Diagnostic management of acute deep vein thrombosis and pulmonary embolism

Peroxisome proliferator‑activated receptor γ alleviates human umbilical vein endothelial cell injury in deep vein thrombosis by blocking endoplasmic reticulum stress

The present study aimed to explore the role of peroxisome proliferator-activated receptor γ (PPARγ) in the development of deep vein thrombosis (DVT), as well as to discover the potential regulatory mechanism of PPARγ. Human umbilical vein endothelial cells (HUVECs) were treated with modified glycated human serum albumin (M-HSA) to mimic DVT. PPARγ expression and activity were detected using western blot analysis and the corresponding activity detection kit, respectively. Cell Counting Kit-8 and the terminal deoxynucleotidyl-transferase-mediated dUTP nick end labeling assays were employed to detect cell viability and apoptosis, respectively. The levels of thrombosis-related factors and inflammatory cytokines were detected by ELISA. The levels of oxidative stress-related factors were determined by the corresponding commercial kits. In addition, tunicamycin (TM), the agonist of endoplasmic reticulum stress (ERS), was applied to investigate the potential mechanism. The results indicated that M-HSA caused reduced expression and activity of PPARγ in HUVECs; these effects were reversed by PPARγ overexpression, which significantly inhibited M-HSA-induced cell viability loss, cell apoptosis, inflammation and oxidative stress in HUVECs. In addition, ERS was activated following M-HSA stimulation in HUVECs, but was suppressed by PPARγ overexpression. Furthermore, TM partly abolished the protective role of PPARγ overexpression against cell viability loss, cell apoptosis, inflammation and oxidative stress in M-HSA-induced HUVECs. In summary, PPARγ antagonized M-HSA-induced HUVEC injury by suppressing the activation of ERS, which provides a novel strategy for the treatment of DVT.

The History of Diagnosing Venous Thromboembolism

An accurate and prompt diagnosis of deep vein thrombosis and/or pulmonary embolism is important to prevent serious complications and mortality. Because the clinical presentation of venous thromboembolism (VTE) is often nonspecific, objective testing by means of radiological imaging is required to confirm the diagnosis. Historically, a diagnosis of VTE involved invasive imaging techniques like contrast venography or conventional pulmonary angiography. Technological developments toward more accurate and less invasive diagnostics have driven the implementation of a variety of newer technologies over the past decades, as well as the derivation and validation of clinical decision rules (CDRs) that can be used to rule out VTE in combination with D-dimer blood tests. In this narrative review, we provide a historical overview of the most notable developments in the imaging techniques and CDRs for VTE diagnosis.

Modern imaging of acute pulmonary embolism

The first-choice imaging test for visualization of thromboemboli in the pulmonary vasculature in patients with suspected acute pulmonary embolism (PE) is multidetector computed tomography pulmonary angiography (CTPA) - a readily available and widely used imaging technique. Through technological advancements over the past years, alternative imaging techniques for the diagnosis of PE have become available, whilst others are still under investigation. In particular, the evolution of artificial intelligence (AI) is expected to enable further innovation in diagnostic management of PE. In this narrative review, current CTPA techniques and the emerging technology photon-counting CT (PCCT), as well as other modern imaging techniques of acute PE are discussed, including CTPA with iodine maps based on subtraction or dual-energy acquisition, single-photon emission CT (SPECT), magnetic resonance angiography (MRA), and magnetic resonance direct thrombus imaging (MRDTI). Furthermore, potential applications of AI are discussed.

Epidemiology, Etiology, and Pathophysiology of Pulmonary Embolism

Over the last 20 years, there has been a progressive increase in the incidence of pulmonary embolism (PE) diagnosis in the United States, Europe, and Australia. Increased use of computed tomography pulmonary angiography has likely contributed in part to this rising incidence. However, it is pertinent to note that the burden of comorbidities associated with PE, such as malignancy, obesity, and advanced age, has also increased over the past 20 years. Time-trend analysis in North American, European, and Asian populations suggests that mortality rates associated with PE have been declining. The reported improved survival rates in PE over the past 20 years are likely, at least in part, to be the result of better adherence to guidelines, improved risk stratification, and enhanced treatment. Factors contributing to the development of venous thromboembolism (VTE) include stasis of blood, hypercoagulability, endothelial injury, and inflammation. In 70 to 80% of cases of PE, the thrombi embolizes from the proximal deep veins of the lower extremities and pelvis. Strong risk factors for VTE include lower extremity fractures and surgeries, major trauma, and hospitalization within the previous 3 months for acute myocardial infarction or heart failure with atrial fibrillation. Acute PE causes several pathophysiological responses including hypoxemia and right ventricle (RV) failure. The latter is a result of pulmonary artery occlusion and associated vasoconstriction. Hemodynamic compromise from RV failure is the principal cause of poor outcome in patients with acute PE.

Cost-Effectiveness of Performing Reference Ultrasonography in Patients with Deep Vein Thrombosis

BACKGROUND

 The diagnosis of recurrent ipsilateral deep vein thrombosis (DVT) with compression ultrasonography (CUS) may be hindered by residual intravascular obstruction after previous DVT. A reference CUS, an additional ultrasound performed at anticoagulant discontinuation, may improve the diagnostic work-up of suspected recurrent ipsilateral DVT by providing baseline images for future comparison.

OBJECTIVES

 To evaluate the cost-effectiveness of routinely performing reference CUS in DVT patients.

METHODS

 Patient-level data (n = 96) from a prospective management study (Theia study; NCT02262052) and claims data were used in a decision analytic model to compare 12 scenarios for diagnostic management of suspected recurrent ipsilateral DVT. Estimated health care costs and mortality due to misdiagnosis, recurrent venous thromboembolism, and bleeding during the first year of follow-up after presentation with suspected recurrence were compared.

RESULTS

 All six scenarios including reference CUS had higher estimated 1-year costs (€1,763-€1,913) than the six without reference CUS (€1,192-€1,474). Costs were higher because reference CUS results often remained unused, as 20% of patients (according to claims data) would return with suspected recurrent DVT. Estimated mortality was comparable in scenarios with (14.8-17.9 per 10,000 patients) and without reference CUS (14.0-18.5 per 10,000). None of the four potentially most desirable scenarios included reference CUS.

CONCLUSION

 One-year health care costs of diagnostic strategies for suspected recurrent ipsilateral DVT including reference CUS are higher compared to strategies without reference CUS, without mortality benefit. These results can inform policy-makers regarding use of health care resources during follow-up after DVT. From a cost-effectiveness perspective, the findings do not support the routine application of reference CUS.

Comparing U.S. and Canadian treatment patterns on venous thromboembolism outcomes in the GARFIELD-VTE registry

BACKGROUND

Economically developed countries continue to find that venous thromboembolism (VTE) is a major cause of morbidity and mortality.

OBJECTIVE

To compare baseline risk profiles and patient workflow patterns between the United States (U.S.) and Canadian management of VTE patients from 2014 to 2017.

METHODS

The Global Anticoagulant Registry in the FIELD (GARFIELD-VTE) is a prospective, observational study of 10,679 patients with objectively confirmed VTE, followed for 3 years. In total 1101 patients enrolled in the U.S. and Canada were included in this analysis.

RESULTS

Median age and body mass index were comparable between the U.S. (60.5; 30.2) and Canadian (59.7; 29) patients. A higher percentage of U.S. patients were black (n = 128, 24.1 %; n = 22, 3.9 %) and had a higher VTE-associated risk profile, including immobilization, hospitalization, and recent surgery. U.S. patients had a higher combined DVT and PE primary diagnoses (20.3 %) and were more likely to be treated in hospitals (77.2 %) than Canadians (13.3 %; 48.1 %). Direct oral anticoagulant therapy (DOAC) was nearly two-fold more frequent in Canadian patients (n = 218, 39.2 %) at the end of 3 years in comparison to the U.S. (n = 118, 23.0 %). Adjusted for sex, recent bleed event, heart failure, chronic immobilization, family history of VTE, history of cancer and prior VTE, and renal insufficiency, the risk of all-cause mortality was 51.9 % higher in patients from the U.S. compared to those in Canada after 3 years. Patients from the U.S. also had a higher likelihood of hospitalization, major bleeding, and recurrent VTE after controlling for prior history and comorbid conditions.

CONCLUSION

Higher rates of adverse VTE-associated outcomes in the U.S. may be attributed to different baseline risk profiles, facility care, and distribution of specialists and their subsequent treatment strategies.

TYPE OF RESEARCH

Global, multicentre, non-interventional, prospective registry titled Global Anticoagulant Registry in the FIELD - Venous Thromboembolism (GARFIELD-VTE).

KEY FINDINGS

531 U.S. and 557 Canadians patients included in study. DOAC use more frequent in Canadian patients after 3 years than U.S. (39.2 % vs. 23.0 %, respectively). Adjusted for sex, recent bleed event, heart failure, chronic immobilization, family history of VTE, history of cancer and prior VTE, and renal insufficiency, all-cause mortality risk remained higher in U.S. patients vs. Canadian patients after 3 years. U.S. patients had higher likelihood of hospitalization, major bleeding, and recurrent VTE.

TAKE-HOME MESSAGE

Higher rates of adverse VTE-associated outcomes in the U.S. may be attributed to different baseline risk profiles, facility care, and composition of specialists and their subsequent treatment strategies.

