A comparison of six weeks with six months of oral anticoagulant therapy after a first episode of venous thromboembolism. Duration of Anticoagulation Trial Study Group

Clinical presentation and therapeutic management of venous thrombosis in young children: a retrospective analysis

BACKGROUND

Venous thromboembolism (VTE) in young children is not well documented.

METHODS

Clinicians from 12 institutions retrospectively evaluated the presentation, therapeutic management, and outcome of VTE in children younger than 2 years seen in 2011-2016. Feasibility of recruiting these children in EINSTEIN-Jr. phase III, a randomized trial evaluating rivaroxaban versus standard anticoagulation for VTE, was assessed.

RESULTS

We identified 346 children with VTE, of whom 227 (65.6%) had central venous catheter-related thrombosis (CVC-VTE), 119 (34.4%) had non-CVC-VTE, and 156 (45.1%) were younger than 1 month. Of the 309 children who received anticoagulant therapy, 86 (27.8%) had a short duration of therapy (i.e. < 6 weeks for CVC-VTE and < 3 months for non-CVC-VTE) and 17 (5.5%) had recurrent VTE during anticoagulation (n = 8, 2.6%) or shortly after its discontinuation (n = 9, 2.9%). A total of 37 (10.7%) children did not receive anticoagulant therapy and 4 (10.5%) had recurrent VTE.The average number of children aged < 0.5 years and 0.5-2 years who would have been considered for enrolment in EINSTEIN-Jr is approximately 1.0 and 0.9 per year per site, respectively.

CONCLUSIONS

Young children with VTE most commonly have CVC-VTE and approximately one-tenth and one-fourth received no or only short durations of anticoagulant therapy, respectively. Recurrent VTE rates without anticoagulation, during anticoagulation or shortly after its discontinuation seem comparable to those observed in adults. Short and flexible treatment durations could potentially increase recruitment in EINSTEIN-Jr. phase III.

Risk of Recurrent Venous Thromboembolism: A Danish Nationwide Cohort Study

PURPOSE

In this study, we aimed to estimate recurrence risk after incident venous thromboembolism, stratified according to unprovoked, provoked, and cancer-related venous thromboembolism in a prospective cohort of inpatients and outpatients receiving routine care.

METHODS

We linked nationwide Danish health registries to identify all patients with incident venous thromboembolism from January 2000 through December 2015. Rates of recurrence were calculated and Cox regression was used to compute hazard ratios (HRs) with 95% confidence intervals (CIs) by incident venous thromboembolism type after adjusting for coexisting risk factors.

RESULTS

The study included 73,993 patients with incident venous thromboembolism (54.1% females; mean age, 62.3 years). At 6-month follow-up, rates per 100 person-years were 6.80, 6.92, and 9.06 for provoked, unprovoked, and cancer-related venous thromboembolism, respectively. At 10-year follow-up, corresponding rates were 2.22, 2.84, and 3.70, respectively. Additionally, at 6-month follow-up, hazard rates of recurrence were comparable for patients with unprovoked venous thromboembolism 1.01 (95% CI, 0.92-1.11) and provoked. At 10-year follow-up, unprovoked venous thromboembolism (HR, 1.17; 95% CI, 1.12-1.23) and cancer-related venous thromboembolism (HR, 1.21; 95% CI, 1.12-1.32) were associated with higher risk of recurrence compared with that found in provoked venous thromboembolism.

CONCLUSIONS

In this nationwide cohort, patients with cancer-related venous thromboembolism had the highest risk of recurrence. At 6-month follow-up, there were similar risks of recurrence for patients with unprovoked and provoked venous thromboembolism. At 10-year follow-up, recurrence risks were similar for patients with unprovoked venous thromboembolism and patients with cancer-related venous thromboembolism. High recurrence risks in all categories indicate that further research is needed to optimize duration of extended anticoagulation for these patients.

Comparative efficacy and safety of low-intensity warfarin therapy in preventing unprovoked recurrent venous thromboembolism: A systematic review and meta-analysis

BACKGROUND

Although there exists potential risk of bleeding, extended 'lifelong' conventional-intensity [international normalized ratio (INR): 2.0-3.0] warfarin anticoagulation is recommended for unprovoked venous thromboembolism (VTE) patients because of risk of recurrent VTE. Whether long-term low-intensity (INR: 1.5-2.0) warfarin therapy reduced the risk of major bleeding without substantially lowered antithrombotic efficacy is not well understood. The aim of this study was to perform a systematic review and meta-analysis to evaluate the risk-benefits of low-intensity warfarin therapy.

METHODS

We conducted a comprehensive search of electronic databases and included randomized control trials (RCTs) that reported efficacy (recurrent VTE) and safety (bleeding episodes) of low-intensity warfarin therapy compared with conventional-intensity warfarin or placebo from inception through Jun 2016.

RESULTS

Four RCTs reporting high GRADE quality evidence were included. Although the relative risk of recurrent VTE with low-intensity therapy was significantly increased [2.96 (95% CI: 1.40 to 6.24), P < .004] compared to conventional-intensity warfarin, there was significant decrease of relative risk when compared with placebo [0.37 (95% CI: 0.24 to 0.56), P < .00001]. As per included publications, no significant major bleeding episodes were observed in low-intensity warfarin group.

CONCLUSIONS

Although less effective than conventional-intensity warfarin therapy this meta-analysis indicates that long-term low-intensity warfarin therapy is highly effective for preventing recurrent VTE than placebo, along with reduced risks of major bleeding and minimizing potential complications.

Anticoagulation in venous Thrombosis

Major studies addressing various aspects of the treatment of deep vein thrombosis are reviewed. It has lately been demonstrated that heparin should be dosed according to body weight and is preferably given as subcutaneous injections twice daily. Alternatively, low-molecular-weight heparins may be given in a fixed dose once daily, which does not require monitoring. Oral anticoagulation should be started concomitantly with heparin and targeted at an international normalized ratio of 2.0-3.0. This treatment should continue for a longer duration than previously accepted, in many cases for 6 months. For patients with contraindications to oral anticoagulation, secondary prophylaxis with a low-molecular-weight heparin is also effective and safe.

New Trends in Anticoagulation Therapy

Anticoagulation pharmacy has been dramatically altered with US Food and Drug Administration (FDA) approval of 5 direct oral anticoagulants, 1 novel reversal agent and, a second designated for fast-track approval. Trial data surrounding current trends in anticoagulant choice for VTE, reversal, and bridging are constantly redefining practice. Extended therapy for unprovoked VTE has expanded to include low-dose direct oral anticoagulants, aspirin, and the use of the HERDOO2 system to identify women who can stop anticoagulant therapy without increased risk of recurrent VTE. Trends in thromboprophylaxis include extended duration low-dose direct oral anticoagulants to prevent VTE in high-risk patients.

