Treatment of distal deep vein thrombosis

2024 Heart Disease and Stroke Statistics: A Report of US and Global Data From the American Heart Association

BACKGROUND

The American Heart Association (AHA), in conjunction with the National Institutes of Health, annually reports the most up-to-date statistics related to heart disease, stroke, and cardiovascular risk factors, including core health behaviors (smoking, physical activity, nutrition, sleep, and obesity) and health factors (cholesterol, blood pressure, glucose control, and metabolic syndrome) that contribute to cardiovascular health. The AHA Heart Disease and Stroke Statistical Update presents the latest data on a range of major clinical heart and circulatory disease conditions (including stroke, brain health, complications of pregnancy, kidney disease, congenital heart disease, rhythm disorders, sudden cardiac arrest, subclinical atherosclerosis, coronary heart disease, cardiomyopathy, heart failure, valvular disease, venous thromboembolism, and peripheral artery disease) and the associated outcomes (including quality of care, procedures, and economic costs).

METHODS

The AHA, through its Epidemiology and Prevention Statistics Committee, continuously monitors and evaluates sources of data on heart disease and stroke in the United States and globally to provide the most current information available in the annual Statistical Update with review of published literature through the year before writing. The 2024 AHA Statistical Update is the product of a full year's worth of effort in 2023 by dedicated volunteer clinicians and scientists, committed government professionals, and AHA staff members. The AHA strives to further understand and help heal health problems inflicted by structural racism, a public health crisis that can significantly damage physical and mental health and perpetuate disparities in access to health care, education, income, housing, and several other factors vital to healthy lives. This year's edition includes additional global data, as well as data on the monitoring and benefits of cardiovascular health in the population, with an enhanced focus on health equity across several key domains.

RESULTS

Each of the chapters in the Statistical Update focuses on a different topic related to heart disease and stroke statistics.

CONCLUSIONS

The Statistical Update represents a critical resource for the lay public, policymakers, media professionals, clinicians, health care administrators, researchers, health advocates, and others seeking the best available data on these factors and conditions.

Incidence of bleeding and recurrence in isolated distal deep vein thrombosis: findings from the Venous Thrombosis Registry in Østfold Hospital

BACKGROUND

Isolated distal deep vein thrombosis (IDDVT) is a common presentation of deep vein thrombosis. There are limited data on the long-term risk of recurrence after IDDVT.

OBJECTIVES

We aimed to determine the short- and long-term incidence of venous thrombosis (VTE) recurrence after cessation of anticoagulation and the 3-month incidence of bleeding during anticoagulant treatment in patients with IDDVT.

METHODS

Between January 2005 and May 2020, 475 patients with IDDVT and without active cancer were identified from the Venous Thrombosis Registry in Østfold Hospital, which is an ongoing registry of consecutive patients with VTE at Østfold Hospital, Norway. Major and clinically relevant, nonmajor bleeding as well as recurrent VTE were registered, and the cumulative incidences of these events were assessed.

RESULTS

The median age of the patients was 59 years (IQR, 48-72 years), 243 (51%) patients were women, and 175 events (36.8%) were classified as unprovoked. The 1-, 5-, and 10-year cumulative incidences of recurrent VTE were 5.6% (95% CI, 3.7-8.4), 14.7% (95% CI, 11.1-19.4), and 27.2% (95% CI, 21.1-34.5), respectively. The recurrence rates were higher for unprovoked IDDVT than for provoked IDDVT. Among the recurrent events, 18 (29%) were pulmonary embolisms and 21 (33%) were proximal deep vein thromboses. The 3-month cumulative incidence of major bleeding was 1.5% (95% CI, 0.7-3.1) overall and 0.8% (95% CI, 0.2-3.1) when restricted to patients treated with direct oral anticoagulants.

CONCLUSION

Despite initial treatment, the long-term risk of VTE recurrence after first-time IDDVT is high. The bleeding rates during anticoagulation, particularly with direct oral anticoagulants, were acceptably low.

Endovenous ablation for venous leg ulcers

BACKGROUND

Venous leg ulcers (VLUs) are a serious manifestation of chronic venous disease affecting up to 3% of the adult population. This typically recalcitrant and recurring condition significantly impairs quality of life, and its treatment places a heavy financial burden upon healthcare systems. The longstanding mainstay treatment for VLUs is compression therapy. Surgical removal of incompetent veins reduces the risk of ulcer recurrence. However, open surgery is an unpopular option amongst people with VLU, and many people are unsuitable for it. The efficacy of the newer, minimally-invasive endovenous techniques has been established in uncomplicated superficial venous disease, and these techniques can also be used in the management of VLU. When used with compression, endovenous ablation aims to further reduce pressure in the veins of the leg, which may impact ulcer healing.

