Antithrombotic therapy for venous thromboembolic disease: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines (8th Edition)

Anti-Xa activity below range is related to thrombosis in patients with severe COVID-19

OBJECTIVE

We aimed to anlayse the relationship between anti-Xa activity below range and thomboembolic events.

DESIGN

Single center prospective observational longitudinal cohort study (February-November 2021).

SETTING

Patients admitted to the ICU of a University Hospital.

PARTICIPANTS

Patients with severe COVID-19 pneumoniae.

INTERVENTIONS

Enoxaparin was used for prophylactic and therapeutic anticoagulation. Enoxaparin dosing and dose adjustment were based on anti-Xa activity according to the hospital protocol.

MAIN VARIABLES OF INTEREST

Target: thomboembolic events.

PREDICTORS

demographics, pharmacotherapy, anti-Xa measurements, clinical data, and laboratory results. Logistic regression was used to identify independent risk factors for thomboembolic events.

RESULTS

Data were available for 896 serum anti-Xa measurements from 228 subjects. Overall, 71.9% were male, with a median age of 62. Most patients needed invasive mechanical ventilation (87.7%) and mortality was 24.1%. A total of 28.9% new thomboembolic events were diagnosed. There were 27.1% anti-Xa measesurements below range. When multivariable logistic regression analysis was performed anti-Xa activity below range (RR, 4.2; p = 0.000), C-reactive protein (25 mg/L increase) (RR, 1.14; p = 0.005) and D-dimer (1000 ng/L increase) (RR, 1.06; p = 0.002) were the independent factors related to new thomboembolic events in patients with severe COVID-19.

CONCLUSIONS

Anti-Xa activity below range, C-reactive protein and D-dimer were the independent factors related to thomboembolic events in patients with severe COVID-19. Purposely designed clinical trials should be carried out to confirm the benefit of an anti-Xa monitoring.

Glass bead-activated clotting time (gb-ACT) for monitoring the anticoagulation effects in elderly patients with high risk of venous thromboembolism (VTE)

BACKGROUND

To find a new bedside method to monitor the anticoagulation effects of low-molecular-weight heparins (LMWHs) in patients with a high risk of venous thromboembolism (VTE).

RESEARCH DESIGN AND METHODS

A total of 32 hospitalized patients (aged ≥60 years) who were at high risk of VTE were assigned to receive subcutaneous LMWH for 5 to 14 days. Plasma anti-factor Xa (anti-Xa) activity was conducted by a chromogenic method, and the glass bead-activated whole blood clotting time (gb-ACT) value was obtained by a Sonoclot Analyzer.

RESULTS

A correlation between the gb-ACT values and the anti-Xa levels was suggested (R = 0.447, p = 0.002), and it was stronger in the older group aged 80 years above (R = 0.467, p = 0.008) and in the group of patients with an eGFR of 30 ~ 60 mL/min (R = 0.565, p = 0.005). The area under the curve (AUC) for gb-ACT by receiver operating characteristic (ROC) curve evaluation was 0.725 (p = 0.011), and the gb-ACT >282.5s provided a sensitivity of 60% and specificity of 74% for anti-Xa >0.800 IU/ml.

CONCLUSIONS

The gb-ACT values detected by a Sonoclot Analyzer could act as a novel bedside method in the monitoring of LMWH anticoagulation.

Imaging of Deep Venous Pathology

Imaging plays an important role in the identification and assessment of clinically suspected venous pathology. The purpose of this article is to review the spectrum of image-based diagnostic tools used in the investigation of suspected deep vein disease, both obstructive (deep vein thrombosis and post-thrombotic vein changes) as well as insufficiency (e.g., compression syndromes and pelvic venous insufficiency). Additionally, specific imaging modalities are used for the treatment and during clinical follow-up. The use of duplex ultrasound, magnetic resonance venography, computed tomography venography and intravascular ultrasound as well as conventional venography will be discussed in this pictorial review.

Standardization of Anti-Xa Assay and its Comparison with Activated Partial Thromboplastin Time for Monitoring Unfractionated Heparin Therapy

Monitoring of anticoagulant activity of unfractionated heparin (UFH) is primarily done with activated partial thromboplastin time (aPTT), which is affected by many factors. Anti-Xa assays are considered to overcome these factors and may provide a better method for monitoring patients on UFH with a narrow therapeutic range. This study aimed to compare the effectiveness of aPTT and anti-Xa assays in UFH monitoring. A prospective non-randomized study was carried out in two stages: first, the anti-Xa assay was standardized using kit instructions; each sample was then analyzed by both tests. The outcomes of the two assays were compared and assessed for agreement of maintaining therapeutic anticoagulant levels. These levels for anti-Xa assay were between 0.3 and 0.7 IU/ml, while it was 1.5-2.5 times the control for aPTT assay. Below this range was regarded as subtherapeutic, and above this as supratherapeutic. A total of 90 samples were tested and analyzed using both assays. Most of them (> 70%) were noted to be in subtherapeutic levels with both tests. The overall concordance was 73.3%, and the estimated kappa value was 0.483 (0.396-0.57). The correlation between aPTT and anti-Xa assay was 0.74 (p < 0.001). With anti-Xa levels in the therapeutic range, aPTT levels were in subtherapeutic in 60% and supratherapeutic in 13.3% cases. Although both the testing strategies had a good agreement and correlation, discordance was observed in interpretative values with anti-Xa levels in therapeutic range and aPTT levels in non-therapeutic range. Its clinical implications need to be evaluated further in future studies.

Direct Oral Anticoagulants for Pulmonary Embolism

Venous thromboembolism (VTE) is the third most common cardiovascular disease. For most patients, the standard of treatment has long consisted on low-molecular-weight heparin followed by vitamin K antagonists, but a number of clinical trials and, subsequently, post-marketing studies have shown that direct oral anticoagulants (DOACs) with or without lead-in heparin therapy are effective alternatives with fewer adverse effects. This evidence has led to important changes in the guidelines on the treatment of VTE, including pulmonary embolism (PE), with the DOACs being now recommended as the first therapeutic choice. Additional research has contributed to identifying low-risk PE patients who can benefit from outpatient management or from early discharge from the emergency department with DOAC treatment. There is evidence to support the use of DOACs in intermediate-risk PE patients as well as in high-risk patients receiving thrombolytic treatment. The use of DOACs has also been proven to be safe and effective in special populations of PE patients, such as patients with renal impairment, liver impairment, and cancer.

How complicated can be a case with immune thrombocytopenic purpura?: postsplenectomy arterial thrombosis

Arterial thrombus associated with the surgery can be seen in postsplenectomy cases, but there is no clear data in patients diagnosed with immune thrombocytopenic purpura (ITP). A 52-year-old female patient was admitted to the emergency department due to ecchymotic skin changes. Her initial platelet count was 6000/mm 3 ; after two courses of high dose-dexamethasone, intravenous immunoglobulin and rituximab, splenectomy was planned for the patient whose platelet count was again <40 000/mm 3 . She presented to the emergency department with complaints of pain and pallor in the right arm in the second week of follow-up. There was a mural thrombus that caused approximately 50% stenosis in the lumen at the division site in the aortic arch, proximal of the right subclavian artery. The patient's clinic was found to be associated with the presence of an aberrant right subclavian artery and postoperative thrombocytosis/inflammation after elimination other prothrombotic conditions.

