Cost-effectiveness of additional catheter-directed thrombolysis for deep vein thrombosis

Current Evidence for Endovascular Therapies in the Management of Acute Deep Vein Thrombosis

Acute lower extremity deep vein thrombosis (DVT), specifically proximal iliofemoral DVT, is a relatively common disorder that can result in a chronic debilitating post-thrombotic syndrome (PTS), with a significant effect on a patient's quality of life. Anticoagulation is first-line therapy; however, percutaneous interventions have emerged as treatment options for patients where there is concern that anticoagulation alone will not resolve the DVT as well as prevent PTS. This paper will discuss the existing data on these interventions and review current endovascular techniques, including catheter-directed thrombolysis, pharmacomechanical thrombectomy, and large-bore mechanical thrombectomy in the management of DVT.

Cost Effectiveness of Early Endovenous Thrombus Removal for Acute Iliofemoral Deep Vein Thrombosis in the United Kingdom

OBJECTIVE

Early clot removal using endovascular intervention aims to reduce post-thrombotic syndrome (PTS) following iliofemoral deep venous thrombosis (DVT). This may reduce long term morbidity but incurs a higher initial cost. This study examined the cost effectiveness of catheter directed thrombolysis (CDT) and pharmacochemical thrombectomy (PMT) compared with oral anticoagulation (OAC) alone for treatment of acute iliofemoral DVT in the United Kingdom.

METHODS

A combined decision tree (acute DVT complications) and Markov model (long term complications [PTS]) was used for decision analytic modelling with five states: no PTS, mild PTS, moderate PTS, severe PTS, and dead. All patients started with acute DVT. Patients who survived acute complications transitioned into the Markov model. Cycle time was six months. A healthcare payer perspective and lifetime horizon was used, adjusting for excess mortality due to history of thrombosis. Data for probabilities, transition probabilities, mortality, and utilities were obtained from the published literature. Cost data were obtained from UK NHS tariffs and published literature. Outcomes were mean lifetime cost, quality adjusted life years (QALYs), and cost effectiveness.

RESULTS

Over a patient's lifetime, OAC was more costly (£37 206) than CDT (£32 043) and PMT (£36 288). Mean lifetime QALYs for OAC (12.9) were lower than CDT (13.5) and PMT (13.3). Therefore, in the incremental cost effectiveness analysis, both CDT and PMT were dominant: CDT was less costly (-£5 163) and more effective (+0.6 QALYs) than OAC, and PMT was also less costly (-£917) and more effective (+0.3 QALYs) than OAC. Results were robust to univariable sensitivity analyses, but probabilistic sensitivity analyses suggested considerable parameter uncertainty.

CONCLUSION

Early interventional treatment of iliofemoral DVT is cost effective in the UK. Future clinical and epidemiological studies are needed to characterise parameter uncertainty. Further analysis of modern practice, alternative treatments, and optimised care models is warranted.

Evaluating pharmacological THRomboprophylaxis in Individuals undergoing superficial endoVEnous treatment across NHS and private clinics in the UK: a multi-centre, assessor-blind, randomised controlled trial-THRIVE trial

INTRODUCTION

Endovenous therapy is the first choice management for symptomatic varicose veins in NICE guidelines, with 56-70 000 procedures performed annually in the UK. Venous thromboembolism (VTE), including deep vein thrombosis (DVT) and pulmonary embolism (PE), is a known complication of endovenous therapy, occurring at a rate of up to 3.4%. Despite 73% of UK practitioners administering pharmacological thromboprophylaxis to reduce VTE, no high-quality evidence supporting this practice exists. Pharmacological thromboprophylaxis may have clinical and cost benefit in preventing VTE; however, further evidence is needed. This study aims to establish whether when endovenous therapy is undertaken: a single dose or course of pharmacological thromboprophylaxis alters the risk of VTE; pharmacological thromboprophylaxis is associated with an increased rate of bleeding events; pharmacological prophylaxis is cost effective.

METHODS AND ANALYSIS

A multi-centre, assessor-blind, randomised controlled trial (RCT) will recruit 6660 participants from 40 NHS and private sites across the UK. Participants will be randomised to intervention (single dose or extended course of pharmacological thromboprophylaxis plus compression) or control (compression alone). Participants will undergo a lower limb venous duplex ultrasound scan at 21-28 days post-procedure to identify asymptomatic DVT. The duplex scan will be conducted locally by blinded assessors. Participants will be contacted remotely for follow-up at 7 days and 90 days post-procedure. The primary outcome is imaging-confirmed lower limb DVT with or without symptoms or PE with symptoms within 90 days of treatment. The main analysis will be according to the intention-to-treat principle and will compare the rates of VTE at 90 days, using a repeated measures analysis of variance, adjusting for any pre-specified strongly prognostic baseline covariates using a mixed effects logistic regression.

ETHICS AND DISSEMINATION

Ethical approval was granted by Brent Research Ethics Committee (22/LO/0261). Results will be disseminated in a peer-reviewed journal and presented at national and international conferences.

TRIAL REGISTRATION NUMBER

ISRCTN18501431.

Society of Interventional Radiology Position Statement on the Endovascular Management of Acute Iliofemoral Deep Vein Thrombosis

PURPOSE

To establish the updated position of the Society of Interventional Radiology (SIR) on the endovascular management of acute iliofemoral deep vein thrombosis (DVT).

MATERIALS AND METHODS

A multidisciplinary writing group with expertise in treating venous diseases was convened by SIR. A comprehensive literature search was conducted to identify studies on the topic of interest. Recommendations were drafted and graded according to the updated SIR evidence grading system. A modified Delphi technique was used to achieve consensus agreement on the recommendation statements.

RESULTS

A total of 84 studies, including randomized trials, systematic reviews and meta-analyses, prospective single-arm studies, and retrospective studies were identified and included in the review. The expert writing group developed 17 recommendations that pertain to the care of patients with acute iliofemoral DVT with the use of endovascular venous interventions.

CONCLUSIONS

SIR considers endovascular thrombus removal to be an acceptable treatment option in selected patients with acute iliofemoral DVT. Careful individualized risk assessment, high-quality general DVT care, and close monitoring during and after procedures should be provided.

