Sex difference in the risk of recurrent venous thrombosis: a detailed analysis in four European cohorts

Proportion of venous thromboembolism attributed to recognized prothrombotic genotypes in men and women

Background

Data on the proportion of venous thromboembolism (VTE) risk attributed to prothrombotic genotypes in men and women are limited.

Objectives

We aimed to estimate the population attributable fraction (PAF) of VTE for recognized, common prothrombotic genotypes in men and women using a population-based case cohort.

Methods

Cases with incident VTE (n = 1493) and a randomly sampled subcohort (n = 13,069) were derived from the Tromsø study (1994-2012) and the Trøndelag Health Study (1995-2008) cohorts. DNA samples were genotyped for 17 single-nucleotide polymorphisms (SNPs) previously associated with VTE. PAFs with 95% bias-corrected CIs (based on 10,000 bootstrap samples) were estimated for SNPs significantly associated with VTE, and a 6-SNP cumulative model was constructed for both sexes.

Results

In women, the individual PAFs for SNPs included in the cumulative model were 16.9% for ABO (rs8176719), 17.6% for F11 (rs2036914), 15.1% for F11 (rs2289252), 8.7% for FVL (rs6025), 6.0% for FGG (rs2066865), and 0.2% for F2 (rs1799963). The cumulative PAF for this 6-SNP model was 37.8%. In men, the individual PAFs for SNPs included in the cumulative model were 21.3% for ABO, 12.2% for F11 (rs2036914), 10.4% for F11 (rs2289252), 7.5% for FVL, 7.8% for FGG, and 1.1% for F2. This resulted in a cumulative PAF in men of 51.9%.

Conclusion

Our findings in a Norwegian population suggest that 52% and 38% of the VTEs can be attributed to known prothrombotic genotypes in men and women, respectively.

A Comprehensive Review of Risk Factors and Thrombophilia Evaluation in Venous Thromboembolism

Venous thromboembolism (VTE), which encompasses deep vein thrombosis (DVT) and pulmonary embolism (PE), is a significant cause of morbidity and mortality worldwide. There are many factors, both acquired and inherited, known to increase the risk of VTE. Most of these result in increased risk via several common mechanisms including circulatory stasis, endothelial damage, or increased hypercoagulability. Overall, a risk factor can be identified in the majority of patients with VTE; however, not all risk factors carry the same predictive value. It is important for clinicians to understand the potency of each individual risk factor when managing patients who have a VTE or are at risk of developing VTE. With this, many providers consider performing a thrombophilia evaluation to further define a patient's risk. However, guidance on who to test and when to test is controversial and not always clear. This comprehensive review attempts to address these aspects/concerns by providing an overview of the multifaceted risk factors associated with VTE as well as examining the role of performing a thrombophilia evaluation, including the indications and timing of performing such an evaluation.

Incidence of Recurrent Venous Thromboembolism in a Population-Based Cohort

The incidence of recurrent venous thromboembolism (VTE) changes over time from the first VTE event and depends on the presence of risk factors. In this study, we aimed to determine the yearly incidence of VTE recurrence during five years of follow-up after a first-ever VTE event. For this cohort study, we identified persons who experienced a validated first-ever VTE between 2006-2014 in northern Sweden. These patients' medical records were reviewed to identify recurrent VTE events during five years of follow-up. The yearly incidence rates (IRs) of recurrent VTE per 100 person-years were calculated and stratified into three groups defined by characteristics at the first-ever VTE event: no risk factors, cancer, or other risk factors. A total of 1413 persons experienced a first-ever VTE during the study period, of whom 213 experienced a recurrent VTE. Among persons without risk factors, the IR was 4.2 during the first year of follow-up, and 4.1 during the fifth year. Among persons with cancer, the IR was 9.5 during the first year, and 5.4 during the fifth year. Among persons with other risk factors, the corresponding IRs were 6.1 and 2.3. In conclusion, after a first-ever VTE event, persons with cancer had the highest recurrence rate during the first years of follow-up. Among persons with cancer who were alive after five years, the incidence of recurrent VTE during the fifth year was similar to that in participants without risk factors.