Six-week low-molecular-weight heparin versus 12-week warfarin for calf deep vein thrombosis: A randomized, prospective, open-label study

Current guidelines suggest a 3-month anticoagulant treatment course for isolated distal deep vein thrombosis (IDDVT), but shorter durations of treatment are frequently prescribed in clinical practice. We investigated whether a 6-week treatment with low-molecular-weight heparin (LMWH) at intermediate dosage can be an effective and safe alternative to vitamin K antagonists (VKA) in patients with IDDVT (non-inferiority trial). In a multicenter, open-label, randomized trial, 260 outpatients with symptomatic IDDVT were randomly assigned to receive either LMWH followed by VKA for 12 weeks or LMWH 1 mg/kg subcutaneously twice a day for 2 weeks followed by 1 mg/kg subcutaneously once a day for 4 weeks. The follow-up was 6 months and the primary endpoint was the composite measure of recurrent venous thromboembolism (VTE) defined as: recurrence or extension of IDDVT, proximal DVT, and pulmonary embolism (PE). The study was stopped prematurely due to slow recruiting rates. The primary efficacy outcome occurred in 14 patients receiving LMWH (10.8%) and in five patients receiving VKA (3.8%); risk difference was 0.069 (95% CI: 0.006-0.132), hazard ratio 2.8 (95% CI: 1.04-7.55). There was one PE in the VKA group and one proximal DVT in the LMWH group. IDDVT recurrence was 10.0% in the LMWH group versus 3.1% in the VKA group (p = .024). Two patients had clinically relevant bleedings (1.6%) in the LMWH group versus one (0.8%) in VKA group (p = .56). In conclusion, VKA for 12 weeks seems superior to LMWH for 6 weeks in reducing the risk of VTE recurrences in our cohort of outpatients with IDDVT.

Stability of Anticoagulation Following Acenocoumarin in Stroke Patients: Role of Pharmacogenomics and Acquired Factors

OBJECTIVE

Pharmacogenomics plays an important role in drug metabolism. A stable anticoagulation is important for primary and secondary prevention of cardioembolic stroke and cerebral venous sinus thrombosis (CVST). We report the role of cytochrome P450 ( CYP2C9*2/*3 ) and vitamin K epoxide reductase subunit 1 ( VKORC1 ) genotypes and acquired causes in maintaining stability of anticoagulation following acenocoumarin in cardioembolic stroke and CVST.

METHODS

The study comprised 157 individuals with cardioembolic stroke and CVST who were on acenocoumarin. Their comorbidities, comedication, and dietary habits were noted. Prothrombin time and international normalized ratio (INR) were measured during follow-up, and the coagulation status was categorized as stable (>50% occasions in therapeutic range) and unstable (>50% below and above therapeutic range). Genotyping of VKORC1 , CYP2C9*2 , and CYP2C9*3 was done by polymerase chain reaction-restriction fragment length polymorphism. Bleeding and embolic complications were noted. The predictors of unstable INR were evaluated using multivariate analysis.

RESULTS

INR was stable in 47.8% and unstable in 52.2% of patients. Patients with mutant genotypes required low dose of acenocoumarin. The predictors of unstable INR were metallic valve (odds ratio [OR] 4.07, 95% confidence interval [CI] 1.23-13.49, P = 0.02), use of digoxin (OR 0.031, 95% CI 0.13-0.74, P = 0.09), proton pump inhibitor (OR 0.23, 95% CI 0.06-0.91, P = 0.037), sodium valproate (OR 0.22, 95% CI 0.05-0.85, P = 0.029), and CYP2C9*2 genotype (OR 5.57, 95% CI 1.19-26.06, P = 0.02).

CONCLUSIONS

Variant genotypes of VKORC1 , CYP2C9*2 , and CYP2C9*3 required lower dose of acenocoumarin, and CYP2C9*2 was associated with unstable INR. Comedication is a modifiable risk factor that needs attention.

Effect of rt-PA on Shear Wave Mechanical Assessment and Quantitative Ultrasound Properties of Blood Clot Kinetics In Vitro

OBJECTIVE

The consequences associated with blood clots are numerous and are responsible for many deaths worldwide. The assessment of treatment efficacy is necessary for patient follow-up and to detect treatment-resistant patients. The aim of this study was to characterize the effect of treatment on blood clots in vitro using quantitative ultrasound parameters.

METHODS

Blood from 10 pigs was collected to form three clots per pig in gelatin phantoms. Clots were subjected to 1) no treatment, 2) rt-PA (recombinant tissue plasminogen activator) treatment after 20 minutes of clotting, and 3) rt-PA treatment after 60 minutes of clotting. Clots were weighted before and after the experiment to assess the treatment effect by the mass loss. The clot kinetics was studied over 100 minutes using elastography (Young's modulus, shear wave dispersion, and shear wave attenuation). Homodyne K-distribution (HKD) parameters derived from speckle statistics were also studied during clot formation and dissolving (diffuse-to-total signal power ratio and intensity parameters).

RESULTS

Treated clots loosed significantly more mass than non-treated ones (P < .005). A significant increase in Young's modulus was observed over time (P < .001), and significant reductions were seen for treated clots at 20 or 60 minutes compared with untreated ones (P < .001). The shear wave dispersion differed for treated clots at 60 minutes versus no treatments (P < .001). The shear wave attenuation decreased over time (P < .001), and was different for clots treated at 20 minutes versus no treatments (P < .031). The HKD intensity parameter varied over time (P < .032), and was lower for clots treated at 20 and 60 minutes than those untreated (P < .001 and P < .02).

CONCLUSION

The effect of rt-PA treatment could be confirmed by a decrease in Young's modulus and HKD intensity parameter. The shear wave dispersion and shear wave attenuation were sensitive to late and early treatments, respectively. The Young's modulus, shear wave attenuation, and HKD intensity parameter varied over time despite treatment.

Management of isolated distal deep vein thrombosis

Isolated distal deep vein thrombosis (DVT) represents up to 50% of all lower limb DVT in ultrasound series and is a frequent medical condition, which management is not well established. Data arising from registries and non-randomized studies suggest that most distal DVTs do not extend to the proximal veins and have an uneventful follow-up when left untreated. This data had some impact on international recommendations like the American College of Chest Physicians (ACCP), whose last version stated that ultrasound surveillance might be an option for selected low-risk patients. However, robust data arising from randomized studies are scarce. Indeed, only seven randomized trials assessing the need for anticoagulation for calf DVT have been published. Many of these trials had an open-label design and were affected by methodological limitations. When considering randomized placebo-controlled trials, one included low-risk patients and was hampered by a limited statistical power (CACTUS study). Nevertheless, data from this trial tend to confirm that the use of therapeutic anticoagulation in low-risk patients with symptomatic calf DVT is not superior to placebo in reducing VTE but is associated with a higher risk of bleeding. A second randomized placebo-controlled trial did not assess the necessity of anticoagulant treatment but rather the long-term risk of recurrence and compared 6 weeks versus 12 weeks of treatment with rivaroxaban (RIDTS study). Finally, the last available randomized trial compared a 3-month versus a 12-month edoxaban treatment in patients with cancer and mainly asymptomatic distal DVT, detected by systematic compression ultrasonography. Overall, available data suggest that the use of therapeutic anticoagulation in low-risk patients with symptomatic calf DVT is not superior to placebo in reducing VTE. High risk patients (previous VTE, active cancer, inpatients) might benefit from a course of anticoagulant treatment. However, the optimal anticoagulant intensity and duration are uncertain and further studies are needed.

Antidote vs. unspecific hemostatic agents for the management of direct oral anticoagulant-related bleeding in trauma

PURPOSE OF REVIEW

The advent of direct oral anticoagulants (DOACs) marks a significant milestone in anticoagulant treatment. However, DOACs can exacerbate bleeding, which is challenging for the treating clinician, especially when combined with traumatic injury.

RECENT FINDINGS

In major bleeding associated with DOACs, rapid reversal of the anticoagulant effects is crucial. Recent observational and nonrandomized interventional trials have demonstrated the effectiveness of the specific antidotes andexanet alfa and idarucizumab as well as the unspecific prothrombin complex concentrates (PCCs) to counteract the anticoagulant effects of DOACs. The European Society of Anaesthesiology and Intensive Care guideline for severe perioperative bleeding and the European trauma guideline propose divergent recommendations for the use of andexanet alfa and PCC to obtain hemostasis in Factor Xa inhibitor-related bleeding. The conflicting recommendations are due to limited evidence from clinical studies and the potential increased risk of thromboembolic complications after the administration of andexanet. Regarding dabigatran-associated major bleeding, both guidelines recommend the specific reversal agent idarucizumab as first-line therapy.

SUMMARY

Current guidelines recommend specific antidots and PCCs in DOAC-related major bleeding. Prospective randomized trials comparing specific vs. nonspecific hemostatic agents in the perioperative setting are needed to evaluate the effectiveness and safety of the hemostatic agents.