Examining the benefit of graduated compression stockings in the prevention of hospital-associated venous thromboembolism in low-risk surgical patients: a multicentre cluster randomised controlled trial (PETS trial)

INTRODUCTION

Hospital-acquired thrombosis (HAT) is defined as any venous thromboembolism (VTE)-related event during a hospital admission or occurring up to 90 days post discharge, and is associated with significant morbidity, mortality and healthcare-associated costs. Although surgery is an established risk factor for VTE, operations with a short hospital stay (<48 hours) and that permit early ambulation are associated with a low risk of VTE. Many patients undergoing short-stay surgical procedures and who are at low risk of VTE are treated with graduated compression stockings (GCS). However, evidence for the use of GCS in VTE prevention for this cohort is poor.

METHODS AND ANALYSIS

A multicentre, cluster randomised controlled trial which aims to determine whether GCS are superior in comparison to no GCS in the prevention of VTE for surgical patients undergoing short-stay procedures assessed to be at low risk of VTE. A total of 50 sites (21 472 participants) will be randomised to either intervention (GCS) or control (no GCS). Adult participants (18-59 years) who undergo short-stay surgical procedures and are assessed as low risk of VTE will be included in the study. Participants will provide consent to be contacted for follow-up at 7-days and 90-days postsurgical procedure. The primary outcome is the rate of symptomatic VTE, that is, deep vein thrombosis or pulmonary embolism during admission or within 90 days. Secondary outcomes include healthcare costs and changes in quality of life. The main analysis will be according to the intention-to-treat principle and will compare the rates of VTE at 90 days, measured at an individual level, using hierarchical (multilevel) logistic regression.

ETHICS AND DISSEMINATION

Ethical approval was granted by the Camden and Kings Cross Research Ethics Committee (22/LO/0390). Findings will be published in a peer-reviewed journal and presented at national and international conferences.

TRIAL REGISTRATION NUMBER

ISRCTN13908683.

Cost-effectiveness Analysis of AngioJet and CDT for Lower Extremity Deep Vein Thrombosis Among Chinese Population

AngioJet has sufficient safety and efficacy in the treatment of acute and subacute lower extremity deep vein thrombosis (LEDVT). But the price of consumables used by AngioJet is relatively high and there is a lack of relevant research on health economics to measure the benefits to patients. Objective of this study is to estimate the cost effectiveness of AngioJet compared with catheter-directed thrombolysis (CDT) among Chinese population. Using a Markov decision model, we compared the 2 treatment strategies in patients with LEDVT. The model captured the development of post-thrombotic syndrome (PTS), recurrent venous thromboembolism, and treatment-related adverse events within a lifetime horizon and the perspective of a third-party payer. Model uncertainty was assessed with one-way and Monte Carl sensitivity analyses. The clinical inputs were obtained from the literature. Costs obtained from the hospital accounts and the literature are expressed in US dollars ($). Utilities were defined as quality adjusted life years (QALY). In cost-effectiveness analysis, AngioJet accumulated $1064.6445/QALY compared with $2080.1561/QALY after CDT treatment alone. AngioJet has higher long-term cost-effectiveness than CDT at a willingness to pay threshold of $11 233.52. One-way sensitivity analysis showed that the utilities of PTS and post-LEDVT state had significant influence on the results and the model maintained a strong stability under  ± 10% fluctuation of utilities. Monte Carl sensitivity analysis shows that AngioJet model has strong stability and AngioJet has higher long-term cost-effectiveness than CDT. AngioJet is likely to be a cost-effective alternative to the CDT for patients with LEDVT.

Catheter-directed thrombolysis for deep vein thrombosis: 2021 update

Catheter-directed thrombolysis (CDT) has been utilized as an adjunct to anticoagulant therapy in selected patients with deep vein thrombosis (DVT) for approximately 30 years. CDT used to be limited to patients with DVT causing acute limb threat and those exhibiting failure of initial anticoagulation, but has expanded over time. Randomized trials evaluating the first-line use of CDT for proximal DVT have demonstrated that CDT does not produce a major reduction in the occurrence of post-thrombotic syndrome (PTS) and that it is poorly suited for elderly patients and those with limited thrombus extent or major risk factors for bleeding. However, CDT does offer selected patients with acute iliofemoral DVT improvement in reducing early DVT symptoms, in achieving reduction in PTS severity, and in producing an improvement in health-related quality of life (QOL). Clinical practice guidelines from medical and surgical societies are now largely aligned with the randomized trial results. This review offers the reader an update on the results of recently completed clinical trials, and additional guidance on appropriate selection of patients with DVT for catheter-directed thrombolytic therapy.

Thrombolytic strategies versus standard anticoagulation for acute deep vein thrombosis of the lower limb

BACKGROUND

Standard treatment for deep vein thrombosis (DVT) aims to reduce immediate complications. Use of thrombolytic clot removal strategies (i.e. thrombolysis (clot dissolving drugs), with or without additional endovascular techniques), could reduce the long-term complications of post-thrombotic syndrome (PTS) including pain, swelling, skin discolouration, or venous ulceration in the affected leg. This is the fourth update of a Cochrane Review first published in 2004.

OBJECTIVES

To assess the effects of thrombolytic clot removal strategies and anticoagulation compared to anticoagulation alone for the management of people with acute deep vein thrombosis (DVT) of the lower limb.

SEARCH METHODS

The Cochrane Vascular Information Specialist searched the Cochrane Vascular Specialised Register, CENTRAL, MEDLINE, Embase, CINAHL and AMED and the World Health Organization International Clinical Trials Registry Platform and ClinicalTrials.gov trials registries to 21 April 2020. We also checked the references of relevant articles to identify additional studies.

SELECTION CRITERIA

We considered randomised controlled trials (RCTs) examining thrombolysis (with or without adjunctive clot removal strategies) and anticoagulation versus anticoagulation alone for acute DVT.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures as recommended by Cochrane. We assessed the risk of bias in included trials with the Cochrane 'Risk of bias' tool. Certainty of the evidence was evaluated using GRADE. For dichotomous outcomes, we calculated the risk ratio (RR) with the corresponding 95% confidence interval (CI). We pooled data using a fixed-effect model, unless we identified heterogeneity, in which case we used a random-effects model. The primary outcomes of interest were clot lysis, bleeding and post thrombotic syndrome.