OBJECTIVES

To determine the effects of superficial endovenous ablation on the healing and recurrence of venous leg ulcers and the quality of life of people with venous ulcer disease.

SEARCH METHODS

In April 2022 we searched the Cochrane Wounds Specialised Register; the Cochrane Central Register of Controlled Trials (CENTRAL); Ovid MEDLINE (including In-Process & Other Non-Indexed Citations); Ovid Embase and EBSCO CINAHL Plus. We also searched clinical trials registries for ongoing and unpublished studies, and scrutinised reference lists of relevant included studies as well as reviews, meta-analyses and health technology reports to identify additional studies. There were no restrictions on the language of publication, but there was a restriction on publication year from 1998 to April 2022 as superficial endovenous ablation is a comparatively new technology.

SELECTION CRITERIA

Randomised controlled trials (RCTs) comparing endovenous ablative techniques with compression versus compression therapy alone for the treatment of VLU were eligible for inclusion. Studies needed to have assessed at least one of the following primary review outcomes related to objective measures of ulcer healing such as: proportion of ulcers healed at a given time point; time to complete healing; change in ulcer size; proportion of ulcers recurring over a given time period or at a specific point; or ulcer-free days. Secondary outcomes of interest were patient-reported quality of life, economic data and adverse events.

DATA COLLECTION AND ANALYSIS

Two reviewers independently assessed studies for eligibility, extracted data, carried out risk of bias assessment using the Cochrane RoB 1 tool, and assessed GRADE certainty of evidence.

MAIN RESULTS

The previous version of this review found no RCTs meeting the inclusion criteria. In this update, we identified two eligible RCTs and included them in a meta-analysis. There was a total of 506 participants with an active VLU, with mean durations of 3.1 months ± 1.1 months in the EVRA trial and 60.5 months ± 96.4 months in the VUERT trial. Both trials randomised participants to endovenous treatment and compression or compression alone, however the compression alone group in the EVRA trial received deferred endovenous treatment (after ulcer healing or from six months). There is high-certainty evidence that combined endovenous ablation and compression compared with compression therapy alone, or compression with deferred endovenous treatment, improves time to complete ulcer healing (pooled hazard ratio (HR) 1.41, 95% CI 1.36 to 1.47; I2 = 0%; 2 studies, 466 participants). There is moderate-certainty evidence that the proportion of ulcers healed at 90 days is probably higher with combined endovenous ablation and compression compared with compression therapy alone or compression with deferred endovenous treatment (risk ratio (RR) 1.14, 95% CI 1.00 to 1.30; I2 = 0%; 2 studies, 466 participants). There is low-certainty evidence showing an unclear effect on ulcer recurrence at one year in people with healed ulcers with combined endovenous treatment and compression when compared with compression alone or compression with deferred endovenous treatment (RR 0.29, 95% CI 0.03 to 2.48; I2 = 78%; 2 studies, 460 participants). There is also low-certainty evidence that the median number of ulcer-free days at one year may not differ (306 (interquartile range (IQR) 240 to 328) days versus 278 (IQR 175 to 324) days) following combined endovenous treatment and compression when compared with compression and deferred endovenous treatment; (1 study, 450 participants). There is low-certainty evidence of an unclear effect in rates of thromboembolism between groups (RR 2.02, 95% CI 0.51 to 7.97; I2 = 78%, 2 studies, 506 participants). The addition of endovenous ablation to compression is probably cost-effective at one year (99% probability at GBP 20,000/QALY; 1 study; moderate-certainty evidence).

AUTHORS' CONCLUSIONS

Endovenous ablation of superficial venous incompetence in combination with compression improves leg ulcer healing when compared with compression alone. This conclusion is based on high-certainty evidence. There is moderate-certainty evidence to suggest that it is probably cost-effective at one year and low certainty evidence of unclear effects on recurrence and complications. Further research is needed to explore the additional benefit of endovenous ablation in ulcers of greater than six months duration and the optimal modality of endovenous ablation.

