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

Prophylactic-dose direct oral anticoagulants for non-hospitalised people with COVID-19: A meta-analysis of randomised controlled trials

Background

Several reviews have been conducted on thromboprophylaxis in non-hospitalised patients with coronavirus disease 2019 (COVID-19). In this systematic review and meta-analysis, we sought to investigate the impact of prophylactic-dose direct oral anticoagulants (DOACs) in this population.

Methods

We searched PubMed, Web of Science, EMBASE and Cochrane Library for randomised controlled trials (RCTs) comparing prophylactic-dose DOACs with placebo or no treatment in non-hospitalised patients with COVID-19 until September 2023. The primary efficacy outcome was a composite of all-cause mortality and thromboembolic events, while major bleeding events were the primary safety outcome. We expressed continuous outcome data as mean differences (MDs) with 95% confidence intervals (CIs) and dichotomous outcome data as risk ratios (RRs) with 95% CIs.

Results

We included six RCTs involving 4307 patients. Prophylactic-dose DOAC therapy compared with placebo or no treatment was associated with significantly decreased risks of the composite outcome of all-cause mortality and thromboembolic events (1.43% vs 2.67% (RR = 0.53; 95% CI = 0.34-0.82, P = 0.004, I2 = 3%)). Major bleeding events were infrequent, and we detected no significant differences between patients assigned to prophylactic-dose DOACs vs placebo or no treatment (0.19% vs 0.05% (RR = 2.50; 95% CI = 0.49-12.87, P = 0.27, I2 = 0%)). The use of prophylactic-dose DOACs was also associated with a reduction in venous thromboembolism, with no difference in all-cause mortality, arterial thromboembolism, hospitalisations, and clinically relevant nonmajor bleeding between two groups. Sensitivity analyses with the leave-one-out method for the primary efficacy and safety outcome did not change the effect estimate substantially.

Conclusions

We found that prophylaxis-dose DOACs could significantly improve clinical outcomes and reduce venous thrombotic events without increasing the risk of major bleeding events compared with placebo or no treatment in non-hospitalised patients with COVID-19.

Registration

PROSPERO: CRD42023466889.

The ımpact of radiofrequency ablation on quality of life/symptoms (VEINES-QOL/Sym questionnaire score) in patients with chronic venous ınsufficiency

Purpose

Chronic venous insufficiency is defined as a progressive disease that impairs the quality of life. Symptomatic patients can be treated with a 97% success rate through endovenous radiofrequency ablation (RFA) procedures. The aim of this study is to evaluate the effect and impact of RFA therapy on both the Venous Insufficiency Epidemiological and Economic Study Quality of Life/Symptom Questionnaire (VEINES-QOL/Sym) scale and the VEINES-QOL/Sym severity score in patients with isolated vena saphena magna insufficiency.

Methods

Between March and June 2018, a retrospective analysis was conducted on 45 patients with a healthy vena saphena parva. They were divided into two groups based on the diameter of the great saphenous vein (GSV). Patients with GSV < 6 mm were assigned to group I (n = 22, 15 males, 7 females, mean age 52.45 ± 13.98 years), while patients with GSV ≥ 6 mm were assigned to group II (n = 23, 14 males, 9 females, mean age 55.04 ± 10.18 years). The pre-procedural Clinical-Etiology-Anatomy-Pathophysiology (CEAP) classification and post-procedural quality of life and symptom assessment at 12-24 months were evaluated using the VEINES-QOL/Sym questionnaire scale.

Results

When all patients were assessed in terms of the VEINES-QOL/Sym questionnaire scale, compared to the previous year, it was found that 57.8% of patients (n = 26) still experienced complaints, and 24.4% of patients (n = 14) reported slightly worse symptoms than the previous year. In group II, 56.5% of patients (n = 13) reported experiencing similar complaints as the previous year, while 30.4% (n = 7) noted slightly worse symptoms.

Conclusions

Our study findings revealed that the increase in vessel diameter does not significantly impact the severity of symptoms and quality of life outcomes after RFA therapy; however, it does have a notable impact on the improvement of symptom characteristics. As a result, early intervention for symptomatic patients is crucial in order to address their symptoms and improve their quality of life.

Nanomicrosphere sustained-release urokinase systems with antioxidant properties for deep vein thrombosis therapy

Deep vein thrombosis (DVT) is a venous return disorder caused by abnormal clotting of blood in deep veins. After thrombosis, most of the thrombus will spread to the deep vein trunk throughout the limb. If DVT is not treated in time, most of them will develop into thrombosis sequelae and even threaten life. Intravenous thrombolytic drugs are the most promising strategy for treating DVT, but current drugs used for thrombolysis suffer from short half-lives and narrow therapeutic indexes. To effectively manage DVT, it is necessary to develop a novel multifunctional drug-loading system to effectively prolong the treatment time and improve the therapeutic efficacy. In this study, a urokinase-loaded protocatechuic aldehyde-modified chitosan microsphere drug-loading platform was constructed for the treatment of DVT. This microsphere adsorbed urokinase well through electrostatic interaction, and the introduction of bovine serum albumin conferred stability to the microspheres. Therefore, the microsphere drug delivery system could achieve slow drug release to effectively dissolve blood fibrin. In addition, chitosan grafted with protocatechuic aldehyde imparted excellent antioxidant activity to the system to reduce free radicals in the blood vessels. Effective management of oxidative stress could avoid abnormal platelet activation and new thrombus formation. The experimental results showed that this microsphere had good biocompatibility, anti-inflammatory properties, and considerable thrombolytic activity. In conclusion, this study provided a new direction and developed a novel multi-functional nano microsphere drug delivery platform for the treatment of DVT.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Factors influencing DVT formation in sepsis

INTRODUCTION

Sepsis is a global public health burden. Deep vein thrombosis (DVT) is the third most common cause of death from cardiovascular disease after heart attacks and strokes. We designed this experiment to investigate the factors influencing DVT formation in patients with sepsis.

