New guidelines from the Thrombosis and Haemostasis Society of Australia and New Zealand for the diagnosis and management of venous thromboembolism

Prescriber perceptions of the safety and efficacy of unfractionated heparin versus low molecular weight heparin in the acute treatment phase: a qualitative study

Background

Intravenous unfractionated heparin (IVUFH) and low molecular weight heparins (LMWH) are first line anticoagulants for the management of acutely unwell patients. The decision to prescribe either IVUFH or an LMWH is complex with minimal direction from clinical guidelines. The aim of this study was to explore individual prescribers' perceptions on prescribing IVUFH or LMWH in patients' acute management.

Methods

Semi-structured interviews were conducted with purposively selected senior medical officers who were from specialities including cardiology, cardiothoracic surgery, respiratory, emergency, vascular surgery, nephrology, neurology and general medicine, identified as those that routinely prescribe IVUFH or LMWH. An interview tool with seven questions and four hypothetical case scenarios guided interview discussions. Interviews were audio recorded, transcribed and inductively coded for thematic analysis.

Results

Twelve doctors participated in interviews between February and October 2022. Mean interview duration was 24 min; data saturation was achieved. Most were senior doctors: one was a registrar and others were staff specialists. Three key themes emerged: (1) rationale for the choice of heparinoid, (2) patient safety considerations and (3) resources required. The themes and subthemes identified the complexity of issues to consider when choosing between IVUFH and LMWH. Multiple factors were considered by participants which were based on previous experiences and institutional capabilities rather than evidence-based medicine.

Conclusion

Future interventions should focus on highlighting LMWH as the preferred heparinoid in most clinical scenarios. The use of IVUFH should be reserved for specific patient cohorts where the benefit of IVUFH outweighs the additional risks.

Practice Variations in the Diagnosis and Treatment of Pulmonary Embolism

Venous thromboembolism is responsible for a significant burden of disease worldwide. Despite the publication of multiple international guidelines, anecdotal evidence suggests significant clinical variation exists in the diagnostic and management pathways of pulmonary embolism (PE). We conducted a retrospective cohort study using electronic medical records to examine clinical variation in patients admitted to a tertiary referral center in Australia with a diagnosis of PE between November 2018 and January 2020. Three hundred cases met the inclusion criteria; we found variation in rates of compression ultrasonography, acute investigation of the right ventricle, and planning of repeat imaging at specialist follow-up. Guidelines do not address the use of compression ultrasonography in already diagnosed PE, are conflicting in their recommendation for acute investigation of the right ventricle, and recommend repeat imaging only if there are persistent symptoms at the time of specialist follow-up. The variations we found in this study may in part be due to physician preference or due to the paucity of evidence for some of these diagnostic practices. Robust future studies are required to guide the use of these investigations in PE.

Canadian Association of Radiologists Cardiovascular Imaging Referral Guideline

The Canadian Association of Radiologists (CAR) Cardiovascular Expert Panel is made up of physicians from the disciplines of radiology, cardiology, and emergency medicine, a patient advisor, and an epidemiologist/guideline methodologist. After developing a list of 30 clinical/diagnostic scenarios, a rapid scoping review was undertaken to identify systematically produced referral guidelines that provide recommendations for one or more of these clinical/diagnostic scenarios. Recommendations from 48 guidelines and contextualization criteria in the Grading of Recommendations, Assessment, Development, and Evaluations (GRADE) for guidelines framework were used to develop 125 recommendation statements across the 30 scenarios (27 unique scenarios as 2 scenarios point to the CAR Thoracic Diagnostic Imaging Referral Guideline and the acute pericarditis subscenario is included under 2 main scenarios). This guideline presents the methods of development and the referral recommendations for acute chest pain syndromes, chronic chest pain, cardiovascular screening and risk stratification, pericardial syndromes, intracardiac/pericardial mass, suspected valvular disease cardiomyopathy, aorta, venous thrombosis, and peripheral vascular disease.

Recommendations for prediction models in clinical practice guidelines for cardiovascular diseases are over-optimistic: a global survey utilizing a systematic literature search

Background

This study aimed to synthesize the recommendations for prediction models in cardiovascular clinical practice guidelines (CPGs) and assess the methodological quality of the relevant primary modeling studies.

Methods

We performed a systematic literature search of all available cardiovascular CPGs published between 2018 and 2023 that presented specific recommendations (whether in support or non-support) for at least one multivariable clinical prediction model. For the guideline-recommended models, the assessment of the methodological quality of their primary modeling studies was conducted using the Prediction model Risk Of Bias ASsessment Tool (PROBAST).

Results

In total, 46 qualified cardiovascular CPGs were included, with 69 prediction models and 80 specific recommendations. Of the 80 specific recommendations, 74 supported 57 models (53 were fully recommended and 4 were conditionally recommended) in cardiovascular practice with moderate to strong strength. Most of the guideline-recommended models were focused on predicting prognosis outcomes (53/57, 93%) in primary and tertiary prevention, focusing primarily on long-term risk stratification and prognosis management. A total of 10 conditions and 7 types of target population were involved in the 57 models, while heart failure (14/57, 25%) and a general population with or without cardiovascular risk factor(s) (12/57, 21%) received the most attention from the guidelines. The assessment of the methodological quality of 57 primary studies on the development of the guideline-recommended models revealed that only 40% of the modeling studies had a low risk of bias (ROB). The causes of high ROB were mainly in the analysis and participant domains.

Conclusions

Global cardiovascular CPGs presented an unduly positive appraisal of the existing prediction models in terms of ROB, leading to stronger recommendations than were warranted. Future cardiovascular practice may benefit from well-established clinical prediction models with better methodological quality and extensive external validation.

Pregnancy in women with mitochondrial disease-A literature review and suggested guidance for preconception and pregnancy care

Mitochondrial donation to reduce the risk of primary mitochondrial disease transmission from mother to child is now permitted under Australian law as part of a clinical trial. The energy demands of pregnancy have the potential to worsen mitochondrial disease symptoms and severity in affected women. We conducted a systematic literature review on mitochondrial disease in pregnancy; five cohort studies and 19 case reports were included. For many women with mitochondrial disease, pregnancy does not have a negative effect on health status. However, serious adverse outcomes may occur. We provide suggested guidelines for preconception counselling and antenatal care.

Optimizing Venous Stenting: Consensus Recommendations for Enhanced Management of Lower Extremity Deep Vein Thrombosis

INTRODUCTION

 Deep vein thrombosis (DVT) poses a complex challenge and often leads to postthrombotic syndrome (PTS), a debilitating complication. The emergence of venous stents offers a potential preventive avenue against this complication. This study aimed to provide consensus recommendations on the use of venous stent for DVT.

MATERIALS AND METHODS

 From June to July 2023, 20 internal medicine, angiology and vascular surgery, and vascular and interventional radiology experts were involved in the Delphi process. Thirty-one recommendations, categorized into three thematic areas, were rigorously evaluated: indications for stent use, stent selection and placement, and monitoring and prevention of complications. Agreement was evaluated using a Likert scale, with consensus defined as agreement by two-thirds of the participants.

RESULTS

 Consensus was reached for 23 (74.2%) of 31 recommendations. The agreement was centered on considerations, such as stent placement in specific acute DVT scenarios, emphasizing pivotal stent characteristics. However, there were divergences in the recommended stent length to prevent migration and stent characteristics based on iliocaval bifurcation morphology. Notably, there was no consensus on whether patients with DVT caused by a major transient risk factor need more than 3 months of anticoagulation therapy or whether aspirin should be added to anticoagulant treatment after venous stenting.

CONCLUSIONS

 These consensus recommendations offer practical insights into optimizing venous stent use to prevent PTS in DVT patients. Addressing the critical aspects of stent selection, placement, and postprocedural care, these recommendations contribute to clinical decision-making. The identified divergences underscore the importance of consensus and thus indicate the need for further investigation.

Finding individualised treatment in obese needing enoxaparin (FIT ONE): a multicentre study of therapeutic enoxaparin and the role of anti-factor Xa monitoring

Enoxaparin is dosed according to actual body weight in treatment of arterial and venous thrombosis. Due to its hydrophilic nature, it distributes according to lean body mass which may be problematic when dosing obese patients as this may increase the risk of bleeding events in this population. The aim was to evaluate current therapeutic enoxaparin dosing strategies, including Antifactor Xa (AFXa) level monitoring, in obese patients and to identify factors that contribute to treatment failure and excess anticoagulation. A retrospective cohort study was conducted reviewing patients administered therapeutic enoxaparin between May 2020 and April 2021. Data were collected on patient characteristics, enoxaparin therapy, AFXa monitoring, and outcomes. Regression models were constructed to assess variables of interest to estimate any association with AFXa levels. In total 762 patients were included in the analysis. The mean initial weight-based dose was 0.95 mg/kg twice daily (SD: ± 0.12, IQR 0.92-1.01) and 1.04 mg/kg once daily (SD: ± 0.26, IQR 0.93-1.12) and 14.4% of patients had AFXa monitoring. Treatment failure was experienced by 2.2%, 5% experienced bleeding. There was no association between the mean actual milligram per kilogram weight-based twice daily doses and subtherapeutic, therapeutic and supratherapeutic AFXa levels (P = 0.135). Obesity was not included in the final regression models due to lack of significance. At a mean therapeutic enoxaparin dose of 0.95 mg/kg twice daily and 1.04 mg/kg once daily no excess in treatment failure or bleeding events were observed in obese patients compared to the product information. Obesity was not an independent variable that affected the achievement of target AFXa levels.