Does central venous stenosis affects the brachial artery flow volume and peripheral vascular resistive index in patients on maintenance hemodialysis? A retrospective study

BACKGROUND

A well-functioning vascular access (VA) is crucial for the patients on maintenance hemodialysis (HD). Central venous stenosis (CVS) is a common, yet, overlooked complication of VA as its diagnosis is challenging. Moreover, its effect on the flow volume (FV) and the peripheral resistive index (RI) was not well discussed before. Despite the availability of doppler ultrasound (DUS) in most centers, direct visualization of central veins using DUS is quite difficult.

METHODS

This is a retrospective single-center self-controlled cohort study that was conducted in a specialized vascular access management tertiary center in Japan and included all patients with CVS who underwent percutaneous transluminal angiography (PTA) with or without vascular stenting in the period from January 2014 to September 2022. The patients were divided according to their VA type into arteriovenous fistula (AVF), and arteriovenous graft (AVG) groups, then subdivided, according to the type of stenosis, into two subgroups: CVS, and mixed central and peripheral venous stenosis (MVS) groups. The FV and RI of the feeding artery were compared in the same procedure before and after PTA to assess the impact of the procedure itself.

RESULTS

Data of 485 percutaneous transluminal angiography procedures (PTA), performed in 95 patients during the period from January 2014 to September 2022, were collected. FV and RI were significantly affected in the patients with MVS than patients with CVS. After PTA, both FV and RI were significantly improved. The improvement rate of FV and RI after PTA were significantly higher in patients with MVS than patients with CVS. However, it was difficult to determine the cut-off value to diagnose or to assess the improvement of CVS.

CONCLUSION

Our findings suggest that FV and RI measurement by DUS are good tools, along with the clinical findings for assessment of CVS in certain situations.

Black holes in compression therapy: A quest for data

OBJECTIVE

Although compression therapy (CT) is considered a crucial conservative treatment in chronic venous disease, strong evidence is missing for many clinical indications. This literature review aims to point out what strong evidence we have for CT and all the clinical scenarios where strong evidence still needs to be included.

METHODS

The research was conducted on MEDLINE with PubMed, Scopus and Web of Science. The time range was set between January 1980 and October 2022. Only articles in English were included.

RESULTS

The main problem with CT is the low scientific quality of many studies on compression. Consequently, we have robust data on the effectiveness of CT only for advanced venous insufficiency (C3-C6), deep vein thrombosis and lymphedema. We have data on the efficacy of compression for venous symptoms control and in sports recovery, but the low quality of studies cannot result in a strong recommendation. For compression in postvenous procedures, superficial venous thrombosis, thromboprophylaxis, post-thrombotic syndrome prevention and treatment, and sports performance, we have either no data or very debated data not allowing any recommendation.

CONCLUSIONS

We need high-level scientific studies to assess if CT can be effective or definitely ineffective in the clinical indications where we still have a paucity of or contrasting data.

ESPEN guideline on chronic intestinal failure in adults - Update 2023

BACKGROUND & AIMS

In 2016, ESPEN published the guideline for Chronic Intestinal Failure (CIF) in adults. An updated version of ESPEN guidelines on CIF due to benign disease in adults was devised in order to incorporate new evidence since the publication of the previous ESPEN guidelines.

METHODS

The grading system of the Scottish Intercollegiate Guidelines Network (SIGN) was used to grade the literature. Recommendations were graded according to the levels of evidence available as A (strong), B (conditional), 0 (weak) and Good practice points (GPP). The recommendations of the 2016 guideline (graded using the GRADE system) which were still valid, because no studies supporting an update were retrieved, were reworded and re-graded accordingly.

RESULTS

The recommendations of the 2016 guideline were reviewed, particularly focusing on definitions, and new chapters were included to devise recommendations on IF centers, chronic enterocutaneous fistulas, costs of IF, caring for CIF patients during pregnancy, transition of patients from pediatric to adult centers. The new guideline consist of 149 recommendations and 16 statements which were voted for consensus by ESPEN members, online in July 2022 and at conference during the annual Congress in September 2022. The Grade of recommendation is GPP for 96 (64.4%) of the recommendations, 0 for 29 (19.5%), B for 19 (12.7%), and A for only five (3.4%). The grade of consensus is "strong consensus" for 148 (99.3%) and "consensus" for one (0.7%) recommendation. The grade of consensus for the statements is "strong consensus" for 14 (87.5%) and "consensus" for two (12.5%).

CONCLUSIONS

It is confirmed that CIF management requires complex technologies, multidisciplinary and multiprofessional activity, and expertise to care for the underlying gastrointestinal disease and to provide HPN support. Most of the recommendations were graded as GPP, but almost all received a strong consensus.

Mendelian Randomization Study Does Not Support a Bidirectional Link between Atherosclerosis and Venous Thromboembolism

AIM

Some observational studies suggested that atherosclerosis increased the risk of venous thromboembolism (VTE), and vice versa. However, the results were conflicting, and the causal relationship is yet to be established. Therefore, we applied Mendelian randomization (MR) analyses to assess the bidirectional causality between coronary heart disease (CHD) and VTE, deep venous thrombosis (DVT), and pulmonary embolism (PE).

METHODS

A total of 184,305 individuals with CHD were included from the CARDIoGRAMplusC4D Consortium. Information on VTE, DVT, and PE were obtained from the FinnGen biobank. Genetic instruments for CHD and VTE were constructed using 37 and 12 single-nucleotide polymorphisms, respectively. Inverse-variance weighted meta-analysis under a random-effect model was used as the preliminary estimate. Five complementary MR methods were also used, including weighted median, MR-Egger, multivariable MR (adjusted for the body mass index), simple mode, and weighted mode methods.

RESULTS

The genetically instrumented VTE (odds ratio [OR]: 1.05; 95% confidence interval [CI]: 1.00-1.11; P=0.06), DVT (OR: 1.03; 95% CI: 0.99-1.08; P=0.19), or PE (OR: 1.07; 95% CI: 0.98-1.16; P=0.11) showed no causal relationships with CHD. There was also no clear evidence showing the causal effects of CHD on VTE (OR: 1.00; 95% CI: 0.82-1.22; P=0.98), DVT (OR: 1.00; 95% CI: 0.79-1.27; P=0.97), or PE (OR: 0.98; 95% CI: 0.82-1.18; P=0.87). No pleiotropic bias was found in the MR analyses. As heterogeneity was significant, a random model was used to minimize the effect of heterogeneity.

CONCLUSIONS

No causal associations existed between CHD and VTE. Arterial and venous thromboses may represent separate entities.

Rivaroxaban treatment for asymptomatic venous thromboembolism: insights from the J'xactly study

BACKGROUND

An established treatment strategy for asymptomatic pulmonary embolism (PE) or deep vein thrombosis (DVT) remains uncertain in Japan; therefore, in this study, we clarify the characteristics and outcomes of symptomatic compared to asymptomatic patients with PE or DVT.

METHODS

This prospective, multicenter sub-analysis of the J'xactly study in Japan included 1,016 patients (mean age, 68; 41% male) with venous thromboembolism (VTE) treated with rivaroxaban.

RESULTS

Asymptomatic PE patients (47% of PE patients) were more likely to have active cancer and asymptomatic proximal DVT at lower severity than symptomatic PE patients, despite no differences in age, sex, or the proportion receiving intensive 30 mg/day-rivaroxaban. Patients with asymptomatic DVT (34% of DVT patients) were older, had higher rates of female sex, active cancer, and distal DVT, and received shorter, less intense rivaroxaban treatment. Incidences did not differ between asymptomatic and symptomatic PE patients for recurrent symptomatic VTE (hazard ratio [HR], 0.60; 95% confidence interval [CI], 0.22-1.62; P = 0.31) or major bleeding (HR, 0.68; 95% CI, 0.20-2.33; P = 0.58), nor between asymptomatic and symptomatic DVT patients for recurrent symptomatic VTE (HR, 0.56; 95% CI, 0.23-1.40; P = 0.21) and major bleeding (HR, 1.47; 95% CI, 0.54-3.97; P = 0.45).