TABLE OF CONTENTS SUMMARY

Global, multicentre, non-interventional, prospective registry titled Global Anticoagulant Registry in the FIELD - Venous Thromboembolism (GARFIELD-VTE). Higher rates of adverse VTE-associated outcomes were observed in U.S. patients vs Canadian patients, which may be attributed to different baseline risk profiles, facility care, and distribution of specialists and their subsequent treatment strategies.

Venous thromboembolism and major bleeding in severe and critical COVID-19 hospitalized patients

Venous thromboembolism (VTE) and major bleeding (MB) are life-threatening complications described in COVID-19 hospitalized patients, and they can be considered two sides of the same coin. This retrospective study aims to evaluate the risk factors for VTE and MB in COVID-19 patients admitted to two Italian hospitals. The medical records of all COVID-19 patients (males 139; 62.3%, mean age 67.2±13.6 years, body weight 88.2±20.6 kg) hospitalized from March 11th to July 31st, 2020, at the Federico II University Hospital and the Sea Hospital, Naples, Italy, were analyzed. The COVID-19 patients were classified into four groups: COVID-19 patients developing VTE and/or MB, COVID-19 patients developing only VTE, COVID-19 patients developing only MB, and COVID-19 patients not developing either VTE or MB. During the hospitalization, 53 COVID-19 patients (24.7%; males 40; 75.5%, mean age 67.2±13.6 years, weight 88.2±20.6 kg) developed VTE, 33 COVID-19 patients (15.3%; males 17; 51.5, mean age 67.3±14.9 years, weight 74.1±14.3 kg) developed MB, and 129 COVID-19 patients did not develop either TVP or MB. No parameters to identify severe COVID-19 complicated by VTE and/or MB were found. However, some clinical and biochemical parameters can be evaluated to predict the risk of MB in order to modify the treatment and take prompt action to reduce mortality.

The role of D-dimer and fibrinogen testing in catheter-directed thrombolysis with urokinase for deep venous thrombosis

BACKGROUND

During catheter-directed thrombolysis (CDT), D-dimer (D-D) are generated in large quantities and fibrinogen (FIB) is continuously consumed. Reduction of FIB increases the risk of bleeding. However, there are currently few studies on the relationship between D-D and FIB concentrations during CDT.

OBJECTIVES

To evaluate the relationship of D-D and FIB concentrations during CDT with urokinase for deep venous thrombosis (DVT).

METHOD

17 patients with lower limb DVT were enrolled and treated with CDT. The concentrations of plasma D-D and FIB were measured every 8 h during thrombolysis. The degree of thrombolysis was evaluated, the change rules of D-D and FIB concentrations were analyzed, and the change curve graphs were drawn. The "thrombus volume," "thrombolysis time," "thrombolysis ratio," "D-D peak," "D-D rising speed," "FIB falling speed," and "duration of D-D elevation" were calculated in each patient. The mixed model was used to simulate the time change trend of the plasma D-D and FIB concentrations. Pearson method and linear regression were used to analyze the correlation and linear relationship, respectively.

RESULTS

The D-D concentration first increased rapidly and then decreased gradually, and the FIB concentration continued to decrease during thrombolysis. The rate of the decline of FIB varies with the urokinase dose. The thrombus volume is positively correlated with D-D rising speed, duration of D-D elevation, D-D peak, and FIB falling speed; the D-D rising speed is positively correlated with the D-D peak and FIB falling speed; and the D-D peak is positively correlated with the FIB falling speed. The correlation coefficients were all statistically significant (p < 0.05). Efficacy reached level I-II in 76.5% patients. No major bleeding occurred in any of the patients.

CONCLUSION

During CDT with urokinase for DVT, the concentrations of D-D and FIB show specific changes, and there are some specific relationships between each other. Understanding these changes and relationships may be helpful to adjust the thrombolysis time and urokinase dose more rationally.

Risk of venous thromboembolism and major bleeding in the clinical course of osteosarcoma and Ewing sarcoma

BACKGROUND

Patients with osteosarcoma (OS) and Ewing sarcoma (ES) are considered to have a high venous thromboembolism (VTE) risk, although the exact incidence and prognostic impact are under-researched in general as well as in relevant age groups.

AIMS

To study the impact of VTE and major bleeding (MB) in OS and ES patients, subdivided in children, Adolescents Young Adults (AYAs; aged 18-39) and older adults.

METHODS

Retrospective single-center chart review in 519 OS and 165 ES patients treated between 1980 and 2018. Patients were followed from sarcoma diagnosis until an outcome of interest (VTE, MB) or death occurred. Cumulative incidences were estimated with death as competing risk. Cox models were used to determine prognostic impact.

RESULTS

Five-year cumulative incidences of VTE were 12 % (95%CI 9.1-15) for OS and 6.7 % (95%CI 3.5-11) for ES patients, mostly happening in patients ≥18 years; the most frequent VTE presentation was catheter-related upper-extremity thrombosis (OS: 18/65, ES: 7/11). Five-year cumulative incidences for MB were 5.8 % (95%CI 4.0-8.1) in OS and 5.4 % (95%CI 2.5-9.8) in ES patients. 192 OS and 77 ES AYAs were included, who faced similar VTE and MB incidences as older adults. In OS, VTE and MB were both associated with mortality (adjusted HRs 2.0 [95%CI 1.4-2.9] and 2.4 [95%CI 1.4-4.0], respectively), whereas in ES this association was only present for MB (aHR 3.4 [95%CI 1.2-9.6]).

CONCLUSIONS

VTE is a frequent complication in adult OS and to a lesser extent in ES patients, while the rate of MB was comparably high in both sarcoma types.

Targeted DNA sequencing to identify genetic aberrations in glioblastoma that underlie venous thromboembolism; a cohort study

BACKGROUND AND OBJECTIVES

Patients with glioblastoma have a high risk of developing venous thromboembolism (VTE). However, the role of underlying genetic risk factors remains largely unknown. Therefore, the aim of this study was to discover whether genetic aberrations in glioblastoma associate with VTE risk.

METHODS

In this cohort study, all consecutive patients diagnosed with glioblastoma in two Dutch hospitals between February 2017 and August 2020 were included. Targeted DNA next-generation sequencing of all glioblastomas was performed for diagnostic purposes and included mutational status of the genes ATRX, BRAF, CIC, FUBP1, H3F3A, IDH1, IDH2, PIK3CA, PTEN and TP53 and amplification/gain or deletion of BRAF, CDKN2A, EGFR, NOTCH1 and PTEN. The primary outcome was VTE within three months before glioblastoma diagnosis until two years after. Cumulative incidences were determined using competing risk analysis adjusting for mortality. Univariable Cox regression analysis was performed to determine hazard ratios.

RESULTS

From 324 patients with glioblastoma, 25 were diagnosed with VTE. Patients with a CDKN2A deletion had a 12-month adjusted cumulative incidence of VTE of 12.5 % (95%CI: 7.3-19.3) compared with 5.4 % (95%CI: 2.6-9.6) in patients with CDKN2A wildtype (p = 0.020), corresponding to a HR of 2.53 (95%CI: 1.12-5.73, p = 0.026). No significant associations were found between any of the other investigated genes and VTE.

CONCLUSION

This study suggests a potential role for CDKN2A deletion in glioblastoma-related VTE. Therefore, once independently validated, CDKN2A mutational status may be a promising predictor to identify glioblastoma patients at high risk for VTE, who may benefit from thromboprophylaxis.

Evaluation of the diagnostic management of deep vein thrombosis in the emergency department of a tertiary hospital in Santa Catarina, Brazil: a cross-sectional study

Background

Venous thromboembolism is an entity that encompasses both deep vein thrombosis and pulmonary thromboembolism. Although protocols for the diagnosis of these diseases are well defined, there is evidence of inappropriate use of diagnostic resources.

Objectives

To define the epidemiological profiles of patients admitted to the emergency department with suspected deep vein thrombosis, to determine rates of inappropriate ordering of D-dimer assays and color venous Doppler echocardiography of the lower limbs, and to identify whether these requests followed the recommendations contained in the 2015 Brazilian Society of Angiology and Vascular Surgery guidelines.

Methods

We conducted a cross-sectional observational study that retrospectively evaluated 168 patients with suspected deep vein thrombosis for whom D-dimer assays were requested. The most common risk factors were measured and the pretest probability was calculated with the Wells score. The epidemiological profile of these patients and the rates of inappropriate D-dimer testing were assessed using descriptive statistics.

Results

The D-dimer requests were inadequate in 55 (32.7%) patients. Venous color Doppler ultrasound was used to examine the lower limbs of 14 (8.3%) of the patients with a low probability according to the Wells score and a negative D-dimer result. No additional diagnostic methods were used in 19 (11.3%) of those with a low probability according to the Wells score and a high D-dimer result. There was unnecessary use of CDUS in 35 (20.8%) cases. The overall rate of inappropriate workup was 53.5%.

Conclusions

Differences were found between clinical practice and the recommendations for diagnostic evaluation of patients with suspected deep vein thrombosis, with inappropriate use of diagnostic tests.

Tumor-expressed microRNAs associated with venous thromboembolism in colorectal cancer

Background

Colorectal cancer patients have an increased risk of developing venous thromboembolism (VTE), resulting in increased morbidity and mortality. Because the exact mechanism is yet unknown, risk prediction is still challenging; therefore, new biomarkers are needed. MicroRNAs (miRNAs) are small, relatively stable RNAs, that regulate a variety of cellular processes, and are easily measured in body fluids.

