What is the effect of venous thromboembolism and related complications on patient reported health-related quality of life? A meta-analysis

Evaluation of venous thromboembolism risk assessment models for hospital inpatients: the VTEAM evidence synthesis

Background

Pharmacological prophylaxis during hospital admission can reduce the risk of acquired blood clots (venous thromboembolism) but may cause complications, such as bleeding. Using a risk assessment model to predict the risk of blood clots could facilitate selection of patients for prophylaxis and optimise the balance of benefits, risks and costs.

Objectives

We aimed to identify validated risk assessment models and estimate their prognostic accuracy, evaluate the cost-effectiveness of different strategies for selecting hospitalised patients for prophylaxis, assess the feasibility of using efficient research methods and estimate key parameters for future research.

Design

We undertook a systematic review, decision-analytic modelling and observational cohort study conducted in accordance with Enhancing the QUAlity and Transparency Of health Research (EQUATOR) guidelines.

Setting

NHS hospitals, with primary data collection at four sites.

Participants

Medical and surgical hospital inpatients, excluding paediatric, critical care and pregnancy-related admissions.

Interventions

Prophylaxis for all patients, none and according to selected risk assessment models.

Main outcome measures

Model accuracy for predicting blood clots, lifetime costs and quality-adjusted life-years associated with alternative strategies, accuracy of efficient methods for identifying key outcomes and proportion of inpatients recommended prophylaxis using different models.

Results

We identified 24 validated risk assessment models, but low-quality heterogeneous data suggested weak accuracy for prediction of blood clots and generally high risk of bias in all studies. Decision-analytic modelling showed that pharmacological prophylaxis for all eligible is generally more cost-effective than model-based strategies for both medical and surgical inpatients, when valuing a quality-adjusted life-year at £20,000. The findings were more sensitive to uncertainties in the surgical population; strategies using risk assessment models were more cost-effective if the model was assumed to have a very high sensitivity, or the long-term risks of post-thrombotic complications were lower. Efficient methods using routine data did not accurately identify blood clots or bleeding events and several pre-specified feasibility criteria were not met. Theoretical prophylaxis rates across an inpatient cohort based on existing risk assessment models ranged from 13% to 91%.

Limitations

Existing studies may underestimate the accuracy of risk assessment models, leading to underestimation of their cost-effectiveness. The cost-effectiveness findings do not apply to patients with an increased risk of bleeding. Mechanical thromboprophylaxis options were excluded from the modelling. Primary data collection was predominately retrospective, risking case ascertainment bias.

Conclusions

Thromboprophylaxis for all patients appears to be generally more cost-effective than using a risk assessment model, in hospitalised patients at low risk of bleeding. To be cost-effective, any risk assessment model would need to be highly sensitive. Current evidence on risk assessment models is at high risk of bias and our findings should be interpreted in this context. We were unable to demonstrate the feasibility of using efficient methods to accurately detect relevant outcomes for future research.

Future work

Further research should evaluate routine prophylaxis strategies for all eligible hospitalised patients. Models that could accurately identify individuals at very low risk of blood clots (who could discontinue prophylaxis) warrant further evaluation.

Study registration

This study is registered as PROSPERO CRD42020165778 and Researchregistry5216.

Funding

This award was funded by the National Institute for Health and Care Research (NIHR) Health Technology Assessment programme (NIHR award ref: NIHR127454) and will be published in full in Health Technology Assessment; Vol. 28, No. 20. See the NIHR Funding and Awards website for further award information.

Effectiveness and cost effectiveness of pharmacological thromboprophylaxis for medical inpatients: decision analysis modelling study

Objective

To determine the balance of costs, risks, and benefits for different thromboprophylaxis strategies for medical patients during hospital admission.

Design

Decision analysis modelling study.

Setting

NHS hospitals in England.

Population

Eligible adult medical inpatients, excluding patients in critical care and pregnant women.

Interventions

Pharmacological thromboprophylaxis (low molecular weight heparin) for all medical inpatients, thromboprophylaxis for none, and thromboprophylaxis given to higher risk inpatients according to risk assessment models (Padua, Caprini, IMPROVE, Intermountain, Kucher, Geneva, and Rothberg) previously validated in medical cohorts.

Main outcome measures

Lifetime costs and quality adjusted life years (QALYs). Costs were assessed from the perspective of the NHS and Personal Social Services in England. Other outcomes assessed were incidence and treatment of venous thromboembolism, major bleeds including intracranial haemorrhage, chronic thromboembolic complications, and overall survival.

Results

Offering thromboprophylaxis to all medical inpatients had a high probability (>99%) of being the most cost effective strategy (at a threshold of £20 000 (€23 440; $25 270) per QALY) in the probabilistic sensitivity analysis, when applying performance data from the Padua risk assessment model, which was typical of that observed across several risk assessment models in a medical inpatient cohort. Thromboprophylaxis for all medical inpatients was estimated to result in 0.0552 additional QALYs (95% credible interval 0.0209 to 0.1111) while generating cost savings of £28.44 (-£47 to £105) compared with thromboprophylaxis for none. No other risk assessment model was more cost effective than thromboprophylaxis for all medical inpatients when assessed in deterministic analysis. Risk based thromboprophylaxis was found to have a high (76.6%) probability of being the most cost effective strategy only when assuming a risk assessment model with very high sensitivity is available (sensitivity 99.9% and specificity 23.7% v base case sensitivity 49.3% and specificity 73.0%).

Conclusions

Offering pharmacological thromboprophylaxis to all eligible medical inpatients appears to be the most cost effective strategy. To be cost effective, any risk assessment model would need to have a very high sensitivity resulting in widespread thromboprophylaxis in all patients except those at the very lowest risk, who could potentially avoid prophylactic anticoagulation during their hospital stay.

Health-related quality of life after first venous thromboembolism in individuals aged 70 years and older

Background

There is limited information on short- and long-term effects of venous thromboembolism (VTE) on health-related quality of life (HRQoL) in the elderly.

Objectives

To assess change in generic HRQoL and disease-specific HRQoL in patients 1 year after the VTE.