Effects of warfarin on biological processes other than haemostasis: A review

Warfarin is the world's most widely used anticoagulant drug. Its anticoagulant activity is based on the inhibition of the vitamin K-dependent (VKD) step in the complete synthesis of a number of blood coagulation factors that are required for normal blood coagulation. Warfarin also affects synthesis of VKD proteins not related to haemostasis including those involved in bone growth and vascular calcification. Antithrombotic activity of warfarin is considered responsible for some aspects of its anti-tumour activity of warfarin. Some aspects of activities against tumours seem not to be related to haemostasis and included effects of warfarin on non-haemostatic VKD proteins as well as those not related to VKD proteins. Inflammatory/immunomodulatory effects of warfarin indicate much broader potential of action of this drug both in physiological and pathological processes. This review provides an overview of the published data dealing with the effects of warfarin on biological processes other than haemostasis.

Duration of anticoagulant therapy in pediatric venous thromboembolism: Current approaches and updates from randomized controlled trials

INTRODUCTION

Compared with the incidence of venous thromboembolism in the adult population, pediatric VTE is rare. Yet, recent data suggest that the incidence of VTE in children is increasing, and little is known about the optimal duration of anticoagulation in pediatrics. Areas covered: This review summarizes current evidence-based adult recommendations and associated clinical trials from which current guidelines on the duration of anticoagulation in children have been extrapolated. It also discusses pediatric expert consensus-based guidelines and current pediatric clinical trials on duration of therapy in pediatric VTE. Expert commentary: The vast majority of pediatric VTE are provoked, and evidence on duration of anticoagulation for pediatric VTE is highly limited, but suggests that a maximum duration of 3 months is reasonable for most patients with provoked VTE, whereas longer duration is likely appropriate for unprovoked VTE. Whether shorter duration than 3 months is optimal for pediatric provoked VTE is as yet unclear. Results from the multinational randomized controlled trial studying the duration of anticoagulant therapy for provoked VTE in patients <21 years old (Kids-DOTT) will be critical to inform the future standard of care in pediatric VTE treatment.

Dynamics of case-fatalilty rates of recurrent thromboembolism and major bleeding in patients treated for venous thromboembolism

In patients with venous thromboembolism (VTE), assessment of the risk of fatal recurrent VTE and fatal bleeding during anticoagulation may help to guide intensity and duration of therapy. We aimed to provide estimates of the case-fatality rate (CFR) of recurrent VTE and major bleeding during anticoagulation in a ‘real life’ population, and to assess these outcomes according to the initial presentation of VTE and its etiology. The study included 41,826 patients with confirmed VTE from the RIETE registry who received different durations of anticoagulation (mean 7.8 ± 0.6 months). During 27,110 patient-years, the CFR was 12.1% (95% CI, 10.2–14.2) for recurrent VTE, and 19.7% (95% CI, 17.4–22.1) for major bleeding. During the first three months of anticoagulant therapy, the CFR of recurrent VTE was 16.1% (95% CI, 13.6–18.9), compared to 2.0% (95% CI, 0–4.2) beyond this period. The CFR of bleeding was 20.2% (95% CI, 17.5–23.1) during the first three months, compared to 18.2% (95% CI, 14.0–23.2) beyond this period. The CFR of recurrent VTE was higher in patients initially presenting with PE (18.5%; 95% CI, 15.3–22.1) than in those with DVT (6.3%; 95% CI, 4.5–8.6), and in patients with provoked VTE (16.3%; 95% CI, 13.6–19.4) than in those with unprovoked VTE (5.5%; 95% CI, 3.5–8.0). In conclusion, the CFR of recurrent VTE decreased over time during anticoagulation, while the CFR of major bleeding remained stable. The CFR of recurrent VTE was higher in patients initially presenting with PE and in those with provoked VTE.

D-dimer and residual vein obstruction as risk factors for recurrence during and after anticoagulation withdrawal in patients with a first episode of provoked deep-vein thrombosis

D-dimer and residual venous obstruction (RVO) have been separately shown to be risk factors for recurrent venous thromboembolism (VTE) after a first episode of unprovoked proximal deep-vein thrombosis (DVT). It was the objective of this study to assess the predictive value of D-dimer and residual vein obstruction (RVO), alone and in combination, for recurrence after provoked DVT of the lower limbs. A total of 296 consecutive patients with a first episode of symptomatic provoked proximal DVT were evaluated at a university hospital in Bologna, Italy. On the day of anticoagulation withdrawal (T0), RVO was determined by compression ultrasonography. D-dimer levels (cut-off: 500 ng/ml) were measured at T0 and after 30 ±10 days (T1). The main outcome was recurrent VTE during a two-year follow-up. D-dimer was abnormal in 11.6% (32/276) and 31% (85/276) of subjects at T0 and at T1, respectively. RVO was present in 44.8% (132/294) of patients. Recurrence rate was 5.1% (15/296; 95% confidence interval [CI]: 3–8%; 3% patient-years; 95% CI: 2–5 %). An abnormal D-dimer either at T0 or at T1 was associated with an adjusted hazard ratio (HR) for recurrence of 4.2 (95% CI:1.2–14.2; p=0.02) and 3.8 (95%CI: 1.2–12.1; p=0.02), respectively, when compared with normal D-dimer. The HR for recurrence associated with RVO was not significant, and RVO did not increase the recurrence risk associated with an abnormal D-dimer either at T0 or T1. In conclusion, an abnormal D-dimer during vitamin K antagonist (VKA) treatment or at one month after VKA withdrawal is a risk factor for recurrence in patients with provoked DVT, while RVO at the time of anticoagulation withdrawal is not.

Acute pulmonary embolism during warfarin therapy and long-term risk of recurrent fatal pulmonary embolism

The clinical characteristics and long-term outcomes of patients presenting with acute pulmonary embolism (PE) during treatment with warfarin have not been described. Clinical details of all patients admitted to a tertiary institution from 2000-2007 with acute PE were retrieved retrospectively, baseline warfarin status and the international normalised ratio (INR) were recorded, and their outcomes tracked using a statewide death registry. Of 923 patients with clearly documented warfarin status included in this study, 83 (9%) were taking warfarin. Mean (± standard deviation) day-1 INR of those taking warfarin was 2.3 ± 0.9, with 67% of patients therapeutically anti-coagulated (INR ≥2.0) at presentation (49 patients with INR <2.5 and 34 with INR ≥2.5). Patients taking warfarin on admission were more likely to have heart failure, atrial fibrillation and valvular heart disease, with similar prevalence of malignancy and ischaemic heart disease, compared to patients not on warfarin. Total mortality of the cohort (mean follow-up 4.0 ± 2.5 years) was 31.6% (in-hospital mortality 1.5%), and was similar between warfarin and no warfarin groups. There was however a greater than four-fold increased risk of post-discharge death due to recurrent PE for the patients taking warfarin on admission (hazard ratio [HR] 4.43, 95% confidence interval [CI] 1.36-14.42, p=0.01). Among patients taking warfarin on admission, day-1 INR <2.5 significantly increased long-term all-cause mortality compared to INR ≥2.5 (adjusted HR 2.51, 95% CI 1.08-5.86, p=0.03). In conclusion, patients presenting with PE during treatment with warfarin have an increased risk of death from recurrent PE. Admission INR appears to have independent long-term prognostic importance in these patients.

