Identifying unprovoked thromboembolism patients at low risk for recurrence who can discontinue anticoagulant therapy

Is Pulmonary Embolism a Chronic Disease?

Pulmonary embolism (PE) is often regarded as an acute disorder, yet emerging evidence underscores its chronic trajectory. Many survivors endure long-term complications, including recurrent thrombosis, persistent dyspnoea, and psychosocial challenges. These sequelae impair functional capacity and quality of life long after the initial event. To address these issues, we suggest that clinicians should adopt an integrated, multidisciplinary model that includes risk stratification for recurrence, structured follow-up, exercise rehabilitation, and support for psychological challenges. Recognising the potential chronic sequalae of PE ultimately fosters comprehensive care aimed at reducing morbidity and improving long-term outcomes for surviv.

Prediction of Recurrent Venous Thromboembolism and Arterial Cardiovascular Events after Discontinuation of Anticoagulation: The R-VTE-predict and MACE-predict Risk Scores

Patients who had venous thromboembolism (VTE) are not only at increased risk of recurrent VTE but also of major adverse cardiovascular events (MACEs) than the general population. Therefore, the prediction of the risk of these events is important for a tailored prevention and mitigation strategy. We aimed to develop simple scores to estimate recurrent VTE and MACE risks after the discontinuation of anticoagulation in a large cohort of individuals who suffered VTE (EDITH cohort). The primary endpoints were recurrent symptomatic VTE and MACE (composite of non-fatal acute coronary syndrome, stroke and cardiovascular death). Arterial thrombotic event (ATE) exclusively was also considered. Independent predictors of main outcomes were derived from multivariable Cox regression models. Weighted integer points based on the effect estimate of identified predictors were used to derive the final risk scores. A total of 1,999 participants (mean age: 54.78 years, 46.4% male, 43.6% unprovoked VTE) were included in the derivation cohort and 10,000 in the validation cohort (built using bootstrapping). During a median post-anticoagulation follow-up of 6.9 years, recurrent VTE occurred in 29.5% of participants and MACE in 14.8%. Independent predictors of recurrent VTE were male sex, age >65 years, cancer-associated VTE, and unprovoked VTE (vs. transient risk factor-associated VTE). Independent predictors of MACE were age >65 years, cancer-associated VTE, hypertension, renal insufficiency, and atrial fibrillation. The risk of recurrent VTE (moderate vs. low: hazard ratio [HR]: 2.62, 95% confidence interval [CI]: 2.06-3.34; high vs. low: HR: 3.78, 95% CI: 2.91-4.89), MACE (moderate vs. low: HR: 6.37, 95% CI: 3.19-12.69; high vs. low: HR: 12.32, 95% CI: 6.09-24.89), and ATE (based on MACE-predict risk score) increased gradually from the lowest to highest of the respective prediction risk score groups. These results were confirmed in the validation cohort with overall reasonable models' discrimination performance (recurrent VTE C-statistic: 0.62-0.63, MACE and ATE C-statistic: 0.72-0.77). Contemporary simple risk scores based on readily available clinical characteristics can reasonably predict the risk of recurrent VTE and MACE after the discontinuation of anticoagulation. These findings may influence the choice of anticoagulation strategy after the acute phase of VTE and, therefore, need confirmation by further studies.

Sex-specific DNA methylation marks associated with sex-biased risk of recurrence in unprovoked venous thromboembolism

BACKGROUND

Whether to stop oral anticoagulants after a first unprovoked venous thromboembolism (VTE) is challenging, partially due to an intriguingly higher risk of VTE recurrence (rVTE) in men after therapy discontinuation. DNA methylation (DNAm) differences between men and women might underlie this sex-biased rVTE risk difference.

OBJECTIVES

To investigate sex-specific associations between DNAm at cytosine-phosphate-guanine (CpG) sites and rVTE.

METHODS

In 417 unprovoked VTE patients, including 101 experiencing recurrences over a 5-year follow-up (REcurrent VEnous thromboembolism Risk Stratification Evaluation [REVERSE] I), we analyzed blood DNAm using the Illumina EPIC array and performed a sex-stratified epigenome-wide association study. We further examined 181 major provoked VTE patients, including 36 recurrences over a 14-year follow-up (the MARseille THrombosis Association [MARTHA]), to investigate whether DNAm is a risk factor for rVTE after anticoagulation therapy.

RESULTS

Hypomethylated CpGs at genes TBC1D22B-cg01060850 and ZHX2-cg07808424 in men and DIP2B-ch.12.1038646R and DENND3-cg03401656 in women were associated with rVTE at genome-wide level (P < 7x10-8). Though not statistically significant, DENND3-cg03401656 had the same direction of effect in MARTHA women. Sensitivity analysis confirmed the robustness of the estimates, including potential confounders, adaptations of the Cox model, non-Europeans, and proximal methylation quantitative trait loci in the association. The associated CpGs were situated at genes for membrane trafficking, corroborating the participation of Rab regulatory proteins in rVTE and transcription factors.

CONCLUSION

We identified DNAm marks as potential risk factors for sex-biased recurrence in unprovoked VTE. Further replication and experimental validation could refine our understanding of the regulation of the identified DNAm sites and help optimize personalized decision-making for long-term anticoagulation after a first VTE.

Role of Artificial Intelligence in the Diagnosis and Management of Pulmonary Embolism: A Comprehensive Review

Pulmonary embolism (PE) remains a critical condition with significant mortality and morbidity, necessitating timely detection and intervention to improve patient outcomes. This review examines the evolving role of artificial intelligence (AI) in PE management. Two primary AI-driven models that are currently being explored are deep convolutional neural networks (DCNNs) for enhanced image-based detection and natural language processing (NLP) for improved risk stratification using electronic health records. A major advancement in this field was the FDA approval of the Aidoc© AI model, which has demonstrated high specificity and negative predictive value in PE diagnosis from imaging scans. Additionally, AI is being explored for optimizing anticoagulation strategies and predicting PE recurrence risk. While further large-scale studies are needed to fully establish AI's role in clinical practice, its integration holds significant potential to enhance diagnostic accuracy and overall patient management.

Obesity and cardiovascular disease: an ESC clinical consensus statement

The global prevalence of obesity has more than doubled over the past four decades, currently affecting more than a billion individuals. Beyond its recognition as a high-risk condition that is causally linked to many chronic illnesses, obesity has been declared a disease per se that results in impaired quality of life and reduced life expectancy. Notably, two-thirds of obesity-related excess mortality is attributable to cardiovascular disease. Despite the increasingly appreciated link between obesity and a broad range of cardiovascular disease manifestations including atherosclerotic disease, heart failure, thromboembolic disease, arrhythmias, and sudden cardiac death, obesity has been underrecognized and sub-optimally addressed compared with other modifiable cardiovascular risk factors. In the view of major repercussions of the obesity epidemic on public health, attention has focused on population-based and personalized approaches to prevent excess weight gain and maintain a healthy body weight from early childhood and throughout adult life, as well as on comprehensive weight loss interventions for persons with established obesity. This clinical consensus statement by the European Society of Cardiology discusses current evidence on the epidemiology and aetiology of obesity; the interplay between obesity, cardiovascular risk factors and cardiac conditions; the clinical management of patients with cardiac disease and obesity; and weight loss strategies including lifestyle changes, interventional procedures, and anti-obesity medications with particular focus on their impact on cardiometabolic risk and cardiac outcomes. The document aims to raise awareness on obesity as a major risk factor and provide guidance for implementing evidence-based practices for its prevention and optimal management within the context of primary and secondary cardiovascular disease prevention.

Fibrinogen genotypes and their impact on recurrence of venous thromboembolism and family history: A prospective population-based study

Venous thromboembolism (VTE) involves blood clot formation in veins, resulting in serious health issues. Fibrinogen, a crucial clotting protein, consists of three polypeptides encoded by the fibrinogen genes: alpha (FGA), beta (FGB) and gamma (FGG). We genotyped most common missense variants in the fibrinogen genes in relation to VTE, recurrence and family history in Malmö Thrombophilia Study, including 1465 VTE patients followed for ~10 years and 429 healthy donors. FGG (rs6063) was significantly associated with increased odds of primary VTE (odds ratio [OR] = 8.2; 95% confidence interval [CI] = 1.05-63.6) after adjusting for age and sex. For recurrent VTE, Cox-regression analysis indicated a higher risk associated with FGA (rs6050) (hazard ratio [HR] = 1.8; 95% CI = 1.1-2.8), with even greater risk for unprovoked recurrent VTE (HR = 2.3; 95% CI = 1.3-4.2), surpassing the well-known factor V Leiden (FVL) (HR = 1.9; 95% CI = 1.2-3.0). Combining risk alleles from FVL and FGA (rs6050) significantly raised the risk for unprovoked recurrent VTE: ≥3 risk alleles (HR = 4.6; 95% CI = 1.9-11.3), two risk alleles (HR = 2.6; 95% CI = 1.4-4.8) and one risk allele (HR = 1.5; 95% CI = 0.8-2.7) compared to 0 risk allele. Prevalence of FGA (rs6050) risk allele was significantly higher in cases with a family history of VTE. We propose FGA (rs6050) as a novel predictor for unprovoked recurrent VTE and it may contribute to the familial occurrence of VTE.