Venous thromboembolism risk assessment scale for prediction of venous thromboembolism in inpatients with cancer: A meta-analysis

AIMS

This meta-analysis was conducted to evaluate the validity of the Caprini venous thromboembolism (VTE) risk assessment scale in predicting the risk of VTE in inpatients with cancer.

METHODS

Studies relating to the Caprini VTE risk assessment scale were systematically retrieved from the MEDLINE, EMBASE, Web of Science, Cochrane Library, BIOSIS Previews, EBSCOhost, and China National Knowledge Infrastructure (CNKI) databases up to May 1, 2022. Two reviewers independently conducted data extraction and quality evaluation. MetaDisc 1.4 and Stata 15.0 software were used for data analysis.

RESULTS

We included 10 studies with 23,644 subjects in our analyses. The results showed that the pooled sensitivity (SEN) and specificity (SPE) were 0.59 (95 % CI: 0.55 to 0.63) and 0.57 (95 % CI:0.57 to 0.58), respectively; the pooled diagnostic odds ratio (DOR) was 6.05 (95 % CI: 2.70 to 13.58); and the area under the curve (AUC) of the summary receiver operating characteristic (SROC) curve was 0.76. Subgroup analysis was performed according to ethnicity (Chinese or non-Chinese), study design (prospective/retrospective), Caprini RAM version (2005/2009), and cut-off (≤7 or > 7).

CONCLUSION

The Caprini VTE risk assessment scale has a moderate ability to predict VTE in surgical inpatients with cancer, as well as in Western populations; Caprini 2009 has a stronger predictive ability than 2005, and its predictive power is better if the cut-off value is >7. Future studies in clinical practice and specific specialties are needed to explore the optimal cut-off value of different cancers. This will improve our accuracy in understanding the risk of VTE in inpatients and help promote timely and targeted prevention. In turn, this will reduce the incidence of VTE and improve the quality of life of inpatients with cancer.

Pulmonary embolism response teams. A description of the first 36-month Australian experience

BACKGROUND

High/intermediate-risk pulmonary embolism (PE) confers increased risk of cardiovascular morbidity and mortality. International guidelines recommend the formation of a PE response team (PERT) for PE management because of the complexity of risk stratification and emerging treatment options. However, there are currently no available Australian data regarding outcomes of PE managed through a PERT.

AIMS

To analyse the clinical and outcome data of patients from an Australian centre with high/intermediate-risk PE requiring PERT-guided management.

METHODS

We performed a retrospective observational study of 75 consecutive patients with high/intermediate-risk PE who had PERT involvement, between August 2018 and July 2021. We recorded clinical and interventional data at the time of PERT and assessed patient outcomes up to 30 days from PERT initiation. We used unpaired t tests to compare right to left ventricular (RV/LV) ratios by computed tomography criteria or transthoracic echocardiogram (TTE) at baseline and after interventions.

RESULTS

Data were available for 74 patients. Initial computed tomography pulmonary angiography RV/LV ratio was increased at 1.65 ± 0.5 and decreased to 1.30 ± 0.29 following PERT-guided interventions (P < 0.001). TTE RV/LV ratio also decreased following PERT-guided management (1.09 ± 0.19 vs 0.93 ± 0.17; P < 0.001). 20% of patients had any bleeding complication, but two-thirds were mild, not requiring intervention. All-cause mortality was 6.8%, and all occurred within the first 7 days of admission.

CONCLUSION

The PERT model is feasible in a large Australian centre in managing complex and time-critical PE. Our data demonstrate outcomes comparable with existing published international PERT data. However, successful implementation at other Australian institutions may require adequate centre-specific resource availability and the presence of multispeciality input.

Oral anticoagulant therapy in older adults

Patients aged ≥65 years not only account for the majority of patients with atrial fibrillation (AF) and venous thromboembolism (VTE), they are also at a higher risk of morbidity, mortality, and undertreatment than younger patients. Several age-related physiological changes with effects on drug pharmacokinetics/-dynamics and blood vessel fragility as well as the higher prevalence of geriatric conditions such as frailty, multimorbidity, polypharmacy, fall risk, dementia, and malnutrition make older persons more vulnerable to disease- and anticoagulation-related complications. Moreover, because older patients with AF/VTE are underrepresented in oral anticoagulation (OAC) trials, evidence on OAC in older adults with AF/VTE is mainly based on subgroup analyses from clinical trials and observational studies. A growing body of such limited evidence suggests that direct oral anticoagulants (DOACs) may be superior in terms of efficacy and safety compared to vitamin K antagonists in older persons with AF/VTE and that specific DOACs may have a differing risk-benefit profile. In this narrative review, we summarize the evidence on epidemiology of AF/VTE, impact of age-related physiological changes, efficacy/safety of OAC, specifically considering individuals with common geriatric conditions, and review OAC guideline recommendations for older adults with AF/VTE. We also propose a research agenda to improve the evidence basis on OAC older individuals with AF/VTE, including the conduct of advanced age-specific and pragmatic studies using less restrictive eligibility criteria and patient-reported health outcomes, in order to compare the effectiveness and safety of different DOACs, and investigate lower-dose regimens and optimal OAC durations in older patients.

NET-targeted nanoparticles for antithrombotic therapy in pregnancy

Pulmonary embolism caused by deep vein thrombosis (DVT) is a major contributor to maternal morbidity and mortality. There is still an unmet need for safe and effective treatment options for DVT during pregnancy. Recent research has shown that neutrophil extracellular trap (NET) formation plays a very vital role in thrombosis. We created nanoparticles surface-modified by neutrophil elastase (NE)-binding peptide that can target activated neutrophils specifically in vitro and in vivo. Prussian blue nanoparticles (PB NPs) designed in the core scavenges abnormally elevated reactive oxygen species (ROS) in the vascular microenvironment and acts as a photothermal agent to mediate photothermal therapy (PTT) to damage fibrin network structure. Based on the data we have included, this noninvasive therapeutic approach is considered safe for both mothers and the fetus. Furthermore, our findings indicate that this therapeutic approach has a significant alleviation effect on intrauterine growth restriction caused by maternal thrombosis.

Pulmonary Embolism in Pregnancy: A Review for Clinical Practitioners

Diagnostic and therapeutic decision-making in pregnancy with suspected pulmonary embolism (PE) is challenging. European and other international professional societies have proposed various recommendations that are ambiguous, probably due to the unavailability of randomized controlled trials. In the following sections, we discuss the supporting diagnostic steps and treatments. We suggest a standardized diagnostic work-up in pregnant patients presenting with symptoms of PE to make evidence-based diagnostic and therapeutic decisions. We strongly recommend that clinical decisions on treatment in pregnant patients with intermediate- or high-risk pulmonary embolism should include a multidisciplinary team approach involving emergency physicians, pulmonologists, angiologist, cardiologists, thoracic and/or cardiovascular surgeons, radiologists, and obstetricians to choose a tailored management option including an interventional treatment. It is important to be aware of the differences among guidelines and to assess each case individually, considering the specific views of the different specialties. This review summarizes key concepts of the diagnostics and acute management of pregnant women with suspected PE that are supportive for the clinician on duty.

Venous thromboembolism (VTE) developing after ankle sprain. Comparison with VTE after knee arthroplasty

BACKGROUND

Venous thromboembolism (VTE) is a critical complication after non-major trauma or surgery. While the risk and severity of VTE following major orthopedic surgery is well-documented, there is significant knowledge gap regarding, non-major trauma such as ankle sprains.

METHODS

We analyzed data from the RIETE registry to assess the clinical characteristics, VTE prophylaxis usage, and outcomes in patients with VTE following ankle sprain versus those post elective knee arthroplasty. We aimed to assess the risk and severity of VTE in a population traditionally considered at lower risk. Risk stratification was performed using the TRiP(cast) score.