Venous thromboembolism among physically active young adult females

Background

Young adult females are at risk of venous thromboembolism (VTE) due to various acquired and transient factors. In recent years, a growing number of females have engaged in strenuous physical activity, but its role as a risk factor for VTE is uncertain.

Objectives

To determine the incidence of VTE in young adult females engaged in strenuous physical activity.

Methods

A large national cohort of female individuals enlisted in the Israeli Defense Forces between 2012 and 2019 was analyzed. The study group consisted of participants undergoing strenuous physical training during their military service, while the control group maintained regular activity levels. We compared the incidence of VTE between the groups and adjusted for potential risk factors using a multivariate Cox analysis.

Results

The cohort included 160,718 female individuals aged 18 to 21years, of whom 11,745 engaged in strenuous physical activity and 148,973 served as controls. During a mean follow-up of 1.7 years, VTE occurred in 5 individuals (0.04%) in the strenuous activity group and 47 individuals (0.03%) in the control group. The incidence per 10,000 person-years was 2.41 (95% CI, 0.78-5.62) for the strenuous activity group and 1.82 (95% CI, 1.34-2.42) for the controls. Strenuous activity did not increase the risk for VTE in univariate or multivariate regression, with a hazard ratio (HR) of 1.27 (95% CI, 0.49-4.22). Use of oral contraceptives was the only significant risk factor, demonstrating dose effect; HR 1.95 (95% CI, 1.06-3.57) for low dose and HR 3.62 (95% CI, 1.40-9.37) for medium estrogen dose contraceptives.

Conclusion

Strenuous physical activity did not increase the risk for VTE among a large cohort of young adult female individuals.

A Comprehensive Review of Risk Factors for Venous Thromboembolism: From Epidemiology to Pathophysiology

Venous thromboembolism (VTE) is the third most common cause of death worldwide. The incidence of VTE varies according to different countries, ranging from 1-2 per 1000 person-years in Western Countries, while it is lower in Eastern Countries (<1 per 1000 person-years). Many risk factors have been identified in patients developing VTE, but the relative contribution of each risk factor to thrombotic risk, as well as pathogenetic mechanisms, have not been fully described. Herewith, we provide a comprehensive review of the most common risk factors for VTE, including male sex, diabetes, obesity, smoking, Factor V Leiden, Prothrombin G20210A Gene Mutation, Plasminogen Activator Inhibitor-1, oral contraceptives and hormonal replacement, long-haul flight, residual venous thrombosis, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, trauma and fractures, pregnancy, immobilization, antiphospholipid syndrome, surgery and cancer. Regarding the latter, the incidence of VTE seems highest in pancreatic, liver and non-small cells lung cancer (>70 per 1000 person-years) and lowest in breast, melanoma and prostate cancer (<20 per 1000 person-years). In this comprehensive review, we summarized the prevalence of different risk factors for VTE and the potential molecular mechanisms/pathogenetic mediators leading to VTE.

Vascular liver diseases: A sex-oriented analysis of the literature

Vascular liver diseases are an heterogenous group of diseases that collectively represent an important health issue in the field of liver diseases. This narrative review was elaborated by the Special Interest Group (SIG) "Gender in Hepatology" of the Italian Association for the Study of the Liver (AISF). We aimed to review the current knowledge regarding the potential role of biological sex in patients with vascular liver diseases such as splanchnic vein thrombosis, hepatic vein thrombosis, porto-sinusoidal vascular disorder, and hereditary hemorrhagic telangiectasia. As vascular liver diseases commonly affect young individuals, including women in childbearing age, we also included a specific section on the management of pregnancy in these challenging patients.

Thrombophilia, Thrombosis and Thromboprophylaxis in Pregnancy: For What and in Whom?