Objective

The aim of this study was to identify novel tumor-expressed miRNAs associated with VTE.

Methods

In a cohort of 418 colorectal cancer patients diagnosed between 2001 and 2015 at the Leiden University Medical Center, 23 patients (5.5%) developed VTE 1 year before or after cancer diagnosis. Based on availability of frozen tumor material, tumor cells of 17 patients with VTE and 18 patients without VTE were isolated using laser capture microdissection and subsequently analyzed on the Illumina sequencing platform NovaSeq600 using 150-bp paired-end sequencing. Cases and controls were matched on age, sex, tumor stage, and grade. Differential miRNA expression was analyzed using edgeR.

Results

A total of 547 miRNAs were detected. Applying a 1.5-fold difference and false discovery rate of <0.1, 19 tumor-miRNAs were differentially regulated in VTE cases versus controls, with hsa-miR-3652, hsa-miR-92b-5p, and hsa-miR-10,394-5p as most significantly downregulated. Seven of the 19 identified miRNAs were predicted to regulate the gonadotropin-releasing hormone receptor pathway.

Conclusion

We identified 19 differentially regulated tumor-expressed miRNAs in colorectal cancer-associated VTE, which may provide insights into the biological mechanism and in the future might have potential to serve as novel, predictive biomarkers.

Incidence and determinants of thrombotic and bleeding complications in patients with glioblastoma

BACKGROUND

Glioblastoma patients are considered to be at high risk of venous thromboembolism (VTE) and major bleeding (MB), although reliable incidence estimates are lacking. Moreover, the risk of arterial thromboembolism (ATE) in these patients is largely unknown. Our aim was to assess the cumulative incidence, predictors, and prognostic impact of VTE, ATE, and MB on subsequent complications and mortality.

METHODS

Cohort study of 967 consecutive patients diagnosed with glioblastoma between 2004-2020 in two hospitals. Patients were followed from 6 months before date of histopathological glioblastoma diagnosis up to 2 years after, or until an outcome of interest (VTE, ATE, and MB) or death occurred, depending on the analysis. Cumulative incidences were estimated with death as competing risk. Cox regression was used to identify predictors and the prognostic impact.

RESULTS

A total of 101 patients were diagnosed with VTE, 50 with ATE, and 126 with MB during a median follow-up of 15 months (interquartile range 9.0-22). The adjusted 1-year cumulative incidence of VTE was 7.5% (95% confidence interval [CI] 5.9-9.3), of ATE 4.1% (95% CI 3.0-5.6), and of MB 12% (95% CI 9.6-14). Older age, type of surgery, and performance status were predictors of VTE. Incident VTE during follow-up was associated with MB (adjusted HR 4.7, 95% CI 2.5-9.0). MB and VTE were associated with mortality (adjusted HR 1.7, 95% CI 1.3-2.1 and 1.3, 95% CI 1.0-1.7, respectively).

CONCLUSION

We found considerable incidences of VTE and MB in glioblastoma patients, with both complications associated with poorer prognosis. Our observations emphasize the need for prospective studies to determine optimal thromboprophylaxis and VTE treatment strategy in these patients.

Anticoagulation strategies and clinical outcomes after bleeding events during anticoagulation therapy for venous thromboembolism in the practice-based Japanese registry

There is a paucity of data on anticoagulation strategies and clinical outcomes after bleeding events for venous thromboembolism (VTE). In a multicenter Japanese registry enrolling 3027 patients with acute symptomatic VTE, after excluding 430 patients with thrombolysis and 207 patients without anticoagulation therapy, the current study population consisted of 2390 patients, who were divided into patients with major bleeding, clinically relevant non-major (CRNM) bleeding and no bleeding during anticoagulation therapy. All-cause death at 90 days after the bleeding events was evaluated as the primary outcome. There were 189 patients with major bleeding, 147 patients with CRNM bleeding, and 2054 patients without bleeding. Among 189 patients with major bleeding, 142 patients (75%) discontinued anticoagulants, of whom patients with temporary discontinuation and those with permanent discontinuation accounted for 63 patients (44%) and 79 patients (56%), and 58 patients (30.7%) died within 90 days after the bleeding events. The multivariable logistic regression model among patients with bleeding events revealed that active cancer and bleeding events within 90 days after VTE diagnosis were independently associated with 90-day mortality after the bleeding events (active cancer: OR 5.05, 95%CI 2.82-9.05; bleeding events within 90 days after VTE diagnosis: OR 2.23, 95%CI 1.25-3.96). In this practice-based large registry, anticoagulants were frequently discontinued in patients who experienced major bleeding events during anticoagulation therapy and nearly half of them restarted anticoagulants with mortality rate of approximately 30% within 90 days after the bleeding events, and active cancer was the most prevalent cause of death.Clinical trial registration COMMAND VTE Registry: http://www.umin.ac.jp/ctr/index.htm . Unique identifier: UMIN000021132.

A new method of monitoring catheter-directed thrombolysis for deep venous thrombosis-application of D-dimer and fibrinogen testing

BACKGROUND

Catheter-directed thrombolysis (CDT) is one of the main treatment methods for acute deep venous thrombosis (DVT), which has the characteristics of long treatment time and large dosage of thrombolytic drugs. In the absence of good monitoring methods, problems such as low thrombolytic efficiency and high risk of bleeding are easy to occur.

OBJECTIVE

To evaluate the value of D-dimer (D-D) and fibrinogen (FIB) testing as a thrombolysis-monitoring method during CDT for acute DVT.

METHODS

Twenty patients with acute DVT were divided into group A and group B. During CDT, the D-D and FIB testing every 8 h were used in group A, and the venography and FIB testing every 24 h in group B. The thrombolysis rate, thrombolysis time, urokinase dosage, and X-ray radiation dose were compared.

RESULTS

The thrombolysis rate in group A was significantly higher than that in group B (p < 0.05), but the number of venography and radiation dose were significantly lower than those in group B (p < 0.05).

CONCLUSION

D-D and FIB testing can improve the thrombolysis rate, reduce the risk of bleeding, and decrease the number of angiograms and X-ray radiation dose during CDT.

Evaluation of the diagnostic management of deep vein thrombosis in the emergency department of a tertiary hospital in Santa Catarina, Brazil: a cross-sectional study

Abstract Background Venous thromboembolism is an entity that encompasses both deep vein thrombosis and pulmonary thromboembolism. Although protocols for the diagnosis of these diseases are well defined, there is evidence of inappropriate use of diagnostic resources. Objectives To define the epidemiological profiles of patients admitted to the emergency department with suspected deep vein thrombosis, to determine rates of inappropriate ordering of D-dimer assays and color venous Doppler echocardiography of the lower limbs, and to identify whether these requests followed the recommendations contained in the 2015 Brazilian Society of Angiology and Vascular Surgery guidelines. Methods We conducted a cross-sectional observational study that retrospectively evaluated 168 patients with suspected deep vein thrombosis for whom D-dimer assays were requested. The most common risk factors were measured and the pretest probability was calculated with the Wells score. The epidemiological profile of these patients and the rates of inappropriate D-dimer testing were assessed using descriptive statistics. Results The D-dimer requests were inadequate in 55 (32.7%) patients. Venous color Doppler ultrasound was used to examine the lower limbs of 14 (8.3%) of the patients with a low probability according to the Wells score and a negative D-dimer result. No additional diagnostic methods were used in 19 (11.3%) of those with a low probability according to the Wells score and a high D-dimer result. There was unnecessary use of CDUS in 35 (20.8%) cases. The overall rate of inappropriate workup was 53.5%. Conclusions Differences were found between clinical practice and the recommendations for diagnostic evaluation of patients with suspected deep vein thrombosis, with inappropriate use of diagnostic tests.

Vaccine-induced immune thrombotic thrombocytopenia

In response to the COVID-19 pandemic, vaccines for SARS-CoV-2 were developed, tested, and introduced at a remarkable speed. Although the vaccine introduction had a major impact on the evolution of COVID-19, some potential rare side-effects of the vaccines were observed. Within a short period, three scientific groups from Norway, Germany, and the UK reported cerebral venous sinus thrombosis with thrombocytopenia and anti-platelet factor 4 (anti-PF4) antibodies in individuals following AstraZeneca–Oxford vaccination and named this new syndrome vaccine-induced immune thrombotic thrombocytopenia (VITT). This syndrome was subsequently reported in individuals who received Johnson & Johnson vaccination. In this Viewpoint, we discuss the epidemiology, pathophysiology, and optimal diagnostic and therapeutic management of VITT. Presentation of an individual with possible VITT should raise prompt testing for anti-PF4 antibodies and initiation of treatment targeting autoimmune processes with intravenous immunoglobulin and prothrombotic processes with non-heparin anticoagulation.

Incidence, timing and risk factors of venous thromboembolic events in patients with pancreatic cancer

INTRODUCTION

Pancreatic cancer is associated with a high risk of venous thromboembolism (VTE). However, comprehensive data on incidence, timing and relevant determinants of VTE in this particular population are scarce. Current study assesses incidence, timing and predictors of VTE in pancreatic cancer through different phases of disease.