RESULTS

Among 1,250 patients with VTE, those with ankle sprain (n = 459) were much younger than those post knee arthroplasty (n = 791), less often female, had fewer comorbidities, and received VTE prophylaxis less often (27% vs. 93 %). During anticoagulation, 26 patients developed recurrent VTE, 31 had major bleeding, and 12 died (fatal PE 3, fatal bleeding 2). There were no differences between the two groups in the rates of VTE recurrences (rate ratio (RR): 1.65; 95%CI: 0.69-3.88) or death (RR: 1.12; 95%CI: 0.33-3.46), but patients with VTE after ankle sprain had a lower rate of major bleeding (RR: 0.39; 95%CI: 0.13-0.99).

CONCLUSIONS

Ankle sprain patients are often undertreated for VTE prophylaxis and have similar severity of VTE than those undergoing elective knee surgery, indicating the need for a more customized approach to VTE management.

Pharmacomechanical thrombectomy of iliofemoral deep vein thrombosis is associated with a low incidence of post-thrombotic syndrome and perioperative complications

BACKGROUND

Iliofemoral deep venous thrombosis (IFDVT) is associated with an incidence of post-thrombotic syndrome (PTS) of up to 50%. PTS is associated with high morbidity, impaired quality of life and a significant economic burden. The aim of the current study was to assess the impact of a single session pharmacomechanical thrombectomy (PMT), dedicated venous stents and a risk mitigation protocol on the rate of PTS.

METHODS

Between 2015 and 2022, patients presenting with acute or subacute IFDVT treated with the same protocol of single session PMT, dedicated venous stents, and risk-mitigation measures were included. Procedural success rate, complications, stent patency and incidence of PTS were determined.

RESULTS

Of 60 patients (58 ± 19 years; 65% male), the procedural success rate was 93%, with 7% of patients experiencing complications but no long-term sequelae or mortality. Most (n = 52; 87%) patients were stented, including 46% across the inguinal ligament. At 3 months post-procedure, primary, assisted primary and secondary stent patency rates were 89%, 93% and 98%, respectively, with no loss of patency or re-interventions after that. At latest follow-up of a median 48 months (n = 32), stent patency rate was 97%, with only three patients (9%) experiencing symptoms of PTS.

CONCLUSION

Single session PMT, dedicated venous stents and a risk-mitigation protocol results in high success rate, excellent long-term stent patency and low incidence of PTS without compromising safety. These results support early intervention for iliofemoral DVT.

Establishment of machine learning-based tool for early detection of pulmonary embolism

BACKGROUND AND OBJECTIVES

Pulmonary embolism (PE) is a complex disease with high mortality and morbidity rate, leading to increasing society burden. However, current diagnosis is solely based on symptoms and laboratory data despite its complex pathology, which easily leads to misdiagnosis and missed diagnosis by inexperienced doctors. Especially, CT pulmonary angiography, the gold standard method, is not widely available. In this study, we aim to establish a rapid and accurate screening model for pulmonary embolism using machine learning technology. Importantly, data required for disease prediction are easily accessed, including routine laboratory data and medical record information of patients.

METHODS

We extracted features from patients' routine laboratory results and medical records, including blood routine, biochemical group, blood coagulation routine and other test results, as well as symptoms and medical history information. Samples with a feature loss rate greater than 0.8 were deleted from the original database. Data from 4723 cases were retained, 231 of which were positive for pulmonary embolism. 50 features were retained through the positive and negative statistical hypothesis testing which was used to build the predictive model. In order to avoid identification as majority-class samples caused by the imbalance of sample proportion, we used the method of Synthetic Minority Oversampling Technique (SMOTE) to increase the amount of information on minority samples. Five typical machine learning algorithms were used to model the screening of pulmonary embolism, including Support Vector Machines, Logistic Regression, Random Forest, XGBoost, and Back Propagation Neural Networks. To evaluate model performance, sensitivity, specificity and AUC curve were analyzed as the main evaluation indicators. Furthermore, a baseline model was established using the characteristics of the pulmonary embolism guidelines as a comparison model.

RESULTS

We found that XGBoost showed better performance compared to other models, with the highest sensitivity and specificity (0.99 and 0.99, respectively). Moreover, it showed significant improvement in performance compared to the baseline model (sensitivity and specificity were 0.76 and 0.76 respectively). More important, our model showed low missed diagnosis rate (0.46) and high AUC value (0.992). Finally, the calculation time of our model is only about 0.05 s to obtain the possibility of pulmonary embolism.

CONCLUSIONS

In this study, five machine learning classification models were established to assess the likelihood of patients suffering from pulmonary embolism, and the XGBoost model most significantly improved the precision, sensitivity, and AUC for pulmonary embolism screening. Collectively, we have established an AI-based model to accurately predict pulmonary embolism at early stage.

Follow-up study of isolated calf muscular vein thrombosis for anticoagulant therapy after primary hip and knee arthroplasty

BACKGROUND

Although isolated calf muscular vein thrombosis (ICMVT) is commonly seen after hip and knee arthroplasty, no treatment guidelines for ICMVT after joint replacement are available. The purpose of this study was to evaluate the outcomes of patients with ICMVT for anticoagulant therapy at different time points after primary hip and knee arthroplasty.

METHODS

Patients with ICMVT after primary hip and knee arthroplasty were included in the study. Diagnosis was established with Doppler ultrasound. Patients were followed up clinically and with Doppler ultrasound at 1, 2, and 3 months. The outcomes were efficacy (complete resolution) and acceptability (hemorrhagic events). Anticoagulant therapy at curative dosage was prescribed for 1 month and was extended for 2 additional months in case of incomplete resolution at 1 month or if propagation was present. The chi-square test was used to compare the outcomes at different time points.

RESULTS

302 patients were taken hip and knee arthroplasty from January 2021 to May 2022, in which 51 patients presented with 51 ICMVTs postoperatively. The incidence of ICMVT was about 16.89%. Resolution of ICMVT was considered complete at 1, 2, and 3 months at 36.73%, 61.22%, and 91.84%, respectively, with significant differences among the time points (P < 0.05). All patients with ICMVT receiving anticoagulant therapy remained free of propagations and hemorrhagic events within 3 months.

CONCLUSION

Our findings provide new insights into the anticoagulant therapy for ICMVT after primary hip and knee arthroplasty, taking oral Rivaroxaban for 3 months is effective and safe, which contributes to provide the reference for clinical practice.

A Nomogram for Predicting Cancer-Associated Venous Thromboembolism in Hospitalized Patients Receiving Chemoradiotherapy for Cancer

PURPOSE

The aim of this study was to develop a novel nomogram to predict cancer-associated venous thromboembolism (CAT) in hospitalized patients with cancer who receive chemoradiotherapy.

METHODS

This was a retrospective cohort study of hospitalized patients with cancer who received chemoradiotherapy between January 2010 and December 2022. Predictive factors for CAT were determined using univariate and multivariate logistic regression analyses, and a risk prediction model based on the nomogram was constructed and validated internally. Nomogram performance was assessed using receiver operating characteristic (ROC), calibration curve, and decision curve analysis (DCA).

RESULTS

A total of 778 patients were eligible for inclusion in this study. The nomogram incorporated 5 independent risk factors: age, cancer stage, use of nonsteroidal anti-inflammatory drugs, D-dimer levels, and history of diabetes mellitus. The area under the curve (AUC) of the nomogram for the training and validation cohorts was 0.816 and 0.781, respectively, with 95% confidence intervals (CIs) of 0.770-0.861 and 0.703-0.860, respectively. The calibration and DCA curves also displayed good agreement and clinical applicability of the nomogram model.

CONCLUSIONS

The incidence of CAT was relatively high among patients with cancer receiving chemoradiotherapy. The nomogram risk model developed in this study has good prediction efficiency and can provide a reference for the clinical evaluation of the risk of adverse outcomes in patients with cancer receiving chemoradiotherapy.

American Society of Hematology 2023 guidelines for management of venous thromboembolism: thrombophilia testing

Hereditary and acquired thrombophilia are risk factors for venous thromboembolism (VTE). Whether testing helps guide management decisions is controversial. These evidence-based guidelines from the American Society of Hematology (ASH) intend to support decision making about thrombophilia testing. ASH formed a multidisciplinary guideline panel covering clinical and methodological expertise and minimizing bias from conflicts of interest. The McMaster University GRADE Centre provided logistical support, performed systematic reviews, and created evidence profiles and evidence-to-decision tables. The Grading of Recommendations Assessment, Development, and Evaluation approach (GRADE) was used. Recommendations were subject to public comment. The panel agreed on 23 recommendations regarding thrombophilia testing and associated management. Nearly all recommendations are based on very low certainty in the evidence due to modeling assumptions. The panel issued a strong recommendation against testing the general population before starting combined oral contraceptives (COCs) and conditional recommendations for thrombophilia testing in the following scenarios: (a) patients with VTE associated with nonsurgical major transient or hormonal risk factors; (b) patients with cerebral or splanchnic venous thrombosis, in settings where anticoagulation would otherwise be discontinued; (c) individuals with a family history of antithrombin, protein C, or protein S deficiency when considering thromboprophylaxis for minor provoking risk factors and for guidance to avoid COCs/hormone replacement therapy; (d) pregnant women with a family history of high-risk thrombophilia types; and (e) patients with cancer at low or intermediate risk of thrombosis and with a family history of VTE. For all other questions, the panel provided conditional recommendations against testing for thrombophilia.