Compared with nonpregnant women, pregnancy carries a four- to fivefold higher risk of venous thromboembolism (VTE). Despite increasing use of heparin prophylaxis in identified high-risk patients, pulmonary embolism still is the leading cause of maternal mortality in the western world. However, evidence on optimal use of thromboprophylaxis is scarce. Thrombophilia, the hereditary or acquired tendency to develop VTE, is also thought to be associated with complications in pregnancy, such as recurrent miscarriage and preeclampsia. In this review, the current evidence on optimal thromboprophylaxis in pregnancy is discussed, focusing primarily on VTE prevention strategies but also discussing the potential to prevent recurrent pregnancy complications with heparin in pregnant women with thrombophilia.

Resistance to activated protein C and impaired TFPI activity in women with previous hormone-induced venous thromboembolism

INTRODUCTION

Hormonal contraception is a well-known risk factor for venous thromboembolism (VTE). APC resistance and impaired functions of protein S and TFPI are thought to play an important role in the pathogenesis of hormone-related VTE. It is unknown, whether women, who develop VTE during hormonal contraception possess a vulnerability in these pathways, making them susceptible to thrombosis.

MATERIALS AND METHODS

Plasma samples were obtained from 57 premenopausal women in average 15.3 years after hormone-associated VTE and from 31 healthy controls. Thrombin generation at high tissue factor (TF) in the absence and in the presence of activated protein C (APC) and at low TF without and with inhibiting anti-protein S- and anti-TFPI-antibodies was measured via calibrated automated thrombography.

RESULTS

Women with previous hormone-related thrombosis had higher thrombin generation at low TF, higher APC resistance, protein S- and TFPI ratios, differences: 219.9 nM IIa.min (95%CI:90.4 to 349.3); 1.88 (95%CI:0.71 to 3.05); 0.13 (95%CI:0.01 to 0.26) and 0.19 (95%CI:0.08 to 0.30), respectively. Thrombin generation at high TF without APC did not differ between the groups. Smoking decreased thrombin generation at low TF by -222.6 nM IIa.min (95%CI: -381.1 to -64.1), the APC sensitivity ratio by -2.20 (95%CI: -3.63 to -0.77) and the TFPI ratio by -0.16 (95%CI: -0.29 to -0.03), but did not influence thrombin generation at high TF.

DISCUSSION

We demonstrated impairment of the protein S/TFPI system and increased APC resistance in women with previous hormone-induced VTE. Smoking decreased thrombin generation at assay conditions, dependent on the function of the TFPI system.

Sex-related differences in D-dimer levels for venous thromboembolism screening

BACKGROUND

D-dimer is generally considered positive above 0.5 mg/L irrespective of sex. However, women have been shown to be more likely to have a positive D-dimer after controlling for other factors. Thus, differences may exist between males and females for using D-dimer as a marker of venous thromboembolic (VTE) disease. We hypothesized that the accuracy of D-dimer tests may be enhanced by using appropriate cutoff values that reflect sex-related differences in D-dimer levels.

METHODS

This research is a secondary analysis of a multicenter, international, prospective, observational study of adult (18+ years) patients suspected of VTE, with low-to-intermediate pretest probability based on Wells criteria ≤ 6 for pulmonary embolism (PE) and ≤ 2 for deep vein thrombosis (DVT). VTE diagnoses were based on computed tomography, ventilation perfusion scanning, or venous ultrasound. D-dimer levels were tested for statistical difference across groups stratified by sex and diagnosis. Multivariable regression was used to investigate sex as a predictor of diagnosis. Sex-specific optimal D-dimer thresholds for PE and DVT were calculated from receiver operating characteristic analyses. A Youden threshold (D-dimer level coinciding with the maximum of sensitivity plus specificity) and a cutoff corresponding to 95% sensitivity were calculated. Statistical difference for cutoffs was tested via 95% confidence intervals from 2,000 bootstrapped samples.

