Recurrent venous thromboembolism and bleeding with extended anticoagulation: the VTE-PREDICT risk score

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.

Acute Pulmonary Embolism: Evidence, Innovation, and Horizons

PURPOSE OF REVIEW

Pulmonary embolism (PE) is the third most common cause of cardiovascular morbidity and mortality. The goal of this review is to discuss the most up-to-date literature on epidemiology, diagnosis, risk stratification, and management of acute PE.

RECENT FINDINGS

Despite an increase in annual incidence rate of PE in the United States and development of multiple advanced therapies for treatment of acute PE, PE-related mortality is not consistently decreasing across populations. Although multiple risk stratification schemes have been developed, it is still unclear which advanced therapy should be used for the individual patient and optimal timing. Fortunately, multiple randomized clinical trials are underway to answer these questions. Nevertheless, up to 50% of patients have persistent reduced quality of life 6 months after acute PE, termed post-PE syndrome. Despite advances in therapeutic options for management of acute PE, many questions remain unanswered, including optimal risk stratification and management of acute PE.

External validation of the Leiden Thrombosis Recurrence Risk Prediction models (L-TRRiP) for the prediction of recurrence after a first venous thrombosis in the Heart and Vascular Health study

Background

Long-term outcome after a first venous thromboembolism (VTE) might be optimized by tailoring anticoagulant treatment duration on individual risks of recurrence and major bleeding. The L-TRRiP models (A-D) were previously developed in data from the Dutch Multiple Environment and Genetic Assessment of Risk Factors for Venous thrombosis study to predict VTE recurrence.

Objectives

We aimed to externally validate models C and D using data from the United States Heart and Vascular Health (HVH) study.

Methods

Data from participants with a first VTE who discontinued initial anticoagulant therapy were used to determine model performance. Missing data were imputed, and results were pooled according to Rubin's rules. To determine discrimination, Harrell's C-statistic was calculated. To assess calibration, the observed/expected (O/E) ratio was estimated, and calibration plots were created, in which we accounted for the competing risk of death. A stratified analysis based on age <70 or >70 years was performed.

Results

Of 1430 participants from the HVH study, 187 experienced an unprovoked VTE recurrence during follow-up. The C-statistics of L-TRRIP models C and D were 0.62 (95% CI, 0.56-0.67) and 0.61 (95% CI, 0.55-0.67), respectively. The O/E ratio (1.00; 95% CI, 0.84-1.17 and 1.09; 95% CI, 0.91-1.27, respectively) and calibration plots indicated good calibration. The discrimination was similar between participants <70 or >70 years, whereas overall calibration was lower in participants <70 years.

Conclusion

The L-TRRiP models showed moderate discrimination and good calibration in a different population and can be used to guide clinical decision making. To assess the added value in daily clinical practice, a management study is needed.

Risk of Recurrent Venous Thromboembolism in Patients with Cancer: An Individual Patient Data Meta-analysis and Development of a Prediction Model

BACKGROUND

 About 7% of patients with cancer-associated venous thromboembolism (CAT) develop a recurrence during anticoagulant treatment. Identification of high-risk patients may help guide treatment decisions.

AIM

 To identify clinical predictors and develop a prediction model for on-treatment recurrent CAT.

METHODS

 For this individual patient data meta-analysis, we used data from four randomized controlled trials evaluating low-molecular-weight heparin or direct oral anticoagulants (DOACs) for CAT (Hokusai VTE Cancer, SELECT-D, CLOT, and CATCH). The primary outcome was adjudicated on-treatment recurrent CAT during a 6-month follow-up. A clinical prediction model was developed using multivariable logistic regression analysis with backward selection. This model was validated using internal-external cross-validation. Performance was assessed by the c-statistic and a calibration plot.