METHODS

In this survey, 918 septic patients admitted to Peking Union Medical College Hospital, who underwent DVT screening were enrolled. The data were collected from June 8, 2013 to October 12, 2022. The differences between septic patients with and without DVT were studied from following aspects: basic information, comorbidities, inflammatory cytokines, albumin, source of infection, sequential organ failure assessment (SOFA) score, coagulation and prognosis.

MAIN RESULTS

In this study, the prevalence of DVT in patients with sepsis was 0.23. Elderly patients with sepsis were prone to DVT (p value < 0.001). In terms of comorbidities, septic patients with hypertension and atrial fibrillation were prone to DVT (p value 0.045 and 0.048). Inflammatory cytokines, such as procalcitonin (PCT), C-reactive protein (CRP), interleukin (IL)-6, IL-8, IL-10, tumor necrosis factor (TNF)-α, had no significant correlation with DVT in patients with sepsis (p value 0.364, 0.882, 0.912, 0.789, 0.245, and 0.780). Levels of serum albumin correlated with DVT in patients with sepsis (p value 0.003). The SOFA total score had no relationship with DVT formation (p value 0.254). Coagulation and respiration function were negatively correlated with DVT (p value 0.018). Liver function was positively correlated with DVT (p value 0.020). Patients in the DVT group had longer duration of mechanical ventilation and longer intensive care unit (ICU) stays (p value < 0.001 and 0.006). There was no significant difference in survival in septic patients with and without DVT (p value 0.868).

CONCLUSIONS

The SOFA total score had no relationship with DVT formation. The function of each organ had different effects on DVT formation. Better coagulation and respiration function, easier DVT formation. Poorer liver function, easier DVT formation. DVT was associated with longer duration of mechanical ventilation and longer ICU stays.

A Narrative Review of Advancements in Understanding and Treating Varicose Veins

Chronic venous disease, with varicose veins as its archetypal manifestation, stands as a pervasive and intricate health quandary, encompassing a vast array of contributing factors. Age, genetics, obesity, pregnancy, and prolonged immobility weave a complex tapestry, underscoring the omnipresence of this ailment. Its societal and economic footprint is undeniably formidable, as diverse classifications underscore its multifaceted character. The intricate interplay of chronic venous disease with diabetes mellitus and neuropathy compounds the challenge, fostering soaring healthcare expenditures and a palpable erosion of quality of life, particularly among women harboring cardiometabolic risk factors. Despite research shedding light on heightened susceptibility within certain demographics, the enigmatic determinants orchestrating the transition from mild to severe chronic venous disease continue to elude us. Varicose veins, marked by the presence of dilated and tortuous subcutaneous vessels, precipitate both physical discomfort and cosmetic concerns, frequently necessitating meticulous clinical evaluation coupled with ultrasound studies to secure a precise diagnosis. Treatment strategies are strategically crafted to ameliorate distressing symptoms, enhance aesthetic concerns, and forestall potential complications. Nevertheless, the prognostication of chronic venous disease remains ensconced in a degree of ambiguity, hinting at the vast terrain yet to be charted in this medical domain. The quest to fathom the intricacies of this condition uncovers an ever-evolving panorama where conservative interventions play an indispensable role in managing mild cases, while interventional procedures like endovenous laser ablation and sclerotherapy step onto the stage for patients grappling with severe symptoms, thus treading the fine line between efficacy and invasiveness. Moreover, a meticulous economic analysis underscores the cost-effectiveness of various therapeutic modalities, thereby bolstering the imperative of a patient-centered approach. As we navigate the labyrinthine complexities of chronic venous disease and varicose vein management, we are inexorably drawn to the pivotal role of customized treatment approaches, as well as the dynamic interplay between scientific progress, patient preferences, and therapeutic innovations in the relentless pursuit of optimized outcomes and an enhanced quality of life.

Six-Month Outcomes of Mechanical Thrombectomy for Treating Deep Vein Thrombosis: Analysis from the 500-Patient CLOUT Registry

PURPOSE

Mechanical thrombectomy for the treatment of deep vein thrombosis (DVT) is being increasingly utilized to reduce symptoms and prevent postthrombotic syndrome (PTS), but more data on clinical outcomes are needed. Mechanical thrombectomy was studied in the ClotTriever Outcomes (CLOUT) registry with 6-month full analysis outcomes reported herein.