Methods

The Age and Thrombosis, Acquired and Genetic risk factors in the elderly (AT-AGE) study is a 2-center case-control study performed in Leiden, the Netherlands, and Vermont, United States, among individuals aged ≥70 years. We measured generic HRQoL using the 36-item Short Form Health Survey (SF-36) and disease-specific HRQoL using the Venous Insufficiency Epidemiological and Economic Study-Quality of Life/Symptoms Questionnaire (VEINES-QoL/Sym) and the Pulmonary Embolism-Specific Quality of Life Questionnaire (PEmb-QoL). All patients completed these questionnaires shortly after their VTE and 1 year later, while controls completed the 36-item Short Form Health Survey questionnaire once. Linear regression for change in quality of life scores was performed and adjusted for potential confounders.

Results

For the current analysis, we included patients who were visited twice (n = 316) and controls (n = 427) with HRQoL information. Mean age of patients and controls was similar (78.8 vs 75.5 years). In patients who survived at least 1 year after the VTE, generic HRQoL improved for both summary scores, but it did not reach the level of the age-matched controls: physical and mental summary scores increased by 5.6 and 5.5 points, respectively, but compared with controls, remained 8.2 and 6.4 points lower. For disease-specific HRQoL, the Pulmonary Embolism-Specific Quality of Life Questionnaire overall score decreased from 21.7% to 15.2%, indicating improved HRQoL. Venous Insufficiency Epidemiological and Economic Study-Quality of Life/Symptoms Questionnaire scores did not change over time.

Conclusion

Overall, the quality of life of patients with VTE was worse than that of controls after 1 year, indicating a long-term impact of VTE diagnosis in the elderly.

Development of a Consensus-Based Cross-Domain Protocol for the Management of Elastic Compression Stocking Therapy in Patients With Deep Venous Thrombosis and Chronic Venous Disease: A Modified Delphi Study

Objective

Elastic compression stocking (ECS) therapy is commonly used in patients with deep venous thrombosis (DVT) and chronic venous disease (CVD). The provision of ECS therapy is complex, and studies indicate a lack of practical guidance and suboptimal collaboration among health care professionals. We aimed to reach consensus on critical issues of ECS therapy among the involved health care professionals and patients.

Methods

A three-round modified Delphi analysis was performed in the Netherlands in which 56 health care professionals (internists, dermatologists, general practitioners, emergency room nurses, home care nurses, medical stocking suppliers, and occupational therapists) and seven patients were invited. The 21 statements included in this analysis were based on information collected from a previously conducted Functional Resonance Analysis Method and Realist Evaluation. We used 7-point Likert scale questions and a 75% threshold for consensus.

Results

Of the 63 persons invited for this study, 59 (94%) agreed to participate and responded in the first questionnaire round; of whom 52 were health care professionals and seven were patients (five DVT and two CVD). The overall response rate for the three questionnaire rounds was 91%. After completion of the rounds, full consensus was achieved on 19 out of 21 statements. No consensus was reached on the need for a follow-up appointment for CVD patients and who should be responsible to determine the ECS type (custom-made or standard).

Conclusion

We identified 19 consensus-driven recommendations on treatment decisions and collaboration in ECS therapy among an interdisciplinary panel of health care professionals and patients. These recommendations form a basis for consensus-driven optimization of ECS therapy and should ideally be incorporated in a general cross-domain protocol for ECS therapy in patients with DVT and CVD.

Quality of Life Status and Influencing Factors Among Patients with Deep Vein Thrombosis

OBJECTIVE

The objective of the study was to describe the quality of life (QoL) status and investigate the influencing factors of QoL among patients with deep vein thrombosis (DVT).

METHODS

A retrospective analysis at a single center was performed, and the clinical data of 161 patients with DVT admitted to West China Hospital of Sichuan University from June 2019 to June 2020 were collected with the Villalta scale, Hospital Anxiety and Depression Scale (HADS), and Chronic Venous Insufficiency Questionnaire (CIVIQ). The relationship between QoL and influencing factors, including characteristics, course of DVT, postthrombotic syndrome (PTS), psychological status, and behaviors, was analyzed by Student's t-test, analysis of variance and multiple linear regression.

RESULTS

A total of 161 patients who completed all the questionnaires between 2019 and 2020 were included, and 110 patients (68%) were male. The mean QoL score acquired by the CIVIQ scale was 74.18±8.44, and the results showed significant differences between patients of different ages, genders, behaviors and psychological statuses (P < 0.05). Multiple regression analysis showed that age (P = 0.024), negative mood (P < 0.001), CCI index (P < 0.001), PTS (P < 0.001) and regular exercise (P = 0.002) influenced the CIVIQ scale evaluation model, in which exercise regularly was a protective factor for QoL, and age, negative mood, CCI index and PTS were risk factors for QoL.

CONCLUSION

The QoL of DVT patients was impaired and associated with age, mood, CCI index and PTS. Regular exercise is beneficial for improving the quality of life of DVT patients.

A clinical decision framework to guide the outpatient treatment of emergency department patients diagnosed with acute pulmonary embolism or deep vein thrombosis: Results from a multidisciplinary consensus panel

The outpatient treatment of select emergency department patients with acute pulmonary embolism (PE) or deep vein thrombosis (DVT) has been shown to be safe, cost effective and associated with high patient satisfaction. Despite this, outpatient PE and DVT treatment remains uncommon. To address this, the American College of Emergency Physicians assembled a multidisciplinary team of content experts to provide evidence-based recommendations and practical advice to help clinicians safely treat patients with low-risk PE and DVT without hospitalization. The emergency clinician must stratify the patient's risk of clinical decompensation due to their PE or DVT as well as their risk of bleeding due to anticoagulation. The clinician must also select and start an anticoagulant and ensure that the patient has access to the medication in a timely manner. Reliable follow-up is critical, and the patient must also be educated about signs or symptoms that should prompt a return to the emergency department. To facilitate access to these recommendations, the consensus panel also created 2 web-based "point-of-care tools."

Risk of a permanent work-related disability pension after incident venous thromboembolism in Denmark: A population-based cohort study

BACKGROUND

Long-term complications of venous thromboembolism (VTE) hamper physical function and impair quality of life; still, it remains unclear whether VTE is associated with risk of permanent work-related disability. We aimed to assess the association between VTE and the risk of receiving a permanent work-related disability pension and to assess whether this association was explained by comorbidities such as cancer and arterial cardiovascular disease.