METHODS

All pancreatic cancer patients treated in our tertiary referral center between 2013 through 2017 were studied. Occurrence of VTE was evaluated from diagnosis through end of follow-up or death. Relevant determinants of VTE were identified in logistic regression models. Hazard ratios were calculated to evaluate impact of VTE on overall survival.

RESULTS

In total, 361 patients were followed for a median period of 43 months; 64 were diagnosed with VTE (18%). Most were tumor related thrombosis (59%), incidental (75%) and occurred after anti-cancer treatment had been stopped (80%), only 1.6% occurred during remission phase. Stage IV pancreatic cancer was a predictor for VTE (hazard ratio (HR) 2.46, 95% confidence interval (CI) 0.9-6.8). Biliary drainage (HR 0.52, 95%CI 0.28-0.98) and tumor resection (HR 0.45, 95%CI 0.45-1.83) were protective factors. VTE was not associated with worse survival (HR 1.3; 95% CI 0.97-1.74).

CONCLUSIONS

VTE in pancreatic cancer is disease-stage dependent, with 80% occurring in advanced phases of disease when patients no longer receive active treatment. We speculate that this is the main reason for the absence of a survival effect of VTE in our cohort. These practice-based findings should be taken into account when considering wide-spread introduction of primary thromboprophylaxis in patients with pancreatic cancer.

Efficacy and safety of a 12-week outpatient pulmonary rehabilitation program in Post-PE Syndrome

BACKGROUND

The Post-Pulmonary Embolism Syndrome (PPES) comprises heterogeneous entities, including chronic thromboembolic disease with/without pulmonary hypertension (CTEPH/CTEPD), and deconditioning.

OBJECTIVES

To assess underlying physiological determinants of PPES, and efficacy and safety of rehabilitation training in these patients.

METHODS

56 consecutive PE patients with persistent dyspnea and/or functional limitations despite ≥3 months of anticoagulation underwent standardized diagnostic work-up including exercise testing as part of routine practice. All diagnostic (imaging and cardiopulmonary function) tests were interpreted by a core group of experienced clinicians. A subgroup of patients without CTEPH or other treatable conditions was referred for a 12-week personalized rehabilitation program, studying changes in physical condition and patient-reported outcome measures.

RESULTS

Persistent vascular occlusions were observed in 21/56 patients (38%) and CTEPH was confirmed in ten (18%). Regarding those without CTEPH, impaired cardiopulmonary responses were evident in 18/39 patients with available CPET data (46%), unrelated to chronic thrombi. Rehabilitation was completed by 27 patients after excluding 29 (patients with CTEPH or treatable comorbidities, refusal, ineligibility, or training elsewhere). Training intensity, PE-specific quality of life (PEmb-QoL) and fatigue (CIS) improved with a median difference of 20 W (p = 0.001), 3.9 points (p < 0.001) and 16 points (p = 0.003), respectively. Functional status (Post-VTE Functional Status Scale) improved ≥1 grade in 18 (67%) patients, and declined in one (3.7%).

CONCLUSIONS

Our findings suggest that abnormal cardiopulmonary responses to exercise are common in patients with PPES and are not limited to those with chronic thrombi. Offering pulmonary rehabilitation to patients not treated otherwise seems safe and promising.

The Use of Point-of-Care Ultrasound (POCUS) in the Diagnosis of Deep Vein Thrombosis

Acute lower extremity proximal deep venous thrombosis (DVT) requires accurate diagnosis and treatment in order to prevent embolization and other complications. Point-of-care ultrasound (POCUS), a clinician performed, and clinician interpreted bedside ultrasound examination has been increasingly used for DVT evaluation mainly in the urgent and critical care setting, but also in the ambulatory clinics and the medical wards. Studies have demonstrated that POCUS has excellent diagnostic accuracy for acute proximal DVT when performed by well-trained users. However, there is significant heterogeneity among studies on the necessary extent of training and universally acceptable standardized education protocols are needed. In this review, we summarize the evidence that supports the use of POCUS to diagnose acute proximal DVT and focus on methodology and current technology, sensitivity and specificity, pre-test probability and the role of D-dimer, time and resources, education, limitations, and future directions.

Detection of upper extremity deep vein thrombosis by magnetic resonance non-contrast thrombus imaging

BACKGROUND

Compression ultrasonography (CUS) is the first-line imaging test for diagnosing upper extremity deep vein thrombosis (UEDVT), but often yields inconclusive test results. Contrast venography is still considered the diagnostic standard but is an invasive technique.

OBJECTIVES

We aimed to determine the diagnostic accuracy of magnetic resonance noncontrast thrombus imaging (MR-NCTI) for the diagnosis of UEDVT.

METHODS

In this international multicenter diagnostic study, we prospectively included patients with clinically suspected UEDVT who were managed according to a diagnostic algorithm that included a clinical decision rule (CDR), D-dimer test, and diagnostic imaging. UEDVT was confirmed by CUS or (computed tomography [CT]) venography. UEDVT was excluded by (1) an unlikely CDR and normal D-dimer, (2) a normal serial CUS or (3) a normal (CT) venography. Within 48 h after the final diagnosis was established, patients underwent MR-NCTI. MR-NCTI images were assessed post hoc by two independent radiologists unaware of the presence or absence of UEDVT. The sensitivity, specificity, and interobserver agreement of MR-NCTI for UEDVT were determined.

RESULTS

Magnetic resonance noncontrast thrombus imaging demonstrated UEDVT in 28 of 30 patients with UEDVT and was normal in all 30 patients where UEDVT was ruled out, yielding a sensitivity of 93% (95% CI 78-99) and specificity of 100% (95% CI 88-100). The interobserver agreement of MR-NCTI had a kappa value of 0.83 (95% CI 0.69-0.97).

CONCLUSIONS

Magnetic resonance noncontrast thrombus imaging is an accurate and reproducible method for diagnosing UEDVT. Clinical outcome studies should determine whether MR-NCTI can replace venography as the second-line imaging test in case of inconclusive CUS.

Changes in Biomarkers of Coagulation, Fibrinolytic, and Endothelial Functions for Evaluating the Predisposition to Venous Thromboembolism in Patients With Hereditary Thrombophilia

The changes in the coagulation, fibrinolytic, and endothelial functions are correlated with the pathophysiology of the thromboembolic diseases during acute illness. However, these changes in patients with hereditary thrombophilia who were not in the acute stage of venous thromboembolism (VTE) are unclear. A panel of 4 biomarkers, including thrombin–antithrombin complex (TAT), plasmin-α2-plasmin inhibitor complex (PIC), tissue-type plasminogen activator/plasminogen activator inhibitor-1 complex (t-PAIC), and soluble thrombomodulin (sTM), were assayed in 100 healthy controls and 100 patients with thrombophilia. Although significantly higher concentrations of TAT, PIC, t-PAIC, and sTM were observed in patients with thrombophilia than in healthy controls, 70 patients showed absolutely normal levels of the above 4 biomarkers. Among the other 30 patients who had at least 1 biomarker out of the corresponding reference interval, 26 of them presented elevated PIC with or without increased TAT. Except for sTM, other 3 biomarkers did not show significant differences in patients with previous VTE compared to those without. Patients with single episode of VTE had obviously lower t-PAIC than those with multiple episodes of VTE, whereas the levels of TAT, PIC, and sTM were unassociated with the number of thrombosis episodes. Most thrombophilia patients who were not in the acute stage of VTE showed normal coagulation, fibrinolytic, and endothelial functions. Thus, we were unable to show that the one-time response of this panel was clinically helpful in determining thrombosis risk in thrombophilia individuals. Future studies should focus on the dynamic monitoring during the chronic phase of VTE to offer special advantages for patients with thrombophilia.

Challenges in the diagnostic approach of suspected pulmonary embolism in COVID-19 patients

Accumulating studies on COVID-19 patients report high incidences of thrombotic complications, but guidance on the best diagnostic approach for suspected pulmonary embolism (PE) in COVID-19 patients is lacking. Diagnosing PE in these patients is challenging as signs and symptoms of PE and COVID-19 show wide overlap, D-dimer levels are often elevated in the absence of thrombosis and computed tomography pulmonary angiography (CTPA) may be unfeasible in the case of severe renal impairment and/or hemodynamic instability.This narrative review discusses available literature and guidelines on current diagnostic algorithms for suspected PE in special patient populations, in particular COVID-19. A special focus is on reviewing the literature aimed at identifying symptoms with a high suspicion for PE and on the diagnostic performance of diagnostic algorithms for suspected PE in the setting of COVID-19.Based on available literature, the index of suspicion for PE should be high in the case of unexplained abrupt worsening of respiratory status, typical symptoms of deep-vein thrombosis and/or acute unexplained right ventricular dysfunction. Despite the lack of prospective diagnostic management studies, we propose to adhere to current diagnostic algorithms applying assessment of pretest probability and D-dimer testing as available evidence suggests that these might be considered safe. Preferably, algorithms using adjusted D-dimer thresholds are recommended as it likely improves the yield of the clinical decision rule/D-dimer combination.

Diagnostic Value of Neutrophil Lymphocyte Ratio and D-Dimer as Biological Markers of Deep Vein Thrombosis in Patients Presenting with Unilateral Limb Edema

Introduction

Patients with deep vein thrombosis (DVT) pose high morbidity and mortality risk thus needing fast and accurate diagnosis. Wells clinical prediction scores with D-dimer testing are traditionally used to rule out patients with low probability of DVT. However, D-dimer testing has a few limitations regarding its relatively low specificity. Neutrophil-lymphocyte ratio (NLR), a marker of inflammation, was found to increase in DVT. Hence, we aimed to evaluate the role of NLR for DVT diagnosis.