MAIN RESULTS

Two new studies were added for this update. Therefore, the review now includes a total of 19 RCTs, with 1943 participants. These studies differed with respect to the thrombolytic agent, the doses of the agent and the techniques used to deliver the agent. Systemic, loco-regional and catheter-directed thrombolysis (CDT) strategies were all included. For this update, CDT interventions also included those involving pharmacomechanical thrombolysis. Three of the 19 included studies reported one or more domain at high risk of bias. We combined the results as any (all) thrombolysis interventions compared to standard anticoagulation. Complete clot lysis occurred more frequently in the thrombolysis group at early follow-up (RR 4.75; 95% CI 1.83 to 12.33; 592 participants; eight studies) and at intermediate follow-up (RR 2.42; 95% CI 1.42 to 4.12; 654 participants; seven studies; moderate-certainty evidence). Two studies reported on clot lysis at late follow-up with no clear benefit from thrombolysis seen at this time point (RR 3.25, 95% CI 0.17 to 62.63; two studies). No differences between strategies (e.g. systemic, loco-regional and CDT) were detected by subgroup analysis at any of these time points (tests for subgroup differences: P = 0.41, P = 0.37 and P = 0.06 respectively). Those receiving thrombolysis had increased bleeding complications (6.7% versus 2.2%) (RR 2.45, 95% CI 1.58 to 3.78; 1943 participants, 19 studies; moderate-certainty evidence). No differences between strategies were detected by subgroup analysis (P = 0.25). Up to five years after treatment, slightly fewer cases of PTS occurred in those receiving thrombolysis; 50% compared with 53% in the standard anticoagulation (RR 0.78, 95% CI 0.66 to 0.93; 1393 participants, six studies; moderate-certainty evidence). This was still observed at late follow-up (beyond five years) in two studies (RR 0.56, 95% CI 0.43 to 0.73; 211 participants; moderate-certainty evidence). We used subgroup analysis to investigate if the level of DVT (iliofemoral, femoropopliteal or non-specified) had an effect on the incidence of PTS. No benefit of thrombolysis was seen for either iliofemoral or femoropopliteal DVT (six studies; test for subgroup differences: P = 0.29). Systemic thrombolysis and CDT had similar levels of effectiveness. Studies of CDT included four trials in femoral and iliofemoral DVT, and results from these are consistent with those from trials of systemic thrombolysis in DVT at other levels of occlusion.

AUTHORS' CONCLUSIONS

Complete clot lysis occurred more frequently after thrombolysis (with or without additional clot removal strategies) and PTS incidence was slightly reduced. Bleeding complications also increased with thrombolysis, but this risk has decreased over time with the use of stricter exclusion criteria of studies. Evidence suggests that systemic administration of thrombolytics and CDT have similar effectiveness. Using GRADE, we judged the evidence to be of moderate-certainty, due to many trials having small numbers of participants or events, or both. Future studies are needed to investigate treatment regimes in terms of agent, dose and adjunctive clot removal methods; prioritising patient-important outcomes, including PTS and quality of life, to aid clinical decision making.

Catheter-Based Therapies and Other Management Strategies for Deep Vein Thrombosis and Post-Thrombotic Syndrome

Acute deep vein thrombosis (DVT) causes substantial short-term and long-term patient morbidity. Medical, lifestyle, and compressive therapies have been investigated for the prevention of pulmonary embolism (PE) and recurrence of venous thromboembolism (VTE). However, patient-centered outcomes such as resolution of presenting DVT symptoms and late occurrence of post-thrombotic syndrome (PTS) have not been prioritized to the same degree. Imaging-guided, catheter-based endovascular therapy has been used in selected patients to alleviate these sequelae, but important questions remain about their optimal use. In this article, we review the available evidence and summarize the rationale for use of catheter-based therapy in specific patient groups.

In-hospital outcomes of catheter-directed thrombolysis versus anticoagulation in cancer patients with proximal deep venous thrombosis

OBJECTIVE

The objective of this study was to determine the rate of complications of catheter-directed thrombolysis (CDT) in cancer patients with deep venous thrombosis (DVT) compared with anticoagulation therapy alone.

METHODS

This observational study used the National Inpatient Sample database to screen for any cancer patients who were admitted with a principal discharge diagnosis of proximal lower extremity or caval DVT between January 2005 and December 2013. Patients treated with CDT plus anticoagulation were compared with those treated with anticoagulation alone using propensity score matching for comorbidities and demographic characteristics. The primary end point was in-hospital mortality. Secondary end points were acute intracranial hemorrhage, inferior vena cava filter placement, acute renal failure, blood transfusion rates, length of stay, and hospital charges.

RESULTS

We identified 31,124 cancer patients with lower extremity proximal or caval DVT, and 1290 (4%) patients were treated with CDT. Comparative outcomes as assessed in the two matched groups of 1297 patients showed that there was no significant difference in in-hospital mortality of patients undergoing CDT plus anticoagulation compared with those treated with anticoagulation alone (2.6% vs 1.9%; P = .23). However, CDT was associated with increased risk of intracranial hemorrhage (1.3% vs 0.4%; P = .017), greater blood transfusion rates (18.6% vs 13.1 %; P < .001), and higher rates of procedure-related hematoma (2.4% vs 0.4%; P < .001). The length of stay (6.0 [4.0-10.0] days vs 4.0 [2.0-7.0] days; P < .001) and hospital charges ($81,535 [$50,968-$127,045] vs $22,320 [$11,482-$41,005]; P < .001) were also higher in the CDT group compared with the control group.

CONCLUSIONS

There was no significant difference in in-hospital mortality of cancer patients who underwent CDT plus anticoagulation compared with anticoagulation alone. CDT was associated with increased in-hospital morbidity and resource utilization compared with anticoagulation alone. Further studies are needed to examine the effect of CDT on the development of PTS in this population.

Cost-Effectiveness of Pharmacomechanical Catheter-Directed Thrombolysis Versus Standard Anticoagulation in Patients With Proximal Deep Vein Thrombosis: Results From the ATTRACT Trial

BACKGROUND

In patients with acute deep vein thrombosis (DVT), pharmacomechanical catheter-directed thrombolysis (PCDT) in conjunction with anticoagulation therapy is increasingly used with the goal of preventing postthrombotic syndrome. Long-term costs and cost-effectiveness of these 2 treatment strategies from the perspective of the US healthcare system have not been compared.