Heart Disease and Stroke Statistics-2023 Update: A Report From the American Heart Association

BACKGROUND

The American Heart Association, in conjunction with the National Institutes of Health, annually reports the most up-to-date statistics related to heart disease, stroke, and cardiovascular risk factors, including core health behaviors (smoking, physical activity, diet, and weight) and health factors (cholesterol, blood pressure, and glucose control) that contribute to cardiovascular health. The Statistical Update presents the latest data on a range of major clinical heart and circulatory disease conditions (including stroke, congenital heart disease, rhythm disorders, subclinical atherosclerosis, coronary heart disease, heart failure, valvular disease, venous disease, and peripheral artery disease) and the associated outcomes (including quality of care, procedures, and economic costs).

METHODS

The American Heart Association, through its Epidemiology and Prevention Statistics Committee, continuously monitors and evaluates sources of data on heart disease and stroke in the United States to provide the most current information available in the annual Statistical Update with review of published literature through the year before writing. The 2023 Statistical Update is the product of a full year's worth of effort in 2022 by dedicated volunteer clinicians and scientists, committed government professionals, and American Heart Association staff members. The American Heart Association strives to further understand and help heal health problems inflicted by structural racism, a public health crisis that can significantly damage physical and mental health and perpetuate disparities in access to health care, education, income, housing, and several other factors vital to healthy lives. This year's edition includes additional COVID-19 (coronavirus disease 2019) publications, as well as data on the monitoring and benefits of cardiovascular health in the population, with an enhanced focus on health equity across several key domains.

RESULTS

Each of the chapters in the Statistical Update focuses on a different topic related to heart disease and stroke statistics.

CONCLUSIONS

The Statistical Update represents a critical resource for the lay public, policymakers, media professionals, clinicians, health care administrators, researchers, health advocates, and others seeking the best available data on these factors and conditions.

Efficacy and safety of sonographer discretion to terminate a venous duplex ultrasound for diagnosis of deep vein thrombosis in coronavirus disease 2019 patients

OBJECTIVE

Sonographers performing venous duplex ultrasound (VDUS) of patients with coronavirus disease 2019 (COVID-19) have an increased risk of exposure owing to their close contact with these patients for an extended period. The objective of the present study was to evaluate the efficacy of a modified COVID-19 VDUS protocol to reduce sonographer exposure to COVID-19 patients.

METHODS

We performed a single-center retrospective review. Patients who had undergone VDUS under the modified COVID-19 protocol between March 1, 2020, and June 30, 2020, with a confirmed or presumed COVID-19 diagnosis at the VDUS were included. The modified COVID-19 protocol was defined as the ability of the sonographer to terminate the examination on detection of an acute deep vein thrombosis (DVT). The primary outcome measures were the number of anatomic deep venous segments recorded by the sonographer, which was used as a surrogate measure for sonographer exposure time, and the number of acute DVTs found on follow-up examinations in segments not visualized at the index VDUS.

RESULTS

A total of 160 lower extremity VDUS (LEVDUS) scans and 72 upper extremity VDUS (UEVDUS) scans were performed using the modified COVID-19 protocol. The index VDUS had found an acute DVT for 44 of 160 patients (27.5%) who had undergone LEVDUS and 26 of 72 (36.6%) who had undergone UEVDUS. On follow-up imaging, 7 of 38 LEVDUS scans (17.9%) and 1 of 10 UEVDUS scans (10%) had demonstrated a new acute DVT. Malignancy and surgery 30 days before imaging were significantly associated with acute lower extremity DVT, and mechanical ventilation and extracorporeal membrane oxygenation were associated with acute upper extremity DVT. On the index VDUS, the average was 10.6 of 12 total visualized segments on LEVDUS and 6.4 of 10 total segments on UEVDUS. Of the index VDUS scans, 35.6% of the LEVDUS and 78.6% of the UEVDUS scans had been abbreviated. The index VDUS scans that were positive for acute DVT had had significantly fewer visualized segments for both lower (8.4 vs 11.5; P < .0001) and upper (4.2 vs 7.6) extremities (P < .0001). On the follow-up examinations, only one of eight new acute DVTs had been found in a patient whose index VDUS had been abbreviated and the corresponding segment not assessed. These findings did not affect the patient's clinical course.

CONCLUSIONS

The modified COVID-19 VDUS protocol reduced sonographers' potential exposure time to COVID-19. Additionally, the clinical efficacy was maintained, with no missed DVTs, despite the abbreviation of the VDUS examinations.