Methods

Data were collected from medical records of patients with suspected DVT at Cipto Mangunkusumo National General Hospital during January–December 2014. Diagnosis of DVT was conducted using lower limb ultrasonography. Diagnostic values for NLR, D-dimer, and NLR + D-dimer were determined by receiver operating characteristic (ROC) analysis to obtain area under the curve (AUC), sensitivity, specificity, negative predictive value, and positive predictive values. Sensitivity and specificity analyses of NLR and D-dimer were also conducted based on Wells score and divided into groups of low and high probability of DVT.

Results

The AUC values for NLR, D-dimer, and NLR + D-dimer were 72.6%, 70.4%, and 76.1%, respectively. The optimal cut-off value determined for NLR was 5.12 with sensitivity of 67.7%, specificity of 67.9%, PPV of 68.85%, and NPV of 64.91% in differentiating subjects with and without DVT. This study also found that D-dimer had sensitivity of 69.4%, specificity of 71.4%, PPV of 72.88%, and NPV of 67.8%. Meanwhile, the NLR + D-dimer combination had sensitivity of 66.1% and specificity of 72.6%. Multivariate analysis showed that NLR (OR: 2.636; 95% CI: 1.144–6.076; p: 0.023) and D-dimer (OR: 4.175; 95% CI: 1.810–9.633; p: 0.001) were associated with DVT.

Conclusion

NLR value has wider AUC than D-Dimer and is relatively easier to obtain and does not require specific assay, thus enabling rapid evaluation of symptomatic patients suspected of having DVT. Adding NLR to D-dimer increased AUC to detect DVT. Therefore, NLR could serve as a complementary diagnostic tool for D-dimer to exclude DVT, especially in low clinical probability patients.

Age-adjusted D-dimer cut-off levels to rule out venous thromboembolism in patients with non-high pre-test probability: Clinical performance and cost-effectiveness analysis

BACKGROUND

As aging was found to be associated with increased D-dimer levels, the question arose whether D-dimer measurement was useful in the diagnostic strategy of venous thromboembolism (VTE) in elderly patients.

AIM OF THE STUDY

To compare retrospectively the performance of six diagnostic strategies based on the three-level Wells scores and various cut-off levels for D-dimer, evaluated using the HemosIL D-Dimer HS 500 assay, in a derivation cohort of 644 outpatients with non-high pretest probability (PTP) of VTE. The clinical usefulness of the best-performing strategy was then confirmed in a multicenter validation study involving 1255 consecutive outpatients with non-high PTP.

RESULTS

The diagnostic strategy based on the age-adjusted cut-off level calculated by multiplying the patient's age by 10 above 50 years was found to perform the best in the derivation study with a better sensitivity-to-specificity ratio than the conventional strategy based on the fixed cut-off level (500 ng/ml), a higher specificity and a negative predictive value (NPV) above 99%. Such an increase in test specificity was confirmed in the validation cohort, with the NPV remaining above 99%. Taking into account the local reimbursement rates of diagnostic tests, using this strategy led to a 6.9% reduction of diagnostic costs for pulmonary embolism and a 5.1% reduction for deep vein thrombosis, as imaging tests would be avoided in a higher percentage of patients.

CONCLUSION

The diagnostic strategy of VTE based on the age-adjusted cut-off level for D-dimer in patients over 50 years was found to be safe, with NPV above 99%, and cost-effective.

Endovascular and medical therapy of May-Thurner syndrome: Case series and scoping literature review

INTRODUCTION

May-Thurner syndrome has been recognized as a cause of chronic venous insufficiency and a trigger for venous thromboembolism. There is no consensus about the definition, diagnosis, and therapeutic approach. We are aiming to describe its characteristics and a scoping literature review.

METHODS

A retrospective review of patients with May-Thurner syndrome from March 2010 to May 2018 and scoping literature review were made.

RESULTS

Seven patients were identified. All patients were female with a median age of 36 (20-60) years. The median time from the first symptom to diagnosis was 3.41 (0.01-9) years. The primary clinical presentation was post-thrombotic syndrome (4 patients). Six patients had at least one risk factor for deep venous thrombosis. All patients underwent angioplasty with stent; patients with acute deep venous thrombosis, furthermore mechanic thrombectomy with or without catheter-directed thrombolysis were done. There were three complications (one patient, lymphedema, and two venous stent thrombosis). Scoping review results were descriptively summarized.

CONCLUSION

May-Thurner syndrome has a varied spectrum of clinical presentation, and clinical awareness is paramount for diagnosis. Its principal complication is the post-thrombotic syndrome, which is associated with high morbidity. There is no consensus on the antithrombotic treatment approach.

Pulmonary infarction in acute pulmonary embolism

Pulmonary infarction results from occlusion of the distal pulmonary arteries leading to ischemia, hemorrhage and ultimately necrosis of the lung parenchyma. It is most commonly caused by acute pulmonary embolism (PE), with a reported incidence of around 30%. Following an occlusion of the pulmonary artery, the bronchial arteries are recruited as primary source of perfusion of the pulmonary capillaries. The relatively higher blood pressure in the bronchial circulation causes an increase in the capillary blood flow, leading to extravasation of erythrocytes (i.e. alveolar hemorrhage). If this hemorrhage cannot be resorbed, it results in tissue necrosis and infarction. Different definitions of pulmonary infarction are used in literature (clinical, radiological and histological), although the diagnosis is nowadays mostly based on radiological characteristics. Notably, the infarcted area is only replaced by a fibrotic scar over a period of months. Hence and formally, the diagnosis of pulmonary infarction cannot be confirmed upon diagnosis of acute PE. Little is known of the impact and relevance of pulmonary infarction in acute PE, and whether specific management strategies should be applied to prevent and/or treat complications such as pain, pneumonia or post-PE syndrome. In this review we will summarize current knowledge on the pathophysiology, epidemiology, diagnosis and prognosis of pulmonary infarction in the setting of acute PE. We highlight the need for dedicated studies to overcome the current knowledge gaps.

Cost-effectiveness of magnetic resonance imaging for diagnosing recurrent ipsilateral deep vein thrombosis

The diagnostic workup of recurrent ipsilateral deep vein thrombosis (DVT) using compression ultrasonography (CUS) can be complicated by persistent intravascular abnormalities after a previous DVT. We showed that magnetic resonance direct thrombus imaging (MRDTI) can exclude recurrent ipsilateral DVT. However, it is unknown whether the application of MRDTI in daily clinical practice is cost effective. The aim of this study was to evaluate the cost effectiveness of MRDTI-based diagnosis for suspected recurrent ipsilateral DVT during first year of treatment and follow-up in the Dutch health care setting. Patient-level data of the Theia study (NCT02262052) were analyzed in 10 diagnostic scenarios, including a clinical decision rule and D-dimer test and imaging with CUS and/or MRDTI. The total costs of diagnostic tests and treatment during 1-year follow-up, including costs of false-positive and false-negative diagnoses, were compared and related to the associated mortality. The 1-year health care costs with MRDTI (range, €1219-1296) were generally lower than strategies without MRDTI (range, €1278-1529). This was because of superior specificity, despite higher initial diagnostic costs. Diagnostic strategies including CUS alone and CUS followed by MRDTI in case of an inconclusive CUS were potential optimal cost-effective strategies, with estimated average costs of €1529 and €1263 per patient and predicted mortality of 1 per 737 patients and 1 per 609 patients, respectively. Our model shows that diagnostic strategies with MRDTI for suspected recurrent ipsilateral DVT have generally lower 1-year health care costs than strategies without MRDTI. Therefore, compared with CUS alone, applying MRDTI did not increase health care costs.

Incidence of thrombotic complications and overall survival in hospitalized patients with COVID-19 in the second and first wave

INTRODUCTION

In the first wave, thrombotic complications were common in COVID-19 patients. It is unknown whether state-of-the-art treatment has resulted in less thrombotic complications in the second wave.

METHODS

We assessed the incidence of thrombotic complications and overall mortality in COVID-19 patients admitted to eight Dutch hospitals between September 1st and November 30th 2020. Follow-up ended at discharge, transfer to another hospital, when they died, or on November 30th 2020, whichever came first. Cumulative incidences were estimated, adjusted for competing risk of death. These were compared to those observed in 579 patients admitted in the first wave, between February 24th and April 26th 2020, by means of Cox regression techniques adjusted for age, sex and weight.

RESULTS

In total 947 patients with COVID-19 were included in this analysis, of whom 358 patients were admitted to the ICU; 144 patients died (15%). The adjusted cumulative incidence of all thrombotic complications after 10, 20 and 30 days was 12% (95% confidence interval (CI) 9.8-15%), 16% (13-19%) and 21% (17-25%), respectively. Patient characteristics between the first and second wave were comparable. The adjusted hazard ratio (HR) for overall mortality in the second wave versus the first wave was 0.53 (95%CI 0.41-0.70). The adjusted HR for any thrombotic complication in the second versus the first wave was 0.89 (95%CI 0.65-1.2).

CONCLUSIONS

Mortality was reduced by 47% in the second wave, but the thrombotic complication rate remained high, and comparable to the first wave. Careful attention to provision of adequate thromboprophylaxis is invariably warranted.