Optimal duration of anticoagulation

Once anticoagulation is stopped, the risk of recurrent venous thromboembolism (VTE) over years after a first episode is consistently around 30%. This risk is higher in patients with unprovoked than in those with (transient) provoked VTE, and among the latter in patients with medical than in those with surgical risk factors. Baseline parameters that have been found to be related to the risk of recurrent VTE are the proximal location of deep-vein thrombosis, obesity, old age, male sex and non-0 blood group, whereas the role of inherited thrombophilia is controversial. The persistence of residual vein thrombosis at ultrasound assessment has consistently been shown to increase the risk, as do persistently high values of D-dimer and the early development of the post-thrombotic syndrome. Although the latest international guidelines suggest indefinite anticoagulation for most patients with the first episode of unprovoked VTE, strategies that incorporate the assessment of residual vein thrombosis and D-dimer have the potential to identify subjects in whom anticoagulation can be safely discontinued. Moreover, new opportunities are offered by a few emerging anti-Xa and anti-IIa oral compounds, which are likely to induce fewer haemorrhagic complications than vitamin K antagonists while preserving the same effectiveness; and by low-dose aspirin, which has the potential to prevent the occurrence of both venous and arterial thrombotic events.

A survey of pediatric hematology/oncology specialists regarding management of central line associated venous thrombosis

Central venous catheters (CVCs) account for the largest proportion of thrombotic events in pediatric patients. Questions remain regarding adequate treatment and prevention methods. We surveyed pediatric hematology/oncology specialists, using hypothetical cases to assess management strategies for acute CVC thrombosis and secondary prevention. Survey respondents varied in the use of the thrombophilia evaluation (33.3%, 41/123) and duration of treatment (6 weeks: 54.1%, 66/122). Secondary CVC prophylaxis was utilized by 36.6% (45/123) of respondents and by 24.4% (30/123) but only if there was a documented thrombophilia. This heterogeneity highlights the need for clinical studies to address these important clinical questions.

Survival and recurrent venous thromboembolism in patients with first proximal or isolated distal deep vein thrombosis and no pulmonary embolism

Essentials The long-term risk of recurrence and death after distal deep vein thrombosis (DVT) is uncertain. We included subjects with first proximal or isolated distal DVT (IDDVT) and no pulmonary embolism. The risk of symptomatic and asymptomatic recurrence is lower after IDDVT (vs. proximal). IDDVT may be associated with a lower long-term risk of death, especially after unprovoked DVT.

SUMMARY

Background A few studies have focused on the risk of recurrence after first acute isolated distal deep vein thrombosis (IDDVT) compared with proximal DVT (PDVT), whereas the incremental risk of death has never been explored beyond the first 3 years after acute event. Methods Our single-center cohort study included patients with first symptomatic acute PDVT or IDDVT. Patients were excluded if they had concomitant pulmonary embolism (PE) or prior venous thromboembolism. The primary outcomes were symptomatic objectively diagnosed recurrent PDVT or PE and all-cause death. Results In total, 4759 records were screened and 831 subjects included: 202 had symptomatic IDDVT and 629 had PDVT. The median age was 66 years and 50.5% were women. A total of 125 patients had recurrent PDVT or PE during 3175 patient-years of follow-up: 109 events occurred after PDVT (17.3%) and 16 after IDDVT (7.9%). Annual recurrence rates were 4.5% (95% confidence interval [CI], 3.7-5.4%) and 2.0% (95% CI, 1.1-3.2%), respectively, for an adjusted hazard ratio (aHR) for IDDVT patients of 0.32 (95% CI, 0.19-0.55). Death occurred in 263 patients (31.6% [95% CI, 28.6-34.9%]) during 5469 patient-years of follow-up for an overall annual incidence rate of 4.8% (95% CI, 4.2-5.4%). The mortality rate was 33.5% (n = 211) in PDVT patients and 25.7% (n = 52) in IDDVT patients. The long-term hazard of death appeared lower for IDDVT patients (aHR, 0.75 [95% CI, 0.55-1.02]), especially after unprovoked events (aHR, 0.58 [95% CI, 0.26-1.31]). Conclusions Compared with PDVT, IDDVT patients were at a lower risk of recurrent VTE. The risk of death appeared lower after IDDVT during a median follow-up of 7.6 years.

Venous thromboembolism: Past, present and future

Venous thromboembolism (VTE), the third most frequent acute cardiovascular syndrome, is associated with a considerable disease burden which continues to grow along with the longer life expectancy of the population worldwide. In the past century, parenteral heparin prophylaxis was established for hospitalised patients at elevated risk of VTE. More recently, non-vitamin K antagonist oral anticoagulants (NOACs) with a direct inhibiting effect on factor Xa or thrombin, underwent extensive testing in clinical trials and have been approved for patients undergoing hip or knee replacement. Clinical investigation is ongoing in further areas of thromboprophylaxis, including medical prophylaxis in patients and high-risk situations in the outpatient setting. The diagnostic approach to suspected VTE is now based on advanced imaging techniques and robust diagnostic algorithms which ensure high sensitivity and specificity. Nevertheless, the role of clinical, or pre-test, probability assessment remains crucial to avoid overdiagnosis and treatment errors. Advances in reperfusion strategies, along progressive establishment of the NOACs as the new standard of anticoagulation treatment, have simplified the management of VTE, improving outcomes and particularly safety. While new molecular targets for anticoagulation are being investigated in the quest to further reduce bleeding risk, adjusting the initial regimen to the patient's risk and finding the optimal duration of anticoagulation after an index VTE event will be some of the top priorities in the years to come. Importantly, and in parallel to new drugs and technical advances in imaging, incentives such as hospital accreditation and funding based on evidence-based practice need to be implemented to increase guideline adherence.

Anticoagulation in patients with isolated distal deep vein thrombosis: a meta-analysis

Essentials The optimal management of isolated distal deep vein thrombosis (IDDVT) is undefined. This meta-analysis aimed to assess the clinical benefit of anticoagulation for IDDVT. Anticoagulation reduced the rate of pulmonary embolism without increasing major bleeding risk. Recurrent thromboembolism was less common with more than 6 weeks vs. 6 weeks of anticoagulation.