MATERIALS AND METHODS

The CLOUT registry is a prospective, all-comer study that enrolled 500 lower extremity DVT patients across 43 US sites treated with mechanical thrombectomy using the ClotTriever System. Core-lab assessed Marder scores and physician-assessed venous patency by duplex ultrasound, PTS assessment using Villalta score, venous symptom severity, pain, and quality of life scores through 6 months were analyzed. Adverse events were identified and independently adjudicated.

RESULTS

All-cause mortality at 30 days was 0.9%, and 8.6% of subjects experienced a serious adverse event (SAE) within the first 30 days, 1 of which (0.2%) was device related. SAE rethrombosis/residual thrombus incidence was 4.8% at 30 days and 8.0% at 6 months. Between baseline and 6 months, venous flow increased from 27.2% to 92.5% of limbs (P < 0.0001), and venous compressibility improved from 28.0% to 91.8% (P < 0.0001), while median Villalta scores improved from 9.0 at baseline to 1.0 at 6 months (P < 0.0001). Significant improvements in venous symptom severity, pain, and quality of life were also demonstrated. Outcomes from iliofemoral and isolated femoral-popliteal segments showed similar improvements.

CONCLUSION

Outcomes from the CLOUT study, a large prospective registry for DVT, indicate that mechanical thrombectomy is safe and demonstrates significant improvement in symptoms and health status through 6 months. Level of Evidence 3: Non-randomized controlled cohort/follow-up study.

Prophylactic anticoagulants for non-hospitalised people with COVID-19

BACKGROUND

The coronavirus disease 2019 (COVID-19) pandemic has impacted healthcare systems worldwide. Multiple reports on thromboembolic complications related to COVID-19 have been published, and researchers have described that people with COVID-19 are at high risk for developing venous thromboembolism (VTE). Anticoagulants have been used as pharmacological interventions to prevent arterial and venous thrombosis, and their use in the outpatient setting could potentially reduce the prevalence of vascular thrombosis and associated mortality in people with COVID-19. However, even lower doses used for a prophylactic purpose may result in adverse events such as bleeding. It is important to consider the evidence for anticoagulant use in non-hospitalised people with COVID-19.

OBJECTIVES

To evaluate the benefits and harms of prophylactic anticoagulants versus active comparators, placebo or no intervention, or non-pharmacological interventions in non-hospitalised people with COVID-19.

SEARCH METHODS

We used standard, extensive Cochrane search methods. The latest search date was 18 April 2022.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) comparing prophylactic anticoagulants with placebo or no treatment, another active comparator, or non-pharmacological interventions in non-hospitalised people with COVID-19. We included studies that compared anticoagulants with a different dose of the same anticoagulant. We excluded studies with a duration of under two weeks.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methodological procedures. Our primary outcomes were all-cause mortality, VTE (deep vein thrombosis (DVT) or pulmonary embolism (PE)), and major bleeding. Our secondary outcomes were DVT, PE, need for hospitalisation, minor bleeding, adverse events, and quality of life. We used GRADE to assess the certainty of the evidence.

MAIN RESULTS

We included five RCTs with up to 90 days of follow-up (short term). Data were available for meta-analysis from 1777 participants. Anticoagulant compared to placebo or no treatment Five studies compared anticoagulants with placebo or no treatment and provided data for three of our outcomes of interest (all-cause mortality, major bleeding, and adverse events). The evidence suggests that prophylactic anticoagulants may lead to little or no difference in all-cause mortality (risk ratio (RR) 0.36, 95% confidence interval (CI) 0.04 to 3.61; 5 studies; 1777 participants; low-certainty evidence) and probably reduce VTE from 3% in the placebo group to 1% in the anticoagulant group (RR 0.36, 95% CI 0.16 to 0.85; 4 studies; 1259 participants; number needed to treat for an additional beneficial outcome (NNTB) = 50; moderate-certainty evidence). There may be little to no difference in major bleeding (RR 0.36, 95% CI 0.01 to 8.78; 5 studies; 1777 participants; low-certainty evidence). Anticoagulants probably result in little or no difference in DVT (RR 1.02, 95% CI 0.30 to 3.46; 3 studies; 1009 participants; moderate-certainty evidence), but probably reduce the risk of PE from 2.7% in the placebo group to 0.7% in the anticoagulant group (RR 0.25, 95% CI 0.08 to 0.79; 3 studies; 1009 participants; NNTB 50; moderate-certainty evidence). Anticoagulants probably lead to little or no difference in reducing hospitalisation (RR 1.01, 95% CI 0.59 to 1.75; 4 studies; 1459 participants; moderate-certainty evidence) and may lead to little or no difference in adverse events (minor bleeding, RR 2.46, 95% CI 0.90 to 6.72; 5 studies, 1777 participants; low-certainty evidence). Anticoagulant compared to a different dose of the same anticoagulant One study compared anticoagulant (higher-dose apixaban) with a different (standard) dose of the same anticoagulant and reported five relevant outcomes. No cases of all-cause mortality, VTE, or major bleeding occurred in either group during the 45-day follow-up (moderate-certainty evidence). Higher-dose apixaban compared to standard-dose apixaban may lead to little or no difference in reducing the need for hospitalisation (RR 1.89, 95% CI 0.17 to 20.58; 1 study; 278 participants; low-certainty evidence) or in the number of adverse events (minor bleeding, RR 0.47, 95% CI 0.09 to 2.54; 1 study; 278 participants; low-certainty evidence). Anticoagulant compared to antiplatelet agent One study compared anticoagulant (apixaban) with antiplatelet agent (aspirin) and reported five relevant outcomes. No cases of all-cause mortality or major bleeding occurred during the 45-day follow-up (moderate-certainty evidence). Apixaban may lead to little or no difference in VTE (RR 0.36, 95% CI 0.01 to 8.65; 1 study; 279 participants; low-certainty evidence), need for hospitalisation (RR 3.20, 95% CI 0.13 to 77.85; 1 study; 279 participants; low-certainty evidence), or adverse events (minor bleeding, RR 2.13, 95% CI 0.40 to 11.46; 1 study; 279 participants; low-certainty evidence). No included studies reported on quality of life or investigated anticoagulants compared to a different anticoagulant, or anticoagulants compared to non-pharmacological interventions.