Computed Tomography Pulmonary Perfusion for Prediction of Short-Term Clinical Outcome in Acute Pulmonary Embolism

Background  Computed tomography pulmonary angiography (CTPA) is the imaging modality of choice for the diagnosis of acute pulmonary embolism (PE). With computed tomography pulmonary perfusion (CTPP) additional information on lung perfusion can be assessed, but its value in PE risk stratification is unknown. We aimed to evaluate the correlation between CTPP-assessed perfusion defect score (PDS) and clinical presentation and its predictive value for adverse short-term outcome of acute PE.

Patients and Methods  This was an exploratory, observational study in 100 hemodynamically stable patients with CTPA-confirmed acute PE in whom CTPP was performed as part of routine clinical practice. We calculated the difference between the mean PDS in patients with versus without chest pain, dyspnea, and hemoptysis and 7-day adverse outcome. Multivariable logistic regression analysis and likelihood-ratio test were used to assess the added predictive value of PDS to CTPA parameters of right ventricle dysfunction and total thrombus load, for intensive care unit admission, reperfusion therapy and PE-related death.

Results  We found no correlation between PDS and clinical symptoms. PDS was correlated to reperfusion therapy ( n  = 4 with 16% higher PDS, 95% confidence interval [CI]: 3.5–28%) and PE-related mortality ( n  = 2 with 22% higher PDS, 95% CI: 4.9–38). Moreover, PDS had an added predictive value to CTPA assessment for PE-related mortality (from Chi-square 14 to 19, p  = 0.02).

Conclusion  CTPP-assessed PDS was not correlated to clinical presentation of acute PE. However, PDS was correlated to reperfusion therapy and PE-related mortality and had an added predictive value to CTPA-reading for PE-related mortality; this added value needs to be demonstrated in larger studies.

Caging the dragon: Research approach to COVID-19-related thrombosis

The incidence of venous thrombosis, mostly pulmonary embolism (PE), ranging from local immunothrombosis to central emboli, but also deep vein thrombosis (DVT) in people with coronavirus disease 2019 (COVID-19) is reported to be remarkably high. The relevance of better understanding, predicting, treating, and preventing COVID-19-associated venous thrombosis meets broad support, as can be concluded from the high number of research, review, and guideline papers that have been published on this topic. The Dutch COVID & Thrombosis Coalition (DCTC) is a multidisciplinary team involving a large number of Dutch experts in the broad area of venous thrombosis and hemostasis research, combined with experts on virology, critically ill patients, pulmonary diseases, and community medicine, across all university hospitals and many community hospitals in the Netherlands. Within the consortium, clinical data of at least 5000 admitted COVID-19-infected individuals are available, including substantial collections of biobanked materials in an estimated 3000 people. In addition to considerable experience in preclinical and clinical thrombosis research, the consortium embeds virology-hemostasis research models within unique biosafety facilities to address fundamental questions on the interaction of virus with epithelial and vascular cells, in relation to the coagulation and inflammatory system. The DCTC has initiated a comprehensive research program to answer many of the current questions on the pathophysiology and best anticoagulant treatment of COVID-19-associated thrombotic complications. The research program was funded by grants of the Netherlands Thrombosis Foundation and the Netherlands Organization for Health Research and Development. Here, we summarize the design and main aims of the research program.

Comparison Between the Diagnostic Performance of 1.5 T and 3.0 T field Strengths for Detecting Deep Vein Thrombosis Using Magnetic Resonance Black-Blood Thrombus Imaging

BACKGROUND

Magnetic resonance (MR) black-blood thrombus imaging (BTI) is an accurate diagnostic technique for detecting deep vein thrombosis (DVT) but to date there have been no studies comparing the diagnostic performance and consistency of this technique at different field strengths. In this study, we evaluated and compared the diagnostic performance of BTI for detecting DVT at 1.5 T and 3.0 T field strengths.

METHODS

A total of 40 patients with DVT were enrolled in this study from November 2015 up to October 2018. All patients underwent BTI, a contrast-free T1-weighted MR imaging technique for detecting DVT, and contrast-enhanced MR venography (CE-MRV) at 1.5 T or 3.0 T field strengths. The MR data analyses used 1160 segments from the venous lumen of the 40 patients. The signal-to-noise ratio and contrast-to-noise ratio between thrombus and muscle/lumen were calculated to compare BTI at 1.5 T or 3.0 T to determine the image performance for thrombus detection at 1.5 T or 3.0 T. Two physicians blinded to the study evaluated all BTI images and calculated the overall sensitivity (SE), specificity (SP), positive predictive value (PPV) and negative predictive value (NPV), accuracy, and diagnostic consistency at 1.5 T and 3.0 T. These images and values were compared to control CE-MRV images that had been obtained by 2 senior physicians and used as reference standards. In addition, the reliability and consistency of diagnoses between observers were also evaluated.

RESULTS

Two study-blind physicians reviewed all BTI images to diagnose thrombus and to determine SE, SP, PPV, NPV, and accuracy. There were no statistical differences in SE, SP, PPV, NPV, or accuracy between the 1.5 T and 3.0 T groups.

CONCLUSIONS

Black-blood thrombus imaging has high SE, SP, and accuracy for DVT diagnosis both at 1.5 T and 3.0 T field strengths. This noninvasive diagnostic technique, which does not require the use of contrast agents, can be widely used in the clinical screening of DVT and follow-up after treatment.

Time-efficient and contrast-free magnetic resonance imaging approach to the diagnosis of deep vein thrombosis on black-blood gradient-echo sequence: a pilot study

Background

Black-blood thrombus imaging (BTI) has shown to be advantageous for the diagnosis of deep vein thrombosis (DVT). However, previous techniques using fast spin echo have a high specific absorption rate. As DANTE (delay alternating with nutation for tailored excitation) black-blood preparation can suppress blood flows over a broad range of velocities, we hypothesized that a DANTE black-blood preparation combined with a fast low-angle shot (FLASH) gradient-echo readout-DANTE-FLASH could be used to diagnose DVT.

Methods

Eleven healthy volunteers and 30 suspected DVT patients were recruited to undergo DANTE-FLASH and magnetic resonance direct thrombus imaging (MRDTI). The suspected DVT patients were also examined by ultrasound (US). For the segment level, a total of 1,066 venous vessel segments were analyzed. Using US and MRDTI as the references, the sensitivity (SE), specificity (SP), positive and negative predictive values (PPV and NPV), and accuracy (ACC) of DANTE-FLASH were calculated. To quantitatively compare image quality between DANTE-FLASH and MRDTI, image signal-to-noise ratio (SNR), apparent contrast-to-noise ratio (CNR) between muscle and the venous lumen, and the apparent CNR between the thrombus and venous lumen were measured. Additionally, diagnostic confidence, image quality, and clot burden were also evaluated.

Results

Using the consensus results of US and MRDTI as a standard reference, the diagnostic SE, SP, PPV, NPV, and ACC of DANTE-FLASH for the 2 readers were 97.0% and 93.2%, 99.0% and 98.2%, 93.4% and 87.9%, 99.6% and 99.0%, and 98.8% and 97.6%, respectively. According to the image quantitative analysis results, DANTE-FLASH demonstrated higher image SNR and CNR than MRDTI. The image quality and diagnostic confidence scores of DANTE-FLASH were higher than MRDTI (3.66±0.44 vs. 3.52±0.52, P<0.001, and 3.84±0.36 vs. 3.76±0.41, P<0.001). There was excellent agreement between DANTE-FLASH and MRDTI on clot burden evaluation.

Conclusions

DANTE-FLASH provided better image quality than MRDTI and accurately detected thrombi. It may, therefore, serve as a safe and convenient alternative for the diagnosis of DVT.

Application value of D-dimer testing and Caprini risk assessment model (RAM) to predict venous thromboembolism (VTE) in Chinese non-oncological urological inpatients: a retrospective study from a tertiary hospital

Background

The Caprini risk assessment model (RAM) and D-dimer testing have been widely used in the prediction of venous thromboembolism (VTE). However, the clinical significance of these testing options are limited in non-oncological urological inpatients because of the low specificity.

Methods

This retrospective study included 1,453 patients who were admitted to the non-oncological unit of the Department of Urology, Xiangya Hospital, Central South University, from January 2018 to December 2018. The highest score of Caprini RAM and the highest D-dimer level were collected in this retrospective study. Ultrasound examinations of the lower extremities or computed tomographic pulmonary arteriography (CTPA) were applied to patients who were suspected of having VTE, if necessary.

Results

A total of 1,453 patients were collected in this study, which included 34 VTE and 1,419 non-VTE patients. The threshold of D-dimer was 0.89 µg/mL, according to the receiver operating characteristic (ROC) curve, with a sensitivity of 82.4%, a specificity of 83.3%, and a negative predictive value (NPV) of 99.5%. The cut-off of the Caprini RAM was 5, with a sensitivity of 76.5%, a specificity of 58.7%, and an NPV of 99.0%. The area under the curve (AUC) was higher for D-dimer (0.86) than for the Caprini score (0.73).

Conclusions

The application of 0.89 µg/mL and a score of 5 as cut-offs for D-dimer testing and Caprini RAM, respectively, could safely decrease the proportion of Chinese non-oncological urological inpatients who needed to undergo further examinations. These new findings may enhance the application value of D-dimer testing and Caprini RAM for Chinese non-oncological urological inpatients.