METHODS AND RESULTS

Between 2009 and 2014, the ATTRACT trial (Acute Venous Thrombosis: Thrombus Removal With Adjunctive Catheter-Directed Thrombolysis) randomized 692 patients with acute proximal DVT to PCDT plus anticoagulation (n=337) or standard treatment with anticoagulation alone (n=355). Costs (2017 US dollars) were assessed over a 24-month follow-up period using a combination of resource-based costing, hospital bills, Medicare reimbursement rates, and the Drug Topics Red Book. Health state utilities were obtained from the Short Form-36. In-trial results and US life tables were used to develop a Markov cohort model to evaluate lifetime cost-effectiveness. For the PCDT group, mean costs of the initial procedure were $13 600; per-patient costs associated with the index hospitalization were $21 509 for PCDT and $3877 for standard care (difference=$17 632; 95% CI, $16 117-$19 243). The 24-month difference in costs was $20 045 (95% CI, $16 093-$24 120). Utility scores increased significantly between baseline and 6 months for both groups, with no significant differences between groups at any follow-up time point. Projected differences in lifetime costs of $16 740 and quality-adjusted life years (QALYs) of 0.08, yield an incremental cost-effectiveness ratio for PCDT of $222 041/QALY gained. In probabilistic sensitivity analysis, the probability that PCDT would achieve a lifetime incremental cost-effectiveness ratio <$50 000/QALY or <$150 000/QALY was 1% and 25%, respectively. For iliofemoral DVT, QALY gains with PCDT were greater, yielding an incremental cost-effectiveness ratio of $137 526/QALY; for femoral-popliteal DVT, standard therapy was an economically dominant strategy.

CONCLUSIONS

With an incremental cost-effectiveness ratio >$200 000/QALY gained, PCDT is not an economically attractive treatment for proximal DVT. PCDT may be of intermediate value in patients with iliofemoral DVT. Clinical Trial Registration URL: https://www.clinicaltrials.gov. Unique identifier: NCT00790335.

The case against catheter-directed thrombolysis in patients with proximal deep vein thrombosis

This article has a companion Point by Chiasakul and Cuker.

Modelling the cost-effectiveness of PCSK9 inhibitors vs. ezetimibe through LDL-C reductions in a Norwegian setting

Aims

Despite the success of statins, there remains unmet clinical need in cardiovascular disease (CVD) prevention. New proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors reduce low-density lipoprotein cholesterol (LDL-C) by 55-65%. Two PCSK9 inhibitors, evolocumab, and alirocumab, were approved for use in Norway but not yet for reimbursement through public national insurance. We aim to explore the cost-effectiveness of these compared with available treatments in a Norwegian setting.

Methods and results

A state transition Markov model was developed to model the cost-effectiveness of PCSK9 inhibitors for prevention of coronary heart disease, ischaemic strokes, and death among high-risk patient subpopulations in Norway, in both primary and secondary settings. Evolocumab and alirocumab are compared against ezetimibe and standard treatment. Risk of CVD is based on population incidence rates and adjusted according to baseline risk factors. Preventative effect of treatment was modelled according to absolute reduction in LDL-C. PCSK9 inhibitors were never found to be cost-effective in primary prevention. In secondary prevention they were cost-effective only for older, high-risk patients. The lowest cost-effectiveness ratios were for heterozygous familial hypercholesterolaemia patients and high-risk diabetics, with €63 200 and €68 400 per quality-adjusted life-year, respectively.

Conclusion

High lifetime costs of PCSK9 inhibitors may not be offset by estimated health gains for most eligible patients. PCSK9 inhibitors are found in the model only to be cost-effective in secondary prevention for older patients with high absolute risk of CVD. This picture is likely to change as price decreases. Future research is needed to determine the long-term preventative effects of PCSK9 inhibitors.

Endovascular and Open Surgery for Deep Vein Thrombosis

The surgical treatment of deep venous thrombosis (DVT) has significantly evolved and is focused on different strategies of early thrombus removal in the acute phase and deep venous recanalization or bypass in the chronic phase. Along with the use of anticoagulation agents, endovascular techniques based on catheter-directed thrombolysis and pharmacomechanical thrombectomy have been increasingly used in patients with acute extensive DVT. Patient selection is crucial to provide optimal outcomes and minimize complications.

How I treat the postthrombotic syndrome

The postthrombotic syndrome (PTS) is a chronic complication of deep vein thrombosis (DVT) that imposes significant morbidity, reduces quality of life, and is costly. After DVT, 20% to 50% of patients will develop PTS, and up to 5% will develop severe PTS. The principal risk factors for PTS are anatomically extensive DVT, recurrent ipsilateral DVT, obesity, and older age. By preventing the initial DVT and DVT recurrence, primary and secondary prophylaxis of DVT will reduce occurrence of PTS. The effectiveness of elastic compression stockings (ECSs) for PTS prevention is controversial. Catheter-directed thrombolysis is not effective to prevent PTS overall but may prevent more severe forms of PTS and should be reserved for select patients with extensive thrombosis, recent symptoms onset, and low bleeding risk. For patients with established PTS, the cornerstone of management is ECS, exercise, and lifestyle modifications. Surgical or endovascular interventions may be considered in refractory cases. Because of a lack of effective therapies, new approaches to preventing and treating PTS are needed. This article uses a case-based approach to discuss risk factors for PTS after DVT, how to diagnose PTS, and available means to prevent and treat PTS, with a focus on new information in the field.