SUMMARY

Background The optimal management of patients with isolated distal deep vein thrombosis (IDDVT), concerning both the need for anticoagulation and its duration, is undefined. Objectives We performed a meta-analysis of randomized and cohort studies in patients with IDDVT to assess the clinical benefit of: (i) anticoagulation versus no anticoagulation; and (ii) anticoagulant treatment for 6 weeks versus for > 6 weeks. Methods The primary outcome of this analysis was recurrent venous thromboembolism (proximal propagation, recurrence of deep vein thrombosis, and pulmonary embolism). Data were pooled and compared by the use of odds ratio (OR) and 95% confidence interval (CI). Results A reduction in the rate of recurrent venous thromboembolism was observed in patients who received anticoagulation relative to those who did not receive anticoagulation (either therapeutic or prophylactic) (20 studies, 2936 patients; OR 0.50, 95% CI 0.31-0.79), without an increase in the risk of major bleeding (OR 0.64, 95% CI 0.15-2.73). The rate of pulmonary embolism was lower in anticoagulant-treated patients than in controls (15 studies, 1997 patients; OR 0.48, 95% CI 0.25-0.91). A lower rate of recurrent venous thromboembolism was observed in patients who received > 6 weeks of anticoagulant therapy than in those who received 6 weeks of anticoagulant therapy (four studies, 1136 patients; OR 0.39, 95% CI 0.17-0.90). Conclusions In patients with IDDVT, anticoagulation (both therapeutic and prophylactic) reduces the rate of recurrent venous thromboembolism and the incidence of pulmonary embolism as compared with no anticoagulation, without an increased risk of major bleeding. Anticoagulation for > 6 weeks should be preferred over shorter durations.

Treatment of Isolated Below the Knee Deep Vein Thrombosis

The natural history of isolated distal deep-vein thrombosis (IDDVT) is still uncertain, as well as the real clinical risks associated with the disease and the need for its diagnosis and treatment. While more and more IDDVTs are diagnosed in everyday clinical practice, their appropriate therapeutic management is, unfortunately, far from straightforward, and different recommendations on how patients with diagnosed IDDVT should be treated are present between expert professionals and even among international guidelines. The present article aims at briefly reviewing the issue of IDDVT therapy in general, particularly focusing on the different approaches to the treatment of the disease that have been suggested by recent guidelines, those that are currently adopted in clinical practice, and necessary future directions.

Characteristics of provoked deep venous thrombosis in a tertiary care center

OBJECTIVE

Provoked deep venous thrombosis (DVT) is precipitated by a specific event. This paper compares the characteristics of provoked DVT in patients with transient risk (TR) factors and patients with continuous risk (CR) factors.

METHODS

A retrospective review of records of all consecutive patients diagnosed with DVT between January 2013 and August 2014 was performed. Patients with provoked DVT were included in the TR group if the provoking event resolved in 2 weeks and they did not have ongoing risk of thrombosis. Patients in the CR group had a provoked DVT with ongoing risk of thrombosis due to individual factors deemed to be ongoing risks of thrombosis, such as cancer, hypercoagulable disorder, and prolonged immobilization. Demographics, risk factors, association with pulmonary embolism (PE) and its severity, risk of recurrent venous thromboembolism (VTE), and mortality were compared between the two groups.

RESULTS

A total of 838 patients were diagnosed with DVT, and 50.7% (425) were provoked. There were 127 (29.9%) patients with TR and 298 (70.1%) with CR. TR patients were younger (60.4 ± 16.3 vs 65.9 ± 16.0; P = .001). TR was more likely to be provoked by surgery (70.9% vs 55.4%; P = .003), whereas CR was more likely to be provoked by immobilization (21.5% vs 12.6%; P = .032). CR patients were affected by cancer (48.7%) and hypercoagulable disorders (4.4%). TR patients were more likely to have calf DVTs (36.2% vs 26.2%; P = .047). There was a trend toward lower association with PE on presentation in TR (17.3% vs 21.1%; P = .072), but that did not reach statistical significance. However, TR factors were more likely to be associated with low-risk PE compared with CR factors (30.2% vs 54.6%; P = .040). After mean follow-up of 7.2 months, CR had higher risk of recurrent VTE (14.0% vs 6.8%; P = .045) and mortality (23.5% vs 7.1%; P < .0001).

CONCLUSIONS

Provoked DVT with CR factors affects older patients and is associated with high recurrence of VTE and mortality compared with provoked DVT with TR factors.

D-dimer at venous thrombosis diagnosis is associated with risk of recurrence

Essentials Whether D-dimer at incident venous thromboembolism (VTE) can predict recurrence-risk is unknown. We explored this association in 454 cancer-free patients with a first lifetime VTE. A low D-dimer at first VTE diagnosis was associated with a low recurrence risk. The association was predominant in patients with deep vein thrombosis and unprovoked VTE. Click to hear Dr Cannegieter's presentation on venous thrombosis: prediction of recurrence SUMMARY: Background Venous thromboembolism (VTE) is a common disease with a high recurrence rate. D-dimer measured after cessation of anticoagulant therapy predicts recurrence, and is used to decide on treatment prolongation. However, whether D-dimer measured at first VTE diagnosis can be used to assess recurrence-risk is unknown. Aims To investigate the association between D-dimer, measured at first VTE diagnosis and risk of recurrent VTE. Methods Information on clinical risk factors and laboratory markers were collected in 454 cancer-free patients with a first VTE. Recurrent VTEs and deaths during follow-up (1994-2012) were recorded. Results During a median follow-up of 3.9 years, 84 patients experienced a recurrent VTE. The crude recurrence rate was 1.7 (95% confidence interval [CI], 1.0-2.9) per 100 person-years in the lower quartile of D-dimer (≤ 1500 ng mL-1 ), and 4.9 (95% CI, 3.9-6.1) per 100 person-years in the upper three quartiles combined, yielding an absolute risk difference of 3.2 per 100 person-years. Patients with D-dimer ≤ 1500 ng mL-1 had 54% lower recurrence-risk than patients with D-dimer > 1500 ng mL-1 (HR, 0.46; 95% CI, 0.25-0.82). The association was particularly pronounced among patients with unprovoked events and deep vein thrombosis, showing a 66% (HR, 0.34; 95% CI, 0.15-0.74) and 68% (HR, 0.32; 95% CI, 0.14-0.71) lower recurrence risk among patients with D-dimer ≤ 1500 ng mL-1 , respectively. Conclusions A low D-dimer (≤ 1500 ng mL-1 ) measured at first VTE diagnosis was associated with a low recurrence risk, particularly among patients with DVT and unprovoked events. Our findings suggest that a clinical decision to avoid prolonged anticoagulant treatment could be considered based on low D-dimer at the time of VTE diagnosis.

Recurrence and mortality after first venous thromboembolism in a large population-based cohort

Essentials Reports on recurrence and mortality after a first venous thromboembolism (VTE) vary considerably. We describe rates of recurrence and mortality in patients with a first VTE from the Tromsø study. The overall recurrence rate was 3.9 per 100 person-years, but this varied widely with time. Despite advances in VTE management, the rates of adverse events are still fairly high.