RESULTS

 After excluding patients using vitamin K antagonists, the combined dataset comprised 2,245 patients with cancer and acute CAT who were treated with edoxaban (23%), rivaroxaban (9%), dalteparin (47%), or tinzaparin (20%). Recurrent on-treatment CAT during the 6-month follow-up occurred in 150 (6.7%) patients. Predictors included in the final model were age (restricted cubic spline), breast cancer (odds ratio [OR]: 0.42; 95% confidence interval [CI]: 0.20-0.87), metastatic disease (OR: 1.44; 95% CI: 1.01-2.05), treatment with DOAC (OR: 0.66; 95% CI: 0.44-0.98), and deep vein thrombosis only as an index event (OR: 1.72; 95% CI: 1.31-2.27). The c-statistic of the model was 0.63 (95% CI: 0.54-0.72) after internal-external cross-validation. Calibration varied across studies.

CONCLUSION

 The prediction model for recurrent CAT included five clinical predictors and has only modest discrimination. Prediction of recurrent CAT at the initiation of anticoagulation remains challenging.

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

Background

After 3 months of anticoagulation for venous thromboembolism (VTE), the decision needs to be made whether to stop anticoagulation or extend treatment indefinitely. The VTE-PREDICT calculator can be used to estimate individual risks of VTE recurrence and bleeding to guide this decision.

Objectives

To evaluate the impact of predicted individual risks of recurrence and bleeding on clinicians' decisions on anticoagulation duration and to assess usefulness of the VTE-PREDICT calculator.

Methods

A randomized controlled trial and within-subject study was conducted among clinicians treating VTE patients. The clinicians were asked to complete an online survey containing 6 fictional case vignettes. Group A proposed anticoagulant duration for each case without additional information first and subsequently after seeing calculator-predicted risks (within-subject analysis). Group B was directly provided with calculator risks and proposed treatment duration for each case vignette (for comparison with group A results in a randomized controlled trial analysis). Then, group B received questions on usefulness and credibility of the calculator.

Results

Forty-five clinicians were assigned to group A and 48 to B. Overall, group A did not propose different anticoagulation durations than group B. However, individual clinicians in group A changed proposed duration in 35% of the cases after seeing the calculator risks. The calculator was considered useful and credible by most clinicians.

Conclusion

Overall, use of the VTE-PREDICT calculator did not affect proposed anticoagulation duration. However, individual clinicians frequently changed their proposed duration after using the calculator, especially for patients with high bleeding risk.

Safety of Sofosbuvir-Based Direct-Acting Antivirals for Hepatitis C Virus Infection and Direct Oral Anticoagulant Co-Administration

Background: Direct oral anticoagulants (DOACs) are recommended for the management of thrombosis prophylaxis, especially in patients with atrial fibrillation. As substrates of cytochrome P450 (CYP) 3A4 and/or P-glycoprotein, they are implicated in potential drug-drug interactions. NS5A/NS5B inhibitors are direct-acting agents (DAAs) against the Hepatitis C Virus (HCV) infection that exert a mild inhibition of P-glycoprotein without effects on CYP3A4. A DOAC and NS5A/NS5B inhibitor co-administration may lead to an increased risk of bleeding. Real-world data on the concomitant use of DOACs and DAAs are scarce. On this purpose, we perform a retrospective analysis on the risk of vascular adverse events (bleeding and thrombosis) among HCV patients under DOAC/DAA therapy, even in advanced liver disease. Methods: Between May 2015 and April 2023, patients treated with sofosbuvir-based DAA regimens and DOACs were consecutively included in this study from 12 Italian medical centers. Baseline characteristics, especially concerning bleeding risk and liver function, were collected. The occurrence of bleeding events, classified as major and minor, was the primary endpoint. Secondary endpoints were the rate of any thrombotic events and/or the need for discontinuation of one or both treatments. Moreover, a cohort of patients, matched by demographic characteristics (age and sex), that switched to vitamin K antagonists (VKAs) during the antiviral treatment was compared with the DOAC/DAA group. Results: A total of 104 patients were included. Thirty-eight of them (36.5%) were cirrhotic. Atrial fibrillation was an indication for anticoagulation in almost all cases (76%). Rivaroxaban (35.6%) was the most used DOAC, followed by apixaban (26.9%), dabigatran (19.2%) and edoxaban (18.3%). Sofosbuvir/velpatasvir (78.8%) was the most prescribed DAA, and all patients were already on anticoagulant therapy before the start of DAAs. During concomitant DOAC/DAA treatment, no major bleeding events were recorded, while four minor bleeding events occurred, but none resulted in DAA or DOAC discontinuation. At univariate analysis, the only additional risk factor statistically related to bleeding events was the anticoagulant therapy (hazard ratio [HR]: 13.2, 95% confidence interval 1,6-109). Performing an evaluation by a LOGIT binomial analysis with demographic characteristics, the antiplatelet therapy remained statistically associated to bleeding events. No significant differences were found in the rate of clinically relevant bleeding when the main population was compared with the VKA-switched cohort. A single major bleeding event leading to anticoagulation and DAA discontinuation was reported in VKA-switched matched cohort. Conclusions: In our study, the concomitant use of NS5A/NS5B inhibitors with DOAC showed good safety, and the only risk factor associated with bleeding events was the concomitant antiplatelet therapy. These findings support the use of DOACs during sofosbuvir-based HCV treatment, even in advanced liver disease. Replacing DOACs with VKAs does not appear to be of clinical benefit.