Catheter-directed thrombolysis of deep vein thrombosis: literature review and practice considerations

Deep vein thrombosis (DVT) is a major health problem worldwide. The risk of pulmonary embolism following DVT is well established, but the long-term vascular sequelae of DVT are often underappreciated, costly to manage, and can have extremely detrimental effects on quality of life. Treatment of DVT classically involves oral anticoagulation, which reduces the risk of pulmonary embolism but does not remove the clot. Anticoagulation therefore does little to prevent the venous damage and scarring that occurs following DVT, leaving the patient at risk for permanent venous insufficiency and development of post-thrombotic syndrome (PTS). Catheter-directed thrombolysis (CDT) is a minimally invasive endovascular treatment that is used as an adjunct to anticoagulation. CDT lowers the risk of PTS by reducing clot burden and protecting against valvular damage. A catheter is advanced directly to the site of thrombosis under fluoroscopy followed by a slow, prolonged infusion of a relatively low dose of thrombolytic agent. CDT restores venous patency faster than anticoagulation, which hastens the relief of acute symptoms. Adjunctive CDT modalities have become increasingly popular among interventional radiologists, allowing for additional mechanical thrombectomy or ultrasound-enhanced thrombolysis at the time of catheter placement. These pharmacomechanical CDT (PCDT) techniques have the potential to reduce treatment time and associated healthcare costs. Numerous observational and retrospective studies have consistently shown a benefit of CDT plus anticoagulation over anticoagulation alone for prevention of PTS. Patients with long life expectancy and acute thrombosis involving the iliac and proximal femoral veins (iliofemoral DVT) have the greatest benefit from CDT, which may decrease the risk of PTS and/or decrease the severity of PTS symptoms if they do occur. Randomized controlled trials remain limited but generally support the observational data. CDT also plays an important role in those with acute limb-threatening venous occlusion or severe symptoms from DVT. Although adverse outcomes are rare, a potential devastating outcome is intracranial bleeding. While the available literature suggests the risk of serious morbidity from bleeding is quite rare, the absolute risk of bleeding is not clear and will require outcomes data from randomized trials. Future studies should also examine the cost-effectiveness of CDT for PTS prevention, particularly with respect to quality-adjusted life years, and compare the effectiveness of available PCDT devices.

Catheter-directed thrombolysis to avoid late consequences of acute deep vein thrombosis

The application of catheter-based methods to treat acute deep vein thrombosis (DVT) has increased in recent years. Catheter-directed thrombolysis (CDT), introduced during the early 1990s, has shown the ability to rapidly eliminate thrombus and is used in many centers as a salvage therapy for DVT patients who exhibit a poor initial response to anticoagulant therapy. However, CDT has disadvantages in terms of safety and resource use. Although CDT methods have evolved substantially to try to address these issues, for most of the last 25years there was little high-quality data on CDT outcomes upon which to base patient care decisions. The paucity of evidence was particularly problematic for long-term outcomes such as recurrent venous thromboembolism (VTE) and the post-thrombotic syndrome (PTS). Fortunately, rigorous studies of CDT are now being completed. Accordingly, the purpose of this article is to: 1) state the known and unknown factors influencing risk and benefit with use of CDT and related methods to treat acute DVT; 2) summarize emerging evidence showing the patient outcomes that occur when CDT is used for first-line management of DVT; and 3) suggest clinical parameters for CDT utilization in light of the available evidence.

Impact of health utility after thrombotic complications following total hip and knee arthroplasty

BACKGROUND

Medical complications and preexisting conditions frequently place the surgeon in the unenviable position of choosing between the serious and potentially life-threatening effects of thrombosis, or the issue of bleeding and surgical site complications. The aim of this research was to determine if health utility could be a consideration before choosing to therapeutically anticoagulate in the hip and knee arthroplasty patient.

METHODS

The quantitative risks and effectiveness of treatment options for venous thromboembolism, atrial fibrillation, acute coronary syndromes, ischaemic stroke and mechanical heart valves were evaluated from previously published data. Previously calculated health utility values were obtained from published studies for both thrombotic events and anticoagulant-related complications at the site of arthroplasty. An impact score was generated through a multiplication of 1 - utility with the rate of the event occurring.

RESULTS

Impact scores associated with revision surgery and deep infection at the arthroplasty site following anticoagulation are higher compared to impact scores in subsets of non-treated venous thromboembolism, low CHADS2 (congestive heart failure, hypertension, age >75, diabetes (1 point each), stroke/transient ischaemic attack (2 points)) atrial fibrillation and potentially some acute coronary syndrome patients. Some anticoagulation strategies in mechanical heart valves are of definite overall patient value due to the significant complications otherwise.

CONCLUSION

Objective calculation of both the benefit and risks of anticoagulation in the post-operative patient is significantly altered by including the effect on patient's quality of life utility value. Therapeutic anticoagulation in some common situations is probable to be of more detriment than benefit when considering health utility.

Intervention radiology for venous thrombosis: early thrombus removal using invasive methods

The post thrombotic syndrome is one of the most dreaded complications of proximal deep vein thrombosis. This syndrome leads to pain and suffering with leg swelling, recalcitrant ulceration and venous claudication which greatly impairs mobility and quality of life. The prevalence can be high in patients with iliofemoral venous involvement particularly in the setting of a proximal venous stenosis, such as occurs in May Thurner syndrome. Anticoagulation alone does not reduce the likelihood of this outcome. Compression therapy may be effective but garment discomfort limits its implementation. Pharmacomechanical thrombectomy, which combines catheter-directed thrombolysis with mechanical thrombus dissolution, provides an attractive treatment strategy for such patients. The rationale and delivery of pharmacomechanical thrombectomy, including patient selection and adjunctive antithrombotic therapy, will be reviewed in addition to tips and tricks for managing difficult patient scenarios.

The postthrombotic syndrome: current evidence and future challenges

Postthrombotic syndrome (PTS) is a chronic complication of deep vein thrombosis (DVT) that develops in 20-50% of patients. PTS manifests as a spectrum of symptoms and signs of chronic venous insufficiency that can impose significant morbidity and have a negative impact on quality of life. Chronic venous hypertension caused by a combination of residual venous obstruction and valvular reflux is believed to play a major role in the pathophysiology of PTS. The Villalta scale is the most widely applied clinical scale used to diagnose and define PTS. Proximal DVT and recurrent ipsilateral DVT are the two principal established risk factors for PTS, and efforts in recent years have been focused on identifying a combination of clinical and biomarker predictors that will define high-risk patients and possibly new therapeutic targets. The best way to prevent PTS is to prevent the occurrence of DVT, and to provide optimal anticoagulation for the acute phase of DVT once it occurs. Recent years have brought progress in our understanding of the role of endovascular techniques in the prevention and treatment of PTS and the subgroups of patients that may benefit from these modalities. Pharmacomechanical catheter-directed thrombolysis is the most promising interventional modality for prevention of PTS. This review summarizes the current state of evidence on PTS of the lower limbs, and highlights areas where uncertainty still exists that require further research.