SUMMARY

Background Previous reports on recurrence and mortality rates after a first episode of venous thromboembolism (VTE) vary considerably. Advances in the management and treatment of VTE during the last 15 years may have influenced the rates of clinical outcomes. Aim To estimate the rates of recurrence and mortality after a first VTE in patients recruited from a large population-based cohort. Method From the Tromsø study, patients (n = 710) with a first, symptomatic, objectively confirmed VTE were included and followed in the period 1994-2012. Recurrent episodes of VTE were identified from multiple sources and carefully validated by review of medical records. Incidence rates and cumulative incidence rates with 95% confidence intervals (CIs) of VTE recurrence and mortality were calculated. Results The mean age of the patients was 68 years (range 28-102 years), and 166 (23.4%) had cancer at the time of first VTE. There were 114 VTE recurrences and 333 deaths during a median study period of 7.7 years (range 0.04-18.2 years). The risk of recurrence was highest during the first year. The overall 1-year recurrence rate was 7.8 (95% CI 5.8-10.6) per 100 person-years (PY), whereas the recurrence rate in the remaining follow-up period (1-18 years) was 3.0 (95% CI 2.4-3.8) per 100 PY. The overall 1-year all-cause mortality rate was 29.9 (95% CI 25.7-34.8) per 100 PY, and in those without cancer the corresponding rate was 23.6 (95% CI 17.8-31.3) per 100 PY. Conclusion Despite advances in VTE management, the rates of adverse events remained fairly high, particularly in the first year following a first VTE.

Risk factors associated with provoked pulmonary embolism

BACKGROUND/AIMS

This study aimed to investigate the risk factors associated with provoked pulmonary embolism (PE).

METHODS

This retrospective cohort study included 237 patients with PE. Patients that had transient risk factors at diagnosis were classified as having provoked PE, with the remaining patients being classified as having unprovoked PE. The baseline clinical characteristics and factors associated with coagulation were compared. We evaluated the risk factors associated with provoked PE.

RESULTS

Of the 237 PE patients, 73 (30.8%) had provoked PE. The rate of respiratory failure and infection, as well as the disseminated intravascular coagulation score and ratio of right ventricular diameter to left ventricular diameter were significantly higher in patients with provoked PE than in those with unprovoked PE. The protein and activity levels associated with coagulation, including protein C antigen, protein S antigen, protein S activity, anti-thrombin III antigen, and factor VIII, were significantly lower in patients with provoked PE than in those with unprovoked PE. Multivariate analysis showed that infection (odds ratio [OR], 3.2; 95% confidence interval [CI], 1.4 to 7.4) and protein S activity (OR, 0.97; 95% CI, 0.95 to 0.99) were significantly associated with provoked PE.

CONCLUSIONS

Protein S activity and presence of infection were important factors associated with provoked PE. We should pay attention to the presence of infection in patients with provoked PE.

Hospital-related first venous thromboembolism and risk of recurrence

Essentials Recurrence risk after a hospital-related venous thromboembolism (VTE) is underinvestigated. We explored this association in a cohort of patients with a first VTE from the Tromsø study. Stratification on hospital-related factors revealed considerable differences in recurrence risk. The recurrence risk was high in cases with a VTE related to hospitalization for medical illness.

SUMMARY

Background Hospitalization is a well-established risk factor for first venous thromboembolism (VTE), but the risk of recurrence, particularly in patients hospitalized for conditions other than cancer or surgery, has scarcely been investigated. The cumulative incidence of recurrence in hospital-related VTE may be influenced by the competing risk of death. Objectives To investigate the risk of recurrence and mortality among patients with a first hospital-related VTE in models with and without death as a competing event. Methods Information on hospital-related risk factors was collected in 822 patients with a first-lifetime VTE derived from the Tromsø study. Recurrent VTEs and deaths were recorded during follow-up (1994-2012). Results During a median of 2.79 years of follow-up, 132 patients experienced a recurrent VTE. Stratification on hospital-related factors revealed considerable differences in recurrence risk. The 5-year cumulative incidence of recurrence was 27.4%, 11.0% and 20.1% in patients with incident VTEs related to cancer, surgery or other medical illness, respectively, and 18.4% in patients with a non-hospital-related first VTE. The mortality rates were high for all subgroups of hospital-related VTE, except for surgery-related events. Consequently, the cumulative incidence of recurrence dropped in the competing risk analyses, showing a 5-year cumulative incidence of 14.4%, 11.7% and 9.7% in patients with a first VTE related to hospitalization for other medical illness, cancer or surgery, respectively. Conclusions Our findings suggest that patients with incident VTEs related to hospitalization for medical illness other than cancer or surgery have a high recurrence-risk, even in the presence of competing risk of death.

Tumor-Specific D-Dimer Concentration Ranges and Influencing Factors: A Cross-Sectional Study

D-dimer level in cancer patients is associated with risk of venous thromboembolism and deep venous thrombosis. Most cancer patients have "abnormal" D-dimer levels based on the current normal reference range. To investigate tumor-specific D-dimer reference range, we compared D-dimer levels for nine different tumour types with healthy controls by using simultaneous quantile regression and constructing a median, 5th percentile, and 95th percentile model of normal tumour D-dimer concentration. Associations with tumour primary site, stage, pathological type, and treatment were also explored. Additionally, 190 patients were tracked to reveal the relevance of initial D-dimer levels to cancer prognosis. D-dimer ranges (median, 5th, 95th) in various cancers (mg/L) were: liver 1.12, 0.27, 5.25; pancreatic 0.96, 0.23, 4.81; breast 0.44, 0.2, 2.17; gastric 0.65, 0.22, 5.03; colorectal 0.73, 0.22, 4.45; lung 0.7, 0.25, 4.0; gynaecological 0.61, 0.22, 3.98; oesophageal 0.23, 0.7, 3.45; and head and neck 0.22, 0.44, 2.19. All were significantly higher than that of healthy controls (0.18, 0.07, 0.57). D-dimer peaked 1-2 days postoperatively but had decreased to the normal range by 1 week. Additionally, cancer patients with high initial D-dimer were shown a tendency of poor prognosis in survival rate. In conclusion, D-dimer levels in cancer depend on patient age, tumour primary site, and tumour stage. Thrombosis prevention is necessary if D-dimer has not decreased to the tumor-specific baseline a week after surgery.