METHODS AND FINDINGS

A Danish nationwide population-based cohort study consisting of 43,769 individuals aged 25 to 66 years with incident VTE during 1995 to 2016 and 218,845 birth year-, sex-, and calendar year-matched individuals from the general population, among whom 45.9% (N = 120,540) were women, was established using Danish national registries. The cohorts were followed throughout 2016, with permanent work-related disability pension as the outcome. Hazard ratios (HRs) with 95% confidence intervals (CIs) for disability pension were computed and stratified by sex and age groups (25 to 34, 35 to 44, 45 to 54, and 55 to 66 years of age) and adjusted for comorbidities and socioeconomic variables. Permanent work-related disability pensions were granted to 4,415 individuals with VTE and 9,237 comparison cohort members (incidence rates = 17.8 and 6.2 per 1,000 person-years, respectively). VTE was associated with a 3-fold (HR 3.0, 95% CI: 2.8 to 3.1) higher risk of receiving a disability pension. Adjustments for socioeconomic status and comorbidities such as cancer and cardiovascular diseases reduced the estimate (HR 2.3, 95% CI: 2.2 to 2.4). The risk of disability pension receipt was slightly higher in men than in women (HR 2.5, 95% CI: 2.3 to 2.6 versus HR 2.1, 95% CI: 2.0 to 2.3). As this study is based on medical and administrative registers, information on post-VTE care, individual health behavior, and workplace factors linked to disability pension in the general population are lacking. Furthermore, as disability pension schemes vary, our results might not be directly generalizable to other countries or time periods.

CONCLUSIONS

In this study, incident VTE was associated with increased risk of subsequent permanent work-related disability, and this association was still observed after accounting for comorbidities such as cancer and cardiovascular diseases. Our results emphasize the social consequences of VTE and may help occupational and healthcare professionals to identify vulnerable individuals at risk of permanent exclusion from the labor market after a VTE event.

Sex-specific differences in the presentation, clinical course, and quality of life of patients with acute venous thromboembolism according to baseline risk factors. Insights from the PREFER in VTE

INTRODUCTION

Sex and the presence of specific provoking risk factors, along with age, influence the presentation and prognosis of venous thromboembolism (VTE). We investigated the presentation, course and quality of life in women and men with acute VTE classified according to their VTE provoking factors.

METHODS

PREFER in VTE is an international, non-interventional registry of patients with a first episode of acute symptomatic VTE. Baseline provoking factors were classified as follows: major transient, minor transient, active cancer, and none identifiable. The primary outcome was recurrent VTE. Quality of life and treatment satisfaction were secondary outcomes.

RESULTS

Of 3,455 patients with acute VTE, 1,623 (47%) were women. The mean age at the time of VTE was 61 (SD 18) in women, 60 (SD 15) in men. The distribution of provoking risk factors was similar between sexes, despite a tendency for higher frequency of minor and major transient risk factors in women, and cancer or unprovoked VTE in men. At 12-month follow-up, VTE recurrence was reported in 74 (6.5%) women and 80 (6.4%) men (absolute risk difference -0.1%, 95% CI -1.9%; +2.1%). In patients with unprovoked VTE, the VTE recurrence rate was 38/612 (6.2%) in women and 53/798 (6.6%) in men (absolute risk difference -0.4, 95% CI -3.0; +2.1%). Multivariable Cox regressions confirmed the absence of sex differences. Quality of life and treatment satisfaction scores one year after VTE were lower in women than in men irrespective of the provoking risk factors (p<0.001 for both scores).

CONCLUSIONS

Despite differences in the provoking risk factors for VTE, women and men had a similar rate VTE recurrence at one year. After acute VTE, women had lower quality of life and treatment satisfaction scores.

Micronized purified flavonoid fraction for the treatment of chronic venous insufficiency, with a focus on postthrombotic syndrome: A narrative review

INTRODUCTION

Postthrombotic syndrome (PTS) is a form of secondary chronic venous insufficiency (CVI) that occurs after deep vein thrombosis (DVT). Effective treatments for PTS are lacking. Micronized purified flavonoid fraction (MPFF) is a venoactive drug used in the treatment of CVI.

OBJECTIVE

To determine whether MPFF is a good candidate to explore as a therapeutic agent for PTS.

METHODS

We performed a narrative review in which we identified 14 systematic reviews, 33 randomized controlled trials, and 19 observational studies that discussed the use of MPFF in CVI, as well as studies that reported on the mechanistic action of MPFF in relation to the pathophysiology of PTS.

RESULTS

MPFF targets a number of pathophysiologic components of PTS. Based on animal models and human studies investigating objective vascular and lymphatic measures, MPFF promotes venous recanalization after DVT, decreases venous remodeling and reflux, inhibits inflammatory processes, improves venous tone and stasis, improves lymphatic circulation, improves capillary hyperpermeability, and decreases tissue hypoxia. Furthermore, MPFF shows promise in improving clinical manifestations, quality of life, and objective venous parameters of CVI. Studies suggest good patient acceptability and tolerability with the use of MPFF in CVI.

CONCLUSION

MPFF is a good candidate to explore as a potential therapy for PTS. Confirmatory high-quality studies are still needed to reinforce the evidence supporting the use of MPFF in CVI. Double-blind randomized controlled trials with clinical endpoints are needed to assess the clinical efficacy of MPFF in the treatment of PTS.

Diagnosis, Clinical Characteristics, and Treatment Modalities of Adolescent May-Thurner Syndrome-associated Deep Venous Thrombosis

May-Thurner syndrome (MTS) predisposes individuals to develop lower extremity deep venous thrombosis (DVT) because of compression of the left common iliac vein. Diagnosis of the anatomic obstruction is critical for effective therapy, as treatment by interventional radiology is often required in addition to anticoagulation to prevent thrombus progression and recurrence. The authors performed a retrospective review of adolescent patients who presented with MTS-associated DVT at a pediatric tertiary care center from 2009 to 2018 to assess for delays in MTS diagnosis after the presentation. Fourteen patients (median age 16.5 y, range, 13.8 to 17.9 y) were included, no DVTs were provoked by a central venous catheter. The median time from DVT to MTS diagnosis was 0.65 months (range, 0 to 21.5 mo). The initial imaging modalities used for DVT diagnosis were not able to diagnosis MTS. All patients were treated with anticoagulation and 13 underwent interventional therapy. Four patients had thrombus progression or recurrence, whereas 6 had complete thrombus resolution on follow-up imaging. Three patients who had a delayed MTS diagnosis had clinical worsening despite therapeutic anticoagulation requiring rehospitalization. Adolescent patients with "unprovoked" left lower extremity DVT should undergo appropriate imaging to diagnose MTS to allow for adequate medical and interventional therapy.