AUTHORS' CONCLUSIONS

We found low- to moderate-certainty evidence from five RCTs that prophylactic anticoagulants result in little or no difference in major bleeding, DVT, need for hospitalisation, or adverse events when compared with placebo or no treatment in non-hospitalised people with COVID-19. Low-certainty evidence indicates that prophylactic anticoagulants may result in little or no difference in all-cause mortality when compared with placebo or no treatment, but moderate-certainty evidence indicates that prophylactic anticoagulants probably reduce the incidence of VTE and PE. Low-certainty evidence suggests that comparing different doses of the same prophylactic anticoagulant may result in little or no difference in need for hospitalisation or adverse events. Prophylactic anticoagulants may result in little or no difference in risk of VTE, hospitalisation, or adverse events when compared with antiplatelet agents (low-certainty evidence). Given that there were only short-term data from one study, these results should be interpreted with caution. Additional trials of sufficient duration are needed to clearly determine any effect on clinical outcomes.

Clinical characteristics and treatment outcomes of 68 patients with spontaneous iliac vein rupture: A case report and systematic review

Objective

Spontaneous iliac vein rupture (SIVR) is a rare but life-threatening condition with limited understanding regarding its clinical presentation, pathogenesis, diagnosis, management, and risk factors for mortality. This study aims to address this gap by providing comprehensive insights into SIVR through personal case reports and a systematic review of previous cases.

Methods

We detail a case of right SIVR caused by inappropriate positioning of the stent in the inferior vena cava and systematically reviewed previous cases. Logistic regression analysis was used to identify risk factors for mortality.

Results

Our SIVR case was successfully managed with percutaneous mechanical thrombectomy and covered stent placement. In the systematic review, 68 patients were included in the analysis with an average age of 62.01 ± 13.25 years; 86.76% were female, 91.17% had left iliac vein rupture, 55.88% presented hemodynamic instability, 76.47% had lower abdomen or iliac fossa pain, 67.64% had deep venous thrombosis (DVT), and 32.35% had May‒Thurner syndrome (MTS). The mortality rates of conservative treatment and open surgery were 2.94% and 17.65%, respectively. All 12 patients receiving endovascular treatment survived. The factors associated with a worse outcome were younger age (52.86 ± 12.96 years, OR: 1.085, 95% CI: 1.002-1.174) and SIVR patients without DVT (OR:10.111, 95% CI: 1.637-62.443).

Conclusion

This first systematic review on SIVR shows that SIVR should be highly suspected in elderly females who develop lower extremity DVT and concurrent lower abdominal pain, particularly those with a retroperitoneal mass and unstable hemodynamics. Thrombosis secondary to MTS may be the main cause of SIVR. Angiography and endovascular therapy should be prioritized for DVT patients with unexplained retroperitoneal hematoma. This study classifies SIVR into two types: iliac vein rupture alone and iliac vein rupture with DVT. These findings provide critical insights for clinicians to accurately diagnose and manage SIVR, thereby improving patient outcomes.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Angiojet pharmacomechanical thrombectomy versus anticoagulant therapy alone in massive cancer-associated thrombosis: a single centre retrospective cohort study

The therapeutic regimen option for the cancer-associated thrombosis (CAT) patients is still a major clinical challenge. The present study aimed to investigate the safety and efficacy of pharmacomechanical catheter-directed thrombolysis (PCDT) with AngioJet treatment compared with the conventional anticoagulation alone therapy in the patients with CAT. We retrospectively reviewed the patients who underwent PCDT and/or anticoagulation for the treatment of CAT between August 1, 2016 and March 1, 2022. Each patient was divided into the PCDT group or the anticoagulation alone group. The baseline demographics, comorbidities, clinical characteristics, treatment details, course data were reviewed. A total of 51 eligible patients were included, of whom 21 were in PCDT group (mean age, 60.1 ± 13.0 years; 52.4% male) and 30 in anticoagulation alone group (mean age, 66.6 ± 11.1 years; 50.0% male). No significant differences regarding age, sex, onset time, limb characteristics, cancer conditions or risk factors were detected (p > .05). After PCDT, grade III lysis was achieved in 8 and grade II lysis in 11 patients. Clinical success was achieved in 90.5% (19/21) patients. The symptoms of leg pain and swelling were significantly improved in both groups. Except for transient macroscopic hemoglobinuria occurring in PCDT group, none of all patients suffered from procedure-related and major complications. Minor complications such as bleeding events occurred in 23.8% (5/21) of patients in PCDT group compared with 10.0% (3/30) in anticoagulation alone group (p > .05). At the 6-month follow-up, iliofemoral patency was found an absolute risk reduction of 37.9% (70.0 vs. 32.1%) (95% CI: 1.183-4.008%; P = 0.010). The incidence of mild PTS was 5.0% (1/20) in PCDT group compared with 10.7% (3/28) in anticoagulation alone group (p > .05). The PCDT is a safe and effective modality in managing patients with CAT, leading to improved clinical outcomes with a low complication. The PCDT was more effective than anticoagulation alone in massive symptom relief and venous patency.