Duration of anticoagulation of venous thromboembolism

Venous thromboembolism (VTE) is a common, serious condition that requires anticoagulation for at least three months to prevent recurrence and long-term complications. After this initial period, the decision to continue or stop anticoagulation depends on the balance between the risk of recurrent VTE and the risk of bleeding. Established guidelines suggest short-term anticoagulation for VTE caused by transient factors and indefinite anticoagulation for recurrent or cancer-associated VTE. However, for a first unprovoked VTE, decision-making remains challenging. Current predictive scores for recurrence and bleeding are not sufficiently reliable, and the safety and efficacy of reduced-dose anticoagulation remain unclear. In the future, precision and patient-centred medicine may improve treatment decisions in this area.

Optimal long-term anticoagulation after acute pulmonary embolism: current state of the art and a look into the near future

PURPOSE OF REVIEW

This review aims to summarize the current state of the art and future directions in optimal long-term anticoagulation following acute pulmonary embolism (PE).

RECENT FINDINGS

Actual studies and guidelines underscore the preference for direct oral anticoagulants (DOAC) in standard therapeutic doses for maintenance therapy post-PE, while considering patient-specific factors and dose-reduction criteria. Risk stratification should always include the assessment of concomitant trigger- or risk factors regarding their strength and persistence. The use of tools like specific scores can facilitate the identification of optimal candidates for long-term therapy, emphasizing once more personalized approaches and strategies. Special patient groups, such as cancer associated thrombosis, chronic thromboembolic pulmonary hypertension or antiphospholipid syndrome require even more tailored therapy approaches.

SUMMARY

Optimal long-term anticoagulation post-PE should be guided by straightforward and individual risk assessment strategies. The array of indications for DOACs has gotten wider in last years, also within special patient groups. Still, chronic thromboembolic pulmonary hypertension and antiphospholipid syndrome remains domain of vitamin K agonists.

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

BACKGROUND

Guidelines suggest indefinite anticoagulation after unprovoked venous thromboembolism (VTE) unless the bleeding risk is high, yet there is no consistent guidance on assessing bleeding risk.

OBJECTIVES

This study aimed to evaluate the performance of 5 bleeding risk tools (RIETE, VTE-BLEED, CHAP, VTE-PREDICT, and ABC-Bleeding).

METHODS

PLATO-VTE, a prospective cohort study, included patients aged ≥40 years with a first unprovoked VTE. Risk estimates were calculated at VTE diagnosis and after 3 months of treatment. Primary outcome was clinically relevant bleeding, as per International Society on Thrombosis and Haemostasis criteria, during 24-month follow-up. Discrimination was assessed by the area under the receiver operating characteristic curve (AUROC). Patients were classified as having a "high risk" and "non-high risk" of bleeding according to predefined thresholds; bleeding risk in both groups was compared by hazard ratios (HRs).

