin G20210A gene mutation while on extended anticoagulant treatment for venous thromboembolism.

BACKGROUND: Thrombophilia predisposes to venous thromboembolism (VTE) because of acquired or hereditary factors. Among them, it has been suggested that gene mutations of the factor V Leiden (FVL) or prothrombin G20210A mutation (PGM) might reduce the risk of bleeding, but little data exist for patients treated using anticoagulants. OBJECTIVES: To assess whether thrombophilia is protective against bleeding. METHODS: This multicentre, multinational, prospective cohort study evaluated adults receiving long-term anticoagulants after a VTE event. We analyzed the incidence of major bleeding as the primary outcome, according to the genotype for FVL and PGM (wild-type and heterozygous/homozygous carriers). RESULTS: Of 2260 patients with genotype testing, during a median follow-up of 3 years, 106 patients experienced a major bleeding event (17 intracranial and 7 fatal). Among 439 carriers of FVL, 19 experienced major bleeding and there were no differences between any mutation vs wild-type (hazard ratio [HR], 0.89 [0.53-1.49]; p = .66). The comparison of major bleeding events between the 158 patients with any-PGM mutation (heterozygous or homozygous) vs wild-type also showed a nonstatistically significant difference with HR of 0.53 (0.19-1.43), p = .21. However, multivariate analysis demonstrated that major bleeds or clinically relevant nonmajor bleeding were statistically less likely for patients with either FVL and/or PGM compared with patients with both wild-type factor V and prothrombin genes (HR, 0.73; 95% CI = 0.55-0.97; p = .03). CONCLUSION: This study demonstrates that thrombophilia, defined as the presence of either FVL or the prothrombin G20210A mutation, is related with a lower rate of major/clinically relevant nonmajor bleeding while on anticoagulants in the extended treatment for VTE.

Anticoagulation stewardship: Descriptive analysis of a novel approach to appropriate anticoagulant prescription.

Background: Anticoagulants are a leading cause of morbidity among hospitalized patients, with prescription errors commonly reported. Literature surrounding anticoagulation stewardship is scarce despite its documented effectiveness in the antimicrobial realm. Objective: To determine the proportion of accepted recommendations on inappropriate anticoagulant prescriptions suggested by a multidisciplinary anticoagulation stewardship program (ASP). Methods: We conducted a descriptive cohort study of hospitalized patients using therapeutic anticoagulation at a large Canadian tertiary care center between September 1, 2019, and February 28, 2020. A multidisciplinary ASP, composed of physicians and pharmacists, was implemented on June 1, 2019. Patient-, anticoagulant-, and admission-related characteristics were collected. The primary outcome was the proportion of accepted ASP team recommendations by the prescribing team. Results: A total of 381 patients were enrolled during the study period, resulting in 553 anticoagulant reviews (1.56 reviews/patient) by the ASP. The most common indications for anticoagulation were atrial fibrillation (n = 276, 72%) and venous thromboembolism (n = 84, 22%). Direct oral anticoagulants were most frequently prescribed (n = 253, 67%), followed by vitamin K antagonists (n = 88, 23%). Among the reviewed prescriptions, 355 of 553 (64%) generated a recommendation; 299 of 355 (84%) recommendations were accepted by the treating team. Dose adjustments were the leading category of recommendations (31%), followed by alerts regarding drug interactions (19%). Conclusion: Inpatient anticoagulant prescriptions were optimized following recommendations by the ASP team. The most frequent types of prescription changes concerned dose adjustments and drug interactions. Further research is required to assess the effect of an ASP on clinical outcomes.

New and known predictors of the postthrombotic syndrome: A subanalysis of the ATTRACT trial.

Introduction: Postthrombotic syndrome (PTS) remains associated with significant clinical and economic burden. This study aimed to investigate known and novel predictors of the development of PTS in participants of the ATTRACT (Acute Venous Thrombosis: Thrombus Removal With Adjunctive Catheter-Directed Thrombolysis) trial. Methods: We used multivariable logistic regression to identify baseline and postbaseline factors that were predictive of the development of PTS during study follow-up, as defined by a Villalta score of 5 or greater or the development of a venous ulcer from 6 to 24 months after enrollment. Results: Among 691 patients in the study cohort (all had proximal deep vein thrombosis [DVT] that extended above the popliteal vein, of which 57% had iliofemoral DVT), 47% developed PTS. Further, we identified that Villalta score at baseline (odds ratio [OR], 1.09 [95% confidence interval [CI], 1.05-1.13] per one-unit increase) and employment status (unemployed due to disability: OR, 3.31 [95% CI, 1.72-6.35] vs. employed more than 35 hours per week) were predictive of PTS. In terms of postbaseline predictors, leg pain severity at day 10 (OR, 1.28 [95% CI, 1.13-1.45] per 1-point increase in a 7-point scale) predicted PTS. Also, patients receiving rivaroxaban on day 10 following randomization had lower rates of PTS (OR, 0.53 [95% CI, 0.33-0.86]) than patients on warfarin. Conclusions: Novel predictors for PTS identified in our study include baseline Villalta score, leg pain severity at 10 days, and unemployed due to disability. Our findings also suggest that the initial choice of anticoagulant to treat DVT may have an impact on the development of PTS.