CONCLUSIONS

The real-world composite adverse event rate for treatment with rivaroxaban, as physician-adjusted for dose and duration, was similar for asymptomatic and symptomatic patients regardless of the presence of PE or DVT, suggesting a favorable safety profile for potential rivaroxaban treatment for asymptomatic VTE.

Comparison of Performances among Four Bleeding-Prediction Scores in Elderly Cancer Patients with Venous Thromboembolism

The performances of RIETE, VTE-BLEED, SWITCO65 + , and Hokusai-VTE scores for predicting major bleeding events in hospitalized elderly cancer patients with venous thromboembolism (VTE) have not been evaluated. This study validated the performances of these scoring systems in a cohort of elderly cancer patients with VTE. Between June 2015 and March 2021, a total of 408 cancer patients (aged ≥ 65 years) with acute VTE were consecutively enrolled. The overall rates of in-hospital major bleeding and clinically relevant bleeding (CRB) were 8.3% (34/408) and 11.8% (48/408), respectively. RIETE score could categorize patients with increasing rate of major bleeding and CRB into low-/intermediate- and high-risk categories (7.1 vs. 14.1%, p = 0.05 and 10.1 vs. 19.7%, p = 0.02, respectively). The discriminative power of the four scores for predicting major bleeding was poor to moderate, indicated by areas under the receiver operating characteristic curves (0.45 [95% confidence interval, CI: 0.35-0.55] for Hokusai-VTE, 0.54 [95% CI: 0.43-0.64] for SWITCO65 + , 0.58 [95% CI: 0.49-0.68] for VTE-BLEED, and 0.61 [95% CI: 0.51-0.71] for RIETE). RIETE score might be used to predict major bleeding in hospitalized elderly cancer patients with acute VTE.

Revisiting Anticoagulation in Spine Surgery: Balancing Venous Thromboembolic Events and Epidural Hematoma

STUDY DESIGN

Retrospective Cohort Study.

OBJECTIVE

Venous thromboembolic events (VTE) and post-operative epidural hematoma (EDH) are significant complications after spine surgery. Guidelines for chemoprophylaxis are controversial and variability amongst surgeons remains. The objective of this study was to establish the incidence of clinical VTE and EDH at our institution and evaluate the association of chemoprophylaxis with clinical VTE and EDH.

METHODS

We conducted a retrospective cohort study of patients undergoing spine surgery at a high-volume tertiary care center in Seattle, WA between January 2016 and December 2019. The Premier Health Care Database and Agency for Healthcare Research and Quality (AHRQ) patient indicators PSI-9 (Perioperative hemorrhage and hematoma) and PSI-12(Perioperative PE or DVT) were used to identify patients experiencing VTE and/or post-operative EDH. The primary outcome was the incidence of clinical VTE and EDH in post-operative spine patients. Secondary outcomes included the association of chemoprophylaxis with clinical VTE and EDH.

RESULTS

From 2016 to 2019, 4587 patients underwent spine surgery, totaling 4764 hospital stays. The incidence of clinical VTE was .21% (10/4764) and the incidence of EDH was .10% (5/4764). Most hemorrhages occurred prior to the initiation of chemoprophylaxis. One patient with EDH received chemoprophylaxis prior to hemorrhage.

CONCLUSIONS

The rate of post-operative clinical VTE and EDH in spine surgery is low. Despite early initiation of chemoprophylaxis after major spine surgery we did not appreciate a high rate of EDH. We attribute our low rate of clinical VTE to multimodal prophylaxis with SCDs, early mobilization and chemoprophylaxis on post-operative day 1.

A Combination of Ex Vivo and In Vivo Strategies for Evaluating How Much New Oral Anticoagulants Exacerbate Experimental Intracerebral Bleeding

Background  Intracerebral hemorrhage is the most serious complication of anticoagulant therapy but the effects of different types of oral anticoagulants on the expansion of these hemorrhages are still unclear. Clinical studies have revealed controversial results; more robust and long-term clinical evaluations are necessary to define their outcomes. An alternative is to test the effect of these drugs in experimental models of intracerebral bleeding induced in animals. Aims  To test new oral anticoagulants (dabigatran etexilate, rivaroxaban, and apixaban) in an experimental model of intracerebral hemorrhage induced by collagenase injection into the brain striatum of rats. Warfarin was used for comparison. Methods  Ex vivo anticoagulant assays and an experimental model of venous thrombosis were employed to determine the doses and periods of time required for the anticoagulants to achieve their maximum effects. Subsequently, volumes of brain hematoma were evaluated after administration of the anticoagulants, using these same parameters. Volumes of brain hematoma were evaluated by magnetic resonance imaging, H&E (hematoxylin and eosin) staining, and Evans blue extravasation. Neuromotor function was assessed by the elevated body swing test. Results and Conclusions  The new oral anticoagulants did not increase intracranial bleeding compared with control animals, while warfarin markedly favored expansion of the hematomas, as revealed by magnetic resonance imaging and H&E staining. Dabigatran etexilate caused a modest but statistically significant increase in Evans blue extravasation. We did not observe significant differences in elevated body swing tests among the experimental groups. The new oral anticoagulants may provide a better control over a brain hemorrhage than warfarin.

Comparative Efficacy of Direct Oral Anticoagulants and Low-Molecular-Weight Heparin in Cancer-Associated Thromboembolism: A Systematic Review and Meta-Analysis

Patients diagnosed with cancer often experience an abnormal occurrence of venous thromboembolism (VTE) and its related complications. In order to evaluate the safety and effectiveness of both treatment approaches, we conducted a comprehensive systematic review and meta-analysis within the realm of cancer-associated thromboembolism. A thorough search was conducted across PubMed, the Cochrane Library, and Embase databases to find studies comparing direct oral anticoagulants (DOACs) with low molecular weight heparins (LMWHs) for the treatment of VTE in patients with malignancy. The analyses utilized the random-effects model. This meta-analysis included 11 studies. The results showed that DOACs were associated with a significantly reduced risk of VTE recurrence (RR: 0.67; 95% CI: 0.55, 0.81, p<0.0001; I2: 0%) and deep vein thrombosis (DVT) (RR: 0.63; 95% CI: 0.46, 0.86, p<0.0001; I2: 0%) compared to LMWHs. However, there was no significant difference in the risk of pulmonary embolism (PE) (RR: 0.76; 95% CI: 0.54, 1.06, p=0.11; I2: 11%) between the two groups. The use of DOACs was also associated with a non-significant increase in the risk of major bleeding events (RR: 1.23; 95% CI: 0.85, 1.78, p: 0.26; I2: 49%), while clinically relevant non-major bleeding (CRNMB) was significantly higher with DOACs (RR: 1.92; 95% CI: 1.11, 3.30, p: 0.02; I2: 81%). Secondary outcomes, such as survival rates and fatal PE, did not show significant differences between the two treatment groups. Our analysis indicates that direct oral anticoagulants exhibit a substantial decrease in the occurrence of VTE recurrence, deep vein thrombosis, and pulmonary embolism when compared to low molecular weight heparin in cancer-associated thromboembolism. However, it should be noted that DOACs carry a higher risk of CRNMB. Based on these findings, DOACs are recommended as a superior therapeutic option for managing cancer-associated thromboembolism compared to LMWH.

Central venous access device practice across haematology and oncology centres in Australia and New Zealand: a cross-sectional survey

Central venous access devices (CVADs) are commonly used in malignancies. We conducted an online, anonymous cross-sectional survey of practice regarding CVAD management in haematology centres among clinicians in Australia and New Zealand. We identified variation in clinical practice regarding CVAD selection, insertion, management and removal. These findings highlight research gaps in CVAD care.

Thrombus Signal on T1-Weighted Black-Blood MR Predicts Outcomes of Catheter-Directed Thrombolysis in Acute Deep Vein Thrombosis

OBJECTIVES

 Catheter-directed thrombolysis (CDT) is an effective therapy for acute deep vein thrombosis (DVT). However, predicting the CDT outcomes remains elusive. We hypothesized that the thrombus signal on T1-weighted black-blood magnetic resonance (MR) can provide insight into CDT outcomes in acute DVT patients.