RESULTS

We included 3,586 subjects for analysis, of whom 61% were female. Race demographics were 63% White, 27% Black/African American, and 6% Hispanic. In the suspected PE cohort, 6% were diagnosed with PE, while in the suspected DVT cohort, 11% were diagnosed with DVT. D-dimer levels were significantly higher in males than females for the PE-positive group and the DVT-negative group, but males had significantly lower D-dimer levels than females in the PE-negative group. Regression models showed male sex as a significant positive predictor of DVT diagnosis, controlling for D-dimer levels. The Youden thresholds for PE patients were 0.97 (95% CI = 0.64 to 1.79) mg/L and 1.45 (95% CI = 1.36 to 1.95) mg/L for females and males, respectively; 95% sensitivity cutoffs for this group were 0.64 (95% CI = 0.20 to 0.89) and 0.55 (95% CI = 0.29 to 1.61). For DVT, the Youden thresholds were 0.98 (95% CI = 0.84 to 1.56) mg/L for females and 1.25 (95% CI = 0.65 to 3.33) mg/L for males with 95% sensitivity cutoffs of 0.33 (95% CI = 0.2 to 0.61) and 0.32 (95% CI = 0.18 to 0.7), respectively.

CONCLUSION

Differences in D-dimer levels between males and females are diagnosis specific; however, there was no significant difference in optimal cutoff values for excluding PE and DVT between the sexes.

Patients with high levels of circulating endothelial progenitor cells (EPC) following at least three months of anticoagulation for unprovoked venous thromboembolism (VTE) are at low risk of recurrent VTE-Results from the ExACT randomised controlled trial

BACKGROUND

There is clinical need for a laboratory biomarker to identify patients who, following an unprovoked venous thrombosis (VTE), are at low VTE recurrence risk and can discontinue anticoagulation after a limited treatment duration (3-6 m). This secondary analysis of the ExACT study aimed to evaluate whether quantitation of peripheral blood endothelial progenitor cells (EPCs) could improve prediction of VTE recurrence risk.

METHODS

The ExACT study was a non-blinded, multicentre RCT comparing extended vs discontinued anticoagulation following a first unprovoked VTE. Adult patients were eligible if they had completed ≥3 months anticoagulation and remained anticoagulated. The primary outcome was time to first recurrent VTE from randomisation. Blood samples were taken at baseline and results correlated with clinical outcome over 2 years follow up. (Trial registration: ISRCTN:73819751 and EUDRACT:2101-022119-20).

FINDINGS

281 patients were recruited, randomised (between July 2011 and February 2015) and followed up for 24 months (Male:Female 2:1, mean age 63). Of these, 273 patients were included in the final analysis. Blood samples were received at baseline for Full Blood Count(n = 216), d-dimers(n = 205) and endothelial progenitor cell (EPC) quantitation by flow cytometry(n = 193). VTE recurrence was lower in the extended vs discontinued anticoagulation arms (5% vs 23%, HR 0.20(95%CI:0.09-0.46,p < 0.001)). Level of EPCs were lower in patients who later developed VTE recurrence (43.41 ± 7.69 cells/ml vs 87.1 ± 7.15 cells/ml, p = 0.02). Survival free from VTE recurrence was significantly improved in patients with EPCs ≥ 100 cells/ml vs EPCs < 100 cells/ml (HR 0.10(95%CI:0.01-0.75,p = 0.025)).

INTERPRETATION

If confirmed, EPC quantitation may represent a novel biomarker that identifies patients at low VTE recurrence risk who are suitable for limited duration anticoagulation.