Comparison of international guideline recommendations for the diagnosis of pulmonary embolism

Pulmonary embolism is one of the leading causes of death due to cardiovascular disease. Timely diagnosis is crucial, but challenging, as the clinical presentation of pulmonary embolism is unspecific and easily mistaken for other common medical emergencies. Clinical prediction rules and D-dimer measurement allow stratification of patients into groups of expected prevalence and are key elements in adequate selection of patients for diagnostic imaging; however, the strengths and weaknesses of the multiple proposed prediction rules, when to measure D-dimer, and which cutoff to apply might be elusive to a significant proportion of physicians. 13 international guidelines authored by medical societies or expert author groups provide recommendations on facets of the diagnostic investigations in suspected pulmonary embolism, some of which are hallmarked by pronounced heterogeneity. This Review summarises key recommendations of each guideline, considers the most recent evidence on the topic, compares guideline recommendations on each facet of the diagnosis of pulmonary embolism, and provides a synthesis on the most common recommendations.

The clinicopathological features of thrombosis with thrombocytopenia syndrome following ChAdOx1-S (AZD1222) vaccination and case outcomes in Australia: a population-based study

Background

Thrombosis with thrombocytopenia syndrome (TTS) associated with viral vector COVID-19 vaccines, including ChAdOx1-S (AstraZeneca AZD1222) vaccine, can result in significant morbidity and mortality. We report the clinicopathological features of TTS following ChAdOx1-S vaccination and summarise the case outcomes in Australia.

Methods

In this cohort study, patients diagnosed with TTS in Australia between 23 March and 31 December 2021 were identified according to predefined criteria. Cases were included if they met the Therapeutic Goods Administration (TGA) probable and confirmed case definitions and were reclassified using Centres for Disease Control and Prevention (CDC) definition for analysis. Data were collected on patient baseline characteristics, clinicopathological features, risk factors, treatment and outcomes.

Findings

A total of 170 TTS cases were identified, with most occurring after the first dose (87%) of ChAdOx1-S. The median time to symptom onset after vaccination and symptom onset to admission was 11 and 2 days respectively. The median age of cases was 66 years (interquartile range 55-74). All except two patients received therapeutic anticoagulation and 66% received intravenous immunoglobulin. Overall, 85.3% of cases were discharged home after a median hospitalisation of 6 days, 9.4% required ongoing rehabilitation and 5.3% died. Eight deaths were related to TTS, with another dying from an unrelated condition while receiving treatment for TTS. Deaths occurred more commonly in those classified as Tier 1 according to the CDC definition and were associated with more severe thrombocytopenia and disease-related haemorrhage.

Interpretation

TTS, while rare, can be severe and have catastrophic outcomes in some individuals. In Australia, the mortality rate was low compared to that reported in other high-income countries. Almost all received therapeutic anticoagulation with no bleeding complications and were successfully discharged. This emphasises the importance of community education and an established pathway for early recognition, diagnosis and treatment of TTS.

Funding

Australian Commonwealth Department of Health and Aged Care. H.A Tran, N. Wood, J. Buttery, N.W. Crawford, S.D. Chunilal, V.M. Chen are supported by Medical Research Future Funds (MRFF) grant ID 2015305.

The clinical application of venous ultrasound in diagnosis and follow-up of lower extremity deep vein thrombosis (DVT): a case-based discussion

Current clinical practice guidelines lack explicit guidance on the indications and appropriate timing of venous ultrasound (US) in lower extremity deep vein thrombosis (DVT) follow-up. Moreover, abnormal findings reported on venous US in DVT follow-up or suspected recurrent DVT may be difficult for clinicians to interpret, which carries risk of harm from inappropriate use of anti- coagulation and increased healthcare resource utilization. Due to the above factors, over-use of ultrasound in diagnosis and follow-up of lower extremity DVT has been reported in western health systems. We have undertaken a case-based discussion and a scoping review of existing guidelines on the use of venousUS following prior diagnosis of DVT, to guide appropriate interpretation of commonly reported US abnormalities and provide our suggestions in the light of best available evidence on appropriate timing to perform follow-up US in management of lower extremity DVT.

Prevalence and predictors of inappropriate dosing of direct oral anticoagulants

BACKGROUND

Information on inappropriate dosing of direct oral anticoagulants (DOACs) is scarce in the Australian context.

AIM

To describe the prevalence and potential predictors of inappropriate dosing of DOACs.

METHODS

Patients who received DOACs during admission under a general medical unit over a 2-year period (from January 2017 to December 2018) were retrospectively studied. Appropriateness of the dosing regimen was verified against the recommendations of the Therapeutic Goods Administration of Australia. Data were obtained from medical records and analysed in univariate and multivariate logistic regression models. The variables associated with under- and overdosing were also determined.

RESULTS

A total of 203 (mean age 71.6 ± 14.5 years, females 52%) patients were studied. Inappropriate dosing occurred in 44 (22%) patients: underdosing 27 (13%) and overdosing 17 (8%). Age ≥75 years (P < 0.01), lower estimated creatinine clearance (CrCl) (P < 0.01), prescription of DOAC prior to index admission (P < 0.01) and higher Charlson Comorbidity Index (P < 0.01), HAS-BLED (P < 0.01) and CHA2 DS2 -VASc (P < 0.01) scores had a significant univariate association with inappropriate dosing. However, in the multivariate logistic regression only lower CrCl (odds ratio (OR) 1.04, 95% confidence interval (CI): 1.01-1.07, P < 0.01) and prescription of DOAC prior to index admission (OR 2.62, 95% CI: 1.01-6.75, P = 0.047) remained significantly associated with inappropriate dosing. Impaired renal function also had a significant association with underdosing (OR 1.04, 95% CI: 1.01-1.07, P = 0.01) and borderline significance with overdosing (OR 1.03, 95% CI: 1.00-1.07, P = 0.06).

CONCLUSION

Inappropriate dosing of DOACs, especially underdosing, is common in clinical practice. Clinicians should exercise due diligence when prescribing DOACs to patients with renal impairment and in outpatient settings.

Adherence and persistence to direct factor Xa inhibitors in the community following newly diagnosed venous thromboembolism: a retrospective pharmacy-linkage study

OBJECTIVES

To assess adherence and persistence to the direct factor Xa inhibitor oral anticoagulants in the community following newly diagnosed venous thromboembolism (VTE).

METHODS

We retrospectively reviewed community pharmacy dispensing data on all patients with newly diagnosed VTE who were prescribed direct factor Xa inhibitors, apixaban or rivaroxaban, between January 2018 and December 2019 at our institution. Proportion of days covered (PDC) was used to assess adherence at 90 days, and 6- and 12 months. Persistence was measured by participants having both dispensed supply of a factor Xa inhibitor at the end of the treatment period and no significant gaps (maximum of 60 days) in supply.

KEY FINDINGS

There were 225 patients identified. Overall PDC at 90 days, 6- and 12 months were 84.6%, 86.2% and 86.1%, respectively. Apixaban had a higher mean overall PDC than rivaroxaban (86.2% and 80.6%, respectively). Females demonstrated higher PDC compared with males (87.3% versus 81.2%). Overall, 133 patients (64%) were persistent with therapy.

CONCLUSIONS

In patients with newly diagnosed VTE treated with a factor Xa inhibitor, adherence rates are high at >80%, with females and those prescribed apixaban exhibiting higher adherence. These findings may assist clinicians in identifying those patients with VTE at risk of poor adherence.

Clinical predictors of pulmonary embolism for inpatients: are computed tomography pulmonary angiograms being requested appropriately?

BACKGROUND

The heterogeneity of inpatient pulmonary embolism (PE) presentations may lead to computed tomography pulmonary angiograms (CTPA) being over-requested. Current clinical predictors for PE, including Wells criteria and Pulmonary Embolism Rule-out Criteria (PERC), have predominantly focussed on outpatient and emergency department populations.

AIM

To determine the clinical indicators for ordering inpatient CTPA and the predictors of positive scans for PE.

METHODS

Consecutive inpatient CTPA (performed >24 h after admission) from January 2017 to December 2017 were retrospectively reviewed. Variables including baseline characteristics, vital signs and risk factors for PE were extracted.