Exploration of the plasma proteomic profile of patients at risk of thromboembolic events

Background

The elevated health burden of thromboembolic events necessitates development of blood-based risk monitoring tools.

Objectives

We explored the potential of mass spectrometry-based plasma proteomics to provide insights into underlying plasma protein signatures associated with treatment and occurrence of thromboembolic events.

Methods

Utilizing a high-throughput, data-independent acquisition, discovery-based proteomics workflow, we analyzed 434 plasma proteomes from different groups of individuals with elevated risk of thromboembolic events, including individuals I) on vitamin K antagonists (VKAs; n = 130), II) with a prior venous thromboembolism (n = 10), III) with acute cerebral venous sinus thrombosis (n = 10, and IV) with SARS-CoV-2 infection (n = 67). Plasma protein levels measured with mass spectrometry were correlated with international normalized ratio and conventional clinical laboratory measurements. Plasma profile differences between different groups were assessed using principal component analysis, moderated t-test, and clustering analysis.

Results

Plasma protein levels were in agreement with conventional clinical laboratory parameters, including albumin and fibrinogen. Levels of vitamin K-dependent proteins inversely correlated with international normalized ratio. In the individual studies, we found decreased levels of vitamin K-dependent coagulation proteins in patients on VKAs, alterations in inflammatory signatures among CVST patients and a distinctive signature indicative of SARS-CoV-2 infection. However, no protein signature associated with a thromboembolic event could be identified neither in individual nor combined studies.

Conclusion

Although VKA treatment-specific and disease-specific signatures were captured, our study highlights that the challenges of discovering biomarkers in patients at risk of thromboembolic events lie in the heterogeneity of individual plasma profiles in relation to treatment and etiology.

Management of patients with venous thromboembolism and a high recurrence risk estimated by the Vienna Prediction Model: a prospective cohort study

Background

The Vienna Prediction Model (VPM) identifies patients with a first unprovoked deep vein thrombosis of the leg and/or pulmonary embolism who have a low recurrence risk and may, therefore, not benefit from extended-phase anticoagulation.

Objectives

The aim of this study was to evaluate patients with a predicted high risk of recurrent venous thromboembolism (VTE).

Methods and Results

We prospectively followed 266 patients in whom the VPM had predicted a recurrence risk of more than 5.5% at 1 year for a median of 13.5 months. Their median age was 56 years, and 96% were men. After the VPM risk assessment, 196 patients restarted anticoagulation. While on anticoagulation, none of the patients experienced recurrent VTE, whereas 4 patients had nonmajor clinically relevant bleeding (absolute bleeding rate, 1.8 [95% CI, 0.5-4.5] events per 100 patient-years). Seventy patients were left untreated after VPM risk assessment for various reasons. Among patients not using anticoagulation, 15 had recurrence (absolute recurrence rate, 18.1 [95% CI, 10.1, 29.9] events per 100 person-years). According to the extended Kaplan-Meier analysis, the probability of VTE recurrence in patients not on anticoagulation was 10.1% and 17.9% at 6 and 12 months after VPM risk assessment, respectively.

Conclusion

Anticoagulant therapy is effective and safe in patients with an unprovoked VTE, in whom the VPM had predicted a high risk of recurrent VTE. If these patients are left untreated, the risk of recurrence is high.

Assessment of Hypercoagulability in Splanchnic Vein Thrombosis by Measurement of the Hemostasis Enzymes Thrombin and Activated Protein C

Splanchnic vein thrombosis (SVT), which is particularly prevalent in myeloproliferative neoplasms (MPNs), has a multifactorial pathomechanism involving the anticoagulant protein C (PC) pathway. To better characterize the hypercoagulable state in SVT we assessed its key enzymes thrombin and activated PC (APC). The study population included 73 patients with SVT, thereof 36 MPN+, confirmed by bone marrow biopsy, 37 MPN-, and 30 healthy controls. Direct measurement of the active enzyme forms of thrombin and APC in the circulation was achieved by using oligonucleotide-based enzyme capture assays (OECA). Additionally, activation markers of coagulation and fibrinolysis were measured. Plasma levels of free thrombin and APC were higher in the MPN+ than in the MPN- cohort, with 0.49 vs. <0.46 pmol/L (p = 0.0057), respectively, 1.23 vs. 0.58 pmol/L (p = 0.0122), and in healthy controls (vs. <0.46 pmol/L, p = 0.0012; vs. 0.54 pmol/L, p = 0.0035). The indirect activation markers prothrombin fragment 1+2, thrombin-antithrombin complex, and D-dimer did not differ between groups. Receiver operating characteristic analysis suggested that SVT patients with MPN can be better distinguished by APC than by conventional indirect thrombin markers. A potential application of these biomarkers to guide anticoagulant therapy and to investigate the role of the PC pathway in MPN-associated hypercoagulability should be further studied.

Genomic Landscape of Thrombosis Recurrence Risk Across Venous Thromboembolism Subtypes

Venous thromboembolism (VT) is a frequent (annual incidence of 1 to 2 per 1,000) and potentially life-threatening (case-fatality rate up to 10%) disease. VT is associated with serious short-term and long-term complications including a recurrence rate of approximately 20% within five years. Anticoagulant therapy, the mainstay of VT treatment, drastically reduces the risk of early VT recurrence, but it exposes patients to a substantial risk of bleeding. We analysed the genomic architecture of VT recurrence using data from 6,571 patients across eight cohorts, 1,816 of whom experienced recurrence, with a particular focus on the clinical manifestation of the type of first VT event. Through genome-wide association studies (GWAS), we identified three loci significantly associated (P<5×10-8) with VT recurrence in the general VT population: GPR149/MME, L3MBTL4, and THSD7B. Protein Quantitative Trait Locus and Mendelian Randomization analyses further identified elevated plasma levels of coagulation factor XI and GOLM2 as risk factors for recurrence, while decreased levels of PCSK9 and pro-IL16 were linked to reduced VT recurrence risk. Subgroup analyses revealed 18 loci associated with VT recurrence, with notable differences between pulmonary embolism (PE) and deep vein thrombosis (DVT). For example, the exonic variant SLC4A1 p.Glu40Lys was significantly associated with recurrence in PE patients (Hazard Ratio (HR)=3.23, P=9.7×10-12) but showed no effect in DVT (HR=1.00, P=0.98). These findings emphasize the role of specific genetic loci and protein pathways in influencing VT recurrence and provide valuable insights into potential therapeutic targets. Further research is needed to clarify the biological mechanisms driving these associations.

Long-term monitoring and treatment of venous thromboembolic disease: recommendations of the Thromboembolic Disease Group of the Spanish Society of Internal Medicine 2024

Venous thromboembolim (VTE) is a highly prevalent condition that requires long-term monitoring and treatment. This monitoring includes: 1) completing the etiological study and determining the risk of VTE recurrence; 2) establishing the optimal duration of anticoagulant treatment, as well as the type of therapy and its dosage; 3) estimating the risk of bleeding, and 4) identifying the occurrence of chronic complications. This consensus document, prepared by the VTE Group of the Spanish Society of Internal Medicine (SEMI), aims to update and establish consensus recommendations on these aspects. The document focuses on four aspects of management: the first includes risk factors for VTE recurrence after an unprovoked VTE episode and describes the predictive scores of VTE recurrence; the second focuses on risk factors for bleeding; the third provides recommendations for long-term follow-up in VTE, addressing specific considerations for screening chronic thromboembolic pulmonary hypertension and post-thrombotic syndrome of the lower limbs; and the fourth provides guidance on the optimal duration of extended anticoagulant treatment, as well as the type of therapy and its dosage. For each area, an exhaustive literature review was conducted, analyzing the updated VTE clinical guidelines and recent studies. This document is intended to be a guide in the long-term management of VTE based on the most current knowledge.