A randomised controlled trial of extended anticoagulation treatment versus standard treatment for the prevention of recurrent venous thromboembolism (VTE) and post-thrombotic syndrome in patients being treated for a first episode of unprovoked VTE (the ExACT study)

Venous thromboembolism (VTE) is prevalent and impactful, with a risk of death, morbidity and recurrence. Post-thrombotic syndrome (PTS) is a common consequence and associated with impaired quality of life (QoL). The ExACT study was a non-blinded, prospective, multicentred randomised controlled trial comparing extended versus limited duration anticoagulation following a first unprovoked VTE (proximal deep vein thrombosis or pulmonary embolism). Adults were eligible if they had completed ≥3 months anticoagulation (remaining anticoagulated). The primary outcome was time to first recurrent VTE from randomisation. The secondary outcomes included PTS severity, bleeding, QoL and D-dimers. Two-hundred and eighty-one patients were recruited, randomised and followed up for 24 months (mean age 63, male:female 2:1). There was a significant reduction in recurrent VTE for patients receiving extended anticoagulation [2·75 vs. 13·54 events/100 patient years, adjusted hazard ratio (aHR) 0·20 (95% confidence interval (CI): 0·09 to 0·46, P < 0·001)] with a non-significant increase in major bleeding [3·54 vs. 1·18 events/100 patient years, aHR 2·99 (95% CI: 0·81-11·05, P = 0·10)]. Outcomes of PTS and QoL were no different between groups. D-dimer results (on anticoagulation) did not predict VTE recurrence. In conclusion, extended anticoagulation reduced VTE recurrence but did not reduce PTS or improve QoL and was associated with a non-significant increase in bleeding. Results also suggest very limited clinical utility of D-dimer testing on anticoagulated patients.

Sex matters: Practice 5P's when treating young women with venous thromboembolism

Sex matters when it comes to venous thromboembolism (VTE). We defined 5P's - period, pill, prognosis, pregnancy, and postthrombotic syndrome - that should be discussed with young women with VTE. Menstrual blood loss (Period) can be aggravated by anticoagulant therapy. This seems particularly true for direct oral anticoagulants. Abnormal uterine bleeding can be managed by hormonal therapy, tranexamic acid, or modification of treatment. The use of combined oral contraceptives (Pill) is a risk factor for VTE. The magnitude of the risk depends on progestagen types and estrogen doses used. In women using therapeutic anticoagulation, concomitant hormonal therapy does not increase the risk of recurrent VTE. Levonorgestrel-releasing intrauterine devices and low-dose progestin-only pills do not increase the risk of VTE. In young women VTE is often provoked by transient hormonal risk factors that affects prognosis. Sex is incorporated as predictor in recurrent VTE risk assessment models. However, current guidelines do not propose using these to guide treatment duration. Pregnancy increases the risk of VTE by 4-fold to 5-fold. Thrombophilia and obstetric risk factors further increase the risk of pregnancy-related VTE. In women with a history of VTE, the risk of recurrence during pregnancy or post partum appears to be influenced by risk factors present during the first VTE. In most women with a history of VTE, antepartum and postpartum thromboprophylaxis with low-molecular-weight heparin is indicated. Women generally are affected by VTE at a younger age then men, and they have to deal with long-term complications (Post-thrombotic syndrome) of deep vein thrombosis early in life.

Risk of Recurrent Venous Thromboembolism After an Initial Episode: Risk Stratification and Implications for Long-term Treatment

PURPOSE OF REVIEW

Venous thromboembolism (VTE) is a common condition with significant associated morbidity and mortality. Recurrent VTE after an initial episode is a preventable medical condition. The following review discusses data supporting recurrence risk estimates after an initial VTE episode as well as treatment strategies to mitigate risk of recurrent VTE.

RECENT FINDINGS

This review particularly highlights methods for stratifying the risk of recurrent VTE and recent studies that have evaluated direct oral anticoagulants for the prevention of recurrent VTE. Risk assessment for VTE recurrence should guide anticoagulation duration. In patients who present with unprovoked VTE events, there remains a high risk of recurrence that is significantly mitigated with extended duration anticoagulation with either a vitamin K antagonist or direct oral anticoagulant.

Sex, gender and venous thromboembolism: do we care enough?