Predictors for the risk and severity of post-thrombotic syndrome in vascular Behçet's disease

OBJECTIVE

Deep vein thrombosis (DVT) of the lower extremities is the most common form of vascular involvement in Behçet disease (BD), frequently leading to post-thrombotic syndrome (PTS) as a disabling complication. We have described the clinical characteristics and predictors of PTS presence among patients with BD and lower extremity DVT. We also used venous Doppler ultrasound (US) examinations in our assessment.

METHODS

Patients with BD (n = 205; 166 men, 39 women; age 39 ± 9.5 years) and a history of DVT were investigated. The Villalta scale was used to assess the presence and severity of PTS. Doppler US examinations were performed within 1 week of the clinical evaluation. The total number of vessels with reflux, thrombi, recanalization, and collateral vessels were calculated.

RESULTS

Of the 205 patients with BD, 62% had had PTS and 18% had had severe PTS. Patients with PTS had had greater reflux (P = .054) and thrombosis (P = .02) scores compared with patients without PTS. Treatment with anticoagulation (AC), immunosuppressive (IS) therapy, or AC combined with IS drugs did not affect the occurrence of PTS. However, patients treated with IS therapy, with or without AC drugs, had a decreased incidence of severe PTS compared with the AC-only group (P = .017). Patients treated with AC plus IS agents also had increased collateral scores compared with patients treated with only IS drugs. Interferon-α use seemed to provide better recanalization scores compared with azathioprine only (1.0 [range, 0-14] vs 2.5 [range, 0-10]; P = .010).

CONCLUSION

Patients with BD and DVT have a high risk of developing severe PTS. IS treatment decreases the development of severe PTS. AC therapy might influence the course of PTS by increasing the collateral scores, and the use of interferon-α also increased recanalization scores. Routine assessment with Doppler US examinations could be helpful in the prediction of severe PTS.

Diagnosis and treatment of iliac vein stenosis

Stenosis of the iliac veins is common in patients with chronic venous insufficiency. The article describes the methods for the diagnosis and treatment of iliac vein stenosis. The causes of iliac vein stenosis include extravasal compression or the consequences of ileofemoral thrombosis. Stenosis of the iliac veins exists in 1/4 of the entire adult population, but clinical manifestations do not occur in all patients. Stenosis of the iliac veins should be considered in case of an unknown edema, more often in the left lower extremity, since venous duplex ultrasound of lower extremities is not sensitive and specific enough when examining the veins above the inguinal ligament. The most accurate diagnostic method is intravascular ultrasound (IVUS) but the appeared computed tomography angiography (CTA) and magnetic resonance angiography (MRA) with high-quality images have become a good replacement for IVUS. The main method of treatment of iliac vein stenosis, besides stenting, isindispensable drug therapy consisting of antithrombotic and phlebotonic drugs.

Long-term risk of postthrombotic syndrome after symptomatic distal deep vein thrombosis: The CACTUS-PTS study

BACKGROUND

After a proximal lower limb deep vein thrombosis (DVT; involving popliteal veins or above), up to 40% of patients develop postthrombotic syndrome (PTS) as assessed by the Villalta scale (VS). Poor initial anticoagulant treatment is a known risk factor for PTS. The risk of developing PTS after isolated distal DVT (infra-popliteal DVT without pulmonary embolism), and the impact of anticoagulant treatment on this risk, are uncertain.

METHODS

Long-term follow-up of CACTUS double-blind trial comparing 6 weeks of s.c. nadroparin (171 IU/kg/d) versus s.c. placebo for a first symptomatic isolated distal DVT. At least 1 year after randomization, patients had a PTS assessment in clinic or by phone using the VS.

RESULTS

After a median follow-up of 6 years, PTS was present in 30% (n = 54) of the 178 patients who had a PTS assessment. PTS was moderate or severe in 24% (n = 13) of cases. There was no statistically significant difference in prevalence of PTS in the nadroparin versus placebo groups (29% versus 32%, P = .6), except in patients without evidence of primary chronic venous insufficiency (9% versus 24%, P = .04). Rates of venous thromboembolism recurrence during follow-up in the nadroparin and placebo groups were, respectively, 8% (n = 7) and 14% (n = 13; P = .2).

CONCLUSION

After a first isolated distal DVT, the risk of PTS is substantial but much lower than that reported after proximal DVT. Anticoagulation with nadroparin doesn't provide any clear benefit to prevent PTS, except in patients without preexisting chronic venous insufficiency. Anticoagulation might be associated with a lower risk of venous thromboembolism recurrence.

Measuring functional limitations after venous thromboembolism: Optimization of the Post-VTE Functional Status (PVFS) Scale

INTRODUCTION

We recently proposed a scale for assessment of patient-relevant functional limitations following an episode of venous thromboembolism (VTE). Further development of this post-VTE functional status (PVFS) scale is still needed.

METHODS

Guided by the input of VTE experts and patients, we refined the PVFS scale and its accompanying manual, and attempted to acquire broad consensus on its use.

RESULTS

A Delphi analysis was performed involving 53 international VTE experts with diverse scientific and clinical backgrounds. In this process, the number of scale grades of the originally proposed PVFS scale was reduced and descriptions of the grades were improved. After these changes, a consensus was reached on the number/definitions of the grades, and method/timing of the scale assessment. The relevance and potential impact of the scale was confirmed in three focus groups totaling 18 VTE patients, who suggested additional changes to the manual, but not to the scale itself. Using the improved manual, the κ-statistics between PVFS scale self-reporting and its assessment via the structured interview was 0.75 (95%CI 0.58-1.0), and 1.0 (95%CI 0.83-1.0) between independent raters of the recorded interview of 16 focus groups members.