Fibrin monomer complex on postoperative day 1 is correlated with the volume of deep vein thrombosis after knee surgery

PURPOSE

Patients undergoing knee surgery are at high risk for deep vein thrombosis (DVT), which is infrequent but potentially life-threatening. It has not been identified how to efficiently detect high-risk DVT while minimizing bleeding complications from anticoagulation. We hypothesized that the degree of activation of thrombotic markers may correlate with the size of the thrombus. Therefore, we investigated the correlation between thrombotic markers and DVT thrombus volume in patients after knee surgery.

METHODS

This retrospective study involved 29 patients who underwent around knee osteotomy or total / unicompartmental knee arthroplasty from 2018 to 2020. Fibrin monomer complex (FMC) at 1, and 7 days after surgery, and D-dimer at 4, and 7 days after surgery were investigated. In addition, the volume of DVT was estimated with ultrasonography at the 7 days after surgery. Body mass index, surgical time, and total volume of blood loss were also evaluated. Factors related to thrombus volume were examined statistically.

RESULTS

Nine patients (31.0%) exhibited asymptomatic distal DVT, whereas 1 patient (3.4%) experienced asymptomatic proximal DVT. No patients had pulmonary embolism. Statistical analysis showed that only FMC concentration on postoperative day 1 was significantly correlated with thrombus volume (p <  0.001, 95% confidence interval 0.41 to 0.839, r = 0.679).

CONCLUSIONS

The FMC concentration was a useful early indicator of deep vein thrombosis after knee surgery. Monitoring the FMC concentration could enable selective identification of patients with a high thrombus volume, which is associated with a high risk for pulmonary embolism.

Therapeutic or prophylactic anticoagulation in acute isolated distal deep vein thrombosis: protocol for a prospective, multicentre, single-blind, randomised controlled trial (TOP-IDDVT)

INTRODUCTION

The efficacy and safety of anticoagulant treatment is not established for patients with acute symptomatic isolated distal deep vein thrombosis (IDDVT). In real-world clinical practice, both therapeutic and prophylactic anticoagulation are used for acute IDDVT. However, therapeutic anticoagulation is associated with higher risk of bleeding than prophylactic anticoagulation. Thus, this study aims to assess the efficacy and safety in patients with first acute symptomatic IDDVT treated with therapeutic or prophylactic anticoagulation using rivaroxaban.

METHODS AND ANALYSIS

This study is a prospective, multicentre, single-blind, randomised controlled trial. Outpatients with a first, acute, symptomatic, objectively confirmed IDDVT in four centres from 1 August 2021 are recruited. Eligible patients are randomised in a 1:1 ratio to receive prophylactic anticoagulation (rivaroxaban 10 mg once a day for 3 months) or therapeutic anticoagulation (rivaroxaban 20 mg once a day for 3 months). All patients are followed for 6 months. The primary efficacy outcome is radiographically confirmed recurrent venous thromboembolism. The primary safety outcome is the incidence of major or clinically relevant non-major bleeding events.

ETHICS AND DISSEMINATION

This study has been approved by the Ethics Committee of Zhongshan Hospital Fudan University (B2021-175R). Study results will be disseminated through peer-reviewed journals.

TRIAL REGISTRATION NUMBER

NCT04967573.

Cost effectiveness analysis of total laparoscopic hysterectomy versus total abdominal hysterectomy for uterine fibroids in Western China: a societal perspective

BACKGROUND

As a common female pelvic tumor, uterine fibroids remain the leading cause for hysterectomy in China. Hysterectomy provides a good surgical treatment of uterine fibroids, and it guarantees the removal of all uterine fibroids without lower risk of recurrence. This study compares the cost effectiveness of total laparoscopic hysterectomy (TLH) versus total abdominal hysterectomy (TAH) for women with uterine fibroids from a societal perspective.

METHODS

An economic analysis was conducted in 392 patients (TLH n = 75; TAH n = 317), including all relevant costs over a 12-month time horizon. Primary outcome was major surgical complications; secondary outcomes were postoperative discomfort symptoms and time of return to normal activities. Clinical, outcomes and costs data were collected from medical records, telephone survey and financial information system. Generalized linear models were used to assess costs and outcomes differences between the two groups. Incremental cost effectiveness ratio (ICER) was used to estimate the cost effectiveness.