: The role of sex and gender in determining clinical presentation, diagnostic approach and outcomes of venous thromboembolism is not fully and systematically addressed, except for hormone-related events in women. A lack of knowledge is also apparent regarding drug prescription patterns, physician bias, enrolment in clinical studies and analysis of sex-related confounders in preclinical and clinical studies. As was shown for cardiovascular disease, ignoring sex and gender in medicine can have important impact on outcomes, including mortality. In this review, we seek to address some aspects of venous thromboembolism such as epidemiology and clinical presentation, recurrence, risk factors, animal studies, safety and efficacy of antithrombotic drugs, highlighting what is known and what is not regarding the role of sex and gender, and hoping to focus some interest and to promote the inclusion of these variables in all future studies on venous thromboembolism.

Risk factors for recurrence in deep vein thrombosis patients following a tailored anticoagulant treatment incorporating residual vein obstruction

BACKGROUND

Finding the optimal duration of anticoagulant treatment following an acute event of deep vein thrombosis (DVT) is challenging. Residual venous obstruction (RVO) has been identified as a risk factor for recurrence, but data on management strategies incorporating the presence of RVO and associated recurrence rates in defined clinical care pathways (CCP) are lacking.

OBJECTIVES

We aimed to investigate the long-term clinical outcomes and predictors of venous thromboembolism (VTE) recurrence in a contemporary cohort of patients with proximal DVT and managed in a CCP incorporating the presence of RVO.

PATIENTS

All patients treated at the Maastricht University Medical Center within an established clinical care pathway from June 2003 through June 2013 were prospectively followed for up to 11 years in a prospective management study.

RESULTS

Of 479 patients diagnosed with proximal DVT, 474 completed the two-year CCP (99%), and 457 (94.7%) the extended follow-up (2231.2 patient-years; median follow-up 4.6 years). Overall VTE recurrence was 2.9 per 100 patient-years, 1.3 if provoked by surgery, 2.1 if a non-surgical transient risk factor was present and 4.0 if unprovoked. Predictors of recurrent events were unprovoked VTE (adjusted hazard ratio [HR] 4.6; 95% CI 1.7, 11.9), elevated D-dimer one month after treatment was stopped (HR 3.3; 1.8, 6.1), male sex (HR 2.8; 1.5, 5.1), high factor VIII (HR 2.2; 1.2, 4.0) and use of contraceptives (HR 0.1; 0.0, 0.9).

CONCLUSIONS

Patients with DVT managed within an established clinical care pathway incorporating the presence of RVO had relatively low incidences of VTE recurrence.

The risk of venous thromboembolism in patients with hepatitis C

Some studies suggest that patients with hepatitis C virus (HCV) infection have an increased risk of deep venous thrombosis (DVT) and pulmonary embolism (PE). Unfortunately, available data on this association are contrasting. A systematic review and meta-analysis of literature studies was performed to evaluate the risk of venous thromboembolism (VTE) associated with HCV. Studies reporting on VTE risk associated with HCV were systematically searched in the PubMed, Web of Science, Scopus and EMBASE databases. Six studies (10 data-sets) showed a significantly increased VTE risk in 100,364 HCV patients as compared with 8,471,176 uninfected controls (odds ratio [OR]: 1.900; 95 % confidence interval [CI]: 1.406, 2.570; p<0.0001). These results were confirmed when specifically considering the risk of DVT (6 studies, OR: 1.918; 95 %CI: 1.351, 2.723; p<0.0001), whereas a trend towards an increased risk of PE was documented in HCV patients (4 studies, OR: 1.811; 95 %CI: 0.895, 3.663; p=0.099). The increased VTE risk associated with HCV infection was consistently confirmed when analysing four studies reporting adjusted risk estimates (OR: 1.876; 95 %CI: 1.326, 2.654; P<0.0001), and after excluding studies specifically enrolling populations exposed to transient risk factors for VTE (4 studies, OR: 1.493; 95 %CI: 1.167, 1.910; p=0.001). Meta-regression models suggested that age and male gender may significantly impact on the risk of VTE associated with HCV-positivity. Results of our metaanalysis suggest that HCV-infected subjects may exhibit an increased risk of VTE. However, further high quality studies are needed to extend and confirm our findings.