RESULTS

Of 514 patients, 38 (7.4%) had an on-treatment bleeding. AUROCs were 0.58 (95% CI, 0.48-0.68) for ABC-Bleeding, 0.56 (95% CI, 0.46-0.66) for RIETE, 0.53 (95% CI, 0.43-0.64) for CHAP, 0.50 (95% CI, 0.41-0.59) for VTE-BLEED, and 0.50 (95% CI, 0.40-0.60) for VTE-PREDICT. The proportion of high-risk patients ranged from 1.4% with RIETE to 36.9% with VTE-BLEED. The bleeding incidence in the high-risk groups ranged from 0% with RIETE to 13.0% with ABC-Bleeding, and in the non-high-risk groups, it varied from 7.7% with ABC-Bleeding to 9.6% with RIETE. HRs ranged from 0.93 (95% CI, 0.46-1.9) for VTE-BLEED to 1.67 (95% CI, 0.86-3.2) for ABC-Bleeding. Recalibration at 3-month follow-up did not alter the results.

CONCLUSION

In this cohort, discrimination of currently available bleeding risk tools was poor. These data do not support their use in patients with unprovoked VTE.

Thrombotic microenvironment responsive crosslinking cyclodextrin metal-organic framework nanocarriers for precise targeting and thrombolysis

Global public health is seriously threatened by thrombotic disorders because of their high rates of mortality and disability. Most thrombolytic agents, especially protein-based pharmaceuticals, have a short half-life in circulation, reducing their effectiveness in thrombolysis. The creation of an intelligent drug delivery system that delivers medication precisely and releases it under regulated conditions at nearby thrombus sites is essential for effective thrombolysis. In this article, we present a unique medication delivery system (MCRUA) that selectively targets platelets and releases drugs by stimulation from the thrombus' microenvironment. The thrombolytic enzyme urokinase-type plasminogen-activator (uPA) and the anti-inflammatory medication Aspirin (acetylsalicylic acid, ASA) are both loaded onto pH-sensitive CaCO3/cyclodextrin crosslinking metal-organic frameworks (MC) that make up the MCRUA system. c(RGD) is functionalized on the surface of MC, which is functionalized by RGD to an esterification reaction. Additionally, the thrombus site's acidic microenvironment causes MCRUA to disintegrate to release uPA for thrombolysis and aiding in vessel recanalization. Moreover, cyclodextrin-encapsulated ASA enables the treatment of the inflammatory environment within the thrombus, enhancing the antiplatelet aggregation effects and promoting cooperative thrombolysis therapy. When used for thrombotic disorders, our drug delivery system (MCRUA) promotes thrombolysis, suppresses rethrombosis, and enhances biosafety with fewer hemorrhagic side effects.

How I treat the co-occurrence of venous and arterial thromboembolism: anticoagulation, antiplatelet therapy, or both?

ABSTRACT

Arterial and venous thromboses are classically considered distinct disease states, with arterial thrombosis mediated predominantly by platelets and therefore, treated with antiplatelet therapy, and venous thrombosis mediated by the plasmatic coagulation system and treated with anticoagulation. However, co-occurrence of arterial and venous events is common, and there is increasing evidence of shared risk factors and pathophysiologic overlap. This presents a management challenge: does the patient with venous and arterial thrombosis, require anticoagulation, antiplatelet therapy, or both? Herein, we present a structured approach to the evaluation and management of patients with venous thrombosis who are also at risk for or have a history of an arterial thromboembolic event. We emphasize the importance of defining the indications for antithrombotic therapy, as well as the evaluation of factors that influence both thrombotic and bleeding risk, including disorder-specific and patient-specific factors, as well as the inherent risk balance of antithrombotic therapy regimens. We illustrate this approach in 4 cases, discussing the unique considerations and recent updates in the management of venous thrombosis, acute noncardioembolic ischemic stroke, coronary artery disease and acute myocardial infarction, and peripheral artery disease after revascularization.

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.