RESULTS

Mean direct costs were $2,925.71 for TLH, $2,436.24 for TAH, respectively. Mean indirect costs were $1,133.22 for TLH, $1,394.85 for TAH, respectively. Incremental societal costs were $256.86 (95%CI: 249.03-264.69). Mean differences in outcome were: 4.53% (95%CI: 4.35-4.71) for major surgical complications; 6.75% (95%CI: 6.45-7.05) for postoperative discomfort symptoms; 1.27 (95%CI: 1.23-1.30) weeks for time to return to normal activities. ICER of TLH was $5,669.16 (95%CI: 5,384.76-5,955.56) per complication averted, $3,801.54 (95%CI: 3,634.81-3,968.28) per postoperative discomfort symptoms averted and $202.96 (95%CI: 194.97-210.95) per week saved to return to normal activities.

CONCLUSIONS

TLH is cost effective compared with TAH in preventing additional complications based on our estimated conservative threshold in China. The findings provide useful information for researchers to conduct further cost effectiveness analysis based on prospective study which can provide stronger and more evidence, in China. In addition, the data may be useful for Chinese health care policy-makers and medical insurance payers to make related health care decisions.

National guidelines on the management of venous thromboembolism: Joint guideline of the Turkish Society of Cardiovascular Surgery, National Society of Vascular and Endovascular Surgery, and Phlebology Society

These evidence-based guidelines from the Turkish Society of Cardiovascular Surgery, National Society of Vascular and Endovascular Surgery, and Phlebology Society intend to support clinicians in best decisions regarding the treatment of venous thromboembolism (VTE). The Editor was selected by the three national societies and was tasked with the recruitment of the recognized panel. All financial support was solely derived from the sponsoring societies without the direct involvement of industry or other external stakeholders. The panel prioritized clinical questions and outcomes according to their importance for clinicians in terms of VTE. The panel agreed on 42 recommendations under 15 headings for the diagnosis, initial management, secondary prevention of VTE, and treatment of recurrent VTE events. Important recommendations included the use of ultrasonography, preference for home treatment over hospital treatment for uncomplicated VTE, preference for direct oral anticoagulants (DOACs) over vitamin K antagonists for primary treatment of cancer and non-cancer-related VTE, extended or indefinite anticoagulation with DOACs in selected high-risk patients. Early catheter-directed thrombectomy was recommended in only young symptomatic patients with a diagnosis of fresh iliofemoral deep vein thrombosis.

Sport and Venous Thromboembolism

BACKGROUND

The occurrence of venous thromboembolisms (VTE) in association with sporting activity has been described but not yet systematically explored. The aim of this study was to determine the sites at which VTE occur in athletes, the accompanying features, and the special features of the symptoms and diagnosis, so that physicians can take the findings into consideration.

METHODS

A search of the literature in the databases PubMed, Web of Science, and Cochrane in accordance with the PRISMA criteria, together with a search of Google Scholar up to 29 February 2020.

RESULTS

No observational studies were identified. A total of 154 case descriptions were evaluated: 89 on upper-extremity deep vein thrombosis (DVT), 53 on lower-extremity DVT, and 12 on pulmonary embolisms with no evidence of thrombosis. Ninety-five percent of the upper-extremity DVT involved the region of the subclavian/axillary vein. Thoracic outlet syndrome (38%), hereditary thrombophilia/a family history of VTE (16%), intensive training (12%), and the use of oral contraceptives (7%) were identified as accompanying features. The upper-extremity DVT occurred mainly in male strength athletes and ball sports players. The lower-extremity DVT were located in the lower leg/knee (30%), the thigh (19 %), or occurred in combination in the lower leg-to-pelvis region (30 %). The features accompanying lower-extremity DVT were hereditary thrombophilia/a family history of VTE (30%), trauma (25%), immobilization (21%), and the use of oral contraceptives (11%). The lower-extremity DVT were found in endurance sports and ball sports. The symptoms may be obscured by sport-specific symptoms/trauma, and diagnosis is often delayed. Early D-dimer determination is useful and is complemented by diagnostic imaging.

CONCLUSION

VTE are found in association with sports. The background factors, the sites of VTE, the types of sports involved, and the accompanying features are all important to know. The symptoms may be obscured, and it may be difficult to reach the correct diagnosis. The possible presence of DVT must be borne in mind.