Downregulation of interleukin-6 and C-reactive protein underlies a novel inhibitory role of microRNA-136-5p in acute lower extremity deep vein thrombosis

Deep vein thrombosis (DVT) comprises a critical and common health condition with high incidence, mortality, and long-term adverse sequelae. Several differentially expressed microRNAs (miRNAs) have emerged as promising prognostic markers in DVT. The present study intended to explore the functional relevance of miR-136-5p in acute lower extremity DVT (LEDVT). Rat models of acute LEDVT were established and miR-136-5p expression was altered by agomir or antagomir to assess its effects. In addition, in vitro gain- and loss-experiments, prior to exposure to CoCl₂, were performed to investigate effects of miR-136-5p on human umbilical vein endothelial cell (HUVEC) apoptosis and levels of interleukin-6 (IL-6) and C-reactive protein (CRP). miR-136-5p was downregulated, whereas IL-6 and CRP were elevated in acute LEDVT patients. Notably, miR-136-5p was confirmed to target both IL-6 and CRP. Overexpression of miR-136-5p led to reduced length, weight, and ratio of weight to length of the venous thrombus. Furthermore, overexpressed miR-136-5p downregulated the expression of IL-6 and CRP, consequently inhibiting HUVEC apoptosis. Conjointly, our data indicate that the overexpression of miR-136-5p has the potential to bind to the 3’-UTR in the mRNAs for IL-6 and CRP and mitigate acute LEDVT, which provides a basis for new therapeutic targets in acute LEDVT treatment.

Magnetic resonance imaging for diagnosis of recurrent ipsilateral deep vein thrombosis

The diagnosis of recurrent ipsilateral deep vein thrombosis (DVT) is challenging, because persistent intravascular abnormalities after previous DVT often hinder a diagnosis by compression ultrasonography. Magnetic resonance direct thrombus imaging (MRDTI), a technique without intravenous contrast and with a 10-minute acquisition time, has been shown to accurately distinguish acute recurrent DVT from chronic thrombotic remains. We have evaluated the safety of MRDTI as the sole test for excluding recurrent ipsilateral DVT. The Theia Study was a prospective, international, multicenter, diagnostic management study involving patients with clinically suspected acute recurrent ipsilateral DVT. Treatment of the patients was managed according to the result of the MRDTI, performed within 24 hours of study inclusion. The primary outcome was the 3-month incidence of venous thromboembolism (VTE) after a MRDTI negative for DVT. The secondary outcome was the interobserver agreement on the MRDTI readings. An independent committee adjudicated all end points. Three hundred five patients were included. The baseline prevalence of recurrent DVT was 38%; superficial thrombophlebitis was diagnosed in 4.6%. The primary outcome occurred in 2 of 119 (1.7%; 95% confidence interval [CI], 0.20-5.9) patients with MRDTI negative for DVT and thrombophlebitis, who were not treated with any anticoagulant during follow-up; neither of these recurrences was fatal. The incidence of recurrent VTE in all patients with MRDTI negative for DVT was 1.1% (95% CI, 0.13%-3.8%). The agreement between initial local and post hoc central reading of the MRDTI images was excellent (κ statistic, 0.91). The incidence of VTE recurrence after negative MRDTI was low, and MRDTI proved to be a feasible and reproducible diagnostic test. This trial was registered at www.clinicaltrials.gov as #NCT02262052.

Safety of a strategy combining D-dimer testing and whole-leg ultrasonography to rule out deep vein thrombosis

Guidelines for the diagnostic workup of deep vein thrombosis (DVT) recommend assessing the clinical pretest probability before proceeding to D-dimer testing and/or compression ultrasonography (CUS) if the patient has high pretest probability or positive D-dimer. Referring only patients with positive D-dimer for whole-leg CUS irrespective of pretest probability may simplify the workup of DVT. In this prospective management outcome study, we assessed the safety of such a strategy. We included consecutive outpatients referred to the Emergency Department at Østfold Hospital, Norway, with suspected DVT between February 2015 and November 2018. STA-Liatest D-Di Plus D-dimer was analyzed for all patients, and only patients with levels ≥0.5 µg/mL were referred for CUS. All patients with negative D-dimer or negative CUS were followed for 3 months to assess the venous thromboembolic rate. One thousand three hundred ninety-seven patients were included. Median age was 64 years (interquartile range, 52-73 years), and 770 patients (55%) were female. D-dimer was negative in 415 patients (29.7%) and positive in 982 patients (70.3%). DVT was diagnosed in 277 patients (19.8%). Six patients in whom DVT was ruled out at baseline were diagnosed with DVT within 3 months of follow-up for a thromboembolic rate of 0.5% (95% confidence interval, 0.2-1.2). A simple diagnostic approach with initial stand-alone D-dimer followed by a single whole-leg CUS in patients with positive D-dimer safely ruled out DVT. We consider this strategy to be a valuable alternative to the conventional workup of DVT in outpatients. This trial was registered at www.clinicaltrials.gov as #NCT02486445.

Safety of using the combination of the Wells rule and D-dimer test for excluding acute recurrent ipsilateral deep vein thrombosis

BACKGROUND

The diagnostic accuracy of clinical probability assessment and D-dimer testing for clinically suspected recurrent deep vein thrombosis (DVT) is largely unknown.

AIM

To evaluate the safety of ruling out acute recurrent DVT based on an unlikely Wells score for DVT and a normal D-dimer test.

METHODS

This was a predefined endpoint of the Theia study in which the diagnostic accuracy of magnetic resonance direct thrombus imaging in acute recurrent ipsilateral DVT was validated. The Wells rule and D-dimer test, performed as part of the study protocol, were not used for management decisions. The primary outcome of this analysis was the incidence of recurrent DVT at baseline or during 3-month follow-up for patients with an unlikely Wells score and a normal D-dimer test.

RESULTS

Results of both Wells score and D-dimer tests were available in 231 patients without anticoagulant treatment. The recurrent DVT prevalence was 45% (103/231). Forty-nine patients had an unlikely Wells score and normal D-dimer test, of whom 3 (6.1%, 95% confidence interval [CI] 1.3%-18%) had recurrent DVT at baseline/follow-up, yielding a sensitivity of 97% (95% CI 92%-99%) and specificity of 36% (95% CI 28%-45%). Thus, if clinical probability scoring and D-dimer testing would have been applied, radiological imaging could have been omitted in 21% of patients with a diagnostic failure rate of 6.1%.

CONCLUSION

By applying clinical probability scoring and D-dimer testing, radiological imaging could be spared in one fifth of patients with suspected recurrent ipsilateral DVT. However, the high failure rate does not support implementation of this strategy in daily practice.

Calf deep vein thrombosis – clinical relevance, diagnostic approaches and therapeutic options

Summary. Isolated distal deep vein thromboses (IDDVT) represent up to 50 % of legs deep vein thromboses (DVT). However, since their natural history is to date unknown, the need to diagnose and treat them is a matter of debate. The diagnostic strategy based on the assessment of pre-test probability and D-dimer demonstrated a scarse efficiency for IDDVT. The choice between a proximal and a complete ultrasonographic approach should be guided by the clinical context, the local expertise and the patient characteristics. Randomized and observational studies have analyzed the need of therapy and compared different regimens of anticoagulation, with conflicting results. Systematic reviews and meta-analyses tend to support the usefulness of an anticoagulant treatment, even if the optimal dose and duration are not still defined. A careful stratification of the patient’s profile, taking into account risk factors for proximal extension, recurrence and bleeding should address the therapeutic approach, which must always be discussed with an adequately informed patient. Further studies aimed to clarify the natural history of IDDVT, and to assess safety and efficacy of lower intensity and shorter duration protocols are urgently needed.

Visibility and image quality of peripheral pulmonary arteries in pulmonary embolism patients using free-breathing combined with a high-threshold bolus-triggering technique in CT pulmonary angiography

Objective

To investigate the visibility of peripheral pulmonary arteries by computed tomography pulmonary angiography (CTPA) and image quality using a free-breathing combined with a high-threshold bolus triggering technique and to explore the feasibility of this technique in pulmonary embolism (PE) patients who cannot hold their breath.

Methods

Patients with suspected PE who underwent CTPA (n=240) were randomly assigned to two groups: free-breathing (n=120) or breath-holding (n=120).

Results

The mean scanning time or visible pulmonary artery distal branches were not different between the groups. Mean CT main pulmonary artery (MPA) values, apical segment (S1), and posterior basal segment (S10) in the free-breathing group were higher compared with the breath-holding group. The subjective image quality score in the free-breathing group was higher compared with the breath-holding group. In the free-breathing group, no respiratory artifact was observed. In the breath-holding group, obvious respiratory artifacts were caused by severe chronic obstructive pulmonary disease (COPD), dyspnea, or other diseases that preclude patients from holding their breath.

Conclusion

The free-breathing mode CTPA combined with a high-threshold bolus triggering technique can provide high quality images with a lower incidence of respiratory and cardiac motion artifacts, which is especially valuable for patients who cannot hold their breath.