Thrombolysis for acute deep vein thrombosis

BACKGROUND

Standard treatment for deep vein thrombosis aims to reduce immediate complications. Use of thrombolysis or clot dissolving drugs could reduce the long-term complications of post-thrombotic syndrome (PTS) including pain, swelling, skin discolouration, or venous ulceration in the affected leg. This is the third update of a review first published in 2004.

OBJECTIVES

To assess the effects of thrombolytic therapy and anticoagulation compared to anticoagulation alone for the management of people with acute deep vein thrombosis (DVT) of the lower limb as determined by the effects on pulmonary embolism, recurrent venous thromboembolism, major bleeding, post-thrombotic complications, venous patency and venous function.

SEARCH METHODS

For this update the Cochrane Vascular Information Specialist (CIS) searched the Specialised Register (February 2016). In addition the CIS searched the Cochrane Register of Studies (CENTRAL (2016, Issue 1)). Trial registries were searched for details of ongoing or unpublished studies.

SELECTION CRITERIA

Randomised controlled trials (RCTs) examining thrombolysis and anticoagulation versus anticoagulation for acute DVT were considered.

DATA COLLECTION AND ANALYSIS

For this update (2016), LW and CB selected trials, extracted data independently, and sought advice from MPA where necessary. We assessed study quality with the Cochrane risk of bias tool. For dichotomous outcomes, we calculated the risk ratio (RR) and corresponding 95% confidence interval (CI). Data were pooled using a fixed-effect model unless significant heterogeneity was identified in which case a random-effects model was used. GRADE was used to assess the overall quality of the evidence supporting the outcomes assessed in this review.

MAIN RESULTS

Seventeen RCTs with 1103 participants were included. These studies differed in the both thrombolytic agent used and in the technique used to deliver it. Systemic, loco-regional and catheter-directed thrombolysis (CDT) were all included. Fourteen studies were rated as low risk of bias and three studies were rated as high risk of bias. We combined the results as any (all) thrombolysis compared to standard anticoagulation. Complete clot lysis occurred significantly more often in the treatment group at early follow-up (RR 4.91; 95% CI 1.66 to 14.53, P = 0.004) and at intermediate follow-up (RR 2.44; 95% CI 1.40 to 4.27, P = 0.002; moderate quality evidence). A similar effect was seen for any degree of improvement in venous patency. Up to five years after treatment significantly less PTS occurred in those receiving thrombolysis (RR 0.66, 95% CI 0.53 to 0.81; P < 0.0001; moderate quality evidence). This reduction in PTS was still observed at late follow-up (beyond five years), in two studies (RR 0.58, 95% CI 0.45 to 0.77; P < 0.0001; moderate quality evidence). Leg ulceration was reduced although the data were limited by small numbers (RR 0.87; 95% CI 0.16 to 4.73, P = 0.87). Those receiving thrombolysis had increased bleeding complications (RR 2.23; 95% CI 1.41 to 3.52, P = 0.0006; moderate quality evidence). Three strokes occurred in the treatment group, all in trials conducted pre-1990, and none in the control group. There was no significant effect on mortality detected at either early or intermediate follow-up. Data on the occurrence of pulmonary embolism (PE) and recurrent DVT were inconclusive. Systemic thrombolysis and CDT had similar levels of effectiveness. Studies of CDT included two trials in femoral and iliofemoral DVT, and results from these are consistent with those from trials of systemic thrombolysis in DVT at other levels of occlusion.

AUTHORS' CONCLUSIONS

Thrombolysis increases the patency of veins and reduces the incidence of PTS following proximal DVT by a third. Evidence suggests that systemic administration and CDT have similar effectiveness. Strict eligibility criteria appears to improve safety in recent studies and may be necessary to reduce the risk of bleeding complications. This may limit the applicability of this treatment. In those who are treated there is a small increased risk of bleeding. Using GRADE assessment, the evidence was judged to be of moderate quality due to many trials having low numbers of participants. However, the results across studies were consistent and we have reasonable confidence in these results.

Antithrombotic Therapy for VTE Disease: CHEST Guideline and Expert Panel Report

BACKGROUND

We update recommendations on 12 topics that were in the 9th edition of these guidelines, and address 3 new topics.

METHODS

We generate strong (Grade 1) and weak (Grade 2) recommendations based on high- (Grade A), moderate- (Grade B), and low- (Grade C) quality evidence.

RESULTS

For VTE and no cancer, as long-term anticoagulant therapy, we suggest dabigatran (Grade 2B), rivaroxaban (Grade 2B), apixaban (Grade 2B), or edoxaban (Grade 2B) over vitamin K antagonist (VKA) therapy, and suggest VKA therapy over low-molecular-weight heparin (LMWH; Grade 2C). For VTE and cancer, we suggest LMWH over VKA (Grade 2B), dabigatran (Grade 2C), rivaroxaban (Grade 2C), apixaban (Grade 2C), or edoxaban (Grade 2C). We have not changed recommendations for who should stop anticoagulation at 3 months or receive extended therapy. For VTE treated with anticoagulants, we recommend against an inferior vena cava filter (Grade 1B). For DVT, we suggest not using compression stockings routinely to prevent PTS (Grade 2B). For subsegmental pulmonary embolism and no proximal DVT, we suggest clinical surveillance over anticoagulation with a low risk of recurrent VTE (Grade 2C), and anticoagulation over clinical surveillance with a high risk (Grade 2C). We suggest thrombolytic therapy for pulmonary embolism with hypotension (Grade 2B), and systemic therapy over catheter-directed thrombolysis (Grade 2C). For recurrent VTE on a non-LMWH anticoagulant, we suggest LMWH (Grade 2C); for recurrent VTE on LMWH, we suggest increasing the LMWH dose (Grade 2C).

CONCLUSIONS

Of 54 recommendations included in the 30 statements, 20 were strong and none was based on high-quality evidence, highlighting the need for further research.