Long-Term Efficacy and Safety of Direct Oral Anticoagulants at Reduced Doses in the Secondary Prevention of Venous Thromboembolism and Post-Thrombotic Syndrome

Background: Anticoagulation for venous thromboembolism (VTE) is required for at least three to six months; however, it is advisable to extend the duration in certain cases, in which case a reduced dose of Direct Oral Anticoagulants (DOACs) may be an option. Our objective was to investigate the efficacy and safety of reduced-dose DOACs in extended anticoagulation treatment compared to full doses. Methods and Results: This retrospective single-centre study included 185 patients treated with DOACs for at least 6 months who were divided into two groups: (1) the Full Dose (FD) group (n = 113) and (2) the Reduced Dose (RD) group (n = 72), which included patients treated with Apixaban at 2.5 mg bis in die (BID) and Rivaroxaban at 10 mg once daily (OD). Post-thrombotic syndrome (PTS) and its progression were evaluated. During an overall follow-up of 48.32 ± 29.49 months, no VTE occurred, and no patients experienced major bleeding; clinically relevant non-major bleeding occurred in three patients in each group (2.7% vs. 4.2% in FD vs. RD, respectively, p = 0.57). From baseline to follow-up, the prevalence of PTS was not significantly decreased in either group (FD: 54.9% vs. 51.3%, p = 0.29; RD 51.4% vs. 44.4%, p = 0.12); conversely, the Villalta score values were significantly decreased at the last follow-up (FD: 5.51 ± 4.18 vs. 5.12 ± 4.36, p < 0.001; RD 5.49 ± 4.06 vs. 5.11 ± 3.73, p = 0.006). Conclusion: In this real-world retrospective registry, very long-term extended anticoagulant therapy with DOACs at full or reduced doses showed comparable efficacy, safety, and impact on PTS progression. Larger studies are needed.

External validation of the PE-SARD risk score for predicting early bleeding in acute pulmonary embolism in the RIETE Registry

INTRODUCTION

The PE-SARD score (syncope, anemia, renal dysfunction) was developed to predict the risk of major bleeding in the acute phase of pulmonary embolism (PE).

METHODS

We analyzed data from 50,686 patients with acute PE included in the RIETE registry to externally validate the PE-SARD score. We calculated the overall reliability of the PE-SARD score, as well as discrimination and calibration for predicting the risk of major bleeding at 30 days. The performance of PE-SARD was compared to the BACS and PE-CH models.

RESULTS

During the first 30 days, 640 patients (1.3 %) had a major bleeding event. The incidence of major bleeding within 30 days was 0.6 % in the PE-SARD-defined low-risk group, 1.5 % in the intermediate-risk group, and 2.5 % in the high-risk group, for an OR of 2.22 (95 % CI, 2.02-2.43) for the intermediate-risk group (vs low-risk group), and 3.94 for the high-risk group (vs low-risk group). The corresponding sensitivity was 81.1 % (intermediate/high vs low risk), and specificity was 85.9 % (95 % CI, 85.8-86.1) (low/intermediate vs high risk). The applicability of PE-SARD was consistent across clinically relevant patient subgroups and over shorter time periods of follow-up (i.e., 3 and 7 days). The C-index was 0.654 and calibration was excellent. The PE-SARD bleeding score improved the major bleeding risk prediction compared with the BACS and PE-CH scores.

CONCLUSIONS

The PE-SARD score identifies PE patients with a higher risk of bleeding, which could assist providers for potentially adjusting PE management, in a framework of shared decision-making with individual patients.

Qualitative experiences, values, and decisional needs of patients with unprovoked venous thromboembolism who suffer bleeding-"This pill will keep you alive tonight"

Background

Contemporary guidelines recommend extended-duration anticoagulation among patients with a first unprovoked venous thromboembolism (VTE). Little is known about whether this recommendation aligns with patient values after a bleeding complication.

Objectives

To explore the experiences, values, and decisional needs of patients with unprovoked VTE related to extended-duration treatment after an anticoagulant-associated bleed.

Methods

In this descriptive, qualitative study, face to face online semistructured interviews were conducted with patients with unprovoked VTE who had experienced bleeding and continued anticoagulant treatment in one academic hospital in Canada. Data were analyzed using directed content analysis to identify themes. Themes were mapped onto the Ottawa Decisional Support Framework to identify decisional needs.

Results

Between September and December 2021, 14 patients were interviewed (age 41-69 years; 9 females). Many patients were not aware of the option to stop anticoagulation and had limited understanding of the decision about treatment duration. Despite the negative quality-of-life impact of clinically relevant bleeding during VTE treatment, the majority continued anticoagulation due to emotional trauma of VTE diagnosis, a perception that bleeding would be more manageable than VTE recurrence, a desire to maintain a connection to subspecialty care or non-VTE related benefits (eg, cancer diagnosis, protection from COVID-19). Patients' decisional needs included lack of choice awareness, inadequate support for participation, lack of personalized risk stratification, and inadequate information on monitoring and managing heavy menstrual bleeding.