Obesity and cardiovascular disease: an ESC clinical consensus statement

The global prevalence of obesity has more than doubled over the past four decades, currently affecting more than a billion individuals. Beyond its recognition as a high-risk condition that is causally linked to many chronic illnesses, obesity has been declared a disease per se that results in impaired quality of life and reduced life expectancy. Notably, two-thirds of obesity-related excess mortality is attributable to cardiovascular disease. Despite the increasingly appreciated link between obesity and a broad range of cardiovascular disease manifestations including atherosclerotic disease, heart failure, thromboembolic disease, arrhythmias, and sudden cardiac death, obesity has been underrecognized and sub-optimally addressed compared with other modifiable cardiovascular risk factors. In the view of major repercussions of the obesity epidemic on public health, attention has focused on population-based and personalized approaches to prevent excess weight gain and maintain a healthy body weight from early childhood and throughout adult life, as well as on comprehensive weight loss interventions for persons with established obesity. This clinical consensus statement by the European Society of Cardiology discusses current evidence on the epidemiology and aetiology of obesity; the interplay between obesity, cardiovascular risk factors and cardiac conditions; the clinical management of patients with cardiac disease and obesity; and weight loss strategies including lifestyle changes, interventional procedures, and anti-obesity medications with particular focus on their impact on cardiometabolic risk and cardiac outcomes. The document aims to raise awareness on obesity as a major risk factor and provide guidance for implementing evidence-based practices for its prevention and optimal management within the context of primary and secondary cardiovascular disease prevention.

Standardized Data Elements for Patients With Acute Pulmonary Embolism: A Consensus Report From the Pulmonary Embolism Research Collaborative

Recent advances in therapy and the promulgation of multidisciplinary pulmonary embolism teams show great promise to improve management and outcomes of acute pulmonary embolism (PE). However, the absence of randomized evidence and lack of consensus leads to tremendous variations in treatment and compromises the wide implementation of new innovations. Moreover, the changing landscape of health care, where quality, cost, and accountability are increasingly relevant, dictates that a broad spectrum of outcomes of care must be routinely monitored to fully capture the impact of modern PE treatment. We set out to standardize data collection in patients with PE undergoing evaluation and treatment, and thus establish the foundation for an expanding evidence base that will address gaps in evidence and inform future care for acute PE. To do so, >100 international PE thought leaders convened in Washington, DC, in April 2022 to form the Pulmonary Embolism Research Collaborative. Participants included physician experts, key members of the US Food and Drug Administration, patient representatives, and industry leaders. Recognizing the multidisciplinary nature of PE care, the Pulmonary Embolism Research Collaborative was created with representative experts from stakeholder medical subspecialties, including cardiology, pulmonology, vascular medicine, critical care, hematology, cardiac surgery, emergency medicine, hospital medicine, and pharmacology. A list of critical evidence gaps was composed with a matching comprehensive set of standardized data elements; these data points will provide a foundation for productive research, knowledge enhancement, and advancement of clinical care within the field of acute PE, and contribute to answering urgent unmet needs in PE management. Evidence produced through the Pulmonary Embolism Research Collaborative, as it is applied to data collection, promises to provide crucial knowledge that will ultimately produce a robust evidence base that will lead to standardization and harmonization of PE management and improved outcomes.

Identification of severely injured children at very low risk of emergent surgery: A national trauma registry study

OBJECTIVE

The number of pediatric trauma patients requiring surgical interventions has been steadily decreasing allowing for a judicious approach to immediately available resources. This study aimed to derive and validate a prediction rule that reliably identifies injured children who are at very low risk for requiring emergency surgery upon emergency department (ED) arrival.

METHODS

A retrospective cohort study of data included in the Israeli National Trauma Registry from January 1, 2011, through December 31, 2020, was conducted. We included children aged 0-14 years who presented to EDs from the scene of injury and were hospitalized. We excluded patients transferred between facilities or with isolated burns. The primary outcome was emergency operative intervention (EOI) performed within one hour of ED arrival. We tested mechanism, GCS, heart rate, and blood pressure as candidate predictors. We then randomized patients to two cohorts, derived and internally validated a prediction rule.

RESULTS

During the study period, 83,859 children met enrollment criteria. The median age was 6 years (IQR 2-10) and 56,867 (67.8 %) were male; 75,450 (90.0 %) sustained blunt trauma. One hundred sixty-nine (0.20 %) children underwent EOI. In the derivation and validation cohorts, 34,138 (81.4 %) and 34,271 (81.7 %) patients, were classified as low risk based on blunt trauma mechanism, normal GCS (15), and low-risk heart rate (according to age). Of those, 8 (0.02 %) and 13 (0.04 %) required an EOI, respectively. In the validation cohort, the prediction rule for EOI had a sensitivity of 84 % (95 % CI 75-91), a specificity of 82 % (95 % CI 81-82), and a negative predictive value of 99.96 % (95 % CI 99.94-99.98). Among children with an Injury Severity Score>15, the sensitivity was 87 % (95 % CI 77-94), the specificity of 57 % (95 % CI 54-59), and the negative predictive value was 98.97 % (95 % CI 98.13-99.44).

CONCLUSIONS

A limited set of physiologic parameters, readily available at hospital admission can effectively identify injured children at very low risk for emergent surgery. For these children, immediate deployment of surgical resources may not be necessary.

Anticoagulation and compression therapy for proximal acute deep vein thrombosis

The treatment of proximal deep vein thrombosis (DVT) of the lower limbs includes an initial management phase, covering the first 1 to 3 weeks, a primary treatment phase, lasting a minimum of 3 months, and a secondary treatment phase for those patients requiring continuing anticoagulation beyond the first 3 to 6 months. During the initial phase most patients with DVT can be managed as outpatients. Exclusion criteria for home treatment include high risk of bleeding, limb threatening DVT or other conditions requiring hospitalisation. Anticoagulant drugs represent the mainstay of treatment and include parenteral drugs such as unfractionated heparin or low molecular weight heparin, and oral drugs such as the vitamin K antagonists and the direct oral anticoagulants (DOACs). DOACs are currently recommended as the first line of treatment for proximal DVT of the lower limbs, with no preference for one DOAC over another. Factors to consider when choosing the anticoagulant strategy include, among others, renal and liver function, underlying diseases such as cancer or the antiphospholipid syndrome, and patient preferences. Indefinite duration of anticoagulation beyond the first 3 to 6 months is recommended for patients with unprovoked DVT and patients with permanent, chronic risk factors. Two DOACs, namely apixaban and rivaroxaban, can be administered at low doses for the secondary prevention of DVT. Elastic compression stockings (ECS) have been used for decades in patients with proximal DVT with the aim of counteracting the venous hypertension generated by the vascular disorder and reducing leg edema and to prevent the post-thrombotic syndrome.

Clinical outcomes after discontinuing anticoagulant therapy in patients with first unprovoked venous thromboembolism

BACKGROUND

The duration of anticoagulation for a first episode of unprovoked venous thromboembolism (VTE) should balance the likelihood of VTE recurrence against the risk of major bleeding.

OBJECTIVES

Analyze rates and case-fatality rates (CFRs) of recurrent VTE and major bleeding after discontinuing anticoagulation in patients with a first unprovoked VTE after at least 3 months of anticoagulation.

METHODS

We compared the rates and CFRs in patients of the Registro Informatizado Enfermedad Trombo Embólica (RIETE) and Contemporary management and outcomes in patients with venous thromboembolism registries. We used logistic regression models to identify predictors for recurrent pulmonary embolism (PE) and major bleeding.

RESULTS

Of 8261 patients with unprovoked VTE in RIETE registry, 4012 (48.6%) had isolated deep vein thrombosis (DVT) and 4250 had PE. Follow-up (median, 318 days) showed 543 recurrent DVTs, 540 recurrent PEs, 71 major bleeding episodes, and 447 deaths. The Contemporary management and outcomes in patients with venous thromboembolism registry yielded similar results. Corresponding CFRs of recurrent DVT, PE, and major bleeding were 0.4%, 4.6%, and 24%, respectively. On multivariable analyses, initial PE presentation (hazard ratio [HR], 3.03; 95% CI, 2.49-3.69), dementia (HR, 1.47; 95% CI, 1.01-2.13), and anemia (HR, 0.72; 95% CI, 0.57-0.91) predicted recurrent PE, whereas older age (HR, 2.11; 95% CI, 1.15-3.87), inflammatory bowel disease (HR, 4.39; 95% CI, 1.00-19.3), and anemia (HR, 2.24; 95% CI, 1.35-3.73) predicted major bleeding. Prognostic scores were formulated, with C statistics of 0.63 for recurrent PE and 0.69 for major bleeding.

CONCLUSION

Recurrent DVT and PE were frequent but had low CFRs (0.4% and 4.6%, respectively) after discontinuing anticoagulation. On the contrary, major bleeding was rare but had high CFR (24%). A few clinical factors may predict these outcomes.