Post-thrombotic syndrome after catheter-directed thrombolysis for deep vein thrombosis (CaVenT): 5-year follow-up results of an open-label, randomised controlled trial

BACKGROUND

Post-thrombotic syndrome is a common complication after acute proximal deep vein thrombosis (DVT) and is associated with reduced quality of life and a substantial cost burden. In the 2-year results of the CaVenT study, additional catheter-directed thrombolysis reduced the risk of post-thrombotic syndrome by 14% compared with conventional therapy, but did not affect quality of life. In this study we report results at the 5-year follow-up, aiming to assess whether findings for post-thrombotic syndrome and quality of life have persisted.

METHODS

Between Jan 3, 2006, and Dec 22, 2009, we recruited patients aged 18-75 years with a first-time high proximal leg DVT from 20 hospitals in the Norwegian southeastern health region. With sealed envelopes, participants were randomly assigned (1:1) to standard treatment with compression stockings and anticoagulants (control group) or to standard treatment plus catheter-directed thrombolysis with alteplase within 21 days from symptom onset. Pre-specified outcomes in this analysis were post-thrombotic syndrome at 5 years as assessed with the Villalta score and scores for quality of life at 5 years with EQ-5D and the disease-specific VEINES-QOL/Sym. Analyses were by intention to treat. The trial is registered with ClinicalTrials.gov, number NCT00251771.

FINDINGS

At 5 year follow-up (last date Oct 14, 2014), data were available for 176 patients (84% of the 209 patients originally randomised)--87 originally assigned to catheter-directed thrombolysis and 89 originally assigned to the control group. 37 patients (43%; 95% CI 33-53) allocated to catheter-directed thrombolysis developed post-thrombotic syndrome, compared with 63 (71%; 95% CI 61-79) allocated to the control group (p<0·0001), corresponding to an absolute risk reduction of 28% (95% CI 14-42) and a number needed to treat of 4 (95% CI 2-7). Four (5%) patients assigned to catheter-directed thrombolysis and one (1%) to standard treatment had severe post-thrombotic syndrome (Villalta score ≥ 15 or presence of an ulcer). Quality-of-life scores with either assessment scale did not differ between the treatment groups.

INTERPRETATION

Additional catheter-directed thrombolysis resulted in a persistent and increased clinical benefit during follow-up for up to 5 years, supporting the use of additional catheter-directed thrombolysis in patients with extensive proximal DVT. However, allocation to this therapy did not lead to better quality of life. The optimal endovascular thrombolytic approach needs further investigation.

FUNDING

Southeastern Norway Regional Health Authority, the Research Council of Norway, University of Oslo, Oslo University Hospital.

A Multicenter, Retrospective Study of the Effectiveness of the Trellis-8 System in the Treatment of Proximal Lower-Extremity Deep Vein Thrombosis

BACKGROUND

Deep vein thrombosis (DVT) occurs in up to 600,000 patients in the United States annually and can lead to long-term morbidity because of the post-thrombotic syndrome. The multicenter isolated-pharmacomechanical thrombolysis device (ISOL-8) study was designed to determine the safety and efficacy of the Trellis™-8 peripheral infusion system when used as the primary intervention to achieve DVT thrombolysis in patients with proximal lower-extremity occlusive DVT, and track the incidence and severity of the post-thrombotic syndrome (PTS) symptoms in patients 2 years after treatment.

METHODS

Data were collected retrospectively from 6 centers on patients treated with the Trellis-8 system, an isolated-pharmacomechanical thrombolysis device (IPMTD). Patients with occlusive lower-extremity DVT involving at least the iliac and/or common femoral vein were included. Patient demographics, medical history, procedure outcomes, complications, and follow-up venous duplex and Venous Clinical Severity Score (VCSS) were collected through 24 months. Data analysis of outcomes were performed at 1 and 12 months. A 24-month analysis was not performed because of the small number of patients for whom 24-month data could be collected.

RESULTS

A total of 151 limbs in 139 patients were treated with IPMTD. The mean ± standard deviation (SD) procedure time was 122.6 ± 63.4 min. Single session treatment was delivered in 69.9% (93 of 133) of cases. Occlusive DVT extended from the femoral into the external and/or common iliac vessel segments in most of the cases (113 of 151 limbs; 74.8%). Before treatment, 23.2% (35 of 151) of the treated limbs, based on a history of prior ipsilateral DVT or preoperative imaging revealing chronic venous scar, were expected to have some chronic venous disease despite presenting with acute symptoms. After treatment, 43.7% (66 of 151) of the limbs showed evidence of chronic thrombus. The average amount (mean ± SD) of thrombolysis, as determined by venogram, was highest in patients who had acute thrombus (81 ± 19.7%), compared with subacute thrombus (61 ± 22.5%) and complex cases involving acute and/or subacute thrombus on chronic scar (56 ± 26.5%). VCSS scoring showed the number of patients with none and/or mild pain, varicose veins, and skin changes at 1-month remained stable at 12 months whereas the percent of patients with none and/or mild venous edema improved from 71.7% at 1 month (38 of 53) to 86.8% (46 of 53) at 12 months. Twenty-four-month follow-up data were available for only 15% (23 of 151) of patients. No clinically significant pulmonary emboli or major periprocedural bleeding events were reported.

CONCLUSIONS

Patients with acute lower-extremity DVT involving the proximal veins can be safely and successfully treated with IPMTD. Major procedural bleeding was absent. The occurrence of severe PTS after primary treatment with Trellis-8 system IPMTD is low. Further long-term follow-up data are needed to confirm the benefit of intervention for thrombus removal compared with standard medical management.

Postthrombotic syndrome: a 2014 update

PURPOSE OF REVIEW

Postthrombotic syndrome (PTS) is the most frequent complication of deep vein thrombosis. Its pathophysiology is incompletely understood and therapeutic options are limited. This review aims to present and discuss recently published studies that have improved our knowledge related to PTS.