Mechanical Thrombectomy for Acute and Subacute Blocked Arteries and Veins in the Lower Limbs: A Health Technology Assessment

Background

A blockage to the blood vessels in the lower extremities may cause pain and discomfort. If left unmanaged, it may lead to amputation or chronic disability, such as in the form of post-thrombotic syndrome. We conducted a health technology assessment of mechanical thrombectomy (MT) devices, which are proposed to remove a blood clot, which may form in the arteries or veins of the lower legs. This evaluation considered blockages in the veins and arteries separately, and included an evaluation of effectiveness, safety, cost-effectiveness, the budget impact of publicly funding MT for lower limb blockages, patient preferences and values, and clinical and health system stakeholders' perspectives.

Method

We performed a systematic literature search of the clinical evidence. We assessed the risk of bias of each included study using the Cochrane tool for randomized controlled trials or the risk of bias among non-randomized studies (RoBANS) tool for nonrandomized studies, and the quality of the body of evidence according to the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) Working Group criteria. We performed a systematic economic literature search. We did not conduct a primary economic evaluation since the clinical evidence is highly uncertain. We also analyzed the budget impact of publicly funding MT treatment for inpatients with arterial acute limb ischemia and acute deep vein thrombosis (DVT) in the lower limb in Ontario. To contextualize the potential value of MT, we spoke with people with acute DVT. To understand the barriers and facilitators of accessing MT, we surveyed clinical and health system stakeholders to gain their perspectives.

Results

We included 40 studies (3 randomized controlled trials and 37 observational studies) in the clinical evidence review. For patients who experience arterial acute limb ischemia, compared with catheter-directed thrombolysis (CDT) alone, MT has greater technical success and patency and reduced hospital length of stay, but the evidence for these outcomes is uncertain (GRADE: Very low). Mechanical thrombectomy may reduce the volume of thrombolytic medication required and CDT infusion time (a determinant for intensive care unit [ICU] need) in patients experiencing acute DVT, but it is uncertain if this is to a meaningful degree (GRADE: Moderate to Very low). It may also reduce the proportion of people who experience post-thrombotic syndrome and overall hospital length of stay, but it is uncertain (GRADE: Very low).We estimated that publicly funding MT for people with arterial acute limb ischemia in Ontario would lead to an annual cost savings of $0.17 million in year 1 to $0.14 million in year 5, for a total savings of $0.83 million over 5 years. This cost savings was mainly attributed to reduced ICU stays among people who received MT, but the results had considerable uncertainty. For the population with acute DVT, publicly funding MT would lead to an additional cost of $0.77 million in year 1 to $1.44 million in year 5, for a total additional cost of $5.5 million over 5 years.The people with acute DVT with whom we spoke reported that MT was generally seen as a positive option, and those who had undergone the procedure reported positively on its value as a treatment to quickly remove a clot. Accessing treatment for DVT could be a barrier, especially in more remote areas of Ontario.Clinicians using the technology advised that facilitators to accessing the technology included perceived improvements in patient outcomes, resourcing requirements, addressing unmet needs, and avoidance of ICU stay. The main barrier identified was cost. Clinicians who were not using the technology advised that barriers were low case-use volume, along with costs for the equipment and for health human resources.

Conclusions

Mechanical thrombectomy may have greater technical success and patency and reduce hospital length of stay for patients experiencing an arterial acute limb ischemia and, for patients with an acute DVT, it may reduce CDT volume and infusion time, the proportion of people who experience post-thrombotic syndrome, and hospital length of stay. Mechanical thrombectomy may reduce the associated ICU costs, but it has higher equipment costs compared with usual care. Publicly funding MT in Ontario for populations with arterial acute limb ischemia may not lead to a substantial budget increase to the province. Publicly funding MT for acute DVT would lead to an additional cost of $5.5 million over 5 years. For people with acute DVT, MT was seen as a potential positive treatment option to remove the clot quickly. Overall, the majority of clinical stakeholders we engaged with (including both those with and without experience with MT) were supportive of the use of the technology.

High systemic inflammation response index level is associated with an increased risk of lower extremity deep venous thrombosis: a large retrospective study

BACKGROUND

The association between inflammation and venous thromboembolism (VTE) has attracted increasing research interest. Recently, the systemic inflammation response index (SIRI) has been proposed as a novel inflammatory biomarker, but its potential association with lower extremity deep venous thrombosis (LEDVT) has not been investigated. Thus, this study aimed to explore the association between SIRI and LEDVT risk in a large sample over a 10-year period (2012-2022).