[Translation into French and republication of: "Management of cancer-associated thromboembolism in vulnerable population"]

Although all patients with cancer-associated thrombosis (CAT) have a high morbidity and mortality risk, certain groups of patients are particularly vulnerable. This may expose the patient to an increased risk of thrombotic recurrence or bleeding (or both), as the benefit-risk ratio of anticoagulant treatment may be modified. Treatment thus needs to be chosen with care. Such vulnerable groups include older patients, patients with renal impairment or thrombocytopenia, and underweight and obese patients. However, these patient groups are poorly represented in clinical trials, limiting the available data on which treatment decisions can be based. Meta-analysis of data from randomised clinical trials suggests that the relative treatment effect of direct oral factor Xa inhibitors (DXIs) and low molecular weight heparin (LMWH) with respect to major bleeding could be affected by advanced age. No evidence was obtained for a change in the relative risk-benefit profile of DXIs compared to LMWH in patients with renal impairment or of low body weight. The available, albeit limited, data do not support restricting the use of DXIs in patients with TAC on the basis of renal impairment or low body weight. In older patients, age is not itself a critical factor for choice of treatment, but frailty is such a factor. Patients over 70 years of age with CAT should undergo a systematic frailty evaluation before choosing treatment and modifiable bleeding risk factors should be addressed. In patients with renal impairment, creatine clearance should be assessed and monitored regularly thereafter. In patients with an eGFR less than 30mL/min/1.72m2, the anticoagulant treatment may need to be adapted. Similarly, platelet count should be assessed prior to treatment and monitored regularly. In patients with grade 3-4, thrombocytopenia (less than 50,000platelets/μL) treatment with a LMWH at a reduced dose should be considered. For patients with CAT and low body weight, standard anticoagulant treatment recommendations are appropriate, whereas in obese patients, apixaban may be preferred.

D-dimer and risk of venous thromboembolism recurrence: Comparison of two studies with similar designs but different laboratory and clinical results

BACKGROUND

D-dimer testing may help deciding the duration of anticoagulation in subjects at high risk of venous thromboembolism (VTE) recurrence. Two management studies on this issue have been published (DULCIS in 2014 and APIDULCIS in 2022). They had similar designs but had important different results. Aim of this article is to compare their results.

METHODS

Both studies were finalized to extend anticoagulation [with vitamin K anticoagulants (VKAs) in DULCIS or apixaban 2.5 mg BID (kindly provided by BMS-Pfizer Collaboration) in APIDULCIS] only in patients with positive D-dimer results.

RESULTS

More D-dimer assays resulted positive in APIDULCIS than in DULCIS (61.1 % vs 47.7 %, respectively; p < 0.0001). While only 4 (0.5 %) refused low dose apixaban in APIDULCIS, the 22.6 % of patients with positive D-dimer refused to resume VKAs in DULCIS; their rates of recurrence were 187 and 8.8 per 100 person-years, respectively (incidence rate ratio [IRR]: 21.2). The incidence of bleeding was low in those receiving apixaban vs those who resumed VKAs (0.4 vs 2.3 per 100 person-years, respectively; IRR 0.17;). While the recurrence rate was low and similar in the studies in subjects who resumed anticoagulation, it was significantly higher in APIDULCIS than in DULCIS in those who stopped anticoagulation for negative D-dimer (5.6 vs 3.0 per 100 person-years, respectively; IRR 1.9).

CONCLUSION

The low dose Apixaban for extended VTE treatment is effective and safe, and well accepted by patients. Why subjects who stopped anticoagulation for negative D-dimer had a higher recurrence rate in APIDULCIS than in DULCIS remains to be explained.

Tutorial: dos and don'ts in clinical prediction research for venous thromboembolism

Clinical prediction modeling has become an increasingly popular domain of venous thromboembolism research in recent years. Prediction models can help healthcare providers make decisions regarding starting or withholding therapeutic interventions, or referrals for further diagnostic workup, and can form a basis for risk stratification in clinical trials. The aim of the current guide is to assist in the practical application of complicated methodological requirements for well-performed prediction research by presenting key dos and don'ts while expanding the understanding of predictive research in general for (clinical) researchers who are not specifically trained in the topic; throughout we will use prognostic venous thromboembolism scores as an exemplar.

Tailored anticoagulant treatment after a first venous thromboembolism: protocol of the Leiden Thrombosis Recurrence Risk Prevention (L-TRRiP) study - cohort-based randomised controlled trial

INTRODUCTION

Patients with a first venous thromboembolism (VTE) are at risk of recurrence. Recurrent VTE (rVTE) can be prevented by extended anticoagulant therapy, but this comes at the cost of an increased risk of bleeding. It is still uncertain whether patients with an intermediate recurrence risk or with a high recurrence and high bleeding risk will benefit from extended anticoagulant treatment, and whether a strategy where anticoagulant duration is tailored on the predicted risks of rVTE and bleeding can improve outcomes. The aim of the Leiden Thrombosis Recurrence Risk Prevention (L-TRRiP) study is to evaluate the outcomes of tailored duration of long-term anticoagulant treatment based on individualised assessment of rVTE and major bleeding risks.

METHODS AND ANALYSIS

The L-TRRiP study is a multicentre, open-label, cohort-based, randomised controlled trial, including patients with a first VTE. We classify the risk of rVTE and major bleeding using the L-TRRiP and VTE-BLEED scores, respectively. After 3 months of anticoagulant therapy, patients with a low rVTE risk will discontinue anticoagulant treatment, patients with a high rVTE and low bleeding risk will continue anticoagulant treatment, whereas all other patients will be randomised to continue or discontinue anticoagulant treatment. All patients will be followed up for at least 2 years. Inclusion will continue until the randomised group consists of 608 patients; we estimate to include 1600 patients in total. The primary outcome is the combined incidence of rVTE and major bleeding in the randomised group after 2 years of follow-up. Secondary outcomes include the incidence of rVTE and major bleeding, functional outcomes, quality of life and cost-effectiveness in all patients.

ETHICS AND DISSEMINATION

The protocol was approved by the Medical Research Ethics Committee Leiden-Den Haag-Delft. Results are expected in 2028 and will be disseminated through peer-reviewed journals and during (inter)national conferences.

TRIAL REGISTRATION NUMBER

NCT06087952.

Choice and Duration of Anticoagulation for Venous Thromboembolism

Venous thromboembolism (VTE) is a prevalent medical condition with high morbidity, mortality, and associated costs. Anticoagulation remains the main treatment for VTE, though the decision on when, how, and for how long to administer anticoagulants is increasingly complex. This review highlights the different phases of VTE management, with special circumstances for consideration such as antiphospholipid syndrome, coronary artery disease, cancer-associated thrombus, COVID-19, and future anticoagulation options. Anticoagulation management will continue to be a complex decision, applying evidence-based medicine to individual patients with the hope of maximizing effectiveness while minimizing risks.

Obesity as a Predictor for Pulmonary Embolism and Performance of the Age-Adjusted D-Dimer Strategy in Obese Patients with Suspected Pulmonary Embolism

INTRODUCTION

 Obesity is a risk factor for venous thromboembolism, but studies evaluating its association with pulmonary embolism (PE) in patients with suspected PE are lacking.

OBJECTIVES

 To evaluate whether body mass index (BMI) and obesity (i.e., BMI ≥30 kg/m2) are associated with confirmed PE in patients with suspected PE and to assess the efficiency and safety of the age-adjusted D-dimer strategy in obese patients.

METHODS

 We conducted a secondary analysis of a multinational, prospective study, in which patients with suspected PE were managed according to the age-adjusted D-dimer strategy and followed for 3 months. Outcomes were objectively confirmed PE at initial presentation, and efficiency and failure rate of the diagnostic strategy. Associations between BMI and obesity, and PE were examined using a log-binomial model that was adjusted for clinical probability and hypoxia.

RESULTS

 We included 1,593 patients (median age: 59 years; 56% women; 22% obese). BMI and obesity were not associated with confirmed PE. The use of the age-adjusted instead of the conventional D-dimer cut-off increased the proportion of obese patients in whom PE was considered ruled out without imaging from 28 to 38%. The 3-month failure rate in obese patients who were left untreated based on a negative age-adjusted D-dimer cut-off test was 0.0% (95% confidence interval: 0.0-2.9%).

CONCLUSION

 BMI on a continuous linear scale and obesity were not predictors of confirmed PE among patients presenting with a clinical suspicion of PE. The age-adjusted D-dimer strategy appeared safe in ruling out PE in obese patients with suspected PE.