RECENT FINDINGS

From a prognostic point of view, some polymorphisms of plasminogen activator inhibitor-1 and platelet endothelial cell adhesion molecule 1 influence the degree of thrombus resolution after deep vein thrombosis and the subsequent rate of PTS, and could help in predicting the risk of PTS. From a therapeutic point of view, the results of a large multicenter placebo-controlled trial suggest an absence of effectiveness of elastic compression stockings to prevent PTS. In addition, although the Cavent trial of catheter-directed thrombolysis to treat ilio-femoral deep vein thrombosis showed significant reduction in the incidence of PTS that was cost-effective, secondary analyses did not show dramatic improvements in quality of life associated with use of catheter-directed thrombolysis.

SUMMARY

Choice of anticoagulant to treat deep vein thrombosis may represent a new cornerstone of PTS therapeutic management. Studies are needed to assess the impact of new oral anticoagulants and the benefit of extended courses of low molecular weight heparins on the risk of PTS.

The Future of Phlebology in Europe

Background

Worldwide superficial and deep venous diseases are common and associated with significant individual and socioeconomic morbidity. Increasing burden of venous disease requires Phlebology to define itself as an independent specialty representing not only patients but the multidisciplinary physicians involved in venous care.

Methods & Results

In this article the scope of venous disease in Europe and subsequent future governance for treatment in the region is discussed. Superficial venous disease is common with 26.9-68.6% of European populations reported to have C2-C6 disease according to the CEAP (Clinical severity, Aetiology, Anatomy and Pathophysiology) scoring system. However, a significant disparity is observed in the treatment of superficial venous disease across Europe. Post thrombotic syndrome (PTS) after deep vein thrombosis (DVT) contributes to the increasing burden of deep venous disease. Aggressive thrombus removal for acute ileofemoral DVT provides a cost-effective 14.4% risk reduction in the development of PTS. Additionally, deep venous lesions requiring endovascular intervention are being increasingly performed to prevent recurrent thrombosis. The European College of Phlebology (ECoP) has been formed to provide a responsible body for the care of the European patient with venous disease. The role of the ECoP includes unifying European member states through standardised guideline production, identification of research strategy and provision of training and accreditation of physicians.

Conclusion

Creation of a European venous disease specific speciality will provide a patient centred approach through understanding of the impact of disease in the region and delivery of high quality diagnostics and treatment from an appropriately certified Phlebologist.

Symptom burden and job absenteeism after treatment with additional catheter-directed thrombolysis for deep vein thrombosis

Introduction

Additional catheter-directed thrombolysis (CDT) for acute deep vein thrombosis (DVT) reduces long-term postthrombotic syndrome and is likely to represent a cost-effective alternative treatment compared to the standard treatment of anticoagulation and elastic compression stockings. Accelerated thrombus resolution has also been suggested to improve symptoms and patient function in the acute phase. We aimed to investigate whether additional CDT led to fewer symptoms and job absenteeism during the first 6 months after initiation of DVT treatment compared to standard treatment alone.

Methods

The Catheter-directed Venous Thrombolysis (CaVenT) study was a multicenter open label, randomized controlled trial of patients ages 18 years to 75 years with a verified high proximal DVT, <21 days of symptoms, and no apparent bleeding risk. Patients were allocated to additional CDT or to standard treatment only. Symptoms were assessed at baseline and at 6 months using items from the generic and disease-specific quality of life questionnaires EQ-5D and VEINES-QOL/Sym, respectively. Individual data on sickness benefits related to venous thromboembolic disease were obtained from the national welfare service.

Results

A total of 90 patients allocated additional CDT and 99 control patients completed long-term follow-up and were included in the analyses. Twenty-four in the CDT arm and 40 controls received sick leave (P = 0.046). When considering working patients only (54 in the CDT arm and 72 controls) this difference was no longer statistically significant. Mean duration of job absenteeism was 86.4 days (95% confidence interval 59.4–113.5) in the CDT arm and 60.1 days (95% confidence interval 42.3–77.8) in controls (P = 0.072). After 6 months, more controls experienced frequent swelling of the leg compared with those allocated to CDT (47 [49.0%] patients versus 25 [29.4%] patients, respectively, [P = 0.007]).

Conclusion

There are limitations to our data, but the findings indicate improved symptom relief and less frequent job absenteeism in patients treated with additional CDT; this expands upon previously established benefits from this treatment.

Health-related quality of life after catheter-directed thrombolysis for deep vein thrombosis: secondary outcomes of the randomised, non-blinded, parallel-group CaVenT study

OBJECTIVES

To investigate whether additional catheter-directed thrombolysis (CDT) improves long-term quality of life (QOL) compared with standard treatment with anticoagulation and compression stockings alone in patients with proximal deep vein thrombosis (DVT).

DESIGN

Open-label randomised controlled trial.

SETTING

19 Hospitals in the Norwegian southeastern health region.

PARTICIPANTS

Patients (18-75 years) with a high proximal DVT, symptoms <21 days and no increased risk of bleeding were eligible. 189 of 209 recruited patients completed 24 months of follow-up.

INTERVENTIONS

Participants were randomised to additional CDT with alteplase for 1-4 days or to standard treatment only with 6 months of anticoagulation and 24 months of compression stockings.

PRIMARY AND SECONDARY OUTCOME MEASURES

Planned secondary outcome measures included QOL as assessed with the generic instrument EQ-5D and the disease-specific instrument VEINES-QOL/Sym. Primary outcome measure was post-thrombotic syndrome (PTS) after 24 months.

RESULTS

After 24 months there were no differences in QOL between the additional CDT and standard treatment arms; mean difference for the EQ-5D index was 0.04 (95% CI -0.10 to 0.17), for the VEINES-QOL score 0.2 (95% CI -2.8 to 3.0) and for the VEINES-Sym score 0.5 (95% CI -2.4 to 3.4; p values>0.37). Independent of treatment arms, patients with PTS had poorer outcomes than patient without PTS; mean difference for EQ-5D was 0.09 (95% CI 0.03 to 0.15), for VEINES-QOL score 8.6 (95% CI 5.9 to 11.2) and for VEINES-Sym score 9.8 (95% CI 7.3 to 12.3; p values<0.001).

CONCLUSIONS

QOL did not differ between patients treated with additional CDT compared with standard treatment alone. Patients who developed PTS reported poorer QOL and more symptoms than patients without PTS. QOL should be included as an outcome measure in clinical studies on patients at risk of PTS.

TRIAL REGISTRATION

NCT00251771.

Venous thromboembolism

Extended treatment