METHODS

All hospitalized patients who underwent lower extremity compression ultrasonography (CUS) examinations were consecutively identified from our hospital information system database. Multivariate logistic regression analysis was used to investigate the association between SIRI and LEDVT risk. Sensitivity, restricted cubic spline and subgroup analyses were also performed.

RESULTS

In total, 12643 patients were included, and 1346 (10.6%) LEDVT events occurred. After full adjustment, a higher SIRI level was significantly associated with an increased risk of LEDVT (odds ratio [OR] = 1.098, 95% confidence interval [CI]: 1.068-1.128, p < 0.001), and patients in quartile 4 had a 2.563-fold higher risk of LEDVT than those in quartile 1 (95% CI: 2.064-3.182, p < 0.001). A nonlinear relationship was observed (P for nonlinearity < 0.001), with an inflection point of 4.17. Below this point, each unit increase in SIRI corresponded to a 35.3% increase in LEDVT risk (95% CI: 1.255-1.458, p < 0.001). No significant difference was found above the inflection point (OR = 1.015, 95% CI: 0.963-1.069, p = 0.582). Sensitivity and subgroup analyses confirmed the robustness of the association. This association also existed in both distal and proximal LEDVT.

CONCLUSION

A High SIRI is significantly associated with an increased risk of LEDVT in hospitalized patients. Given that the SIRI is a readily available biomarker in clinical settings, its potential clinical use deserves further exploration.

Pharmacological interventions for preventing venous thromboembolism in people undergoing bariatric surgery

BACKGROUND

Venous thromboembolism (VTE), which comprises deep vein thrombosis (DVT) and pulmonary embolism (PE), is the leading cause of preventable death in hospitalised people and the third most common cause of mortality in surgical patients. People undergoing bariatric surgery have the additional risk factor of being overweight. Although VTE prophylaxis in surgical patients is well established, the best way to prevent VTE in those undergoing bariatric surgery is less clear.

OBJECTIVES

To evaluate the benefits and harms of pharmacological interventions (alone or in combination) on venous thromboembolism and other health outcomes in people undergoing bariatric surgery compared to the same pharmacological intervention administered at a different dose or frequency, the same pharmacological intervention or started at a different time point, another pharmacological intervention, no intervention or placebo.

SEARCH METHODS

We used standard, extensive Cochrane search methods. The latest search date was 1 November 2021.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) and quasi-RCTs in males and females of any age undergoing bariatric surgery comparing pharmacological interventions for VTE (alone or in combination) with the same pharmacological intervention administered at a different dose or frequency, the same pharmacological intervention started at a different time point, a different pharmacological intervention, no treatment or placebo.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methods. Our primary outcomes were 1. VTE and 2. major bleeding. Our secondary outcomes were 1. all-cause mortality, 2. VTE-related mortality, 3. PE, 4. DVT, 5. adverse effects and 6. quality of life. We used GRADE to assess certainty of evidence for each outcome.

MAIN RESULTS

We included seven RCTs with 1045 participants. Data for meta-analysis were available from all participants. Four RCTs (597 participants) compared higher-dose heparin to standard-dose heparin: one of these studies (139 participants) used unfractionated heparin (UFH) and the other three (458 participants) used low-molecular-weight heparin (LMWH). One study compared heparin versus pentasaccharide (198 participants), and one study compared starting heparin before versus after bariatric surgery (100 participants). One study (150 participants) compared combined mechanical and pharmacological (enoxaparin) prophylaxis versus mechanical prophylaxis alone. The duration of the interventions ranged from seven to 15 days, and follow-up ranged from 10 to 180 days. Higher-dose heparin versus standard-dose heparin Compared to standard-dose heparin, higher-dose heparin may result in little or no difference in the risk of VTE (RR 0.55, 95% CI 0.05 to 5.99; 4 studies, 597 participants) or major bleeding (RR 1.19, 95% CI 0.48 to 2.96; I2 = 8%; 4 studies, 597 participants; low-certainty) in people undergoing bariatric surgery. The evidence on all-cause mortality, VTE-related mortality, PE, DVT and adverse events (thrombocytopenia) is uncertain (effect not estimable or very low-certainty evidence). Heparin versus pentasaccharide Heparin compared to a pentasaccharide after bariatric surgery may result in little or no difference in the risk of VTE (RR 0.83, 95% CI 0.19 to 3.61; 1 study, 175 participants) or DVT (RR 0.83, 95% CI 0.19 to 3.61; 1 study, 175 participants). The evidence on major bleeding, PE and mortality is uncertain (effect not estimable or very low-certainty evidence). Heparin started before versus after the surgical procedure Starting prophylaxis with heparin 12 hours before surgery versus after surgery may result in little or no difference in the risk of VTE (RR 0.11, 95% CI 0.01 to 2.01; 1 study, 100 participants) or DVT (RR 0.11, 95% CI 0.01 to 2.01; 1 study, 100 participants). The evidence on major bleeding, all-cause mortality and VTE-related mortality is uncertain (effect not estimable or very low-certainty evidence). We were unable to assess the effect of this intervention on PE or adverse effects, as the study did not measure these outcomes. Combined mechanical and pharmacological prophylaxis versus mechanical prophylaxis alone Combining mechanical and pharmacological prophylaxis (started 12 hours before surgery) may reduce VTE events in people undergoing bariatric surgery compared to mechanical prophylaxis alone (RR 0.05, 95% CI 0.00 to 0.89; number needed to treat for an additional beneficial outcome (NNTB) = 9; 1 study, 150 participants; low-certainty). We were unable to assess the effect of this intervention on major bleeding or morality (effect not estimable), or on PE or adverse events (not measured). No studies measured quality of life.