Management of cancer-associated thromboembolism in vulnerable population

Although all patients with cancer-associated thrombosis (CAT) have a high morbidity and mortality risk, certain groups of patients are particularly vulnerable. This may expose the patient to an increased risk of thrombotic recurrence or bleeding (or both), as the benefit-risk ratio of anticoagulant treatment may be modified. Treatment thus needs to be chosen with care. Such vulnerable groups include older patients, patients with renal impairment or thrombocytopenia, and underweight and obese patients. However, these patient groups are poorly represented in clinical trials, limiting the available data, on which treatment decisions can be based. Meta-analysis of data from randomised clinical trials suggests that the relative treatment effect of direct oral factor Xa inhibitors (DXIs) and low molecular weight heparin (LMWH) with respect to major bleeding could be affected by advanced age. No evidence was obtained for a change in the relative risk-benefit profile of DXIs compared to LMWH in patients with renal impairment or of low body weight. The available, albeit limited, data do not support restricting the use of DXIs in patients with CAT on the basis of renal impairment or low body weight. In older patients, age is not itself a critical factor for choice of treatment, but frailty is such a factor. Patients over 70 years of age with CAT should undergo a systematic frailty evaluation before choosing treatment and modifiable bleeding risk factors should be addressed. In patients with renal impairment, creatine clearance should be assessed and monitored regularly thereafter. In patients with an eGFR<30mL/min/1.72m2, the anticoagulant treatment may need to be adapted. Similarly, platelet count should be assessed prior to treatment and monitored regularly. In patients with grade 3-4, thrombocytopenia (<50,000 platelets/μL) treatment with a LMWH at a reduced dose should be considered. For patients with CAT and low body weight, standard anticoagulant treatment recommendations are appropriate, whereas in obese patients, apixaban may be preferred.

D-dimer diagnostics: can I use any D-dimer assay? Bridging the knowledge-to-action gap

A State of the Art lecture titled "D-dimer Diagnostics: Can I use any D-dimer assay? Bridging the Knowledge-to-Action gap" was presented at the International Society on Thrombosis and Haemostasis Congress in 2023, included in the session on the clinical impact of variability in commonly used coagulation assays. Here, we review the role of D-dimer, primarily in the outpatient diagnosis of patients with venous thromboembolism (VTE) when combined with clinical decision rules. We focus on the recent large management trials that have studied adjustments of VTE exclusion thresholds for D-dimer based on either prior clinical probability of VTE or patient age, and the resultant benefit of reduced imaging for VTE and improved diagnostic efficiency. In this context, we report on the significant variability between D-dimer results and the multiple D-dimer assays in use worldwide using data from international external quality assurance programs. This variability is particularly high at typical VTE exclusion thresholds. We discuss the potential clinical impact of D-dimer assay substitution on accuracy of diagnosis and risk stratification of patients with VTE. Finally, we summarize relevant new data on this topic presented during the 2023 International Society on Thrombosis and Haemostasis Congress and outline future priorities urgently needed to harmonize D-dimer results and reporting that will require international collaboration among multiple stakeholders with an overall goal to close this knowledge-to-action gap.

Balancing risks of recurrent venous thromboembolism and bleeding with extended anticoagulation: a decision analysis

Background

A decision to stop or continue anticoagulation after 3 months of anticoagulation for venous thromboembolism (VTE) should be made by weighing individual risks of recurrence and bleeding.

Objectives

To determine the optimal ratio of recurrence risk reduction to increase the risk of bleeding in terms of maximizing quality-adjusted life years (QALYs) gained.

Methods

Using a microsimulation model, outcomes within 5 years were simulated after assigning extended treatment if absolute recurrence risk reduction outweighed absolute increase in clinically relevant bleeding risk (International Society on Thrombosis and Haemostasis definition), weighted by a certain ratio. Data were simulated based on the Bleeding Risk Study, a prospective cohort including patients after ≥3 months of anticoagulation for unprovoked VTE or provoked VTE with history of VTE. The VTE-PREDICT risk score was used to estimate 5-year risks of recurrent VTE and clinically relevant bleeding.

Results

Among 10,000 individuals (mean age, 60.2 years, 36% female), the ratio of 0.90 (95% CI, 0.51-3.40; ie, bleeding is considered 0.90 the severity of recurrent VTE), with 99% of patients assigned extended anticoagulation, was considered optimal and resulted in 93 (95% CI, -23 to 203) additional QALYs compared with the least favorable ratio (5.10, 0% extended anticoagulation). At the optimal ratio, treatment based on VTE-PREDICT yielded 44 (95% CI, -69 to 157) additional QALYs versus standard of care.

Conclusion

With the current evidence, the optimal ratio between relevant bleeding risk and absolute recurrence risk reduction remains uncertain. Our results confirm that clinical equipoise exists regarding the decision to stop or continue anticoagulation after initial VTE treatment, emphasizing the importance of shared decision-making.

The Vienna Prediction Model for identifying patients at low risk of recurrent venous thromboembolism: a prospective cohort study

BACKGROUND AND AIMS

Patients with unprovoked venous thromboembolism (VTE) have a high recurrence risk, and guidelines suggest extended-phase anticoagulation. Many patients never experience recurrence but are exposed to bleeding. The aim of this study was to assess the performance of the Vienna Prediction Model (VPM) and to evaluate if the VPM accurately identifies these patients.

METHODS

In patients with unprovoked VTE, the VPM was performed 3 weeks after anticoagulation withdrawal. Those with a predicted 1-year recurrence risk of ≤5.5% were prospectively followed. Study endpoint was recurrent VTE over 2 years.

RESULTS

A total of 818 patients received anticoagulation for a median of 3.9 months. 520 patients (65%) had a predicted annual recurrence risk of ≤5.5%. During a median time of 23.9 months, 52 patients had non-fatal recurrence. The recurrence risk was 5.2% [95% confidence interval (CI) 3.2-7.2] at 1 year and 11.2% (95% CI 8.3-14) at 2 years. Model calibration was adequate after 1 year. The VPM underestimated the recurrence risk of patients with a 2-year recurrence rate of >5%. In a post-hoc analysis, the VPM's baseline hazard was recalibrated. Bootstrap validation confirmed an ideal ratio of observed and expected recurrence events. The recurrence risk was highest in men with proximal deep-vein thrombosis or pulmonary embolism and lower in women regardless of the site of incident VTE.

CONCLUSIONS

In this prospective evaluation of the performance of the VPM, the 1-year rate of recurrence in patients with unprovoked VTE was 5.2%. Recalibration improved identification of patients at low recurrence risk and stratification into distinct low-risk categories.

Risk Scores in Venous Thromboembolism Guidelines of ESC, ACCP, and ASH: An Updated Review

Venous thromboembolism (VTE) is associated with high morbidity and mortality. Risk scores associated with VTE have been widely used in clinical practice. Among numerous scores published, those included in guidelines are usually typical risk scores which have been extensively validated and globally recognized. This review provides an updated overview of the risk scores associated with VTE endorsed by 3 guidelines which are highly recognized in the field of VTE including the European Society of Cardiology, American College of Chest Physicians, and American Society of Hematology, focusing on the development, modification, validation, and comparison of these scores, to provide a comprehensive and updated understanding of all the classic risk scores associated with VTE to medical readers including but not limited to cardiologists, pulmonologists, hematologists, intensivists, physicians, surgeons, and researchers. Although each score recommended by these guidelines was more or less validated, there may still be room for further improvement. It may still be necessary to seek simpler, more practical, and more universally applicable VTE-related risk scores in the future.

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.

Miniaturized Stacked Transducer for Intravascular Sonothrombolysis With Internal-Illumination Photoacoustic Imaging Guidance and Clot Characterization

Thromboembolism in blood vessels can lead to stroke or heart attack and even sudden death unless brought under control. Sonothrombolysis enhanced by ultrasound contrast agents has shown promising outcome on effective treatment of thromboembolism. Intravascular sonothrombolysis was also reported recently with a potential for effective and safe treatment of deep thrombosis. Despite the promising treatment results, the treatment efficiency for clinical application may not be optimized due to the lack of imaging guidance and clot characterization during the thrombolysis procedure. In this paper, a miniaturized transducer was designed to have an 8-layer PZT-5A stacked with an aperture size of 1.4 × 1.4 mm2 and assembled in a customized two-lumen 10-Fr catheter for intravascular sonothrombolysis. The treatment process was monitored with internal-illumination photoacoustic tomography (II-PAT), a hybrid imaging modality that combines the rich contrast of optical absorption and the deep penetration of ultrasound detection. With intravascular light delivery using a thin optical fiber integrated with the intravascular catheter, II-PAT overcomes the penetration depth limited by strong optical attenuation of tissue. In-vitro PAT-guided sonothrombolysis experiments were carried out with synthetic blood clots embedded in tissue phantom. Clot position, shape, stiffness, and oxygenation level can be estimated by II-PAT at clinically relevant depth of ten centimeters. Our findings have demonstrated the feasibility of the proposed PAT-guided intravascular sonothrombolysis with real-time feedback during the treatment process.