METHODS

 A total of 117 patients with acute iliofemoral DVT were enrolled for T1-weighted black-blood MR before CDT in this prospective study. Based on the signal contrast between thrombus and adjacent muscle, patients were categorized into the iso-intense thrombus (Iso-IT), hyper-intense thrombus (Hyper-IT), and mixed iso-/hyper-intense thrombi (Mixed-IT) groups. Immediate treatment outcome (i.e., vein patency) and long-term treatment outcome (i.e., the incidence rate of postthrombotic syndrome) were accessed by the same expert. Histological analysis and iron quantification were performed on thrombus samples to characterize the content of fibrin, collagen, and the ratio of Fe³⁺ to total iron.

RESULTS

 Compared to Mixed-IT and Hyper-IT groups, the Iso-IT group had the best lytic effect (90.5 ± 1.6% vs. 78.4 ± 2.6% vs. 46.5 ± 3.3%, p < 0.001), lowest bleeding ratio (0.0 vs. 11.8 vs. 13.3, p < 0.001), and the lowest incidence rate of postthrombotic syndrome on 24 months (3.6 vs. 18.4 vs. 63.4%, p < 0.001) following CDT. The Iso-IT group had a significantly lower ratio of Fe³⁺ to total iron (93.1 ± 3.2% vs. 97.2 ± 2.1%, p = 0.034) and a higher content of fibrin (12.5 ± 5.3% vs. 4.76 ± 3.18%, p = 0.023) than Hyper-IT.

CONCLUSION

 Thrombus signal characteristics on T1-weighted black-blood MR is associated with CDT outcomes and possesses potential to serve as a noninvasive approach to guide treatment decision making in acute DVT patients.

KEY POINTS

· Thrombus signal on T1-weighted black-blood MR is associated with lytic therapeutic outcome in acute DVT patients.. · Presence of iso-intense thrombus revealed by T1-weighted black-blood MRI is associated with successful thrombolysis, low bleeding ratio, and low incidence of the postthrombotic syndrome.. · T1-weighted thrombus signal characteristics may serve as a noninvasive imaging marker to predict CDT treatment outcomes and therefore guide treatment decision making in acute DVT patients..

Bleeding Risk in Elderly Patients with Venous Thromboembolism Who Would Have Been Excluded from Anticoagulation Trials

Older patients with venous thromboembolism (VTE) are underrepresented in clinical anticoagulation trials. We examined to which extent elderly patients with VTE would be excluded from such trials and compared the bleeding risk between hypothetically excluded and enrolled patients. We studied 991 patients aged ≥65 years with acute VTE in a prospective multicenter cohort. We identified 12 landmark VTE oral anticoagulation trials from the eighth and updated ninth American College of Chest Physician Guidelines. For each trial, we abstracted the exclusion criteria and calculated the proportion of our study patients who would have been excluded from trial participation. We examined the association between five common exclusion criteria (hemodynamic instability, high bleeding risk, comorbidity, co-medication, and invasive treatments) and major bleeding (MB) within 36 months using competing risk regression, adjusting for age, sex, and periods of anticoagulation. A median of 31% (range: 20-52%) of our patients would have been excluded from participation in the landmark trials. Hemodynamic instability (sub-hazard ratio [SHR]: 2.2, 95% CI: 1.1-4.7), comorbidity (SHR: 1.5, 95% CI: 1.1-2.2), and co-medication (SHR: 1.5, 95% CI: 1.0-2.3) were associated with MB. Compared to eligible patients, those with ≥2 exclusion criteria had a twofold (SHR: 2.16, 95% CI: 1.38-3.39) increased risk of MB. Overall, about one-third of older patients would not be eligible for participation in guideline-defining VTE anticoagulation trials. The bleeding risk increases significantly with the number of exclusion criteria present. Thus, results from such trials may not be generalizable to older, multimorbid, and co-medicated patients.

Benefits of early mobilization in patients with deep venous thrombosis: a scope review

Objective: Deep venous thrombosis (DVT) is a blood flow obstruction caused by the formation of a thrombus in deep system veins, with higher prevalence in lower limbs. Bed restriction has been indicated in patients with DVT in order to avoid pulmonary embolism caused by displacement of the thrombus. However, immobility has recently been considered a risk factor for DVT, not only due to blood flow stasis, but also by secondary complications as muscle atrophy and weakness. Objective was to review the possible benefits of early mobilization in patients with DVT in the intensive care unit. Methods: A scope review of literature was conducted. The following keywords were used: deep venous thrombosis, early mobilization and physical therapy. The search was made on Pubmed and Scielo databases. Results: 20 studies were found and 7 articles were included in the review using the exclusion criteria. Conclusion: Early mobilization association with anticoagulation and compression was described as essential in the treatment of DVT, reducing deleterious effects of immobility, pain, edema, and promoting quality of life improvement.

Perioperative Management of Incidental Pulmonary Embolisms on Trauma CT Scans: A Narrative Review

Unsuspected pulmonary embolism (PE) may be identified on an initial trauma computed tomography (CT) scan. The clinical importance of these incidental PEs remains to be elucidated. In patients who require surgery, careful management is needed. We sought to investigate the optimal perioperative management of such patients, including the use of pharmacological and mechanical thromboprophylaxis, possible thrombolytic therapy, and inferior vena cava (IVC) filters. A literature search was conducted, and all relevant articles were identified, investigated, and included. Medical guidelines were also consulted where appropriate. Pharmacological thromboprophylaxis is the mainstay of preoperative treatment, and low-molecular-weight heparins, fondaparinux, and unfractionated heparin may all be used. It has been suggested that prophylaxis should be administered as soon as possible after trauma. Such agents may be contraindicated in patients with significant bleeding, and mechanical prophylaxis and inferior vena cava filters may be favoured in these patients. Therapeutic anticoagulation and thrombolytic therapies may be considered but are associated with an increased risk of haemorrhage. Delaying surgery might help to minimise the risk of recurrent venous thromboembolism, and any interruption of prophylaxis must be strategically planned. Recommendations for postoperative care include a continuation of prophylaxis and therapeutic anticoagulation, with follow-up clinical evaluation within six months. Incidental PE is a common finding on trauma CT scans. Although the clinical significance is unknown, careful management of the balance between anticoagulation and bleeding is needed, especially in trauma patients and even more so in trauma patients requiring surgery.

The anticoagulation length of therapy and risk of new adverse events in venous thromboembolism (ALTERNATIVE) study: Design and survey results

The Anticoagulation Length of Therapy and Risk of New Adverse Events In Venous Thromboembolism (ALTERNATIVE) study was designed to compare the benefits and harms of different treatment options for extended treatment of venous thromboembolism (VTE). In this paper, we describe the study cohort, survey data collection, and preliminary results. We identified 39,605 adult patients (age ≥ 18 years) from two large integrated health care delivery systems who were diagnosed with incident VTE and received initial anticoagulation therapy of 3 months or longer. A subset of the cohort (12,737) was invited to participate in a survey. Surveys were completed in English, Spanish or Mandarin via a mailed questionnaire, an online secure web link, or telephone. The survey domains included demographics, personal medical history, anticoagulant treatment history, anticoagulant treatment satisfaction, health-related quality of life and health literacy. A total of 5,017 patients participated in the survey for an overall response rate of 39.4%. The mean (SD) age of the survey respondents was 63.0 (14.5) years and self-reported race was 76.0% White/European, 11.1% Black/African American, and 3.8% Asian/Pacific Islander and 14.0% reported Hispanic ethnicity. Sixty percent of respondents completed the web survey, while 29.0% completed the mail-in paper survey, and 11.0% completed the survey via telephone. The ALTERNATIVE Study will address knowledge gaps by comparing several treatment alternatives for the extended management of VTE so that this information could be used by patients and clinicians to make more informed, patient-centered treatment choices.

Low Anti-Factor Xa Level Predicts 90-Day Symptomatic Venous Thromboembolism in Surgical Patients Receiving Enoxaparin Prophylaxis: A Pooled Analysis of Eight Clinical Trials

OBJECTIVE

To examine the relationship between enoxaparin dose adequacy, quantified with anti-Factor Xa (aFXa) levels, and 90-day symptomatic venous thromboembolism (VTE) and postoperative bleeding.