AUTHORS' CONCLUSIONS

Higher-dose heparin may make little or no difference to venous thromboembolism or major bleeding in people undergoing bariatric surgery when compared to standard-dose heparin. Heparin may make little or no difference to venous thromboembolism in people undergoing bariatric surgery when compared to pentasaccharide. There are inadequate data to draw conclusions about the effects of heparin compared to pentasaccharide on major bleeding. Starting prophylaxis with heparin 12 hours before bariatric surgery may make little or no difference to venous thromboembolism in people undergoing bariatric surgery when compared to starting heparin after bariatric surgery. There are inadequate data to draw conclusions about the effects of heparin started before versus after surgery on major bleeding. Combining mechanical and pharmacological prophylaxis (started 12 hours before surgery) may reduce VTE events in people undergoing bariatric surgery when compared to mechanical prophylaxis alone. No data are available relating to major bleeding. The certainty of the evidence is limited by small sample sizes, few or no events, and risk of bias concerns. Future trials must be sufficiently large to enable analysis of relevant clinical outcomes, and should standardise the time of treatment and follow-up. They should also address the effect of direct oral anticoagulants and antiplatelets, preferably grouping them according to the type of intervention.

Analysis of the Preventive Action of Rivaroxaban against Lower Extremity Deep Venous Thrombosis in Patients after Laparoscopic Radical Gastrectomy

Background

Gastric carcinoma (GC) is a common lethal cancer in the world. Patients are prone to develop lower extremity deep venous thrombosis (LEDVT) after laparoscopic radical gastrectomy (LRG), which threatens their life and health.

Purpose

This research is to clarify the preventive action of rivaroxaban (Riv) against LEDVT in patients undergoing LRG.

Methods

A retrospective study was conducted on 70 patients with GC admitted for LRG between January 2019 and January 2022, including 40 patients (observation group) receiving Riv treatment and 30 patients (conventional group) treated with air wave pressure therapy apparatus. Quality of life, coagulation function, LEDVT formation, and complications were compared between groups.

Results

The observation group had better recovery of life quality than the control group, along with more effective inhibition of coagulation disorders, less DVT formation, and fewer complications.

Conclusions

Compared with air wave pressure therapy apparatus, Riv has better preventive action against LEDVT in GC patients after LRG.

Deep Venous Thrombosis

Venous thromboembolism (VTE) is the third most common cardiovascular disorder, affecting up to 5% of the population. VTE commonly manifests as lower-extremity deep venous thrombosis (DVT) or pulmonary embolism. Half of these events are associated with a transient risk factor and may be preventable with prophylaxis. Direct oral anticoagulants are effective and safe and carry a lower risk for bleeding than vitamin K antagonists. Many patients with VTE will have a chronic disease requiring long-term anticoagulation. Postthrombotic syndrome affects 25% to 40% of patients with DVT and significantly impacts function and quality of life.

Antiplatelet agents for the treatment of deep venous thrombosis

BACKGROUND

Antiplatelet agents may be useful for the treatment of deep venous thrombosis (DVT) when used in addition to best medical practice (BMP), which includes anticoagulation, compression stockings, and clinical care such as physical exercise, skin hydration, etc. Antiplatelet agents could minimise complications such as post-thrombotic syndrome (PTS) and pulmonary embolism (PE). They may also reduce the recurrence of the disease (recurrent venous thromboembolism (recurrent VTE)). However, antiplatelet agents may increase the likelihood of bleeding events.

OBJECTIVES

To assess the effects of antiplatelet agents in addition to current BMP compared to current BMP (with or without placebo) for the treatment of DVT.

SEARCH METHODS

The Cochrane Vascular Information Specialist searched the Cochrane Vascular Specialised Register, CENTRAL, MEDLINE, Embase and CINAHL databases and World Health Organization International Clinical Trials Registry Platform and ClinicalTrials.gov trials registers to 7 December 2021. The review authors searched LILACS and IBECS databases (15 December 2021) and also checked the bibliographies of included trials for further references to relevant trials, and contacted specialists in the field, manufacturers and authors of the included trials.

SELECTION CRITERIA

We considered randomised controlled trials (RCTs) examining antiplatelet agents compared to BMP following initial standard anticoagulation treatment for DVT. We included studies where antiplatelet agents were given in addition to current BMP compared to current BMP (with or without placebo) for the treatment of DVT (acute: treatment started within 21 days of symptom onset; chronic: treatment started after 21 days of symptom onset). We evaluated only RCTs where the antiplatelet agents were the unique difference between the groups (intervention and control).