RESULTS

A total of 312 CTPA was reviewed (average patient age 67 years; 46% male) and 36 CTPA were positive for PE (11.5%). The average time to inpatient CTPA request was 7 days. Clinical indicators associated with positive scans were hypoxia (odds ratio (OR) 2.4; 95% confidence interval (CI) 1.1-5.6), tachypnoea (OR 2.5; 95% CI 1.2-6.0), recent surgery or immobilisation (OR 2.7; 95% CI 1.2-6.4), S1Q3T3 pattern on electrocardiogram (ECG; OR 7.2; 95% CI 1.4-35.7) and right bundle branch block pattern on ECG (OR 4.7; 95% CI 1.6-13.1). Hypotension, fever and malignancy were not significant. Both PERC and Wells criteria had poor positive predictive value (12% and 27% respectively), but the negative predictive value for PERC and Wells was 100% and 95.8% respectively.

CONCLUSION

Inpatient CTPA appear to be over-requested and can potentially be rationalised based on a combination of clinical predictors and Wells criteria and/or PERC rule. Further prospective studies are needed to develop accurate clinical decision tools targeted towards inpatients.

Mortality data from omission of early thromboprophylaxis in critically ill patients highlights the importance of an individualised diagnosis-related approach

BACKGROUND

Venous thromboembolism (VTE) prophylaxis is effective in reducing VTE events, however, its impact on mortality is unclear. We examined the association between omission of VTE prophylaxis within the first 24 h after intensive care unit (ICU) admission and hospital mortality.

METHODS

Retrospective analysis of prospectively collected data from the Australian New Zealand Intensive Care Society Adult Patient Database. Data were obtained for adult admissions between 2009 and 2020. Mixed effects logistic regression models were used to evaluate the association between omission of early VTE prophylaxis and hospital mortality.

RESULTS

Of the 1,465,020 ICU admissions, 107,486 (7.3%) did not receive any form of VTE prophylaxis within the first 24 h after ICU admission without documented contraindication. Omission of early VTE prophylaxis was independently associated with 35% increased odds of in-hospital mortality (odds ratios (OR): 1.35; 95% CI: 1.31-1.41). The associations between omission of early VTE prophylaxis and mortality varied by admission diagnosis. In patients diagnosed with stroke (OR: 1.26, 95% CI: 1.05-1.52), cardiac arrest (OR: 1.85, 95% CI: 1.65-2.07) or intracerebral haemorrhage (OR: 1.48, 95% CI: 1.19-1.84), omission of VTE prophylaxis was associated with increased risk of mortality, but not in patients diagnosed with subarachnoid haemorrhage or head injury.

CONCLUSIONS

Omission of VTE prophylaxis within the first 24 h after ICU admission was independently associated with increased risk of mortality that varied by admission diagnosis. Consideration of early thromboprophylaxis may be required for patients with stroke, cardiac arrest and intracerebral haemorrhage but not in those with subarachnoid haemorrhage or head injury. The findings highlight the importance of individualised diagnosis-related thromboprophylaxis benefit-harm assessments.

Direct-Acting Oral Anticoagulant Therapy in Cancer Patients-A Review

Venous thromboembolism (VTE) is an important aspect in cancer patients. There are various pharmacological methods used for thrombotic event treatment. DOACs (direct-acting oral anticoagulants) are gaining popularity among both physicians and researchers and are slowly starting to replace VKAs (vitamin K antagonists), thus becoming a substitute or alternative option for LMWHs (low-molecular-weight heparins). In this article, we present DOACs' main therapeutic advantages and disadvantages in patients with cancer. The only major concern with using DOACs is the higher risk of bleeding; however, there are discrepancies in this matter. There are still some types of cancer for which DOACs are not recommended. Specific cancer types may influence the efficacy of DOAC therapy. Additionally, race and ethnicity may affect therapy in cancer patients with DOACs. A sizeable number of clinical trials are focused on comparing DOACs with other anticoagulants. The current guidelines of different scientific associations are not unanimous in their DOAC assessments. There is still a need for more evidence of DOACs' potential advantages over other methods of anticoagulation in cancer patients to facilitate their position in this recommendation. This literature review presents the current state of knowledge about the use of DOACs in patients with neoplastic growth.

Sclerotherapy of lower limb veins: Indications, contraindications and treatment strategies to prevent complications - A consensus document of the International Union of Phlebology-2023

BACKGROUND

Sclerotherapy is a non-invasive procedure commonly used to treat superficial venous disease, vascular malformations and other ectatic vascular lesions. While extremely rare, sclerotherapy may be complicated by serious adverse events.

OBJECTIVES

To categorise contraindications to sclerotherapy based on the available scientific evidence.

METHODS

An international, multi-disciplinary panel of phlebologists reviewed the available scientific evidence and developed consensus where evidence was lacking or limited.

RESULTS

Absolute Contraindications to sclerotherapy where the risk of harm would outweigh any benefits include known hypersensitivity to sclerosing agents; acute venous thromboembolism (VTE); severe neurological or cardiac adverse events complicating a previous sclerotherapy treatment; severe acute systemic illness or infection; and critical limb ischaemia. Relative Contraindications to sclerotherapy where the potential benefits of the proposed treatment would outweigh the risk of harm or the risks may be mitigated by other measures include pregnancy, postpartum and breastfeeding; hypercoagulable states with risk of VTE; risk of neurological adverse events; risk of cardiac adverse events and poorly controlled chronic systemic illness. Conditions and circumstances where Warnings and Precautions should be considered before proceeding with sclerotherapy include risk of cutaneous necrosis or cosmetic complications such as pigmentation and telangiectatic matting; intake of medications such as the oral contraceptive and other exogenous oestrogens, disulfiram and minocycline; and psychosocial factors and psychiatric comorbidities that may increase the risk of adverse events or compromise optimal treatment outcomes.

CONCLUSIONS

Sclerotherapy can achieve safe clinical outcomes provided that (1) patient-related risk factors and in particular all material risks are (1a) adequately identified and the risk benefit ratio is clearly and openly discussed with treatment candidates within a reasonable timeframe prior to the actual procedure; (1b) when an individual is not a suitable candidate for the proposed intervention, conservative treatment options including the option of 'no intervention as a treatment option' are discussed; (1c) complex cases are referred for treatment in controlled and standardised settings and by practitioners with more expertise in the field; (1d) only suitable individuals with no absolute contraindications or those with relative contraindications where the benefits outweigh the risks are offered intervention; (1e) if proceeding with intervention, appropriate prophylactic measures and other risk-mitigating strategies are adopted and appropriate follow-up is organised; and (2) procedure-related risk factors are minimised by ensuring the treating physicians (2a) have adequate training in general phlebology with additional training in duplex ultrasound, procedural phlebology and in particular sclerotherapy; (2b) maintain their knowledge and competency over time and (2c) review and optimise their treatment strategies and techniques on a regular basis to keep up with the ongoing progress in medical technology and contemporary scientific evidence.

Application of Nanotechnology in Thrombus Therapy

A thrombus is a blood clot that forms in the lumen of an artery or vein, restricting blood flow and causing clinical symptoms. Thrombosis is associated with many life-threatening cardiovascular diseases. However, current clinical therapeutic technologies still have many problems in targeting, enrichment, penetration, and safety to meet the thrombosis treatment needs. Therefore, researchers devote themselves to developing nanosystems loaded with antithrombotic drugs to address this paradox in recent years. Herein, the existing thrombosis treatment technologies are first reviewed; and then, their advantages and disadvantages are outlined based on a brief discussion of thrombosis's definition and formation mechanism. Furthermore, the need and application cases for introducing nanotechnology are discussed, focusing on thrombus-specific targeted ligand modification technology and microenvironment-triggered responsive drug release technology. Then, nanomaterials that can be used to design antithrombotic nanotherapeutic systems are summarized. Moreover, a variety of drug delivery technologies driven by nanomotors in thrombosis therapy is also introduced. Last of all, a prospective discussion on the future development of nanotechnology for thrombosis therapy is highlighted.

Tinzaparin for venous thromboembolism in patients with renal impairment: a single-centre, prospective pilot study

BACKGROUND

Low molecular weight heparins (LMWH) are used extensively for prophylaxis and treatment of venous thromboembolism (VTE), bridging therapy for warfarin and standard of care in cancer-associated VTE (CA-VTE). Tinzaparin has the highest molecular weight of all LMWH and relies least on renal clearance to Cockcroft-Gault creatinine clearance (CrCl) of 20 mL/min. Previous pharmacological studies have demonstrated safety and effectiveness in elderly patients. Prospective clinical trials have confirmed these findings to CrCl 20 mL/min and in CA-VTE. We describe the pilot program developed at Concord Repatriation General Hospital for tinzaparin.

AIMS

We aim to confirm the deliverability of tinzaparin in patients with renal insufficiency.