Supplementary Material to this article is available online at www.thrombosis-online.com.

Sensitized mutagenesis screen in Factor V Leiden mice identifies thrombosis suppressor loci

Factor V Leiden (F5L ) is a common genetic risk factor for venous thromboembolism in humans. We conducted a sensitized N-ethyl-N-nitrosourea (ENU) mutagenesis screen for dominant thrombosuppressor genes based on perinatal lethal thrombosis in mice homozygous for F5L (F5L/L ) and haploinsufficient for tissue factor pathway inhibitor (Tfpi+/- ). F8 deficiency enhanced the survival of F5L/LTfpi+/- mice, demonstrating that F5L/LTfpi+/- lethality is genetically suppressible. ENU-mutagenized F5L/L males and F5L/+Tfpi+/- females were crossed to generate 6,729 progeny, with 98 F5L/LTfpi+/- offspring surviving until weaning. Sixteen lines, referred to as "modifier of Factor 5 Leiden (MF5L1-16)," exhibited transmission of a putative thrombosuppressor to subsequent generations. Linkage analysis in MF5L6 identified a chromosome 3 locus containing the tissue factor gene (F3). Although no ENU-induced F3 mutation was identified, haploinsufficiency for F3 (F3+/- ) suppressed F5L/LTfpi+/- lethality. Whole-exome sequencing in MF5L12 identified an Actr2 gene point mutation (p.R258G) as the sole candidate. Inheritance of this variant is associated with suppression of F5L/LTfpi+/- lethality (P = 1.7 × 10-6), suggesting that Actr2p.R258G is thrombosuppressive. CRISPR/Cas9 experiments to generate an independent Actr2 knockin/knockout demonstrated that Actr2 haploinsufficiency is lethal, supporting a hypomorphic or gain-of-function mechanism of action for Actr2p.R258G Our findings identify F8 and the Tfpi/F3 axis as key regulators in determining thrombosis balance in the setting of F5L and also suggest a role for Actr2 in this process.

Optimal long-term pharmacological treatment of patients with venous thromboembolism that was unprovoked or associated with weak risk factors

INTRODUCTION

Unprovoked venous thromboembolism (VTE) tend to recur. Many factors, patient- or event-related, influence the individual risk of recurrence. After initial and long-term (usually for 3-6 months) anticoagulant therapy, extended anticoagulation has been recommended in patients at high risk of recurrence, provided they do not have a high risk of bleeding. Areas covered: The effect of different risk factors on the risk of recurrence is discussed, as well as risk factors for bleeding. The estimation of individual balance between these two risks is crucial to decide which can be the best treatment duration in single patients. The use of direct oral anticoagulants, with likely less risk of bleeding, may influence the balance. D-dimer assessment during and after anticoagulation is stopped is also commented for its role to help identifying the individual risk of recurrence. Expert commentary: All patients with a first VTE should be reconsidered after the initial 3-6 months of treatment. Anticoagulation can then be stopped or continued in relation to low or very high risk of recurrence, respectively. Serial D-dimer assessment during the first 2 or 3 months after anticoagulation is stopped is useful in patients with uncertain risk evaluation (especially after unprovoked events).

The long-term recurrence risk of patients with unprovoked venous thromboembolism: an observational cohort study

Essentials Long-term recurrence risk of venous thromboembolism (VTE) is uncertain. We performed a prospective cohort study of 839 patients with first unprovoked VTE. VTE recurrence risk is high, particularly in men with proximal thrombosis or pulmonary embolism. Sex and VTE site determine the recurrence risk and should be considered for patient counseling.