CONCLUSION

We improved the PVFS scale and demonstrated broad consensus on its relevance, optimal grades, and methods of assessing among international VTE experts and patients. The interobserver agreement of scale grade assignment was shown to be good-to-excellent. The PVFS scale may become an important outcome measure of functional impairment for quality of patient care and in future VTE trials.

Different strategies for pharmacological thromboprophylaxis for lower-limb immobilisation after injury: systematic review and economic evaluation

BACKGROUND

Thromboprophylaxis can reduce the risk of venous thromboembolism (VTE) during lower-limb immobilisation, but it is unclear whether or not this translates into meaningful health benefit, justifies the risk of bleeding or is cost-effective. Risk assessment models (RAMs) could select higher-risk individuals for thromboprophylaxis.

OBJECTIVES

To determine the clinical effectiveness and cost-effectiveness of different strategies for providing thromboprophylaxis to people with lower-limb immobilisation caused by injury and to identify priorities for future research.

DATA SOURCES

Ten electronic databases and research registers (MEDLINE, EMBASE, Cochrane Database of Systematic Reviews, Database of Abstracts of Review of Effects, the Cochrane Central Register of Controlled Trials, Health Technology Assessment database, NHS Economic Evaluation Database, Science Citation Index Expanded, ClinicalTrials.gov and the International Clinical Trials Registry Platform) were searched from inception to May 2017, and this was supplemented by hand-searching reference lists and contacting experts in the field.

REVIEW METHODS

Systematic reviews were undertaken to determine the effectiveness of pharmacological thromboprophylaxis in lower-limb immobilisation and to identify any study of risk factors or RAMs for VTE in lower-limb immobilisation. Study quality was assessed using appropriate tools. A network meta-analysis was undertaken for each outcome in the effectiveness review and the results of risk-prediction studies were presented descriptively. A modified Delphi survey was undertaken to identify risk predictors supported by expert consensus. Decision-analytic modelling was used to estimate the incremental cost per quality-adjusted life-year (QALY) gained of different thromboprophylaxis strategies from the perspectives of the NHS and Personal Social Services.

RESULTS

Data from 6857 participants across 13 trials were included in the meta-analysis. Thromboprophylaxis with low-molecular-weight heparin reduced the risk of any VTE [odds ratio (OR) 0.52, 95% credible interval (CrI) 0.37 to 0.71], clinically detected deep-vein thrombosis (DVT) (OR 0.40, 95% CrI 0.12 to 0.99) and pulmonary embolism (PE) (OR 0.17, 95% CrI 0.01 to 0.88). Thromboprophylaxis with fondaparinux (Arixtra®, Aspen Pharma Trading Ltd, Dublin, Ireland) reduced the risk of any VTE (OR 0.13, 95% CrI 0.05 to 0.30) and clinically detected DVT (OR 0.10, 95% CrI 0.01 to 0.94), but the effect on PE was inconclusive (OR 0.47, 95% CrI 0.01 to 9.54). Estimates of the risk of major bleeding with thromboprophylaxis were inconclusive owing to the small numbers of events. Fifteen studies of risk factors were identified, but only age (ORs 1.05 to 3.48), and injury type were consistently associated with VTE. Six studies of RAMs were identified, but only two reported prognostic accuracy data for VTE, based on small numbers of patients. Expert consensus was achieved for 13 risk predictors in lower-limb immobilisation due to injury. Modelling showed that thromboprophylaxis for all is effective (0.015 QALY gain, 95% CrI 0.004 to 0.029 QALYs) with a cost-effectiveness of £13,524 per QALY, compared with thromboprophylaxis for none. If risk-based strategies are included, it is potentially more cost-effective to limit thromboprophylaxis to patients with a Leiden thrombosis risk in plaster (cast) [L-TRiP(cast)] score of ≥ 9 (£20,000 per QALY threshold) or ≥ 8 (£30,000 per QALY threshold). An optimal threshold on the L-TRiP(cast) receiver operating characteristic curve would have sensitivity of 84-89% and specificity of 46-55%.

LIMITATIONS

Estimates of RAM prognostic accuracy are based on weak evidence. People at risk of bleeding were excluded from trials and, by implication, from modelling.

CONCLUSIONS

Thromboprophylaxis for lower-limb immobilisation due to injury is clinically effective and cost-effective compared with no thromboprophylaxis. Risk-based thromboprophylaxis is potentially optimal but the prognostic accuracy of existing RAMs is uncertain.

FUTURE WORK

Research is required to determine whether or not an appropriate RAM can accurately select higher-risk patients for thromboprophylaxis.

STUDY REGISTRATION

This study is registered as PROSPERO CRD42017058688.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

Pulmonary embolism response teams: Purpose, evidence for efficacy, and future research directions

Pulmonary embolism (PE) is a major cause of morbidity and mortality in the United States. Although new therapeutic tools and strategies have recently been developed for the diagnosis and treatment of patients with PE, the outcomes for patients who present with massive or high-risk PE remain dismal. To address this crisis, pulmonary embolism response teams (PERTs) are being created around the world in an effort to immediately and simultaneously engage multiple specialists to determine the best course of action and coordinate the clinical care for patients with acute PE. The scope of this review is to describe the PERT model and purpose, present the structure and organization, examine the available evidence for efficacy and usefulness, and propose future directions for research that is needed to demonstrate the value of PERT and determine if this multidisciplinary approach represents a new standard of care.

Iliac vein compression: epidemiology, diagnosis and treatment

Iliac vein compression (LIVC) is a prevalent finding in the general population, but a smaller number of patients are symptomatic. ILVC should be considered in symptomatic patients with unexplained unilateral lower leg swelling. Patients typically complain of one or more of the following symptoms: lower leg pain, heaviness, venous claudication, swelling, hyperpigmentation and ulceration. ILVC can be thrombotic, combined with acute or chronic DVT, or non-thrombotic. ILVC is best diagnosed with intravascular ultrasound (IVUS), but computed tomography angiography (CTA) and magnetic resonance angiography (MRA) have emerged as valid screening tests. Venography underestimates the severity of ILVC but may provide insights into the anatomy and the presence of collaterals. Based on current available evidence, endovascular therapy with stenting remains the main treatment strategy for ILVC. Dedicated nitinol venous stents are currently under review by the Food and Drug Administration for potential approval in the United States. These stents have been released outside the US. There is no consensus to the optimal anticoagulation regimen post-ILVC stenting. Oral anticoagulants, however, remain a preferred therapy in patients with history of thrombotic ILVC.