Management of idiopathic venous thromboembolism

INTRODUCTION

Idiopathic or unprovoked venous thromboembolism is an event occurring in the absence of any apparent provoking or triggering environmental risk factors, such as surgery, trauma, and immobilization. Areas covered: Unprovoked VTE can be associated with occult cancer, but only limited, and not extensive cancer screening, may be warranted, as the rate of occult cancer is low in such patients. Routine thrombophilia testing is not currently recommended as it does not influence the management of the disease. The duration of anticoagulation for unprovoked VTE after the first three months is still debated as the disease tends to recur regardless of treatment duration. Expert commentary: Prognostic scores incorporating patient related risk factors, such as age and sex, and global markers of hypercoagulability, such as D-dimer, have been proposed for identifying high risk patients who are candidates for extended anticoagulation beyond three months. Direct oral anticoagulants, aspirin and sulodexide could be alternative to vitamin K antagonists (VKA) for long term treatment in such patients. The most up to date guidelines suggest DOACs over VKA for non-cancer VTE in the first three months and also long-term in subjects at low or moderate risk of bleeding, albeit with grade 2B strength of recommendation.

Warfarin use and prostate cancer risk in the Finnish Randomized Study of Screening for Prostate Cancer

OBJECTIVE

Anticoagulants, especially vitamin K antagonists (VKAs) such as warfarin, have been hypothesized to have antitumor properties, and use of VKAs has been associated with a lower prostate cancer (PCa) risk. This study estimated PCa risk among users of warfarin and other anticoagulants.

MATERIALS AND METHODS

All anticoagulant use among 78,615 men during 1995-2009 was analyzed. Cox regression, adjusted for age, screening trial arm and use of other medications, with medication use as a time-dependent variable, was used to estimate PCa risk overall, and by tumor grade and stage.

RESULTS

In total, 6537 men were diagnosed with PCa during 1995-2009 (1210 among warfarin users). Compared to non-users, warfarin use was associated with an increased risk of PCa [multivariable-adjusted hazard ratio (HR) = 1.11, 95% confidence interval (CI) 1.01-1.22]. This was limited to short-term, low-dose use, and was not observed in long-term use. A similar overall risk increase was observed for Gleason grade 7-10 PCa. Low-dose, short-term use of warfarin was associated with an increased risk of metastatic PCa. However, the increase in risk vanished with continued use. Compared to other anticoagulants, low-dose use of warfarin was associated with a slightly elevated overall PCa risk (HR = 1.19, 95% CI 1.00-1.43). The increase in risk disappeared in long-term, high-dose use.

CONCLUSIONS

This study, which included a larger number of PCa cases with warfarin exposure than previous studies, does not support previous notions of decreased risk of PCa among warfarin users. A similar risk of PCa was found among warfarin users and the general population, and no difference in risk was found between warfarin and other anticoagulants.

Home Therapy With LMWH in Deep Vein Thrombosis: Randomized Study Comparing Single and Double Daily Administrations

The aim of this study was to assess the effectiveness of low-molecular-weight heparin (LMWH) treatment of deep vein thrombosis (DVT) in terms of the evolution of thrombosis, the incidence of adverse events, and compliance with heparin treatment using 2 types of LMWH available on the market administered in therapeutic doses throughout the period of treatment (Nadroparin) or at therapeutic doses only during the first month of treatment followed by a prophylactic phase at half dose (Parnaparin). A randomized prospective study was carried out on patients under observation with a recent diagnosis of DVT. The objectives of the study were to confirm the effectiveness of therapy with LMWH in terms of prevention of the risk of thromboembolism, of relapse of DVT, and of hemorrhagic complications, and to complete an evaluation of venous recanalization and residual valve competence in the 2 groups of patients. From December 2002 to June 2005, we randomized a total of 91 patients (51 in the Parnaparin group and 40 in the Nadroparin group). Overall, there was 1 case of nonfatal pulmonary embolism (1.1%) at 7 days into therapy with LMWH. There were 3 cases (3.3%) of progression of thrombosis despite therapy with LMWH, 2 cases (5%) in the Nadroparin group, and 1 case (2%) in the Parnaparin group (P = NS), and after suspension of the therapy, there was 1 case of relapse of thrombosis. Three of the 4 thrombotic events occurred in patients with active neoplasia. Moreover, only 1 major hemorrhagic event (1.1%) required blood transfusion. The Doppler ultrasound in the follow-up showed a complete resolution of 56% of the vein thromboses at an average of 6.1 ± 4.6 (mean ± SD) months. Valve competence recovered in 65.9% of cases with no significant difference between the 2 heparin groups. Home treatment of sural and femoral-popliteal DVT using LMWH represents a safe and effective method in the prevention of pulmonary embolism and encourages the process of recanalization of the thrombosed vessel, especially in cases of sural and/or popliteal DVT. Administration can be carried out with the same degree of safety at the therapeutic dose throughout the period of treatment or can be halved after the first month of treatment. In patients with active neoplasia, treatment with oral anticoagulant therapy must be considered.

Controversies in venous thromboembolism: the unique case of isolated distal deep vein thrombosis

Venous thromboembolism (VTE) represents the third leading cause of cardiovascular mortality, and it is the main cause of preventable mortality in hospitalized patients. Among VTE, there is the unique case of isolated distal deep vein thrombosis (IDDVT), which still lacks an agreement in terms of optimal therapeutic strategy. Although most IDDVTs are self-limiting and associated with a very low risk of embolic complications, still not all IDDVTs can be safely identified as stable. Lack of strong scientific evidence, fear of thromboembolic complications, and risk of bleeding upon initiation of anticoagulant treatment result in very heterogeneous therapeutic strategies among physicians. Here, we provide a comprehensive review of the literature, highlight the many controversial issues regarding IDDVTs, and call for a consensus of experts aimed to shed new light on the gray areas of IDDVT management and therapy.

Risk of recurrent venous thromboembolism after discontinuation of vitamin K antagonist treatment: a nested case-control study

Essentials Vitamin K antagonists (VKA) in venous thromboembolism (VTE) lower the risk of recurrences. 41 841 VKA-treated VTE patients had 1242 recurrent VTEs on therapy or early after cessation. An increased risk of recurrence was found in the first 120 days after VKA cessation. Patient education for the early detection of recurrent VTE after VKA cessation is recommended.

SUMMARY

Background The standard treatment for venous thromboembolism (VTE) and the prevention of recurrent VTE (rVTE) consists of anticoagulant therapy. The optimal duration of anticoagulation depends on the presence of risk factors for rVTE. Objectives To estimate the risk of rVTE in association with time since discontinuation of vitamin K antagonist (VKA) treatment. Methods From the UK Clinical Practice Research Datalink with linked information on hospitalization and cause of death, a cohort of patients with a first VTE receiving initial VKA treatment between 2001 and 2013 was formed. With a nested case-control approach, patients with incident rVTE (cases) were matched to patients with VTE but without rVTE (controls). Adjusted rate ratios (RRs) of rVTE associated with time since VKA discontinuation relative to current VKA use were estimated from conditional logistic regression. Results The VTE cohort comprised 41 841 patients with 1242 rVTEs and 6205 matched controls. The RR of rVTE was increased within 60 days following VKA discontinuation (RR 2.23, 95% confidence interval [CI] 1.71-2.91) and within 61-120 days following VKA discontinuation (RR 1.49, 95% CI 1.08-2.05) relative to current VKA use. The increased RR corresponded to excess incidence rates of 6.72 (95% CI 3.90-10.06) rVTE cases per 100 person-years within 60 days, and of 2.68 (95% CI 0.42-5.58) rVTE cases per 100 person-years within 61-120 days after VKA discontinuation. Conclusions VKA discontinuation results in a transient increased risk of rVTE, which peaks within 60 days and lasts for up to 120 days after VKA discontinuation. Specific patient education for increased vigilance for signs and symptoms of recurrences is recommended in this period.