Low D-dimer levels at diagnosis of venous thromboembolism are associated with reduced risk of recurrence: data from the TROLL registry

BACKGROUND

Venous thromboembolism (VTE) is a frequent disease with a high risk of recurrence. It has been suggested that the D-dimer level at the time of VTE diagnosis can be used to identify patients at a low risk of recurrence.

OBJECTIVES

We aimed to investigate the impact of D-dimer levels measured at the time of VTE diagnosis on the risk of recurrence in a large cohort of patients with a first-time VTE.

METHODS

The study included 2585 patients with first symptomatic non-cancer-associated VTE from the Venous Thrombosis Registry in Østfold Hospital (TROLL) (2005-2020). All recurrent events during the follow-up were recorded, and cumulative incidences of recurrence were estimated according to D-dimer levels of ≤1900 ng/mL (≤25th percentile) and >1900 ng/mL.

RESULTS

During a median follow-up of 3.3 years, 395 patients experienced a recurrent VTE. The 1- and 5-year cumulative incidences of recurrence were 2.9% (95% CI: 1.8-4.6) and 11.4% (95% CI: 8.7-14.8), respectively, in those with a D-dimer concentration of ≤1900 ng/mL and 5.0% (95% CI, 4.0-6.1) and 18.3% (95% CI: 16.2-20.6), respectively, in those with a D-dimer concentration of >1900 ng/mL, respectively. In patients with unprovoked VTE, the 5-year cumulative incidence was 14.3% (95% CI: 10.3-19.7) in the ≤1900-ng/mL category, and 20.2% (95% CI: 17.3-23.5) in the >1900-ng/mL category.

CONCLUSIONS

D-dimer levels within the lowest quartile, measured at the time of VTE diagnosis, were associated with lower recurrence risk. Our findings imply that D-dimer levels measured at the time of diagnosis may be used to identify patients with VTE at a low risk of recurrent VTE.

A Scoring System to Determine the Risk Factors Causing Recurrent Pulmonary Thromboembolism

BACKGROUND

The risk of recurrence in pulmonary embolism is the highest in the first week after the acute event. Although it decreases over time, it may remain high for months depending on compliance with treatment and the nature of the underlying risk factor. Our study aimed to identify risk factors that lead to recurrence in pulmonary thromboembolism (PTE) patients and establish an easy-to-use scoring system that determines the risk of recurrence after the first embolism.

METHODS

We retrospectively evaluated 1452 patients who were diagnosed with acute PTE between 7/1/2014 and 7/1/2019. Demographic data, comorbidities and clinical data of the patients, and risk factors were recorded. The relationship of the examined parameters with recurrent PTE was evaluated.

RESULTS

Diabetes mellitus (DM), hypertension, obesity, and the presence of at least one hereditary risk factor were found to be associated with recurrence. The sensitivity of our score was 66.9%, the specificity was 63.2%, the positive predictive value was 19%, and the negative predictive value was 93.7%. The risk of recurrence in the patients identified as high-risk in the scoring system was 3.47 times higher than those identified as low-risk.

CONCLUSION

In terms of risk of recurrence, special attention should be paid to patients with diabetes, HT, obesity and any of the hereditary risk factors. Using scoring systems to determine the risk of recurrence will be valuable and interesting as it is easy-to-use, gives quick results and provides quantitative results.

Elevated plasma complement factor H related 5 protein is associated with venous thromboembolism

Venous thromboembolism (VTE) is a common, multi-causal disease with potentially serious short- and long-term complications. In clinical practice, there is a need for improved plasma biomarker-based tools for VTE diagnosis and risk prediction. Here we show, using proteomics profiling to screen plasma from patients with suspected acute VTE, and several case-control studies for VTE, how Complement Factor H Related 5 protein (CFHR5), a regulator of the alternative pathway of complement activation, is a VTE-associated plasma biomarker. In plasma, higher CFHR5 levels are associated with increased thrombin generation potential and recombinant CFHR5 enhanced platelet activation in vitro. GWAS analysis of ~52,000 participants identifies six loci associated with CFHR5 plasma levels, but Mendelian randomization do not demonstrate causality between CFHR5 and VTE. Our results indicate an important role for the regulation of the alternative pathway of complement activation in VTE and that CFHR5 represents a potential diagnostic and/or risk predictive plasma biomarker.

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.

Prevention, Diagnostics and Treatment of Deep Vein Thrombosis. Russian Experts Consensus

The guidelines are developed in accordance with the requirements of the Ministry of Health of the Russian Federation by the all-Russian public organization «Association of Phlebologists of Russia» with participation of the Association of Cardiovascular Surgeons of Russia, the Russian Society of Surgeons, the Russian Society of Angiologists and Vascular Surgeons, the Association of Traumatologists and Orthopedists of Russia, the Association of Oncologists of Russia, the Russian Society of Clinical Oncology, Russian Society of Oncohematologists, Russian Society of Cardiology, Russian Society of Obstetricians and Gynecologists.

Residual pulmonary vascular obstruction and recurrence after acute pulmonary embolism: a systematic review and meta-analysis of individual participant data

We aimed to assess the relationship between residual pulmonary vascular obstruction (RPVO) on planar lung scan after completion of at least 3 months of anticoagulant therapy for acute pulmonary embolism (PE) and the risk of recurrent venous thromboembolism (VTE) or death due to PE one year after treatment discontinuation. The systematic review was registered with the International Prospective Registry of Systematic Reviews (PROSPERO: CRD42017081080). The primary outcome measure was to generate a pooled estimate of the rate of recurrent VTE at one year in patient with RPVO diagnosed on planar lung scan after discontinuation of at least 3 months of anticoagulant treatment for an acute PE. Individual data were obtained for 809 patients. RPVO (ie, obstruction >0%) was found in 407 patients (50.3%) after a median of 6.6 months of anticoagulant therapy for a first acute PE. Recurrent VTE or death due to PE occurred in 114 patients (14.1%), for an annual risk of 6.4% (95% confidence interval, 4.7%-8.6%). Out of the 114 recurrent events, 63 occurred within one year after discontinuation of anticoagulant therapy corresponding to a risk of 8.1% (6.4%-9.8%) at 1 year. The risk of recurrent VTE at one year was 5.8% (4.4-7.2) in participants with RPVO <5%, vs 11.7% (9.5-13.8) in participants with RPVO ≥5%. RPVO is a significant predictor of the risk of recurrent venous thromboembolism. However, the risk of recurrent events remains too high in patients without residual perfusion defect for it to be used as a stand-alone test to decide on anticoagulation discontinuation.

Role of factor VIII, IX, and XI in venous thrombosis recurrence risk in adults and children: A systematic review

Background

Predicting recurrent venous thromboembolic events (VTEs) is challenging in clinical practice for both adults and children, but it is relevant for clinical management. Identifying laboratory risk factors for VTE recurrence may aid in clinical decision-making.

Objective

The goal of this systematic review is to investigate the predictive role of FVIII, IX, or XI in recurrent VTE in adult and pediatric patients with a first VTE.

Methods

A systematic review of the published literature was conducted in databases MEDLINE In-Process, Other Nonindexed Citations, MEDLINE Epub Ahead of Print, EMBASE Classic + EMBASE (OvidSP), and Cochrane (Wiley). We included observational and interventional studies that comprised adults or children with a first VTE, FVIII, FIX, and/or FXI and objectively confirmed VTE recurrence. The quality in prognosis studies tool was used to assess the risk of bias.

Results

We identified 2177 unique studies, of which 19 were included (18 for adults and 1 for children). The risk of bias was overall low to moderate. The studies were heterogenous with regards to population (provoked/unprovoked primary VTE), exposure (type of assay and cut-off values), and statistical analysis results (measures of association and modeling strategy). In adults, contradictory evidence was found for FVIII and FXI as outcome predictors, while no research could establish if FIX predicts VTE recurrence. Data in pediatrics were limited. Given the extensive heterogeneity of the literature, a meta-analysis was not performed.

Conclusions

Overall, there is contradictory evidence that FVIII, FIX, or FXI predict recurrent VTE in adults and children. Addressing heterogeneity is a relevant aspect to consider in future studies investigating prognostic factors for VTE recurrence.