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Measuring functional limitations after venous thromboembolism: A call to action

The main objectives of therapeutic trials in venous thromboembolism (VTE) are to prevent recurrent VTE, major bleeding and death. While these outcomes are indeed highly relevant, they are also rare and do not fully capture the overall functional outcome of VTE patients. Importantly, functional limitations after VTE are prevalent after both deep vein thrombosis and pulmonary embolism occurring in up to 50% of patients. These post-VTE syndromes are associated with a decreased quality of life, higher risk of depressive disorders, unemployment and increased utilization of healthcare resources. Because of the major impact of functional limitations on individual patients and society as a whole, development of tools able to capture functional outcomes in clinical trials are urgently needed. We anticipate that a standardized post-VTE functional status scale will aid in demarcating effective and ineffective VTE therapies on functional outcomes in trials with appropriately powered sample sizes, as well as pave the road for value-based healthcare. The scale that we have in mind covers the entire spectrum of functional outcomes ranging from no symptoms to death. Moreover, it focuses on both limitations in usual activity as well as changes in lifestyle. The scale is not meant to replace current diagnostic or prognostic scores for post-VTE syndromes, but to be used as an outcome measure to evaluate the overall consequences of VTE on functional status. This review is a call for action to the VTE community to join forces and support further development of the proposed scale, a process of which we summarize the necessary steps.

Incidence and Risk Factors for Post-Thrombotic Syndrome in Patients With Deep Vein Thrombosis Following Total Knee and Hip Arthroplasty

BACKGROUND

Deep vein thrombosis (DVT) is common after total joint arthroplasty (TJA), and can cause the sequela of post-thrombotic syndrome (PTS), which is associated with decreased quality of life and increased treatment cost. The purpose of this study is to determine the incidence and risk factors for PTS in patients with DVT following primary unilateral total knee and hip arthroplasty.

METHODS

We conducted this follow-up study involving patients developing DVT after primary unilateral total knee arthroplasty or total hip arthroplasty at our institution between April 2010 and March 2017. Each patient received a follow-up clinical interview regarding PTS-related symptoms and signs. We introduced demographic, clinical, and surgical data into the analysis to identify the risk factors for PTS.

RESULTS

A total of 182 patients with postoperative DVT were enrolled with a mean follow-up time of 3.6 years. The incidence of PTS was 9.3% in patients developing DVT after TJA. Malignancy (P = .033), previous surgery in ipsilateral lower extremity (P = .013), and blood transfusion (P = .022) appeared to be the risk factors for PTS.

CONCLUSION

We determined the incidence and risk factors for PTS in patients with DVT following TJA. Preventive measures should be used for patients at high risk of PTS.

Persian Version of VEINES-QOL/Sym Questionnaire in Iranian Patients With Deep Venous Thrombosis: Cross-Cultural Adaptation and Psychometric Properties

BACKGROUND AND PURPOSE

The present study was done to assess the cultural adaption and psychometric properties of Persian version of VEINES-QOL/Sym questionnaire in Iranian patients with deep venous thrombosis (DVT).

METHODS

This cross-cultural psychometrics study was conducted in 2016. About 270 DVT patients completed a Persian version of the VEINES-QOL/Sym questionnaire. The face, content, and construct validity were assessed. Internal consistency, test-retest, and construct reliability (CR) were used to assess reliability.

RESULTS

Three-factor solution was extracted that explaining 71.373% of the total variance. Goodness-of-fit indices (GFI; χ²(68) =332.037, p < .05, χ²/df = 4.882, GFI = .862, CFI = .928, NFI = .914, IFI = .928, RMSEA (90% confidence interval) =.091 [.081, .110]) in the final VEINES-QOL/Sym questionnaire structure demonstrated the adequacy of the three-domain structure. The reliability was greater than .70.

CONCLUSIONS

The VEINES-QOL/Sym questionnaire was found to be a valid and reliable assessment tool for quality of life in Iranian patients with DVT.

Reduced incidence of vein occlusion and postthrombotic syndrome after immediate compression for deep vein thrombosis

Thus far, the association between residual vein occlusion and immediate compression therapy and postthrombotic syndrome is undetermined. Therefore, we investigated whether compression therapy immediately after diagnosis of deep vein thrombosis affects the occurrence of residual vein obstruction (RVO), and whether the presence of RVO is associated with postthrombotic syndrome and recurrent venous thromboembolism. In a prespecified substudy within the IDEAL (individualized duration of elastic compression therapy against long-term duration of therapy for prevention of postthrombotic syndrome) deep vein thrombosis (DVT) study, 592 adult patients from 10 academic and nonacademic centers across The Netherlands, with objectively confirmed proximal DVT of the leg, received no compression or acute compression within 24 hours of diagnosis of DVT with either multilayer bandaging or compression hosiery (pressure, 35 mm Hg). Presence of RVO and recurrent venous thromboembolism was confirmed with compression ultrasonography and incidence of postthrombotic syndrome as a Villalta score of at least 5 at 6 and 24 months. The average time from diagnosis until assessment of RVO was 5.3 (standard deviation, 1.9) months. A significantly lower percentage of patients who did receive compression therapy immediately after DVT had RVO (46.3% vs 66.7%; odds ratio, 0.46; 95% confidence interval, 0.27-0.80; P = .005). Postthrombotic syndrome was less prevalent in patients without RVO (46.0% vs 54.0%; odds ratio, 0.65; 95% confidence interval, 0.46-0.92; P = .013). Recurrent venous thrombosis showed no significant association with RVO. Immediate compression should therefore be offered to all patients with acute DVT of the leg, irrespective of severity of complaints. This study was registered at ClinicalTrials.gov (NCT01429714) and the Dutch Trial registry in November 2010 (NTR2597).