Managing Extended Oral Anticoagulation After Unprovoked Venous Thromboembolism

Venous thromboembolism (VTE), which includes deep venous thrombosis and pulmonary embolism, is a major public health problem associated with increased morbidity and mortality. Despite the high recurrence risk associated with unprovoked VTE, extended anticoagulation remains controversial. Oral antithrombotic agents for extended VTE treatment comprise the vitamin K antagonists, aspirin, and the direct oral anticoagulants (also known as target-specific oral anticoagulants and formerly known as the new or novel oral anticoagulants) including rivaroxaban, dabigatran, apixaban, and edoxaban. The efficacy of these anticoagulants in reducing the risk of VTE recurrence (>80%-90% relative risk reduction) is offset by the risk of major bleeding that approaches 3% per year. Stratifying risks of recurrence and bleeding to identify patients at low, intermediate, or high risk and carefully considering the pharmacologic profile of the antithrombotic agents will help clinicians in choosing the optimal anticoagulant and duration and/or surveillance strategy. This review will discuss the current guidelines for extended VTE treatment, review the clinical trials involving the direct oral anticoagulants, and present the clinical considerations and concerns involving extended therapy.

Compression Stockings for Prevention of Postthrombotic Syndrome: A Systematic Review and Meta-Analysis

OBJECTIVE

The present meta-analysis aimed to evaluate the efficacy and safety of compression stockings for postthrombotic syndrome (PTS) prevention in patients with deep venous thrombosis (DVT).

METHODS

Randomized controlled trials (RCTs) regarding the use of compression stockings for prevention of PTS were identified from the Medline, PubMed, and Embase databases as well as the Cochrane library. The resulting manuscripts were analyzed according to the criteria in the Cochrane Handbook for Systematic Reviews of Interventions.

RESULTS

Six RCTs involving 1465 patients with DVT were included. The meta-analysis indicated no statistical differences between the compression stocking and the control groups in PTS incidence, using either the Villalta scale (odds ratio [OR], 0.63; 95% confidence interval [CI], 0.23-1.74) or the Ginsberg scale (OR, 1.13; 95% CI, 0.72-1.77). Based on the Villalta scale categorization, there were no differences in the incidence of mild-moderate PTS (OR, 0.71; 95% CI, 0.36-1.41) or incidence of severe PTS (OR, 0.68; 95% CI, 0.15-3.11). The difference in the recurrence of venous thromboembolism (OR, 0.89; 95% CI, 0.61-1.30) was also not significant. In the 3 RCTs that reported side effects of compression stockings, they were primarily related to discomfort, including itching, erythema, and rash.

CONCLUSION

The present meta-analysis has indicated that compression stockings may not prevent PTS, as determined by either the Villalta or the Ginsberg scale, in patients with DVT. However, owing to the limited number of trials, the evidence is not strong enough to draw a reliable conclusion. Further larger, randomized, double-blind, placebo-controlled, multicenter trials are needed.

Long-term Anticoagulation With Rivaroxaban for Preventing Recurrent VTE: A Benefit-Risk Analysis of EINSTEIN-Extension

BACKGROUND

Short-term anticoagulant treatment for acute DVT or pulmonary embolism (PE) effectively reduces the risk of recurrent disease during the first 6 to 12 months of therapy. Continued anticoagulation often is not instituted because of the perception among physicians that the risk of major bleeding will outweigh the risk of new venous thrombotic episodes.

METHODS

The authors performed a benefit-risk analysis by using the randomized EINSTEIN-Extension trial, which compared continued rivaroxaban with placebo in 1,197 patients with symptomatic DVT or PE who had completed 6 to 12 months of anticoagulation and in whom physicians had equipoise with respect to the need for continued anticoagulation. One-year Kaplan-Meier rates and rate differences of recurrent VTE and major bleeding were calculated. Benefits and risks were assessed using rate differences scaled to a population size of 10,000 patients treated for 1 year.

RESULTS

Recurrent VTE occurred in eight recipients of rivaroxaban and 42 patients receiving placebo. In a population of 10,000 patients treated for 1 year, rivaroxaban treatment would have resulted in 665 (95% CI, 246-1,084) fewer recurrent VTEs than would placebo (number needed to treat = 15). Major bleeding occurred in four (0.7%) and zero patients, respectively. Rivaroxaban treatment would have resulted in 68 (95% CI, 2-134) more major bleeding events than would placebo (number needed to harm = 147). Kaplan-Meier analysis showed early recurrent VTE reduction with rivaroxaban that continued to improve throughout treatment; major bleeding increased gradually, plateauing at approximately 100 days.

CONCLUSIONS

A clinically important benefit and a favorable benefit-risk profile of continued rivaroxaban anticoagulation was observed.

TRIAL REGISTRY

ClinicalTrials.gov; No.: NCT00439725; URL: www.clinicaltrials.gov.

Association between micro particle-tissue factor activity, factor VIII activity and recurrent VTE in patients with acute pulmonary embolism

Studies on the association between microparticle expressing tissue factor (MP-TF) activity, FVIII activity (FVIII:C) and recurrent VTE yielded inconclusive results. We studied these associations in patients diagnosed with acute pulmonary embolism. Plasma levels of MP-TF and FVIII activity were measured in 277 patients with a first and 72 patients with a recurrent VTE. All patients were categorized based on the quintiles of MP-TF and FVIII activity in those with a single VTE. For both markers, odds ratios (ORs) for recurrent VTE were computed using patients in the lowest quintile as a reference group. No association was observed between MP-TF activity and recurrent VTE, with an OR of 1.4 (95 % CI 0.7–2.9) in the highest quintile of MP-TF activity. Compared with the reference group, patients in the highest quintile of FVIII:C were at increased risk of recurrent VTE, OR 4.2 (95 % CI 1.4–12.2). MP-TF activity was not associated with recurrent VTE whereas high FVIII:C levels were associated with a 4-fold increased risk of VTE recurrence. Future prospective studies are necessary to explore the potential of FVIII:C as a tool for risk stratification, either by itself or in combination with other pro-thrombotic markers.