METHODS

Twenty patients were established on tinzaparin as therapeutic anticoagulation with CrCl or CKD-EPI estimated glomerular filtration rate (eGFR) 20-50 mL/min with an indication for anticoagulation. Tinzaparin was given as a subcutaneous injection at 175 units/kg as a single daily dose, rounded to the nearest vial size. Tinzaparin anti-Xa levels were tested at Days 2, 7 and 14 (±1 day) and transition to oral anticoagulants were allowed at clinician discretion.

RESULTS

No accumulation of tinzaparin was seen into Day 14. Two patients required dose-adjustment, five patients had bleeding complications (two major, three minor) and four patients died during follow-up, all attributable to patients' comorbidities. CrCl and body surface area-standardised CrCl were significantly correlated with tinzaparin anti-Xa level only on Day 2, and this effect was lost when patients with CrCl >50 mL/min were excluded. Data from our cohort confirm the deliverability of therapeutic tinzaparin in patients with CrCl or CKD-EPI eGFR 20-50 mL/min. Bleeding and death outcomes were also comparable to other trials using tinzaparin in CA-VTE.

CONCLUSION

For patients with renal insufficiency, tinzaparin represents an attractive alternative anticoagulant with once-daily administration in a range of potential indications.

High systemic inflammation response index level is associated with an increased risk of lower extremity deep venous thrombosis: a large retrospective study

BACKGROUND

The association between inflammation and venous thromboembolism (VTE) has attracted increasing research interest. Recently, the systemic inflammation response index (SIRI) has been proposed as a novel inflammatory biomarker, but its potential association with lower extremity deep venous thrombosis (LEDVT) has not been investigated. Thus, this study aimed to explore the association between SIRI and LEDVT risk in a large sample over a 10-year period (2012-2022).

METHODS

All hospitalized patients who underwent lower extremity compression ultrasonography (CUS) examinations were consecutively identified from our hospital information system database. Multivariate logistic regression analysis was used to investigate the association between SIRI and LEDVT risk. Sensitivity, restricted cubic spline and subgroup analyses were also performed.

RESULTS

In total, 12643 patients were included, and 1346 (10.6%) LEDVT events occurred. After full adjustment, a higher SIRI level was significantly associated with an increased risk of LEDVT (odds ratio [OR] = 1.098, 95% confidence interval [CI]: 1.068-1.128, p < 0.001), and patients in quartile 4 had a 2.563-fold higher risk of LEDVT than those in quartile 1 (95% CI: 2.064-3.182, p < 0.001). A nonlinear relationship was observed (P for nonlinearity < 0.001), with an inflection point of 4.17. Below this point, each unit increase in SIRI corresponded to a 35.3% increase in LEDVT risk (95% CI: 1.255-1.458, p < 0.001). No significant difference was found above the inflection point (OR = 1.015, 95% CI: 0.963-1.069, p = 0.582). Sensitivity and subgroup analyses confirmed the robustness of the association. This association also existed in both distal and proximal LEDVT.

CONCLUSION

A High SIRI is significantly associated with an increased risk of LEDVT in hospitalized patients. Given that the SIRI is a readily available biomarker in clinical settings, its potential clinical use deserves further exploration.

Comparison of Maintenance Dose Predictions by Warfarin Dosing Algorithms Based on Chinese and Western Patients

Warfarin has a long record of safe and effective clinical use, and it remains one of the most commonly prescribed drugs for the prevention and treatment of thromboembolic conditions even in the era of direct oral anticoagulants. To address its large interindividual variability and narrow therapeutic window, the Clinical Pharmacogenetics Implementation Consortium has recommended using pharmacogenetic dosing algorithms, such as the ones developed by the International Warfarin Pharmacogenetics Consortium (IWPC) and by Gage et al, to dose warfarin when genotype information is available. In China, dosing algorithms based on local patient populations have been developed and evaluated for predictive accuracy of warfarin maintenance doses. In this study, percentage deviations of doses predicted by 15 Chinese dosing algorithms from that by IWPC and Gage algorithms were systematically evaluated to understand the differences between Chinese and Western algorithms. In general, dose predictions by Chinese dosing algorithms tended to be lower than those predicted by IWPC or Gage algorithms for the most prevalent VKORC1 and CYP2C9 genotypes in the Chinese population. The extent of negative prediction deviation appeared to be largest in the younger age group with smaller body weight. Our findings are consistent with previous reports that Asians have a higher sensitivity to warfarin and require lower doses than Western populations.

Risk factors and new inflammatory indicators of deep vein thrombosis after adult patella fractures

OBJECTIVE

This study aimed to investigate the association between new inflammatory indicators at admission and the occurrence of preoperative deep vein thrombosis (DVT) in patients with patella fractures.

METHODS

A retrospective analysis of the medical records of patients aged 18 years or older who underwent surgical treatment for unilateral closed patella fractures at our hospital between August 2016 and August 2020. The incidence of preoperative DVT was detected by Duplex ultrasound (DUS). Partial blood routine and biochemical indexes were collected at admission, and the neutrophil-to-lymphocyte ratio (NLR), monocyte-to-lymphocyte ratio (MLR), and platelet-to-lymphocyte ratio (PLR) of inflammatory indexes were also calculated. ROC was used to analyze the cut-off value NLR, MLR, and PLR for predicting preoperative DVT, and univariate and multivariate analyses of the risk factors for preoperative DVT of patella fractures, and to verify whether other risk factors affecting the relationship between validation indexes and preoperative DVT.

RESULTS

A total of 500 patients were included, of which 39 patients (7.8%) developed preoperative DVT. After univariate and multivariate analysis, preoperative time (in each day delay), male (vs. female), D-dimer > 0.6 mg/L, total cholesterol (TC) > 5.6 mmol/L, and PLR > 189.8 were the risk factors for preoperative DVT in patients with patella fracture. Inflammation index PLR combined with the other four risk factors significantly improved the predictive efficacy of preoperative DVT compared with PLR (P = 0.009).

CONCLUSION

Inflammatory index PLR is a risk factor for preoperative DVT in patients with patella fracture, and the efficacy of PLR in predicting DVT can be significantly improved when other risk factors (male, D-dimer > 0.6 mg/L, TC > 5.6 mmol/L, and PLR > 189.8 of preoperative time in each day delay) are combined. These data are useful for the clinical identification of patients at high risk of preoperative DVT in patella fractures.

Management and Outcomes of Adults Diagnosed with Acute Pulmonary Embolism in Primary Care: Community-Based Retrospective Cohort Study

BACKGROUND

The management and outcomes of patients diagnosed with acute pulmonary embolism in primary care have not been characterized.

OBJECTIVE

To describe 30-day outcomes stratified by initial site-of-care decisions DESIGN: Multicenter retrospective cohort study PARTICIPANTS: Adults diagnosed with acute pulmonary embolism in primary care in a large, diverse community-based US health system (2013-2019) MAIN MEASURES: The primary outcome was a composite of 30-day serious adverse events (recurrent venous thromboembolism, major bleeding, and all-cause mortality). The secondary outcome was 7-day pulmonary embolism-related hospitalization, either initial or delayed.

KEY RESULTS

Among 652 patient encounters (from 646 patients), median age was 64 years; 51.5% were male and 70.7% identified as non-Hispanic white. Overall, 134 cases (20.6%) were sent home from primary care and 518 cases (79.4%) were initially referred to the emergency department (ED) or hospital. Among the referred, 196 (37.8%) were discharged home from the ED without events. Eight patients (1.2%; 95% CI 0.5-2.4%) experienced a 30-day serious adverse event: 4 venous thromboemboli (0.6%), 1 major bleed (0.2%), and 3 deaths (0.5%). Seven of these patients were initially hospitalized, and 1 had been sent home from primary care. All 3 deaths occurred in patients with known metastatic cancer initially referred to the ED, hospitalized, then enrolled in hospice following discharge. Overall, 328 patients (50.3%) were hospitalized within 7 days: 322 at the time of the index diagnosis and 6 following initial outpatient management (4 clinic-only and 2 clinic-plus-ED patients).

CONCLUSIONS

Patients diagnosed with acute pulmonary embolism in this primary care setting uncommonly experienced 30-day adverse events, regardless of initial site-of-care decisions. Over 20% were managed comprehensively by primary care. Delayed 7-day pulmonary embolism-related hospitalization was rare among the 51% treated as outpatients. Primary care management of acute pulmonary embolism appears to be safe and could have implications for cost-effectiveness and patient care experience.

A ten-year review of the impact of the transition from warfarin to direct oral anticoagulant - Has venous thromboembolism treatment become safer?

BACKGROUND

The introduction of direct oral anticoagulants (DOAC) has resulted in a paradigm shift in the management of venous thromboembolism (VTE). We evaluate the impact of the transition to DOAC, over the last decade, on overall VTE clinical outcomes including in first unprovoked major VTEs.