Conclusion

Despite the impact of anticoagulant-associated bleeding on quality of life, patients preferred continuing with anticoagulation for reasons extending beyond secondary VTE prevention. Effective decision-support interventions are needed to address unmet decisional needs.

Oxidative stress in acute pulmonary embolism: emerging roles and therapeutic implications

Oxidative stress is an imbalance between the body's reactive oxygen species and antioxidant defense mechanisms. Oxidative stress is involved in the development of several cardiovascular diseases, such as pulmonary hypertension, atherosclerosis, and diabetes mellitus. A growing number of studies have suggested the potential role of oxidative stress in the pathogenesis of pulmonary embolism. Biomarkers of oxidative stress in pulmonary embolism have also been explored, such as matrix metalloproteinases, asymmetric dimethylarginine, and neutrophil/lymphocyte ratio. Here, we comprehensively summarize some oxidative stress mechanisms and biomarkers in the development of acute pulmonary embolism and summarize related treatments based on antioxidant stress to explore effective treatment strategies for acute pulmonary embolism.

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.

Provoked vs minimally provoked vs unprovoked VTE: does it matter?

Venous thromboembolism (VTE) is a multifactorial disease, and its risk depends on exposure to risk factors and predisposing conditions. Based on their strength of association with a VTE episode, risk factors are classified as major or minor and determined using a temporal pattern to be transient or persistent. All patients with VTE should receive anticoagulant treatment for at least 3 months in the absence of an absolute contraindication. Beyond this period, selected patients may be candidates for an extended phase of anticoagulation aimed at secondary VTE prevention. The risk of recurrent VTE if anticoagulation is discontinued is probably the main driver of decision-making regarding extended treatment. The risk of recurrence after VTE associated with major risk factors is low if the risk factor is no longer present. In this case, treatment can be discontinued. If the major risk factor is persistent, anticoagulation should be continued. After VTE occurring in the absence of risk factors, anticoagulation should probably be continued indefinitely if the risk for bleeding is low and preferably with minimal effective doses of anticoagulants. VTE occurring after exposure to minor risk factors is probably the most challenging situation, especially if the clinical manifestation was acute pulmonary embolism. Understanding the actual role of minor risk factors in the occurrence of VTE helps in estimating the risk of recurrence and avoiding the dangers associated with unnecessary anticoagulation. The availability of safer strategies for anticoagulation could allow personalized strategies for secondary prevention of VTE.

Case Report: PROS1 (p.Leu584Arg) pathogenic mutation causes portal and superior mesenteric venous thromboembolism

Background

Genetic and acquired risk factors are fundamental to developing venous thromboembolism. Autosomal dominant protein S deficiency caused by pathogenic mutations in the PROS1 gene is a well-known risk factor for thrombophilia.

Case presentation

We report a 30-year-old male patient who presented to the hospital with portal vein thrombosis. The patient had a history of abdominal pain for one month. Abdominal vascular CT showed venous thrombosis in the portal vein and superior mesenteric vein. He was diagnosed with "portal and superior mesenteric vein thrombosis, small bowel obstruction and necrosis, acute upper gastrointestinal bleeding (UGIB), hemorrhagic shock." Serum protein S levels were decreased, and gene sequencing revealed a heterozygous missense mutation in PROS1, c.1571T > G (p.Leu584Arg). The patient received anticoagulation therapy with Enoxaparin Sodium and rivaroxaban, transjugular intrahepatic portosystemic shunt (TIPS), and ICU treatments. Although the patient had a severe bleeding event during anticoagulation therapy, he recovered well after active treatment and dynamic monitoring of anti-Xa.

Conclusion

Hereditary protein S deficiency caused by a mutation in the PROS1 gene is the genetic basis of this patient, and Enoxaparin Sodium and rivaroxaban have been shown to be highly effective.