SUMMARY BACKGROUND DATA

Surgical patients often develop "breakthrough" VTE events-those which occur despite receiving chemical anticoagulation. We hypothesize that surgical patients with low aFXa levels will be more likely to develop 90-day VTE, and those with high aFXa will be more likely to bleed.

METHODS

Pooled analysis of eight clinical trials (N = 985) from a single institution over a 4 year period. Patients had peak steady state aFXa levels in response to a known initial enoxaparin dose, and were followed for 90 days. Survival analysis log-rank test examined associations between aFXa level category and 90-day symptomatic VTE and bleeding.

RESULTS

Among 985 patients, 2.3% (n = 23) had symptomatic 90-day VTE, 4.2% (n = 41) had 90-day clinically relevant bleeding, and 2.1% (n = 21) had major bleeding. Patients with initial low aFXa were significantly more likely to have 90-day VTE than patients with adequate or high aFXa (4.2% vs 1.3%, P = 0.007). In a stratified analysis, this relationship was significant for patients who received twice daily (6.2% vs 1.5%, P = 0.003), but not once daily (3.0% vs 0.7%, P = 0.10) enoxaparin. No association was seen between high aFXa and 90-day clinically relevant bleeding (4.8% vs 2.9%, P = 0.34) or major bleeding (3.6% vs 1.6%, P = 0.18).

CONCLUSIONS

This manuscript establishes inadequate enoxaparin dosing as a plausible mechanism for breakthrough VTE in surgical patients, and identifies anticoagulant dose adequacy as a novel target for process improvement measures.

Cannula provoked upper extremity superficial vein thrombophlebitis: are we overtreating?

Cannula provoked upper extremity superficial vein thrombophlebitis (UESVT) is common. Retrospective audit of 93 consecutive patients, 51% male, median age 57 years (range 20-91), with symptomatic UESVT revealed varied management including symptomatic management (37%), prophylactic (37%) and higher dose anticoagulation (27%). There was 2% (95% confidence interval (CI) 0-7.6) thrombus extension and 1% (95% CI 0-5.9) major bleeding, both limited to cancer. We argue anticoagulation is unnecessary in most UESVT patients.

Length of Anticoagulation in Provoked Venous Thromboembolism: A Multicenter Study of How Real‐World Practice Mirrors Guideline Recommendations

Background

For more than a decade, guidelines have recommended a limited 3 months of anticoagulation for the treatment of provoked venous thromboembolism (VTE). How closely real‐world practice follows guideline recommendations is not well described.

Methods and Results

In our multicenter, retrospective cohort study, we evaluated trends in anticoagulation duration for patients enrolled in the MAQI 2 (Michigan Anticoagulation Quality Improvement Initiative) registry who were receiving anticoagulation for a provoked VTE. The MAQI 2 registry comprises 6 centers in Michigan that manage patients' long‐term anticoagulation. We identified 474 patients on warfarin and 302 patients on direct oral anticoagulants who were receiving anticoagulation for a primary indication of provoked VTE between 2008 and 2020. Using a predefined threshold of 120 days (3 months plus a buffer period), predictors of extended anticoagulant use were identified using multivariable logistic regression. Most patients received >120 days of anticoagulation, regardless of which medication was used. The median (25th–75th percentile) length of treatment for patients taking warfarin was 142 (91–234) days and for direct oral anticoagulants was 180 (101–360) days. Recurrent VTE (odds ratio [OR], 2.75 [95% CI, 1.67–4.53]), history of myocardial infarction (OR, 3.92 [95% CI, 1.32–11.7]), and direct oral anticoagulant rather than warfarin use (OR, 2.22 [95% CI, 1.59–3.08]) were independently associated with prolonged anticoagulation.

Conclusions

In our cohort of patients with provoked VTE, most patients received anticoagulation for longer than the guideline‐recommended 3 months. This demonstrates a potential opportunity to improve care delivery and reduce anticoagulant‐associated bleeding risk.

Acute Limb Arterial Ischemia Following Iliac Vein Stenting in the Setting of a Frozen Pelvis

The authors report on a young patient with previous radiation to her pelvis who presented with acute limb ischemia following iliac vein stenting believed to be secondary to extrinsic iliac artery compression in the setting of a frozen pelvis. She underwent revascularization and a trans-femoral amputation, ultimately needing a femoral to femoral artery crossover bypass in order to achieve amputation stump healing. This case describes a potential arterial complication of venous stenting in a previously irradiated field.

Secondary prevention of venous thromboembolism: Predictors and outcomes of guideline adherence in a long-term prospective cohort study

Background

Prevention of recurrent venous thromboembolism (VTE) is considered a main goal of VTE management. However, the extent to which physicians adhere to the recommendations from evidence-based guidelines is unknown.

Aim

From a large, prospective clinical cohort, we aimed to (1) quantify the adherence of treatment recommendations to evidence-based guidelines and establish its predictors, and (2) estimate its impact on clinical outcomes and costs in patients with VTE.

Methods

We included 6'243 consecutive patients with VTE treated at the university outpatient unit. Detailed clinical characteristics and treatment recommendations were recorded. Adherence of treatment recommendations to evidence-based guidelines at risk assessment was assessed in terms of duration of anticoagulant treatment. Data on death were obtained from the Swiss Central Compensation Office. Health care claims data recorded between 2014 and 2019 were retrieved from Helsana, one of the largest Swiss health insurance companies.

Results

The adherence to evidence-based guidelines was 36.1%. Among patients with non-adherence, overtreatment was present in 70.1%. Significant patient-related predictors of guideline adherence were (a) age above 50 years, (b) male sex, (c) pulmonary embolism, (d) unprovoked VTE, (e) multiple VTE, (f) laboratory tests not ordered, and (g) various cardiovascular comorbidities. Non-adherence was not significantly associated with mortality, hospitalization, admission to nursing home, and costs.

Conclusions

The adherence to evidence-based guidelines was low, and several unrelated predictors appeared. Although these results need to be confirmed in other settings, they highlight the need for implementation of evidence-based guidelines in clinical practice.

Unanswered questions in cancer-associated thrombosis

Cancer-associated venous thromboembolism (VTE) is a leading cause of morbidity and mortality in patients with cancer. Treatment of cancer-associated VTE comes with a heightened risk of anticoagulant-related bleeding that differs by choice of anticoagulant as well as by patient- and disease-specific risk factors. Available data from randomized controlled trials and observational studies in cancer-associated VTE suggest that direct oral anticoagulants are effective, continuing anticoagulation beyond six months is indicated in those with active cancer and that patients who develop 'breakthrough' thrombotic events can be effectively treated. We review the evidence that addresses these key clinical questions and offer pragmatic approaches in individualizing care. While significant investigative efforts over the past decade have made impactful advances, future research is needed to better define the factors that contribute to anticoagulant-related bleeding and VTE recurrence, in order to aid clinical decision-making that improves the care of patients with cancer-associated VTE.

Outpatient versus inpatient treatment for acute pulmonary embolism

BACKGROUND

Pulmonary embolism (PE) is a common life-threatening cardiovascular condition, with an incidence of 23 to 69 new cases per 100,000 people each year. For selected low-risk patients with acute PE, outpatient treatment might provide several advantages over traditional inpatient treatment, such as reduction of hospitalisations, substantial cost savings, and improvements in health-related quality of life. This is an update of an earlier Cochrane Review.

OBJECTIVES

To assess the effects of outpatient versus inpatient treatment in low-risk patients with acute PE.

SEARCH METHODS

We used standard, extensive Cochrane search methods. The latest search date was 31 May 2021.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) of outpatient versus inpatient treatment of adults (aged 18 years and over) diagnosed with low-risk acute PE.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methods. Our primary outcomes were short- and long-term all-cause mortality. Secondary outcomes were bleeding, adverse effects, recurrence of PE, and patient satisfaction. We used GRADE to assess certainty of evidence for each outcome.