METHOD

A retrospective analysis of all VTE admissions in non-cancer patients from January 2011 to December 2020 at Northern Health, Victoria, Australia. "Warfarin era" included events that occurred between January 2011 and December 2014 and "DOAC era" from January 2016.

RESULTS

There were 2687 cases involving 2508 patients (45.9 % males; median age 63 years). 98 % were symptomatic and 1261 events (47 %) were unprovoked. 1003 events occurred during the warfarin era (79 % warfarin, 6 % DOAC) and 1479 during the DOAC era (18 % warfarin, 70 % DOAC). While recurrent thrombosis during the acute phase of treatment was comparable, there were fewer recurrences during the long-term preventative phase of treatment in the DOAC era compared to warfarin era (HR 0.602, 95 % CI: 0.393-0.924, p0.020). Clinically significant bleeding events were lower in the DOAC era (HR 0.623, 95 % CI: 0.395-0.985, p = 0.043). A subanalysis of first unprovoked major VTE events (n = 602) demonstrated a significant reduction in recurrent VTE during the long-term preventative phase of treatment in the DOAC era (HR 0.296, 95 % CI: 0.097-0.901, p = 0.032) with no difference in clinically significantly bleeding rates (HR 0.529, 95 % CI 0.219-1.280, p = 0.158) between the eras.

CONCLUSION

Treatment outcomes for VTE appear to have improved over time with reduced rate of thrombotic and clinically significant bleeding complications in the DOAC era.

IVIg-exposure and thromboembolic event risk: findings from the UK Biobank

BACKGROUND

Arterial and venous thromboembolic events (TEEs) have been associated with intravenous Ig use, but the risk has been poorly quantified. We aimed to calculate the risk of TEEs associated with exposure to intravenous Ig.

METHODS

We included participants from UK Biobank recruited over 3 years, data extracted September 2020.The study endpoints were incidence of myocardial infarction, other acute ischaemic heart disease, stroke, pulmonary embolism and other venous embolism and thrombosis.Predictors included known TEE risk factors: age, sex, hypertension, smoking status, type 2 diabetes mellitus, hypercholesterolaemia, cancer and past history of TEE. Intravenous Ig and six other predictors were added in the sensitivity analysis.Information from participants was collected prospectively, while data from linked resources, including death, cancer, hospital admissions and primary care records were collected retrospectively and prospectively.  FINDINGS: 14 794 of 502 492 individuals had an incident TEE during the study period. The rate of incident events was threefold higher in those with prior history of TEE (8 .7%) than those without previous history of TEE (3.0%).In the prior TEE category, intravenous Ig exposure was independently associated with increased risk of incident TEE (OR=3.69 (95% CI 1.15 to 11.92), p=0.03) on multivariate analysis. The number needed to harm by exposure to intravenous Ig in those with a history of TEE was 5.8 (95% CI 2.3 to 88.3).Intravenous Ig exposure did not increase risk of TEE in those with no previous history of TEE.

INTERPRETATION

Intravenous Ig is associated with increased risk of further TEE in individuals with prior history of an event with one further TEE for every six people exposed. In practice, this will influence how clinicians consent for and manage overall TEE risk on intravenous Ig exposure.

Prevention of venous thromboembolic events in patients with lower leg immobilization after trauma: Systematic review and network meta-analysis with meta-epsidemiological approach

BACKGROUND

Lower limb trauma requiring immobilization is a significant contributor to overall venous thromboembolism (VTE) burden. The clinical effectiveness of thromboprophylaxis for this indication and the optimal agent strategy are still a matter of debate. Our main objective was to assess the efficacy of pharmacological thromboprophylaxis to prevent VTE in patients with isolated temporary lower limb immobilization after trauma. We aimed to estimate and compare the clinical efficacy and the safety of the different thromboprophylactic treatments to determine the best strategy.

METHODS AND FINDINGS

We conducted a systematic review and a Bayesian network meta-analysis (NMA) including all available randomized trials comparing a pharmacological thromboprophylactic treatment to placebo or to no treatment in patients with leg immobilization after trauma. We searched Medline, Embase, and Web of Science until July 2021. Only RCT or observational studies with analysis of confounding factors including adult patients requiring temporary immobilization for an isolated lower limb injury treated conservatively or surgically and assessing pharmacological thromboprophylactic agents or placebo or no treatment were eligible for inclusion. The primary endpoint was the incidence of major VTE (proximal deep vein thrombosis, symptomatic VTE, and pulmonary embolism-related death). We extracted data according to Preferred Reporting Items for Systematic Reviews and Meta-analyses for NMA and appraised selected trials with the Cochrane review handbook. Fourteen studies were included (8,198 patients). Compared to the control group, rivaroxaban, fondaparinux, and low molecular weight heparins were associated with a significant risk reduction of major VTE with an odds ratio of 0.02 (95% credible interval (CrI) 0.00 to 0.19), 0.22 (95% CrI 0.06 to 0.65), and 0.32 (95% CrI 0.15 to 0.56), respectively. No increase of the major bleeding risk was observed with either treatment. Rivaroxaban has the highest likelihood of being ranked top in terms of efficacy and net clinical benefit. The main limitation is that the network had as many indirect comparisons as direct comparisons.

CONCLUSIONS

This NMA confirms the favorable benefit/risk ratio of thromboprophylaxis for patients with leg immobilization after trauma with the highest level of evidence for rivaroxaban.

TRIAL REGISTRATION

PROSPERO CRD42021257669.

Isolated distal DVT in trauma: A study of the management of isolated distal deep vein thrombosis acquired as an inpatient in trauma patients

BACKGROUND

Isolated distal deep vein thromboses (IDDVT) are common complications of trauma inpatient admission, however their management is controversial. We aimed to analyse outcomes in patients admitted to a level three tertiary referral centre who received therapeutic anticoagulation compared to those that did not. We hypothesised that therapeutic anticoagulation would be safe and effective in trauma inpatients who develop IDDVT.

METHODS

We performed a review of the electronic case notes of all patients with venous thromboembolism listed as a complication whilst admitted as an inpatient under the trauma unit at a tertiary institution over a 4-year period, from October 2014 to October 2018. Demographic data was collected, as well as data regarding management, major bleeding and progression of thrombosis to proximal DVT or PE.

RESULTS

91 IDDVT in trauma inpatients were identified. 33 patients received therapeutic anticoagulation within seven days of their diagnosis. No major bleeding was observed in this group, while one episode of thrombus progression was observed. 58 patients were not given therapeutic anticoagulation within seven days of IDDVT diagnosis. There were seven episodes of thrombus progression in this group on median day 5 post diagnosis, while no major bleeding was observed.

CONCLUSION

Only approximately 1/3rd of patients with IDDVT after trauma received therapeutic anticoagulation, and in these selected cases it appears safe. Those who did not receive therapeutic anticoagulation had a significant rate of thrombosis extension into the proximal system and pulmonary embolus. Further studies on correctly identifying who can be safely anticoagulated are required and for those who cannot be, these data show more aggressive surveillance and prophylaxis needs to be considered.

Predicting the risk of recurrent venous thromboembolism: Impact and therapeutic consequences of inherited thrombophilia

BACKGROUND

Over the past decades, thrombophilia testing in patients with venous thrombo-embolism has increased tremendously. However, the role of inherited thrombophilie in prediction the risk of recurrence remains controversial. Consequently, it is still unclear whether thrombophilia testing influences decisions regarding duration of anticoagulation in clinical practices. The aim of this study was to evaluate the impact if inherited thrombophilia on venous thrombosis treatment decisions and on predicting the risk of recurrence.

METHODS

A retrospective longitudinal study (January 2011-Decembre 2016) including 131 patients with confirmed venous thrombo-embolism referred to the hematology laboratory from the internal medicine department for inherited thrombophilia screening was carried out.

RESULTS

The mean age patients was 39.4 years and the sex ratio (M/F) was 0.61. Inherited thrombophilia was confirmed in 27.5% of patients. A long term anticoagulation was decided in 46.9% of patients with thrombophilia. There was no significant difference in the duration of anticoagulation between patients with or without thrombophilia. Thrombosis recurrence was recorded in 16 (17%) patients. The 24 years cumulative incidence of recurrence was 19% in patients with thrombophilia and 17% in those without (plog Rank= 0.6). Inherited thrombophilia was not associated with increased risk of recurrence after treatment withdrawal (Hazard ratio=1.31 IC (0.47-3.63); P=0.6).

CONCLUSION

In clinical practice, inherited thrombophilia did not influence anticoagulation duration and was not associated with a higher venous thrombosis risk of recurrence. It seems to be less relevant for decision making than presumed.

Developing a Nomogram-Based Scoring Tool to Estimate the Risk of Pulmonary Embolism

Background

Pulmonary embolisms (PEs) are clinically challenging because of their high morbidity and mortality. This study aimed to develop a scoring tool for predicting PEs to improve their clinical management.