SUMMARY

Background The long-term recurrence risk (ltRR) of venous thromboembolism (VTE) is uncertain. Objective To assess the ltRR of patients with first unprovoked VTE. Patients/methods Patients were classified into three categories: distal deep vein thrombosis (DVT), proximal DVT or pulmonary embolism (PE), that is, PE associated with DVT or isolated PE. Patients with major thrombophilia or antithrombotic therapy were excluded. The endpoint was recurrent symptomatic VTE. Results A total of 839 patients were followed for a median of 7.7 years. VTE recurred in 263 patients (31%). After 10 and 20 years, the cumulative ltRR was 32% (95% confidence interval [CI], 29-36) and 44% (95% CI, 38-49) with 3.9 (95% CI, 3.3-4.6) and 3.3 (95% CI, 2.7-4.0) events per 100 patient-years, respectively. The adjusted hazard ratio was 2.1 (95% CI, 1.4-3.2) and 2.1 (95% CI, 1.4-3.2) for patients with proximal DVT or PE compared with patients with distal DVT and was 2.1 (95% CI, 1.6-2.9) for men compared with women. At 10 years, 4.7 (95% CI, 3.8-5.8) events per 100 patient-years occurred in men with proximal DVT or PE, 2.4 (95% CI, 1.2-4.4) in men with distal DVT, 1.9 (95% CI, 1.2-2.8) in women with proximal DVT or PE and 0.9 (95% CI, 0.2-1.9) in women with distal DVT. Conclusion The ltRR of patients with first unprovoked VTE is high and dependent upon sex and VTE site.

Male-specific risk of first and recurrent venous thrombosis: a phylogenetic analysis of the Y chromosome

Essentials Men have an unexplained higher risk of a first and recurrent venous thrombosis (VT) than women. We studied the role of the major European Y chromosome haplogroups in first and recurrent VT. In contrast to a study on coronary artery disease, haplogroup I was not linked to VT risk. Haplogroup E-carriers may have an increased risk of recurrent VT, but a larger study is needed.

SUMMARY

Background The risk of venous thrombosis (VT) recurrence is higher in men than in women. When reproductive risk factors are excluded, this sex difference is also apparent for a first VT. The current explanations for this difference are insufficient. Objectives To study the association between chromosome Y haplogroups and the risks of a first and recurrent VT. Methods Y chromosomes of 3742 men (1729 patients; 2013 controls) from the MEGA case-control study were tracked into haplogroups according to the phylogenetic tree. We calculated the risk of a first VT by comparing the major haplogroups with the most frequent haplogroup. For recurrence risk, 1645 patients were followed for a mean of 5 years, during which 350 developed a recurrence (21%; MEGA follow-up study). We calculated recurrence rates for the major haplogroups, and compared groups by calculating hazard ratios. Results We observed 13 haplogroups, of which R1b was the most frequent (59%). The major haplogroups were not associated with a first VT, with odds ratios ranging from 1.01 to 1.15. Haplogroup E carriers had the highest recurrence rate (53.5 per 1000 person-years, 95% confidence interval [CI] 33.3-86.1), whereas haplogroup R1a carriers had the lowest recurrence rate (24.3 per 1000 person-years, 95% CI 12.6-46.6). As compared with haplogroup R1b carriers, both haplogroups were not significantly associated with recurrence risk. Conclusions In contrast to a study on coronary artery disease, our results do not show a clear predisposing effect of Y haplogroups on first and recurrent VT risk in men. It is therefore unlikely that Y variation can explain the sex difference in VT risk.

Predicted burden of venous disease

Chronic venous disease is a common condition with clinical signs and symptoms ranging from spider veins, to varicose veins, to active venous ulceration. Both superficial and deep venous dysfunction may be implicated in the development of this disease. Socio-economic factors are shaping our population, with increasing age and body mass index resulting in significant pressure on healthcare systems worldwide. These risk factors also lead to an increased risk of developing superficial and/or deep venous insufficiency, increasing disease prevalence and morbidity. In this chapter, the authors review the current and future burden of chronic venous disease from an epidemiological, quality of life and economic perspective.