Management of Venous Thromboembolisms: Part I. The Consensus for Deep Vein Thrombosis

Deep vein thrombosis (DVT) is a potentially catastrophic condition because thrombosis, left untreated, can result in detrimental pulmonary embolism. Yet in the absence of thrombosis, anticoagulation increases the risk of bleeding. In the existing literature, knowledge about the epidemiology of DVT is primarily based on investigations among Caucasian populations. There has been little information available about the epidemiology of DVT in Taiwan, and it is generally believed that DVT is less common in Asian patients than in Caucasian patients. However, DVT is a multifactorial disease that represents the interaction between genetic and environmental factors, and the majority of patients with incident DVT have either inherited thrombophilia or acquired risk factors. Furthermore, DVT is often overlooked. Although symptomatic DVT commonly presents with lower extremity pain, swelling and tenderness, diagnosing DVT is a clinical challenge for physicians. Such a diagnosis of DVT requires a timely systematic assessment, including the use of the Wells score and a D-dimer test to exclude low-risk patients, and imaging modalities to confirm DVT. Compression ultrasound with high sensitivity and specificity is the front-line imaging modality in the diagnostic process for patients with suspected DVT in addition to conventional invasive contrast venography. Most patients require anticoagulation therapy, which typically consists of parenteral heparin bridged to a vitamin K antagonist, with variable duration. The development of non-vitamin K oral anticoagulants has revolutionized the landscape of venous thromboembolism treatment, with 4 agents available,including rivaroxaban, dabigatran, apixaban, and edoxaban. Presently, all 4 drugs have finished their large phase III clinical trial programs and come to the clinical uses in North America and Europe. It is encouraging to note that the published data to date regarding Asian patients indicates that such new therapies are safe and efficacious. Ultimately, our efforts to improve outcomes in patients with DVT rely on the awareness in the scientific and medical community regarding the importance of DVT.

KEY WORDS

Combination therapy; Hypertension; α1-blocker.

Effects of anticoagulation provider continuity on time in therapeutic range for warfarin patients

Anticoagulation (AC) clinics use the percentage of time in the therapeutic INR range (%TTR) to characterize the quality of management for patients treated with warfarin. In order to guide policy and procedure changes, the purpose of this quality improvement (QI) study was to characterize the AC patient population at The Johns Hopkins Hospital (JHH). We set out to investigate the impact of AC clinic provider continuity on the quality of anticoagulation management. This QI study is a retrospective chart review of 525 warfarin patients managed by pharmacists in the Hematology AC Management Clinic at JHH from June 28, 2013 to November 1, 2014. We recorded patient demographic and clinical characteristics and the quality of AC management using %TTR, and compared these parameters between patients with (Group A) and without a primary AC (Group B). Group A patients had a significantly higher %TTR than Group B patients (53.2 vs. 46.5 %, p = 0.008). In conclusion, we found that patients with a primary AC clinic provider had a higher %TTR than patients with multiple providers. If confirmed prospectively, this approach to warfarin management could represent one technique for AC clinics to optimize patient management and clinical outcomes.

Retrospective review on isolated distal deep vein thrombosis (IDDVT) - A benign entity or not?

INTRODUCTION

Isolated distal deep venous thrombosis (IDDVT) is traditionally associated with less severe clinical sequelae, with ongoing debate on multiple aspects of its management. Despite numerous studies evaluating its acute management, there remains a paucity of data evaluating long-term complications such as recurrence and subsequent malignancy. We aim to evaluate the characteristics of IDDVT in institutions that routinely perform whole leg ultrasonography, and the risks of recurrence and complications in comparison to major venous thromboembolism (major VTE; defined as above-knee or proximal DVT and pulmonary embolism (PE)).

METHODS

Retrospective evaluation of consecutive IDDVT and major VTE from July 2011 to December 2012 in a hospital network in Melbourne, Australia. Patients were followed up for a minimum of 24months. Patients with active malignancy were excluded.

RESULTS

Of 1024 VTE cases, there were 164 non-cancer patients (92 males, 72 females, median age of 61years) with IDDVT. Compared to major VTE, IDDVT was more likely to be provoked (73% vs 59%, p<0.01), has shorter duration of anticoagulation (median 3.5months vs 6.0months, p<0.01) and less clinically significant bleeding (2.4% vs 6.7%, p=0.05), independent of duration of therapy. Recurrence was non-inferior compared to major VTE (10% vs 7%, p=0.36) and 60% recurred with major VTE. Three (1.8%) were subsequently diagnosed with cancer (vs 1.9% in major VTE, p=0.97).

CONCLUSIONS

IDDVT has non-inferior rates of recurrence and subsequent cancer detection compared to major VTE and hence, its clinical significance should not differ from major VTE. Further studies are required to determine the adequate length of anticoagulation.

A risk score for prediction of recurrence in patients with unprovoked venous thromboembolism (DAMOVES)

BACKGROUND

In patients with unprovoked venous thromboembolism (VTE), the optimal duration of anticoagulation is anchored on estimating the risk of disease recurrence. We aimed to develop a simple risk assessment model that improves prediction of the recurrence risk.

METHODS

In a prospective cohort study, 398 patients with a first unprovoked VTE were followed up for a median of 21.3months after discontinuation of anticoagulation. We excluded patients with a strong thrombophilic defect. Preselected clinical and laboratory variables were analyzed based on the independent confirmation of the impact on the recurrence risk, simplicity of assessment, and reproducibility. Multivariable Cox regression analysis was used to develop a recurrence score that was subsequently internally validated by bootstrap analysis.

RESULTS

A total of 65 patients (16.3%) had recurrent VTE. In all patients, VTE recurred spontaneously. Male sex (HR=2.89 [95% CI 1.21-6.90] P=0.016), age (HR=1.0310 per additional decade [95% CI 1.01-1.07] P=0.011), obesity (HR=3.92 [95% CI 1.75-8.75] P=0.0001), varicose veins (HR=4.14 [95% CI 1.81-9.43] P=0.0001), abnormal D-dimer during anticoagulation (HR=13.66 [95% CI 4.74-39.37] P=0.0001), high factor VIII coagulant activity (HR=1.01 [95% CI 1.00-1.02] P=0.028) and heterozygous of factor V Leiden and/or Prothrombin G20210A mutation (HR=13.86 [95% CI 5.87-32.75] P=0.0001) were related to a higher recurrence risk. Using these variables, we developed a nomogram [hereafter referred to as DAMOVES score (D-dimer, Age, Mutation, Obesity, Varicose veins, Eight, Sex)] for prediction of recurrence in an individual patient.

CONCLUSIONS

The DAMOVES score can be used to predict recurrence risk in patients with a first unprovoked VTE and may be useful to decide whether anticoagulant therapy should be continued indefinitely or stopped after an initial treatment period of at least 3months.