Treatment of distal deep vein thrombosis

BACKGROUND

The treatment of distal (below the knee) deep vein thrombosis (DVT) is not clearly established. Distal DVT can either be treated with anticoagulation, or monitored with close follow-up to detect progression to the proximal veins (above the knee), which requires anticoagulation. Proponents of this monitoring strategy base their decision to withhold anticoagulation on the fact that progression is rare and most people can be spared from potential bleeding and other adverse effects of anticoagulation.

OBJECTIVES

To assess the effects of different treatment interventions for people with distal (below the knee) deep vein thrombosis (DVT).

SEARCH METHODS

The Cochrane Vascular Information Specialist searched the Cochrane Vascular Specialised Register, CENTRAL, MEDLINE, Embase and CINAHL databases and World Health Organization International Clinical Trials Registry Platform and ClinicalTrials.gov trials registers to 12 February 2019. We also undertook reference checking to identify additional studies.

SELECTION CRITERIA

Randomised controlled trials (RCTs) for the treatment of distal DVT.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected trials and extracted data. We resolved disagreements by discussion. Primary outcomes of interest were recurrence of venous thromboembolism (VTE), DVT and major bleeding and follow up ranged from three months to two years. We performed fixed-effect model meta-analyses with risk ratio (RRs) and 95% confidence intervals (CIs). We assessed the certainty of the evidence using GRADE.

MAIN RESULTS

We identified eight RCTs reporting on 1239 participants. Five trials randomised participants to anticoagulation for up to three months versus no anticoagulation. Three trials compared anticoagulation treatment for different time periods. Anticoagulant compared to no intervention or placebo for distal DVT treatment Anticoagulation with a vitamin K antagonist (VKA) reduced the risk of recurrent VTE during follow-up compared with participants receiving no anticoagulation (RR 0.34, 95% CI 0.15 to 0.77; 5 studies, 496 participants; I² = 3%; high-certainty evidence), and reduced the risk of recurrence of DVT (RR 0.25, 95% CI 0.10 to 0.67; 5 studies, 496 participants; I² = 0%; high-certainty evidence). There was no clear effect on risk of pulmonary embolism (PE) (RR 0.81, 95% CI 0.18 to 3.59; 4 studies, 480 participants; I² = 0%; low-certainty evidence). There was little to no difference in major bleeding with anticoagulation compared to placebo (RR 0.76, 95% CI 0.13 to 4.62; 4 studies, 480 participants; I² = 26%; low-certainty evidence). There was an increase in clinically relevant non-major bleeding events in the group treated with anticoagulants (RR 3.34, 95% CI 1.07 to 10.46; 2 studies, 322 participants; I² = 0%; high-certainty evidence). There was one death, not related to PE or major bleeding, in the anticoagulation group. Anticoagulation for three months or more compared to anticoagulation for six weeks for distal DVT treatment Three RCTs of 736 participants compared three or more months of anticoagulation with six weeks of anticoagulation. Anticoagulation with a VKA for three months or more reduced the incidence of recurrent VTE to 5.8% compared with 13.9% in participants treated for six weeks (RR 0.42, 95% CI 0.26 to 0.68; 3 studies, 736 participants; I² = 50%; high-certainty evidence). The risk for recurrence of DVT was also reduced (RR 0.32, 95% CI 0.16 to 0.64; 2 studies, 389 participants; I² = 48%; high-certainty evidence), but there was probably little or no difference in PE (RR 1.05, 95% CI 0.19 to 5.88; 2 studies, 389 participants; I² = 0%; low-certainty evidence). There was no clear difference in major bleeding events (RR 3.42, 95% CI 0.36 to 32.35; 2 studies, 389 participants; I² = 0%; low-certainty evidence) or clinically relevant non-major bleeding events (RR 1.76, 95% CI 0.90 to 3.42; 2 studies, 389 participants; I² = 1%; low-certainty evidence) between three months or more of treatment and six weeks of treatment. There were no reports for overall mortality or PE and major bleeding-related deaths.

AUTHORS' CONCLUSIONS

Our review found a benefit for people with distal DVT treated with anticoagulation therapy using VKA with little or no difference in major bleeding events although there was an increase in clinically relevant non-major bleeding when compared to no intervention or placebo. The small number of participants in this meta-analysis and strength of evidence prompts a call for more research regarding the treatment of distal DVT. RCTs comparing different treatments and different treatment periods with placebo or compression therapy, are required.