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methodological procedures. Two review authors independently extracted data and assessed risk of bias of the trials. Any disagreements were resolved by discussion with a third review author. We calculated outcome effects using risk ratio (RR) or mean difference (MD) with a 95% confidence interval (CI) and the number needed to treat to benefit (NNTB).

MAIN RESULTS

We included six studies with 1625 eligible participants, with data up to 37.2 months of follow-up. For one preplanned comparison (i.e. antiplatelet agents plus BMP versus BMP plus placebo) for acute DVT we identified no eligible studies for inclusion. In acute DVT, antiplatelet agents plus BMP versus BMP alone was assessed by one study (500 participants), which reported on four outcomes until 6 months of follow-up. There were no deaths and no cases of major bleeding reported. The participants who received antiplatelet agents showed a lower risk of PTS (RR 0.74, 95% CI 0.61 to 0.91; 1 study, 500 participants; very low-certainty evidence). The control group presented a lower risk of adverse events compared to the intervention group (RR 2.88, 95% CI 1.06 to 7.80; 1 study, 500 participants; very low-certainty evidence). This study did not provide information for recurrent VTE or PE. In chronic DVT, antiplatelet agents plus BMP versus BMP alone was assessed by one study (224 participants). The study authors reported four relevant outcomes, three of which (major bleeding, mortality and adverse events) showed no events during the 3 years of follow-up. Therefore, an effect estimate could only be reported for recurrent VTE, favouring antiplatelet agents plus BMP versus BMP alone (RR 0.12, 95% CI 0.05 to 0.34; 1 study, 224 participants; very low-certainty evidence). For the outcomes PE and PTS, this study did not present information which could be used for analysis. In chronic DVT, antiplatelet agents plus BMP versus BMP plus placebo was assessed by four studies (901 participants). The meta-analysis of this pooled data showed a lower risk of recurrent VTE for the antiplatelet agents group (RR 0.65, 95%, CI 0.43 to 0.96; NNTB = 14; low-certainty evidence). For major bleeding, we found no clear difference between placebo and intervention groups until 37.2 months of follow-up (RR 0.98, 95% CI 0.29 to 3.34; 1 study, 583 participants; moderate-certainty evidence). In PE fatal/non-fatal outcome, we found no clear difference with the use of antiplatelet agents (RR 0.52, 95% CI 0.23 to 1.14; 1 study, 583 participants; moderate-certainty evidence). For all-cause mortality, the overall effect of antiplatelet agents did not differ from the placebo group (RR 0.48, 95% CI 0.21 to 1.06; 3 studies, 649 participants; moderate-certainty evidence). The adverse events outcome did not show a clear difference (RR 1.57, 95% CI 0.34 to 7.19; 2 studies, 621 participants; moderate-certainty evidence). There is no assessment of PTS in these studies. We downgraded the certainty of evidence for risk of bias, indirectness, imprecision and publication bias.

AUTHORS' CONCLUSIONS

In chronic DVT settings, following the initial standard treatment with anticoagulants, there is low-certainty evidence that antiplatelet agents in addition to BMP may reduce recurrent VTE, (NNTB = 14) when compared to BMP plus placebo. Moderate-certainty evidence shows no clear difference in adverse events, major bleeding and PE when antiplatelet agents are used in addition to BMP compared to BMP plus placebo. In acute and chronic DVT settings, following the initial standard treatment with anticoagulants, we can draw no conclusions for antiplatelet agents in addition to BMP compared to BMP alone due to very low-certainty evidence.  Trials of high methodological quality, that are large and of sufficient duration to detect significant clinical outcomes are needed. Trials should ideally last more than 4 years in order to estimate the long-term effect of antiplatelet agents. Trials should include people with acute and chronic DVT and provide relevant individual data, such as the outcome for each index event (DVT or PE), the use of an inferior vena cava (IVC) filter, whether the DVT is provoked or unprovoked, and the age of participants.

Enhanced thrombolysis by endovascular low-frequency ultrasound with bifunctional microbubbles in venous thrombosis: in vitro and in vivo study

There is a need to improve the efficacy and safety of endovascular techniques in venous thrombotic diseases, and microbubble enhanced sonothrombolysis is a promising approach. However, whether endovascular low-frequency ultrasound (LFUS) can be utilized in microbubble enhanced sonothrombolysis is unclear. Here, we present a catheter-based thrombolytic system that combines unfocused low-frequency low-intensity ultrasound with novel fibrin-targeted drug-loaded bifunctional microbubbles. We develop an in vitro flow model and an in vivo rabbit inferior vena cava (IVC) thrombosis model to evaluate the safety and efficacy of the thrombolytic system. The results indicate that microbubble enhanced sonothrombolysis with endovascular LFUS treatment for 30 min is equally effective compared to pure pharmacologic treatment. Furthermore, the thrombolytic efficacy of this system is safely and substantially improved by the introduction of a fibrin-targeted drug-loaded bifunctional microbubble with a reduction of the fibrinolytic agent dosage by 60%. The microbubble enhanced endovascular LFUS sonothrombolysis system with excellent thrombolytic efficacy may serve as a new therapeutic approach for venous thrombotic diseases.