DVT Intervention in the Post-ATTRACT Era

PURPOSE OF REVIEW

Patients suffering from acute lower extremity deep vein thrombosis (DVT) are at risk for developing chronic limb pain, heaviness, and fatigue, known as the post-thrombotic syndrome (PTS).

RECENT FINDINGS

Although several studies have shown that catheter-directed therapy reduces clot burden and may improve clinical outcomes, the multicenter randomized controlled ATTRACT trial showed no difference in PTS or quality of life at 2 years between patients treated with pharmacomechanical catheter-directed thrombolysis (PCDT) and those treated with anticoagulation alone, and a higher major bleeding rate in the PCDT group. PCDT is not indicated for most patients diagnosed with lower extremity DVT. Since PCDT may benefit patients with iliofemoral DVT, intervention can be considered in this subset of patients if they are at low risk of bleeding.

Pulmonary embolism

Pulmonary embolism (PE) is caused by emboli, which have originated from venous thrombi, travelling to and occluding the arteries of the lung. PE is the most dangerous form of venous thromboembolism, and undiagnosed or untreated PE can be fatal. Acute PE is associated with right ventricular dysfunction, which can lead to arrhythmia, haemodynamic collapse and shock. Furthermore, individuals who survive PE can develop post-PE syndrome, which is characterized by chronic thrombotic remains in the pulmonary arteries, persistent right ventricular dysfunction, decreased quality of life and/or chronic functional limitations. Several important improvements have been made in the diagnostic and therapeutic management of acute PE in recent years, such as the introduction of a simplified diagnostic algorithm for suspected PE as well as phase III trials demonstrating the value of direct oral anticoagulants in acute and extended treatment of venous thromboembolism. Future research should aim to address novel treatment options (for example, fibrinolysis enhancers) and improved methods for predicting long-term complications and defining optimal anticoagulant therapy parameters in individual patients, and to gain a greater understanding of post-PE syndrome.

Prevention and treatment of the post-thrombotic syndrome

Post thrombotic syndrome (PTS) is a common chronic complication of deep vein thrombosis of the leg (DVT). Treatment options are limited therefore emphasis is placed on its prevention. Several risk factors have been recognized, but were so far not used for risk stratification or translation into prediction models. Early interventions did not yet result in more successful preventive treatment strategies; for the acute phase of DVT there is equipoise on the value of elastic compression, as well as on catheter directed thrombolysis. There are no drugs specifically targeted at PTS prevention. The use of anticoagulant medication such as direct oral anticoagulants (DOACs) might decrease PTS incidence, but this needs to be corroborated. Both research into more effective treatment options as well as future PTS management may benefit from a uniform diagnostic strategy and the use of prediction rules to better allocate treatment and thereby increase treatment efficacy.

Postthrombotic Syndrome in Patients Treated With Rivaroxaban or Warfarin for Venous Thromboembolism

Postthrombotic syndrome (PTS) is a frequent complication of venous thromboembolism (VTE). Using MarketScan claims data from January 2012 to June 2015, we identified adults with a primary diagnosis code for VTE during a hospitalization/emergency department visit, ≥6 months of insurance coverage prior to the index event and newly started on rivaroxaban or warfarin within 30 days of the index VTE. Patients with <4-month follow-up postindex event or a claim for any anticoagulant during 6-month baseline period were excluded. Differences in baseline characteristics between rivaroxaban and warfarin users were adjusted for using inverse probability of treatment weights based on propensity scores. Patients were followed for the development of PTS starting 3 months after the index VTE. Cox regression was performed and reported as hazard ratios with 95% confidence intervals (CIs). In total, 10 463 rivaroxaban and 26 494 warfarin users were followed for a mean of 16 ± 9 (range, 4-39) months. Duration of anticoagulation was similar between cohorts (median = 6 months). Rivaroxaban was associated with a 23% (95% CI: 16-30) reduced hazard of PTS versus warfarin. Rivaroxaban was associated with a significant risk reduction in symptoms of PTS compared to warfarin in patients with VTE treated in routine practice.

Direct oral anticoagulants for the treatment of cancer-associated venous thromboembolism

Cancer patients with venous thromboembolism (VTE) are at increased risk for both bleeding and VTE recurrence. Anticoagulation with low-molecular-weight heparin (LMWH) is the standard of care during the initial and longterm treatment phase (i.e. during the first 3 – 6 months of therapy) based on its overall beneficial safety and efficacy profile compared to vitamin K antagonists (VKAs). The direct oral anticoagulants (DOACs) rivaroxaban, apixaban, edoxaban, and dabigatran are approved for the treatment of acute VTE, and the combined six phase-3 trials have included > 1500 patients with active cancer, as defined by variable selection criteria. Subgroup analyses of these patients, either pooled or separately reported, suggest that DOACs could be a safe and efficacious alternative to VKA therapy for the treatment of cancer-associated VTE. However, the populations of cancer patients included in the DOAC and LMWH trials are not comparable with regard to mortality and VTE risk, and no specific data from direct head-to-head comparisons of DOACs with LMWHs are currently available. The use of DOACs for the management of VTE in cancer is thus not recommended by clinical practice guidelines.

A randomised controlled trial comparing venous stenting with conservative treatment in patients with deep venous obstruction: research protocol

INTRODUCTION

Deep venous obstruction (DVO) has a great impact on quality of life (QoL) comparable to angina pectoris or chronic pulmonary disease. Post-thrombotic scar formation and May-Thurner syndrome (MTS) are the most common causes of DVO. Conventional treatment of DVO focuses on reducing pain or leg swelling by use of (pain) medication and therapeutic elastic stockings. In the past, a venous bypass was offered in severe post-thrombotic cases, but this procedure showed bad clinical and patency outcomes. With the introduction of percutaneous angioplasty and dedicated venous stents new opportunities were created. Deep venous stenting has been shown to be effective in retrospective case series. However, there is no prior research in which QoL after interventional treatment is compared with QoL after conventional treatment. Currently, there is a debate about the true additional value of interventional treatment. We investigate whether those patients who are treated with stenting experience a change in short form 36 (SF-36) and the Veines-QoL/Sym questionnaires compared with conventionally treated patients.