Isolated distal deep vein thrombosis: What have we learnt from the OPTIMEV study?

The OPTIMEV (OPTimisation de l'Interrogatoire dans l'évaluation du risque throMbo-Embolique Veineux) study has provided some important and innovative information for the management of lower extremity isolated distal deep vein thrombosis (distal DVT). Indeed, if distal deep-vein thrombosis (DVT) therapeutic management is nowadays still debated, before the OPTIMEV study, the clinical relevance of these DVT itself was questioned. Via the publication of 6 articles, between 2009 and 2022, assessing risk factors, therapeutic management, and outcomes of 933 patients with distal DVT we were able to demonstrate that: - When distal deep veins are systematically screened for suspicion of DVT, distal DVT are the most frequent clinical presentation of the venous thromboembolic disease (VTE). This is also true in case of combined oral contraceptive related VTE. - Distal DVT share the same risk factors as proximal DVT and constitute two different clinical expressions of the same disease: the VTE disease. However, the weight of these risk factors differs: distal DVT are more often associated with transient risk factors whereas proximal DVT are more associated with permanent risk factors. - Deep calf vein and muscular DVT share the same risk factors, short and long-term prognoses. - In patients without history of cancer, risk of unknown cancer is similar in patients with a first distal or proximal DVT. - After 3years and once anticoagulation has been stopped, distal DVT recur twice less as proximal DVT and mainly as distal DVT; However, in cancer patients, prognosis of distal and proximal DVT appear similar in terms of death and VTE recurrence.

Overall haemostatic potential (OHP) assay can risk stratify for venous thromboembolism recurrence in anticoagulated patients

Assessing the risk of recurrent venous thromboembolism (VTE), particularly when patients are anticoagulated, remains a major challenge largely due to the lack of biomarkers. Blood was sampled from adult VTE patients recruited between January 2018 and September 2020, while receiving therapeutic anticoagulation. Results were compared to 144 healthy subjects (34.7% male, median age 42 years). Overall haemostatic potential (OHP) assay, a spectrophotometric assay, was performed on platelet-poor plasma, in which fibrin formation (triggered by small amounts of thrombin (overall coagulation potential, OCP)) and fibrinolysis (by the addition of thrombin and tissue plasminogen activator (OHP)) are simultaneously measured. Results were obtained from 196 patients (52.6% male, mean age 57.1 years). Compared to healthy subjects, VTE patients displayed significantly higher OCP (39.6 vs 34.5 units, p < 0.001) and OHP (9.3 vs 6.4 units, p < 0.001) as well as lower overall fibrinolytic potential (75.6 v s81.1%, p < 0.001). All 16 VTE recurrences, including 11 unprovoked, occurred above an OCP cut-off of 40^th percentile (recurrence rate 4.32/100 patient-years (100PY), 95% confidence interval (CI) 2.39-7.80, p = 0.002). Of 97 patients who subsequently discontinued anticoagulation, all unprovoked VTE recurrences (n = 9) occurred above the 40^th OCP percentile (recurrence rate 9.10/100PY, 95% CI 4.74-17.49, p = 0.005) and the 40^th OHP percentile (recurrence rate 8.46/100PY, 95% CI 4.40-16.25, p = 0.009). Our pilot study demonstrates that the OHP assay can detect a hypercoagulable and hypofibrinolytic state in anticoagulated VTE patients and may be able to risk stratify VTE recurrence, allowing for more individualised decision on long-term anticoagulation. Further larger prospective studies are required.

Combined oral contraceptive-associated venous thromboembolism revealing an antiphospholipid syndrome: International retrospective study of outcomes

INTRODUCTION

Limitations in the data used to define thromboprophylaxis for patients with antiphospholipid antibodies (aPLAbs) and thrombosis include uncertainties after an initial provoked venous thromboembolic event (VTE). We aimed to study such cases associated with combined oral contraceptive (COC) intake.

METHODS

We retrospectively analysed thrombotic outcomes after a first COC-associated VTE and positive aPLAbs, with a low risk HERDOO2 score, on low-dose aspirin (LDA) secondary thromboprophylaxis, seen from 2010 to 2021 in 3 tertiary referral centres, one in France and 2 in Russia. Data from 264 patients (distal deep vein thrombosis DVT: 62.9 %), cumulating in 1327.7 patient-years of observation, were collected.

RESULTS

There were 22 cases of thrombosis: 16 distal DVTs, 3 proximal, 1 pulmonary embolism (PE) and 2 transient ischemic attacks. Recurrence rate was 1.66 per 100 patient-years (p-y; 95 % CI: 0.96-2.33). No major bleeding occurred. Risk factors affecting recurrence-free survival were the time between first COC intake and VTE (p < 0.0001; the shortest, the lower), proximal DVT (p = 0.021), active smoking (p = 0.039), an associated systemic disease (p = 0.043) and circulating monocyte counts (p = 0.001).

CONCLUSIONS

We observed a low risk of recurrence which was modulated by classical risk factors for VTE. These observational data may provide clues for future randomized controlled trials.

Obesity as a Risk Factor for Venous Thromboembolism Recurrence: A Systematic Review

Background and Objectives: Venous thromboembolism (VTE) encompasses Deep Venous Thrombosis (DVT) and Pulmonary Embolism (PE). The duration of anticoagulant therapy following a VTE event partly relies on the risk of recurrent VTE which depends on the clinical setting where VTE occurred and the VTE risk factors present. Obesity is considered a minor risk factor and studies in the literature have provided conflicting results on whether obesity influences the development of recurrences. The aim of the present study is to assess the effect of obesity on VTE recurrence in patients that suffered from a previous VTE event. Materials and Methods: We conducted systematic research for English language studies in Medline, Scopus and ProQuest databases in order to identify publications that assess the risk of VTE recurrence in obesity. Inclusion criteria were: 1. Diagnosis of VTE, 2. Definition of obesity as a body mass index ≥30 kg/m², 3. Report of the risk of obesity on VTE recurrence, 4. Adult human population. We did not include case reports, review studies or studies that assessed other forms of thrombosis and/or used other definitions of obesity. We used the Newcastle-Ottawa scale to address the quality of the studies. Results: Twenty studies were included in the analysis, of which 11 where prospective cohort studies, 6 were retrospective cohort studies, 1 was a cross-sectional study, and 2 were post-hoc analysis of randomized clinical trials. Obesity was significantly associated with recurrences in 9 studies and in 3 of them the association was significant only in females. Conclusions: There is heterogeneity between the studies both in their design and results, therefore the effect of obesity on VTE recurrence cannot be adequately estimated. Future randomized clinical studies with appropriately selected population are needed in order to streamline the effect of obesity on VTE recurrence.

C-reactive protein, immunothrombosis and venous thromboembolism

C-reactive protein (CRP) is a member of the highly conserved pentraxin superfamily of proteins and is often used in clinical practice as a marker of infection and inflammation. There is now increasing evidence that CRP is not only a marker of inflammation, but also that destabilized isoforms of CRP possess pro-inflammatory and pro-thrombotic properties. CRP circulates as a functionally inert pentameric form (pCRP), which relaxes its conformation to pCRP* after binding to phosphocholine-enriched membranes and then dissociates to monomeric CRP (mCRP). with the latter two being destabilized isoforms possessing highly pro-inflammatory features. pCRP* and mCRP have significant biological effects in regulating many of the aspects central to pathogenesis of atherothrombosis and venous thromboembolism (VTE), by directly activating platelets and triggering the classical complement pathway. Importantly, it is now well appreciated that VTE is a consequence of thromboinflammation. Accordingly, acute VTE is known to be associated with classical inflammatory responses and elevations of CRP, and indeed VTE risk is elevated in conditions associated with inflammation, such as inflammatory bowel disease, COVID-19 and sepsis. Although the clinical data regarding the utility of CRP as a biomarker in predicting VTE remains modest, and in some cases conflicting, the clinical utility of CRP appears to be improved in subsets of the population such as in predicting VTE recurrence, in cancer-associated thrombosis and in those with COVID-19. Therefore, given the known biological function of CRP in amplifying inflammation and tissue damage, this raises the prospect that CRP may play a role in promoting VTE formation in the context of concurrent inflammation. However, further investigation is required to unravel whether CRP plays a direct role in the pathogenesis of VTE, the utility of which will be in developing novel prophylactic or therapeutic strategies to target thromboinflammation.