Effects of altered blood flow induced by the muscle pump on thrombosis in a microfluidic venous valve model

Deep vein thrombosis (DVT) often occurs in the lower limb veins of bedridden patients and greatly reduces the quality of life. The altered blood flow in venous valves induced by the insufficient efficacy of the muscle pump is commonly considered as a main factor. However, it is still a great challenge to observe the altered blood flow in real time, and its role in the formation of thrombi is poorly understood. Here we make a microfluidic venous valve model with flexible leaflets in a deformable channel that can mimic the motion of valves and the compression of vessels by muscle contraction, and identify the stasis and intermittent reflux in the valve pocket generated by the muscle pump. A thrombus forms in the stasis flow, while the intermittent reflux removes the fibrin and inhibits the growth of the thrombus. A flexible microfluidic device that can mimic the motion of valves and the contraction of vessels would have wide applications in the research on cardiovascular diseases.

Lack of diagnostic utility of the ECG-derived ventricular gradient in patients with suspected acute pulmonary embolism

INTRODUCTION

The YEARS algorithm was successfully developed to reduce the number of computed tomography pulmonary angiography (CTPA) investigations in the diagnostic management of patients with suspected pulmonary embolism (PE), although half of patients still needed to be referred for CTPA. We hypothesized that ECG derived ventricular gradient optimized for right ventricular pressure overload (VG-RVPO), an easy to use tool for detecting PE-induced pulmonary hypertension (PH), may further improve the efficiency of the YEARS algorithm.

METHODS

In this post-hoc analysis of the Years study, ECGs of 479 patients with suspected PE managed according to the YEARS algorithm were available for analysis. The diagnostic performance of VG-RVPO was assessed and likelihood ratios were calculated.

RESULTS

PE was diagnosed in 88 patients (18%). In patients with confirmed PE, 34% had an abnormal VG-RVPO versus 24% of those without PE (odds ratio 1.6; 95%CI 0.94-2.6). The mean VG-RVPO was -22 ± 13 and did not differ between the two patient groups (-22 versus -20; mean difference - 2, 95% CI -4.8 to 1.3). The sensitivity of VG-RVPO for PE was 24% (95%CI 34-45), the specificity 76% (95%CI 71-80) and the c-statistic 0.45 (95% CI 0.38-0.51). When combined with the YEARS algorithm, the likelihood ratios of VG-RVPO remained close to 1.0. Ruling out PE in patients with an indication for CTPA based on a normal VG-RVPO would have resulted in 58 missed cases.

CONCLUSIONS

The VG-RVPO has no diagnostic value for suspected acute PE, either as stand-alone diagnostic test or combined with the YEARS algorithm.

CONDENSED ABSTRACT

This post-hoc analysis of the YEARS study failed to demonstrate incremental diagnostic value of VG-RVPO for acute PE, either as stand-alone diagnostic test or combined with the YEARS algorithm. Nevertheless, the role of VG-RVPO recorded on admission could potentially be valuable in the risk stratification of PE during hospitalization, although this remains to be studied.

Effectiveness and Safety of Apixaban for Treatment of Venous Thromboembolism in Daily Practice

Introduction  Phase 3 trials have shown comparable efficacy of direct oral anticoagulants (DOACs) and vitamin K antagonists in patients with acute venous thromboembolism (VTE), with less major bleeding events in patients randomized to DOAC treatment. With DOACs being increasingly used in clinical practice, evaluation of the DOACs in daily practice-based conditions is needed to confirm their safety and effectiveness. The aim of this study is to evaluate the effectiveness and safety of apixaban in VTE patients in daily practice. Methods  In this retrospective cohort study, consecutive patients diagnosed with VTE in two Dutch hospitals (Leiden University Medical Center, Leiden and Haga Teaching Hospital, The Hague) were identified based on administrative codes. We assessed recurrent VTE, major bleeding and mortality during a 3-month follow-up period in those treated with apixaban. Results  Of 671 consecutive VTE patients treated with apixaban, 371 presented with acute pulmonary embolism (PE) and 300 patients with deep-vein thrombosis. During 3 months treatment, 2 patients had a recurrent VTE (0.3%; 95% confidence interval [CI]: 0.08-1.1), 12 patients had major bleeding (1.8%; 95% CI: 1.0-3.2), and 11 patients died (1.6%; 95% CI: 0.9-2.9), of which one patient with recurrent PE and one because of a intracerebral bleeding. Conclusion  In this daily practice-based cohort, apixaban yielded a low incidence of recurrent VTE, comparable to the phase 3 AMPLIFY study patients. The incidence of major bleeding was higher than in the AMPLIFY-study patients, reflecting the importance of daily practice evaluation and the fact that results from phase III clinical studies cannot be directly extrapolated toward daily practice.

Current practice patterns of outpatient management of acute pulmonary embolism: A post-hoc analysis of the YEARS study

BACKGROUND

Studies have shown the safety of home treatment of patients with pulmonary embolism (PE) at low risk of adverse events. Management studies focusing on home treatment have suggested that 30% to 55% of acute PE patients could be treated at home, based on the HESTIA criteria, but data from day-to-day clinical practice are largely unavailable.

AIM

To determine current practice patterns of home treatment of acute PE in the Netherlands.

METHOD

We performed a post-hoc analysis of the YEARS study. The main outcomes were the proportion of patients who were discharged <24 h and reasons for admission if treated in hospital. Further, we compared the 3-month incidence of PE-related unscheduled readmissions between patients treated at home and in hospital.

RESULTS

Of the 404 outpatients with PE included in this post-hoc analysis of the YEARS study, 184 (46%) were treated at home. The median duration of admission of the hospitalized patients was 3.0 days. The rate of PE-related readmissions of patients treated at home was 9.7% versus 8.6% for hospitalized patients (crude hazard ratio 1.1 (95% CI 0.57-2.1)). The 3-month incidence of any adverse event was 3.8% in those treated at home (2 recurrent VTE, 3 major bleedings and two deaths) compared to 10% in the hospitalized patients (3 recurrent VTE, 6 major bleedings and fourteen deaths).

CONCLUSIONS

In the YEARS study, 46% of patients with PE were treated at home with low incidence of adverse events. PE-related readmission rates were not different between patients treated at home or in hospital.

Home treatment of patients with cancer-associated venous thromboembolism - An evaluation of daily practice

BACKGROUND

Home treatment of cancer-associated venous thromboembolism (VTE) is challenging due to the high risk of adverse events. While home treatment is quite agreeable to cancer patients, studies evaluating the safety of VTE home treatment in this setting are largely unavailable.

METHODS

This was an observational study in patients with cancer-associated VTE. The main outcomes were the proportion of patients treated at home (hospital discharge <24 h after diagnosis) and the 3-month incidence of VTE-related adverse events (major bleeding, recurrent VTE and/or suspected VTE-related mortality) in patients managed in hospital versus at home.

RESULTS

A total of 183 outpatients were diagnosed with cancer-associated VTE: 69 had deep vein thrombosis (DVT) and 114 had pulmonary embolism (PE ± DVT). Of those, 120 (66%) were treated at home; this was 83% for patients with DVT and 55% for patients with PE (±DVT). The 3-month incidence of any VTE-related adverse event was 13% in those treated at home versus 19% in the hospitalized patients (HR 0.48; 95%CI 0.22-1.1), independent of initial presentation as PE or DVT. All-cause 3-month mortality occurred in 33 patients treated as inpatient (54%) compared to 29 patients treated at home (24%; crude HR 3.1 95%CI 1.9-5.0).

CONCLUSIONS

Two-third of patients with cancer-associated VTE - including PE - were selected to start anticoagulant treatment at home. Cancer-associated VTE is associated with high rates of VTE-related adverse events independent of initial in hospital or home treatment. However, home treatment may be a good option for selected patients with cancer-associated DVT or PE.

Validation and impact of a simplified clinical decision rule for diagnosing pulmonary embolism in primary care: design of the PECAN prospective diagnostic cohort management study

INTRODUCTION

Combined with patient history and physical examination, a negative D-dimer can safely rule-out pulmonary embolism (PE). However, the D-dimer test is frequently false positive, leading to many (with hindsight) 'unneeded' referrals to secondary care. Recently, the novel YEARS algorithm, incorporating flexible D-dimer thresholds depending on pretest risk, was developed and validated, showing its ability to safely exclude PE in the hospital environment. Importantly, this was accompanied with 14% fewer computed tomographic pulmonary angiography than the standard, fixed D-dimer threshold. Although promising, in primary care this algorithm has not been validated yet.

METHODS AND ANALYSIS

The PECAN (Diagnosing Pulmonary Embolism in the context of Common Alternative diagNoses in primary care) study is a prospective diagnostic study performed in Dutch primary care. Included patients with suspected acute PE will be managed by their general practitioner according to the YEARS diagnostic algorithm and followed up in primary care for 3 months to establish the final diagnosis. To study the impact of the use of the YEARS algorithm, the primary endpoints are the safety and efficiency of the YEARS algorithm in primary care. Safety is defined as the proportion of false-negative test results in those not referred. Efficiency denotes the proportion of patients classified in this non-referred category. Additionally, we quantify whether C reactive protein measurement has added diagnostic value to the YEARS algorithm, using multivariable logistic and polytomous regression modelling. Furthermore, we will investigate which factors contribute to the subjective YEARS item 'PE most likely diagnosis'.

ETHICS AND DISSEMINATION

The study protocol was approved by the Medical Ethical Committee Utrecht, the Netherlands. Patients eligible for inclusion will be asked for their consent. Results will be disseminated by publication in peer-reviewed journals and presented at (inter)national meetings and congresses.

TRIAL REGISTRATION

NTR 7431.