METHODS AND ANALYSIS

This is a randomised trial comparing conservative deep venous management to interventional treatment. A total of 130 patients with post-thrombotic syndrome (PTS) or MTS, eligible for interventional percutaneous treatment, who did not have previous deep venous intervention will be included. Patients will be randomised to conservative treatment or venous stenting and stratified for the PTS or MTS subgroup. Conservative treatment consists of either one or a combination of pain medications, manual lymphatic drainage, compression stockings and regular post-thrombotic anticoagulant therapy.The primary outcome is the QoL change after 12 months compared with baseline QoL. Secondary outcomes are QoL changes at 6 weeks, clinical assessment of DVO, recurrence rate of deep venous thrombosis at 6 weeks and 12 months, and the total amount of working days lost. Intervention-specific outcomes include complications and patency.

ETHICS AND DISSEMINATION

The protocol is approved by the Medical Ethics Committee of Academisch ziekenhuis Maastricht/Universiteit Maastricht, The Netherlands (protocol number NLNL55641.068.15 / METC 161008).We aim to publish the results of this study in a peer reviewed journal and present our findings at national or international conferences.

TRIAL REGISTRATION NUMBER

The study protocol was registered at www.clinicaltrials.gov (registration number: NCT03026049) on 17 January 2017.

Quality of Life, Dyspnea, and Functional Exercise Capacity Following a First Episode of Pulmonary Embolism: Results of the ELOPE Cohort Study

BACKGROUND

We aimed to evaluate health-related quality of life (QOL), dyspnea, and functional exercise capacity during the year following the diagnosis of a first episode of pulmonary embolism.

METHODS

This was a prospective multicenter cohort study of 100 patients with acute pulmonary embolism recruited at 5 Canadian hospitals from 2010-2013. We measured the outcomes QOL (by Short-Form Health Survey-36 [SF-36] and Pulmonary Embolism Quality of Life [PEmb-QoL] measures), dyspnea (by the University of California San Diego Shortness of Breath Questionnaire [SOBQ]) and 6-minute walk distance at baseline and 1, 3, 6, and 12 months after acute pulmonary embolism. Computed tomography pulmonary angiography was performed at baseline, echocardiogram was performed within 10 days, and cardiopulmonary exercise testing was performed at 1 and 12 months. Predictors of change in QOL, dyspnea, and 6-minute walk distance were assessed by repeated-measures mixed-effects models analysis.

RESULTS

Mean age was 50.0 years; 57% were male and 80% were treated as outpatients. Mean scores for all outcomes improved during 1-year follow-up: from baseline to 12 months, mean SF-36 physical component score improved by 8.8 points, SF-36 mental component score by 5.3 points, PEmb-QoL by -32.1 points, and SOBQ by -16.3 points, and 6-minute walk distance improved by 40 m. Independent predictors of reduced improvement over time were female sex, higher body mass index, and percent-predicted VO₂ peak <80% on 1 month cardiopulmonary exercise test for all outcomes; prior lung disease and higher pulmonary artery systolic pressure on 10-day echocardiogram for the outcomes SF-36 physical component score and dyspnea score; and higher main pulmonary artery diameter on baseline computed tomography pulmonary angiography for the outcome PEmb-QoL score.

CONCLUSIONS

On average, QOL, dyspnea, and walking distance improve during the year after pulmonary embolism. However, a number of clinical and physiological predictors of reduced improvement over time were identified, most notably female sex, higher body mass index, and exercise limitation on 1-month cardiopulmonary exercise test. Our results provide new information on patient-relevant prognosis after pulmonary embolism.

Epidemiology of the post-thrombotic syndrome

The post thrombotic syndrome (PTS) refers to clinical manifestations of chronic venous insufficiency (CVI) following a deep-vein thrombosis (DVT). PTS is the most frequent complication of DVT, which develops in 20 to 50% of cases after proximal DVT and is severe in 5-10% of cases. The reported prevalence of PTS differs widely among studies because of differences in study populations, tools used to assess PTS, and time interval between acute DVT and PTS assessment. The two most important predictors of PTS are extensive proximal character of DVT and previous ipsilateral DVT. Other reported risk factors include pre-existing CVI, obesity, quality of anticoagulant treatment, older age and residual venous obstruction. Standardization of PTS assessment tools combined with the development of patient self-reported PTS scales are likely to constitute a breakthrough in research of the epidemiology of PTS, by allowing comparison between studies, meta-analyses and increasing the feasibility of longer follow-up of DVT patients. This should enable identification of patient populations at high risk of severe PTS, new predictors of PTS and targets for potential new treatments. In this perspective, identification of biomarkers that are predictive of PTS such as markers of inflammation is crucial in ongoing research.

Assessment of quality of life, satisfaction with anticoagulation therapy, and adherence to treatment in patients receiving long-course vitamin K antagonists or direct oral anticoagulants for venous thromboembolism

INTRODUCTION

Direct oral anticoagulants (DOACs) have shown non-inferiority and ease of use compared to vitamin K antagonists (VKA) in the treatment of venous thromboembolism (VTE). No study so far has been directed toward real-life experience of outpatients receiving anticoagulants for VTE in France.

METHODS

This is an observational descriptive real-life epidemiological study, using three validated questionnaires (Morisky Medication Adherence Scale-8, EQ-5D, and part 2 of the Perception of Anticoagulant Treatment Questionnaire), to assess adherence, quality of life, and satisfaction in 100 VTE outpatients receiving anticoagulation therapy by VKA (primary or switched from DOAC to VKA) or by DOAC (primary or switched from VKA to DOAC).

RESULTS

Patients were very much satisfied with their treatment in both DOAC and VKA groups. Despite advantages of DOACs, therapeutic adherence was only moderate. The best adherence scores were observed in the primary VKA switched to DOAC for at least 3 months (S-DOAC) subgroup. Quality of life was better in the DOAC group mainly because of the absence of the requirement for blood testing. Most of the complaints concerned the pain/discomfort dimension in the VKA group and anxiety/depression dimension in the DOAC group.

CONCLUSION

Patients were satisfied with their anticoagulant treatment, especially when they were involved in choosing the anticoagulant, and the treatment suited them. Quality of life of patients in the DOAC group was better than in the VKA group, but adherence remains to be improved. This study highlights the importance of the physician-patient relationship, pretreatment initiation, and follow-up of any anticoagulation therapy throughout.