Postthrombotic syndrome and quality of life after deep vein thrombosis in patients treated with edoxaban versus warfarin.

Background: Postthrombotic syndrome (PTS) is a long-term complication after deep vein thrombosis (DVT) and can affect quality of life (QoL). Pathogenesis is not fully understood but inadequate anticoagulant therapy with vitamin K antagonists is a known risk factor for the development of PTS. Objectives: To compare the prevalence of PTS after acute DVT and the long-term QoL following DVT between patients treated with edoxaban or warfarin. Methods: We performed a long-term follow-up study in a subset of patients with DVT who participated in the Hokusai-VTE trial between 2010 and 2012 (NCT00986154). Primary outcome was the prevalence of PTS, defined by the Villalta score. The secondary outcome was QoL, assessed by validated disease-specific (VEINES-QOL) and generic health-related (SF-36) questionnaires. Results: Between 2017 and 2020, 316 patients were enrolled in 26 centers in eight countries, of which 168 (53%) patients had been assigned to edoxaban and 148 (47%) to warfarin during the Hokusai-VTE trial. Clinical, demographic, and thrombus-specific characteristics were comparable for both groups. Mean (SD) time since randomization in the Hokusai-VTE trial was 7.0 (1.0) years. PTS was diagnosed in 85 (51%) patients treated with edoxaban and 62 (42%) patients treated with warfarin (adjusted odds ratio 1.6, 95% CI 1.0-2.6). Mean differences in QoL scores between treatment groups were not clinically relevant. Conclusion: Contrary to our hypothesis, the prevalence of PTS tended to be higher in patients treated with edoxaban compared with warfarin. No differences in QoL were observed. Further research is warranted to unravel the role of anticoagulant therapy on development of PTS.

Predictors of Clinical Outcomes of Pharmacomechanical Catheter-Directed Thrombolysis for Acute Iliofemoral Deep Vein Thrombosis: Analysis of a Multicenter Randomized Trial.

PURPOSE: To identify the baseline patient characteristics that predict who will benefit from pharmacomechanical catheter-directed thrombolysis (PCDT) of acute iliofemoral deep vein thrombosis (DVT). MATERIALS AND METHODS: In the Acute Venous Thrombosis: Thrombus Removal with Adjunctive Catheter-Directed Thrombolysis (ATTRACT) multicenter randomized trial, 381 patients with acute iliofemoral DVT underwent PCDT and anticoagulation or anticoagulation alone. The correlations between baseline factors and venous clinical outcomes were evaluated over 24 months using post hoc regression analyses. Interaction terms were examined to evaluate for differential effects by treatment arm. RESULTS: Patients with clinically severe DVT (higher baseline Villalta score) experienced greater effects of PCDT in improving 24-month venous outcomes, including moderate or severe postthrombotic syndrome (PTS) (odds ratios [ORs] and 95% confidence intervals [CIs] per unit increase in the baseline Villalta scores were as follows: for PCDT, OR, 1.08 [95% CI, 1.01-1.15]; for control, OR, 1.20 [95% CI, 1.12-1.29]; Pinteraction = .03), PTS severity (between-arm differences in the Villalta [Pinteraction = .004] and Venous Clinical Severity Scale [VCSS] [Pinteraction = .002)] scores), and quality of life (between-arm difference in the Venous Insufficiency Epidemiological and Economic Study Quality of Life score; Pinteraction = .025). Patients with previous DVT had greater effects of PCDT on 24-month PTS severity than those in patients without previous DVT (mean [95% CI] between-arm difference in the Villalta score, 4.2 [1.56-6.84] vs 0.9 [-0.44 to 2.26], Pinteraction = .03; mean [95% CI] between-arm difference in the VCSS score, 2.6 [0.94-4.21] vs 0.3 [-0.58 to 1.14], Pinteraction = .02). The effects of PCDT on some but not all outcomes were greater in patients presenting with left-sided DVT (Villalta PTS severity, Pinteraction = .04; venous ulcer, Pinteraction = .0499) or a noncompressible popliteal vein (PTS, Pinteraction = .02). The effects of PCDT did not vary by sex, race, ethnicity, body mass index, symptom duration, hypertension, diabetes, or hypercholesterolemia. CONCLUSIONS: In patients with acute iliofemoral DVT, greater presenting clinical severity (higher baseline Villalta score) and a history of previous DVT predict enhanced benefits from PCDT.

American Society of Hematology living guidelines on the use of anticoagulation for thromboprophylaxis for patients with COVID-19: March 2022 update on the use of anticoagulation in critically ill patients.