Role of Physical Therapists in the Management of Individuals at Risk for or Diagnosed With Venous Thromboembolism: Evidence-Based Clinical Practice Guideline 2022

No matter the practice setting, physical therapists work with patients who are at risk for or who have a history of venous thromboembolism (VTE). In 2016, the first clinical practice guideline (CPG) addressing the physical therapist management of VTE was published with support by the American Physical Therapy Association's Academy of Cardiovascular and Pulmonary Physical Therapy and Academy of Acute Care, with a primary focus on lower extremity deep vein thrombosis (DVT). This CPG is an update of the 2016 CPG and contains the most current evidence available for the management of patients with lower extremity DVT and new key action statements (KAS), including guidance on upper extremity DVT, pulmonary embolism, and special populations. This document will guide physical therapist practice in the prevention of and screening for VTE and in the management of patients who are at risk for or who have been diagnosed with VTE. Through a systematic review of published studies and a structured appraisal process, KAS were written to guide the physical therapist. The evidence supporting each action was rated, and the strength of statement was determined. Clinical practice algorithms based on the KAS were developed that can assist with clinical decision-making. Physical therapists, along with other members of the health care team, should implement these KAS to decrease the incidence of VTE, improve the diagnosis and acute management of VTE, and reduce the long-term complications of VTE.

D-dimer: old dogmas, new (COVID-19) tricks

D-dimer is a fibrin degradation product encompassing multiple cross-linked D domains and/or E domains present in the original fibrinogen molecule, whose generation is only theoretically possible when hemostasis and fibrinolysis pathways are concomitantly activated. D-dimer measurement has now become a pillar in the diagnosis/exclusion and prognostication of venous thromboembolism (VTE) and disseminated intravascular coagulation (DIC), when incorporated into validated clinical algorithms and especially using age-adjusted diagnostic thresholds. Although emerging evidence is also supporting its use for predicting the duration of anticoagulant therapy in certain categories of patients, the spectrum of clinical applications is constantly expanding beyond traditional thrombotic pathologies to the diagnosis of acute aortic dissection, acute intestinal ischemia and cerebral venous thrombosis among others, embracing also clinical management of coronavirus disease 2019 (COVID-19). Recent findings attest that D-dimer elevations are commonplace in patients with severe acute respiratory syndrome (SARS-CoV-2) infection (especially in those with thrombosis), its value predicts the clinical severity (up to death) of COVID-19 and remains more frequently increased in COVID-19 patients with post-discharge clinical sequelae. Further, D-dimer-based anticoagulant escalation may be associated with a lower risk of death in patients with severe SARS-CoV-2 infection and, finally, D-dimer elevation post-COVID-19 vaccination mirrors an increased risk of developing vaccine-induced thrombocytopenia and thrombosis (VITT).

Extended Anticoagulation After Pulmonary Embolism: A Multicenter Observational Cohort Analysis

Background Pulmonary embolism (PE) has a long-term risk of adverse events, which can be prevented by extended anticoagulation. We compared clinical characteristics and outcomes between patients treated with 2-year extended anticoagulation and those who were not, in a population who had completed an initial phase of 3 to 6 months of anticoagulant therapy after acute PE. Methods and Results Observational cohort analysis of patients with PE who survived an initial phase of 3 to 6 months anticoagulation. Primary efficacy outcome was all-cause death or recurrent venous thromboembolism. Primary safety outcome was major bleeding. In total, 858 (71.5%) patients were treated with and 341 (28.5%) were treated without extended anticoagulant therapy during the active study period. Age <65 years, intermediate-high or high-risk index PE, normal platelet count, and the absence of concomitant antiplatelet treatment were independently associated with the prescription of extended anticoagulation. The mean duration of the active phase was 2.1±0.3 years. The adjusted rate of the primary efficacy outcome was 2.1% in the extended group and 7.7% in the nonextended group (P<0.001) for patients treated with extended anticoagulant therapy. Rate of bleeding were similar between the extended anticoagulant group and the nonextended group. Conclusions Extended oral anticoagulation over 2 and a half years after index PE seems to provide a net clinical benefit compared with no anticoagulation in patients with PE selected to receive extended anticoagulation. Randomized clinical trials are warranted to explore the potential benefit of extended anticoagulation in patients with PE, especially those with transient provoking factors but residual risk.

Shear Wave Elastography and Quantitative Ultrasound as Biomarkers to Characterize Deep Vein Thrombosis In Vivo

OBJECTIVE

Investigate shear wave elastography (SWE) and quantitative ultrasound (QUS) parameters in patients hospitalized for lower limb deep vein thrombosis (DVT).

METHOD

Sixteen patients with DVT were recruited and underwent SWE and radiofrequency data acquisitions for QUS on day 0, day 7, and day 30 after the beginning of symptoms, in both proximal and distal zones of the clot identified on B-mode scan. SWE and QUS features were computed to differentiate between thrombi at day 0, day 7, and day 30 following treatment with heparin or oral anticoagulant. The Young's modulus from SWE was computed, as well as QUS homodyned K-distribution (HKD) parameters reflecting blood clot structure. Median and interquartile range of SWE and QUS parameters within clot were taken as features.

RESULTS

In the proximal zone of the clot, the HKD ratio of coherent-to-diffuse backscatter median showed a significant decrease from day 7 to day 30 (P = .036), while the HKD ratio of diffuse-to-total backscatter median presented a significant increase from day 7 to day 30 (P = .0491). In the distal zone of the clot, the HKD normalized intensity of the echo envelope median showed a significant increase from day 0 to day 30 (P = .0062). No SWE features showed statistically significant differences over time. Nonetheless, a trend of lower median of Young's modulus within clot for patients who developed a pulmonary embolism was observed.

CONCLUSION

QUS features may be relevant to characterize clot's evolution over time. Further analysis of their clinical interpretation and validation on a larger dataset would deserve to be studied.

Anticoagulants: dose control methods and inhibitors

These days, anticoagulants are in great demand. They are used as a prophylaxis for thromboembolic complications in various diseases and conditions in general therapeutic practice, cardiology, neurology, as well as obstetrics to manage high-risk pregnancies. The relevance of anticoagulants competent use has come to the fore in connection with the emergence of a new disease – COVID-19 and its serious complications such as developing thrombotic storm, in which the timely applied anticoagulant therapy is the key to the success of therapy. The risk of bleeding should be considered when using any anticoagulant. Age, impaired renal function and concomitant use of antiplatelet agents are common risk factors for bleeding. Moreover, only vitamin K antagonists and heparin have specific antidotes – vitamin K and protamine, respectively. Inhibitors of other anticoagulants are universal presented as inactivated or activated prothrombin complex concentrate and recombinant factor VIIa. Hemodialysis effectively reduces dabigatran concentration, activated charcoal is effective in the case of recent oral administration of lipophilic drugs. Research on new antidotes of currently available anticoagulants is under way, similar to testing of new types of anticoagulants that are sufficiently effective in preventing and treating thromboembolic complications with minimal risk of hemorrhagic. The main contraindication to anticoagulants use is the doctor's ignorance of the mechanisms of drug action and opportunities for suppressing its effect.

Apixaban Use in Obese Patients: A Review of the Pharmacokinetic, Interventional, and Observational Study Data

Abstract

Relatively little is known about the influence of extreme body weight on the pharmacokinetics (PK), pharmacodynamics (PD), efficacy, and safety of drugs used in many disease states. While direct oral anticoagulants (DOACs) have an advantage over warfarin in that they do not require routine drug monitoring, some may regard this convenience as less compelling in obese patients. Some consensus guidelines discourage using DOACs in patients weighing > 120 kg or with a body mass index > 35–40 kg/m², given a sparsity of available data in this population and the concern that fixed dosing in obese patients might lead to decreased drug exposure and lower efficacy. Per the prescribing information, apixaban does not require dose adjustment in patients weighing above a certain threshold (e.g., ≥ 120 kg). Data from healthy volunteers and patients with nonvalvular atrial fibrillation (NVAF) or venous thromboembolism (VTE) have shown that increased body weight has a modest effect on apixaban’s PK. However, the paucity of exposure data in individuals > 120 kg and the lack of guideline consensus on DOAC use in obese patients continue to raise concerns about potential decreased drug exposure at extreme weight. This article is the first to comprehensively review the available PK data in obese individuals without NVAF or VTE, and PK, PD, efficacy, effectiveness, and safety data for apixaban in obese patients with either NVAF or VTE, including subgroup analyses across randomized controlled trials and observational (real-world) studies. These data suggest that obesity does not substantially influence the efficacy, effectiveness, or safety of apixaban in these patients.

Trial Registration ARISTOTLE: NCT00412984; AVERROES: NCT00496769; AMPLIFY: NCT00643201; AMPLIFY-EXT: NCT00633893; ADVANCE-1: NCT00371683; ADVANCE-2: NCT00452530; ADVANCE-3: NCT00423319

Video abstract