Methods

Clinical, laboratory, and imaging parameters were retrospectively collected from suspected PE patients who had cough or chest pain and were hospitalized in West China Hospital of Sichuan University from May 2015 to April 2020. The final diagnosis of PE was defined based on findings from computed tomographic pulmonary angiography (CTPA). In this study, patients were randomly divided 2:1 into derivation and validation cohorts, which were used to create and validate, respectively, a nomogram. Model performance was estimated with the area under the receiver operating characteristic curve and a calibration curve.

Results

Our study incorporated data on more than 100 features from 1480 patients (811 non-PE, 669 PE). The nomogram was constructed using important predictive features including D-dimer, APTT, FDP, platelet count, sodium, albumin and cholesterol and achieved AUC values of 0.692 with the derivation cohort (95% CI 0.688–0.696, P < 0.01) and 0.688 with the validation cohort (95% CI 0.653–0.723, P < 0.01). The calibration curve showed good agreement between the probability predicted by the nomogram and the actual probability.

Conclusion

In this study, we successfully developed a nomogram that can predict the risk of PE, which can not only improve the clinical management of PE patients but also decrease unnecessary CTPA scans and their adverse effects.

Trends and risk factors for omission of early thromboprophylaxis in Australian and New Zealand ICUs between 2009 and 2020

Purpose

Venous thromboembolism (VTE) prophylaxis is effective in reducing VTE events; however, it is underutilized in critically ill patients. We examined trends and risk factors for omission of early thromboprophylaxis within the first 24 h after admission in Australian and New Zealand intensive care units (ICUs) between 2009 and 2020.

Methods

Retrospective analysis of data from the Australian New Zealand Intensive Care Society Adult Patient Database. Data were obtained for 1,465,020 adult admissions between 2009 and 2020. Mixed effects logistic regression modeling (accounting for the random effects of the contributing ICUs) was used to identify factors associated with omission of early thromboprophylaxis.

Results

A total of 107,486 (7.3%) ICU patients did not receive any form of thromboprophylaxis within the first 24 h after ICU admission without obvious reasons. Omission of early thromboprophylaxis declined from 13.7% in 2009 to 4% in 2020 (by 70.8%) (P < 0.001). Younger patients were more like to miss out on VTE prophylaxis (odds ratios (OR)_{per 10-year increase} 0.94, 95% CI 0.95–0.99). A documented process for monitoring VTE prophylaxis (ORs 0.90, 95% CI 0.87–0.93) and having a medical lead, dedicated for coordinating ICU quality (OR_{per 0.1 increase in full-time equivalent} 0.97, 95% CI 0.93–0.99), are associated with less omission of VTE prophylaxis.

Conclusion

Omission of thromboprophylaxis within the first 24 h after ICU admission has declined steadily over the past decade. Documented process for monitoring VTE prophylaxis and having a medical lead for coordinating quality of ICU care could be potential targets for sustaining the improvement in VTE prophylaxis use.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00134-022-06672-7.

Defying Occam's Razor: A Case of Pulmonary Embolism Masked By Cardiac Tamponade

BACKGROUND

Occam's razor instructs physicians to assume one single cause for multiple symptoms, whereas Hickam's dictum encourages them to suspect multiple concurrent pathologies. Although the general practice is to follow Occam's razor, occasionally Hickam's dictum reigns supreme. Here we present one such case, where the concurrent presence of two life-threatening pathologies posed clinical challenges in diagnosis and management.

CASE REPORT

Although cardiac tamponade and pulmonary embolism (PE) are known complications of malignancy, their concomitant existence is rare. Here we report a patient who presented with shortness of breath found to have both cardiac tamponade and submassive PE. Although the cardiac tamponade was initially diagnosed in the Emergency Department by bedside ultrasound and treated with pericardiocentesis, only a few hours later, when she deteriorated, the submassive PE was diagnosed, which was treated with heparin infusion and subsequently transitioned to a newer oral anticoagulant. The patient was later diagnosed as having primary breast cancer and metastatic lung adenocarcinoma. Why Should an Emergency Physician Be Aware of This? This raised unique diagnostic challenges, as both cardiac tamponade and PE present with obstructive shock. The increased right heart pressure from the PE could have paradoxically protected the patient from the tamponade effects of the pericardial effusion. Furthermore, the presence of cardiac tamponade may also mask the typical echocardiographic features of PE. The concurrent presence of two pathologies raised challenges and dilemmas in management. This case shows that physicians should maintain a high degree of suspicion of two pathologies when the patient deteriorates after the first pathology has been appropriately treated.

Investigating the Source of Fatal Pulmonary Thromboembolism in a Coronial Postmortem Population

ABSTRACT

The incidence of how often a deep vein thrombosis is found in the calves of the legs at coronial postmortem examination is unclear. This study retrospectively examined postmortem examination reports from Australian Coronial investigations of sudden death resulting from pulmonary thromboembolism to determine the likelihood of dissection of the deep veins of calves of the legs revealing the source of a pulmonary thromboembolism. From 450 cases taken from the National Coronial Information System (NCIS) for 2016, the postmortem reports of 327 cases were reviewed to provide demographic details of victims of sudden death from pulmonary thromboembolism. In 235 cases, it was possible to determine in 76.6% a thrombus had been found in the deep veins of the calves of the legs after dissection. In 141 cases, it was documented that both sides had been examined. From these, it was determined there was no statistically significant difference in the prevalence of thrombus in either side. However, it was shown that the presence of an abnormality of a lower limb (such as leg or hip infection, burns, surgery and nonoperated fractures, or a larger circumference) increased the likelihood that a deep vein thrombus would be found on that side.

Risk Factors for Post-Thrombotic Syndrome in Patients With a First Proximal Deep Venous Thrombosis Treated With Direct Oral Anticoagulants

The incidence of post-thrombotic syndrome (PTS) in patients with deep vein thrombosis (DVT) treated with direct oral anticoagulants (DOACs) remains a matter of debate. Hence, our endeavor to investigate a large cohort of patients with a first episode of proximal DVT treated with DOACs to ascertain the incidence and predisposing risk factors for PTS. All consecutive patients referred to the Thrombotic and Haemorrhagic Diseases Unit of Padova University Hospital (Italy) between January 2014 and January 2018 for a first episode of proximal DVT were considered for enrollment. Participants received DOACs for a minimum period of 3 months. PTS was assessed using the Villalta score up to 36 months after DVT diagnosis. Among 769 enrolled patients (M/F 353/416, age range 26–87 years), 152 (19.8%) developed PTS and 30 (3.9%) developed severe PTS. The adjusted hazard ratio was significant for obesity (1.64, 95% CI 1.28–2.39) and DVT site (femoral and/or iliac veins vs popliteal vein) (1.23, 95% CI 1.15–3.00). The incidence of PTS is not negligible in patients with proximal DVT despite the use of DOACs. We identified obesity and iliofemoral DVT as possible risk factors for PTS. Larger prospective studies are needed to confirm our findings and optimize therapeutic strategies.

Effect of a state hospital formulary on medicines utilisation in Australia

ObjectiveThe provision of medicines through state public hospitals is comparatively restrictive compared with the federally funded Pharmaceutical Benefits Scheme (PBS). Individual states are progressively moving towards statewide medicines formularies. Although a statewide formulary has existed in Queensland for some time. The effects of hospital formularies on medicines utilisation and policy in Australia has not been quantified. Thus, the aim of the present study was to quantify the effects of the Queensland Health List of Approved Medicines (LAM) on medicines utilisation in Queensland at a state and PBS-purchasing level and describe the implications for medicines policy.MethodsThis study used a quasi-experimental design with an interrupted time series (with control for PBS) examining utilisation effects of medicines within the therapeutic classes of proton pump inhibitors and non-vitamin K oral anticoagulants with LAM listing or delisting.ResultsThe LAM was demonstrated to be highly effective at controlling utilisation within Queensland Health purchasing. Effects on PBS utilisation were evident, resulting in increases in generic utilisation (where available) and associated reduced total costs both within Queensland Health and to the PBS. The full benefit is likely underestimated due to limitations in the PBS datasets.ConclusionThe LAM is a highly effective state medicines policy tool with demonstrable effects on PBS utilisation. With increased use of statewide medicines formularies, this will be an increasingly relevant aspect of Australia's overall medicines policy.What is known about the topic?State medicines policy is comparatively restrictive compared with the federal PBS. Most Australian states have, or are developing, statewide medicines formularies.What does this paper add?By examining several classes of medicines, a substantial quantitative effect of the Queensland state formulary on both state and PBS medicines utilisation can be demonstrated. Increased use of generic medicines and reduced costs are seen.What are the implications for practitioners?With increased use of state medicines formularies, state medicines formularies will become increasingly relevant to medicines policy makers and advocates at both the state and federal level.