BACKGROUND: COVID-19-related critical illness is associated with an increased risk of venous thromboembolism (VTE). OBJECTIVE: These evidence-based guidelines of the American Society of Hematology (ASH) are intended to support patients, clinicians, and other health care professionals in decisions about the use of anticoagulation for patients with COVID-19. METHODS: ASH formed a multidisciplinary guideline panel, including 3 patient representatives, and applied strategies to minimize potential bias from conflicts of interest. The McMaster University Grading of Recommendations Assessment, Development and Evaluation (GRADE) Centre supported the guideline development process, including performing systematic evidence reviews (up to January 2022). The panel prioritized clinical questions and outcomes according to their importance for clinicians and patients. The panel used the GRADE approach to assess evidence and make recommendations, which were subject to public comment. This is an update to guidelines published in February 2021 and May 2021 as part of the living phase of these guidelines. RESULTS: The panel made 1 additional recommendation: a conditional recommendation for the use of prophylactic-intensity over therapeutic-intensity anticoagulation for patients with COVID-19-related critical illness who do not have suspected or confirmed VTE. The panel emphasized the need for an individualized assessment of thrombotic and bleeding risk. CONCLUSIONS: This conditional recommendation was based on very low certainty in the evidence, underscoring the need for additional, high-quality, randomized controlled trials comparing different intensities of anticoagulation for patients with COVID-19-related critical illness.

Predicting major bleeding during extended anticoagulation for unprovoked or weakly provoked venous thromboembolism.

No clinical prediction model has been specifically developed or validated to identify patients with unprovoked venous thromboembolism (VTE) who are at high risk of major bleeding during extended anticoagulation. In a prospective multinational cohort study of patients with unprovoked VTE receiving extended anticoagulation after completing ≥3 months of initial treatment, we derived a new clinical prediction model using a multivariable Cox regression model based on 22 prespecified candidate predictors for the primary outcome of major bleeding. This model was then compared with modified versions of 5 existing clinical scores. A total of 118 major bleeding events occurred in 2516 patients (annual risk, 1.7%; 95% confidence interval [CI], 1.4-2.1). The incidences of major bleeding events per 100 person-years in high-risk and non-high-risk patients, respectively, were 3.9 (95% CI, 3.0-5.1) and 1.1 (0.8-1.4) using the newly derived creatinine, hemoglobin, age, and use of antiplatelet agent (CHAP) model; 3.3 (2.6-4.1) and 1.0 (0.7-1.3) using modified ACCP score, 5.3 (0.6-19.2) and 1.7 (1.4-2.0) using modified RIETE score, 3.1 (2.3-3.9) and 1.1 (0.9-1.5) using modified VTE-BLEED score, 5.2 (3.3-7.8) and 1.5 (1.2-1.8) using modified HAS-BLED score, and 4.8 (1.3-12.4) and 1.7 (1.4-2.0) using modified outpatient bleeding index score. Modified versions of the ACCP, VTE-BLEED, and HAS-BLED scores help identify patients with unprovoked VTE who are at high risk of major bleeding and should be considered for discontinuation of anticoagulation after 3 to 6 months of initial treatment. The CHAP model may further improve estimation of bleeding risk by using continuous predictor variables, but external validation is required before its implementation in clinical practice.

American Society of Hematology living guidelines on the use of anticoagulation for thromboprophylaxis in patients with COVID-19: January 2022 update on the use of therapeutic-intensity anticoagulation in acutely ill patients.

BACKGROUND: COVID-19-related acute illness is associated with an increased risk of venous thromboembolism (VTE). OBJECTIVE: These evidence-based guidelines from the American Society of Hematology (ASH) are intended to support patients, clinicians, and other health care professionals in making decisions about the use of anticoagulation in patients with COVID-19. METHODS: ASH formed a multidisciplinary guideline panel that included patient representatives and applied strategies to minimize potential bias from conflicts of interest. The McMaster University GRADE Centre supported the guideline development process and performed systematic evidence reviews (through November 2021). The panel prioritized clinical questions and outcomes according to their importance for clinicians and patients. The panel used the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach to assess evidence and make recommendations, which were subject to public comment. This is an update to guidelines published in February 2021 as part of the living phase of these guidelines. RESULTS: The panel made one additional recommendation. The panel issued a conditional recommendation in favor of therapeutic-intensity over prophylactic-intensity anticoagulation in patients with COVID-19-related acute illness who do not have suspected or confirmed VTE. The panel emphasized the need for an individualized assessment of risk of thrombosis and bleeding. The panel also noted that heparin (unfractionated or low molecular weight) may be preferred because of a preponderance of evidence with this class of anticoagulants. CONCLUSION: This conditional recommendation was based on very low certainty in the evidence, underscoring the need for additional, high-quality, randomized controlled trials comparing different intensities of anticoagulation in patients with COVID-19-related acute illness.