MAIN RESULTS

We did not identify any new studies for this update. We included a total of two RCTs involving 453 participants. Both trials discharged participants randomised to the outpatient group within 36 hours of initial triage, and both followed participants for 90 days. One study compared the same treatment regimens in both outpatient and inpatient groups, and the other study used different treatment regimens. There was no clear difference in treatment effect for the outcomes of mortality at 30 days (risk ratio (RR) 0.33, 95% confidence interval (CI) 0.01 to 7.98; 2 studies, 453 participants; low-certainty evidence), mortality at 90 days (RR 0.98, 95% CI 0.06 to 15.58; 2 studies, 451 participants; low-certainty evidence), major bleeding at 14 days (RR 4.91, 95% CI 0.24 to 101.57; 2 studies, 445 participants; low-certainty evidence) and at 90 days (RR 6.88, 95% CI 0.36 to 132.14; 2 studies, 445 participants; low-certainty evidence), minor bleeding (RR 1.08, 95% CI 0.07 to 16.79; 1 study, 106 participants; low-certainty evidence), recurrent PE within 90 days (RR 2.95, 95% CI 0.12 to 71.85; 2 studies, 445 participants; low-certainty evidence), and patient satisfaction (RR 0.97, 95% CI 0.90 to 1.04; 2 studies, 444 participants; moderate-certainty evidence). We downgraded the certainty of the evidence because the CIs were wide and included treatment effects in both directions, the sample sizes and numbers of events were small, and it was not possible to determine the effect of missing data or the presence of publication bias. The included studies did not assess PE-related mortality or adverse effects, such as haemodynamic instability, or adherence to treatment.

AUTHORS' CONCLUSIONS

Currently, only low-certainty evidence is available from two published randomised controlled trials on outpatient versus inpatient treatment in low-risk patients with acute PE. The studies did not provide evidence of any clear difference between the interventions in overall mortality, bleeding, or recurrence of PE.

Diuretics Versus Volume Expansion in the Initial Management of Acute Intermediate High-Risk Pulmonary Embolism

AIMS

The very early management of pulmonary embolism (PE), a part from antithrombotic treatment, has been little studied. Our aim was to compare the effects of diuretic therapy (DT) versus volume expansion (VE) in patients hospitalized for PE with RV dysfunction.

METHODS AND RESULTS

We conducted a randomized open-label multicentric study including patients with intermediate high-risk PE. Patients were randomized between diuretics or saline infusion. The primary endpoint was time to troponin (Tp) normalization. Secondary endpoints were time to normalization of B-type natriuretic peptide (BNP), changes in echocardiographic RV function parameters and treatment tolerance. Sixty patients presenting intermediate high-risk PE were randomized. Thirty received DT and 30 VE. We noted no changes in Tp kinetics between the two groups. In contrast, faster normalization of BNP was obtained in the DT group: 56 [28-120] vs 108 [48-144] h: p = 0.05, with a shorter time to 50%-decrease from peak value 36 [24-48] vs 54 [41-67] h, p = 0.003 and a higher rate of patients with a lower BNP concentration within the first 12 h (42% vs 12% p < 0.001). RV echocardiographic parameters were unchanged between the groups. One dose 40 mg furosemide was well-tolerated and not associated with any serious adverse events.

CONCLUSION

In the acute management of intermediate high-risk PE, initial therapy including diuretic treatment is well-tolerated and safe. Although changes in Tp kinetics and echocardiographic RV dysfunction parameters did not differ, normalization of BNP is achieved more quickly in the DT group. This finding, which need to be confirmed in trials with clinical end points, may reflects a rapid improvement in RV function using one dose 40 mg furosemide.

TRIAL REGISTRY

Clinical Trial Registration NCT02531581.

Embolic Stroke in Setting of Iliac Vein Stenosis in an Avid Cyclist

External iliac vein stenosis related to cycling has rarely been reported as a cause of deep vein thrombosis. Ischemic stroke occurring in this condition due to paradoxical embolism across a preexisting patent foramen ovale (PFO) has yet to be reported. Here we report a case of embolic ischemic strokes in a young, avid cyclist with no prior known vascular risk factors. A thorough cerebrovascular workup revealed a right-to-left shunt on transesophageal echocardiogram that prompted venous thrombosis evaluation. Pelvic MR venogram demonstrated a 3.5 cm high-grade stenosis of the right external iliac vein, concerning for possible prior thrombotic disease. His strokes were deemed most likely a result of paradoxical emboli originating in the pelvis at the site of right external iliac vein stenosis. The patient ultimately opted for PFO closure for secondary stroke prevention, as he wished to continue daily cycling. This case highlights the importance of neurohospitalists considering iliac vein stenosis as a potential cause of embolic stroke of undetermined source, especially in young patients who are avid cyclists, as part of a thorough vascular workup.

Predictors of recurrence of venous thromboembolic disease after discontinuing of anticoagulation: a prospective cohort study

Objective

We aim to evaluate factors associated with the recurrence of thromboembolic episodes among patients with a first episode of venous thromboembolic disease during anticoagulation treatment and at least one year after treatment suspension.

Methods

A prospective cohort of patients with a first episode of deep vein thrombosis confirmed by Doppler ultrasound and initiated anticoagulation treatment. Participants were registered in the Institutional Registry of Thromboembolic Disease between June 2015 and March 2019. Patients with cancer, with permanent inferior vena cava filter implant, and those who refused to participate or did not provide informed consent were excluded. All patients were evaluated within treatment at 30 days and at least one year after the suspension of anticoagulation with a D-dimer study and an ultrasound. All patients were evaluated for recurrence, bleeding (major and minor), and death.

Results

A total of 304 patients were recruited during the study period. Seventy-three percent were female, and the median age was 80 years. The rate of recurrence rate during anticoagulation treatment was 5% (N = 16/303; 95% confidence interval: 3 to 8), and 5% during post-suspension follow-up (N = 11/202; 95%CI: 3 to 9). The overall bleeding rate was 13% (N = 39; 95%CI: 9 to 17), and 5% for major bleeding. Patients who recurred had higher basal D-dimer mean, higher neutrophils and monocytes, and a higher prevalence of age-adjusted D-dimer ratio greater than 0.5 before discontinuation. In addition, they more frequently had complete leg involvement by ultrasound and received a shorter treatment.

Conclusions

Although some baseline and pre-suspension parameters had a higher recurrence incidence, statistical significance was not reached, probably due to small statistical power and a short-term follow-up.

Coagulation and Aging: Implications for the Anesthesiologist

Purpose of Review

This narrative review focuses on aging-related modifications in coagulation resulting in increased thromboembolic and hemorrhagic risk of the elderly. We further discuss the current evidence and emerging data relating the perioperative treatment of elderly patients with antithrombotic therapy.

Recent Findings

Relevant changes in all elements of the Virchow’s triad can be found with aging. Increased blood stasis due to immobility, progressive endothelial dysfunction with altered microcirculation, elevated concentrations of several coagulation factors, and increased platelet reactivity all lead to a procoagulant state. Elderly people are, therefore, commonly treated with oral anticoagulation and antiplatelet drugs. This antithrombotic therapy might be essentially causative for their increased bleeding risk.

Summary

Elderly patients are at increased risk for thromboembolism due to changes in the hemostatic system in combination with frailty and multimorbidity. Both the thromboembolic due to aging and bleeding risk due to antithrombotic therapy need special attention in the elderly surgical patients.

Anticoagulation Treatment in Venous Thromboembolism: Options and Optimal Duration

Venous thromboembolism (VTE), clinically presenting as deep-vein thrombosis (DVT) or pulmonary embolism (PE), constitutes a major global healthcare concern with severe complications, long-term morbidity and mortality. Although several clinical, genetic and acquired risk factors for VTE have been identified, the molecular pathophysiology and mechanisms of disease progression remain poorly understood. Anticoagulation has been the cornerstone of therapy for decades, but there still are uncertainties regarding primary and secondary VTE prevention, as well as optimal therapy duration. In this review we discuss the role of factor Xa in coagulation cascade and the different choices of anticoagulation therapy based on patients' predisposing risk factors and risk of event recurrence. Further, we compare newer agents to traditional anticoagulation treatment, based on most recent studies and guidelines.

Endothelial progenitor cells overexpressing platelet derived growth factor-D facilitate deep vein thrombosis resolution

To assess the therapeutic efficacy of PDGF-D-overexpressing endothelial progenitor cells (EPCs) in deep vein thrombosis. Inferior vena cava thrombosis was induced in female Sprague Dawley (SD) rats. Animals were injected via the distal vena cava with EPCs overexpressing PDGF-D after transfection with a lentiviral vector containing the PDGF-D gene. The effect on thrombosis in animals who received EPCs was evaluated using MSB staining, immunohistochemistry, immunofluorescence, and venography; the steady-state mRNA and protein levels of PDGF-D and its receptor (PDGF-Rβ) were determined by RT-PCR and Western blotting, respectively; and the PDGF-D-induced mobilization of circulating EPCs was estimated by flow cytology. Compared with controls, injection of EPCs overexpressing PDGF-D was associated with increased thrombosis resolution; recanalization; PDGF-D and PDGF-Rβ expression; induction of monocyte homing; and mobilization of EPCs to the venous circulation. In a rat model, transplantation of PDGF-D-overexpressing EPCs facilitated the resolution of deep vein thrombosis.

Comparison of clinical outcomes using activated partial thromboplastin time versus antifactor-Xa for monitoring therapeutic unfractionated heparin: A systematic review and meta-analysis

INTRODUCTION

Continuous intravenous unfractionated heparin (UFH) is a mainstay of therapeutic anticoagulation in the acute setting. The two most common laboratory tests for monitoring UFH are the activated partial thromboplastin time (aPTT) and antifactor Xa (anti-Xa) heparin assay. We reviewed the available evidence to evaluate if the choice of monitoring test for UFH therapy is associated with a difference in the clinical outcomes of bleeding, thrombosis, or mortality.

MATERIALS AND METHODS

MEDLINE, Cochrane database, and conference abstracts from the Society of Critical Care Medicine, the American Society of Hematology, and the American College of Clinical Pharmacy were searched for all studies comparing aPTT and anti-Xa monitoring for therapeutic UFH that evaluated outcomes for bleeding, thrombotic events, or mortality. Risk of bias was assessed with the Cochrane Risk of Bias Tool and Newcastle Ottawa Scale. Pooled relative risk ratios were calculated using an inverse variance-weighted random-effects model.

RESULTS

Ten studies (n = 6677) were included for analysis. The use of anti-Xa compared to aPTT was not associated with an increased risk of bleeding (RR 1.03; 95% CI 0.8-1.22 I² = 4%) or an increased risk of thrombotic events (RR 0.99; 95% CI 0.76-1.30, I² = 3%). There was no difference in mortality within individual studies but the data were not suitable for pooled analysis.

CONCLUSIONS

Pooled data comparing aPTT vs. anti-Xa for monitoring therapeutic UFH did not suggest differences in the outcomes of bleeding or thrombosis.

Venous Thromboembolism and Pulmonary Embolism: Strategies for Prevention and Management

Perioperative venous thromboembolism (VTE) is a common complication within the surgical patient population. Perioperative mechanical and chemoprophylaxis have been shown to reduce the incidence of both deep venous thrombosis and pulmonary embolism. Prophylactic regimen must be tailored to the patient's individual risk factors as well as the nature of the procedure. In the event of VTE, treatment most commonly includes long-term anticoagulation, whereas more severe cases may require lytic or mechanical interventions.

Clot Degradation Under the Action of Histotripsy Bubble Activity and a Lytic Drug

Deep vein thrombosis is a major source of morbidity worldwide. For critical obstructions, catheter-directed thrombolytics are the frontline therapy to achieve vessel recanalization. Techniques that aid lytic therapy are under development to improve treatment efficacy and reduce procedure-related complications. Histotripsy is one such adjuvant under development that relies on focused ultrasound for in situ nucleation of bubble clouds. Prior studies have demonstrated synergistic effects for clot dissolution when histotripsy is combined with lytic therapy. The success of this combination approach is hypothesized to promote thrombolytic efficacy via two mechanisms: erythrocyte fractionation (hemolysis) and increased lytic activity (fibrinolysis). In this study, the contributions of hemolysis and fibrinolysis to clot degradation under histotripsy and a lytic were quantified with measurements of hemoglobin and D-dimer, respectively. A linear regression analysis was used to determine the relationship between hemoglobin, D-dimer, and the overall treatment efficacy (clot mass loss). A similar analysis was conducted to gauge the role of bubble activity, which was assessed with passive cavitation imaging, on hemolysis and fibrinolysis. Tabulation of these data demonstrated hemolysis and fibrinolysis contributed equally to clot mass loss. Furthermore, bubble cloud activity promoted the generation of hemoglobin and D-dimer in equal proportion. These studies indicate a multifactorial process for clot degradation under the action of histotripsy and a lytic therapy.

Effect of Antithrombotic Therapy on Bleeding after Argon Plasma Coagulation for Gastric Neoplasms

Background/Aims

Postprocedural bleeding is known to be relatively low after argon plasma coagulation (APC) for gastric neoplasms; however, there are few studies proving the effect of antithrombotic agents. This study aimed to analyze the incidence of delayed bleeding (DB) based on antithrombotic agents administered and to identify the risk factors for DB in APC for gastric tumors.

Methods

A total of 785 patients with 824 lesions underwent APC for single gastric neoplasm between January 2011 and January 2018. After exclusion, 719 and 102 lesions were classified as belonging to the non-antithrombotics (non-AT) and AT groups, respectively. The clinical outcomes were compared between the two groups, and we determined the risk factors for DB in gastric APC.

Results

Of the total 821 cases, DB occurred in 20 cases (2.4%) 17 cases in the non-AT group and three cases in the AT group (2.4% vs 2.9%, p=0.728). Multivariate analysis of the risk factors for DB confirmed the following significant, independent risk factors male sex (odds ratio, 7.66; 95% confidence interval, 1.02 to 57.69; p=0.048) and chronic kidney disease (odds ratio, 4.51; 95% confidence interval, 1.57 to 13.02; p=0.005). Thromboembolic events and perforation were not observed in all patients regardless of whether they took AT agents.

Conclusions

AT therapy is acceptably safe in gastric APC because it does not significantly increase the incidence of DB. However, patients with chronic kidney disease or male sex need to receive careful follow-up on the incidence of post-APC bleeding.

Successful Treatment of Massive Pulmonary Embolism with Rescue Fibrinolysis in Young Patient with Homocystinemia - Case Report

Pulmonary embolism (PE) is the most frequently missed diagnosis in the urgent clinical department with serious consequences. Patients with unprovoked PE have increased risk of recurrent PE. Approximately 5 to 8% of PE patients have inherited thrombophilias. A solated homocystinemia is a rare cause of unprovoked acute pulmonary embolism. Timely diagnosis and proper treatment can prevent complications, costs and mortality and provide patient better quality of life. We are presenting a 42-year-old woman was admitted to our emergency department with the first episode of severe dyspnea and chest pain. She had no history of previous cardiovascular or respiratory disease and no history of previous pulmonary embolism (PE) or deep vein thrombosis (DVT). Urgent echocardiography showed indirect signs of pulmonary embolism which was confirmed by the pulmonary artery CT angiography performed one day after the patient’s admission. After two days of heparin infusion, she developed a hemodynamic instability with cardiogenic shock and was treated successfully with fibrinolysis. After the clinical stabilization, she was put on the rivaroxaban therapy, which was recommended for additional six months. The thrombophilia profile was done two weeks after stopping the therapy with rivaroxaban. The thrombophilia panel came back positive for high levels of homocysteine (67 μmol/L), with other thrombophilia results within normal limits. The patient was stable during the follow-up period. Pulmonary embolism should be always suspected in younger patients with acute severe dyspnea even without provocable risk factors. High suspicion level and fast diagnosis are lifesaving. In younger patients presented with unprovoked pulmonary embolism, clinicians should consider inherited prothrombotic factors and homocystinemia as a potential cause. Rescue fibrinolysis is a lifesaving therapy in hemodynamic worsening in intermediate high-risk PE patients. A longer anticoagulation therapy should be considered in these cases with novel oral anticoagulants that are recommended as safer and superior therapy.