Acute treatment of venous thromboembolism

Sonothrombolysis Using Microfluidically Produced Microbubbles in a Murine Model of Deep Vein Thrombosis

The need for safe and effective methods to manage deep vein thrombosis (DVT), given the risks associated with anticoagulants and thrombolytic agents, motivated research into innovative approaches to resolve blood clots. In response to this challenge, sonothrombolysis is being explored as a technique that combines microbubbles, ultrasound, and thrombolytic agents to facilitate the aggressive dissolution of thrombi. Prior studies have indicated that relatively large microbubbles accelerate the dissolution process, either in an in vitro or an arterial model. However, sonothrombolysis using large microbubbles must be evaluated in venous thromboembolism diseases, where blood flow velocity is not comparable. In this study, the efficacy of sonothrombolysis was validated in a murine model of pre-existing DVT. During therapy, microfluidically produced microbubbles of 18 μm diameter and recombinant tissue plasminogen activator (rt-PA) were administered through a tail vein catheter for 30 min, while ultrasound was applied to the abdominal region of the mice. Three-dimensional ultrasound scans were performed before and after therapy for quantification. The residual volume of the thrombi was 20% in animals post sonothrombolysis versus 52% without therapy ( p = 0.012 < 0.05 ), indicating a significant reduction in DVT volume. Histological analysis of tissue sections confirmed a reduction in DVT volume post-therapy. Therefore, large microbubbles generated from a microfluidic device show promise in ultrasound-assisted therapy to address concerns related to venous thromboembolism.

In-hospital mortality and associated factors among patients admitted with venous thromboembolism at selected public hospitals of Harar Town, Eastern Ethiopia

Background

Venous thromboembolism is the third most common cause of cardiovascular death and is responsible for more than 3 million deaths annually worldwide. Despite high rates of morbidity and mortality associated with venous thromboembolism, limited studies have been conducted on in-hospital mortality and its associated factors in Ethiopia, particularly in study settings.

Objective

To assess in-hospital mortality and associated factors among patients admitted with venous thromboembolism at selected public hospitals of Harar town, Eastern Ethiopia, from 10 March 2018 to 8 March 2022.

Methods

A retrospective cohort study design was conducted among 502 patients admitted with venous thromboembolism at Hiwot Fana Comprehensive Specialized Hospital and Jugal General Hospital using a simple random sampling technique. Data extraction formats were used to collect data from patient medical record cards. Then data were coded and entered into EpiData version 3.1 computer programs and exported to SPSS version 26 for analysis. Bivariate and multivariate backward Cox regression analysis was used to verify the associated factors of in-hospital mortality among venous thromboembolism patients. A p-value of less than 0.05 at a 95% confidence interval was used to establish a statistically significant association.

Results

A total of 502 patient medical record cards with outcome variables were included in the study. More than half of the patients 350 (69.7%) were females. Among the 502 patients who were admitted with venous thromboembolism, 8.2% (95% CI: 5.6-10.6) of patients had in-hospital mortality. DM (AHR = 4.28, 95% CI: 1.80-10.15, p = 0.001) and unfractionated heparin duration (AHR = 10.26, 95% CI: 2.45-43.01, p = 0.001) were statistically significant association with venous thromboembolism mortality.

Conclusion

Approximately 8.2% of venous thromboembolism patients died in the hospital. Diabetes and heparin were independently associated with higher mortality. Therefore, it is better to give more attention to the patients co-morbid with diabetes mellitus and for unfractionated heparin treatment duration to reduce venous thromboembolism mortality.

Thrombotic microenvironment responsive crosslinking cyclodextrin metal-organic framework nanocarriers for precise targeting and thrombolysis

Global public health is seriously threatened by thrombotic disorders because of their high rates of mortality and disability. Most thrombolytic agents, especially protein-based pharmaceuticals, have a short half-life in circulation, reducing their effectiveness in thrombolysis. The creation of an intelligent drug delivery system that delivers medication precisely and releases it under regulated conditions at nearby thrombus sites is essential for effective thrombolysis. In this article, we present a unique medication delivery system (MCRUA) that selectively targets platelets and releases drugs by stimulation from the thrombus' microenvironment. The thrombolytic enzyme urokinase-type plasminogen-activator (uPA) and the anti-inflammatory medication Aspirin (acetylsalicylic acid, ASA) are both loaded onto pH-sensitive CaCO3/cyclodextrin crosslinking metal-organic frameworks (MC) that make up the MCRUA system. c(RGD) is functionalized on the surface of MC, which is functionalized by RGD to an esterification reaction. Additionally, the thrombus site's acidic microenvironment causes MCRUA to disintegrate to release uPA for thrombolysis and aiding in vessel recanalization. Moreover, cyclodextrin-encapsulated ASA enables the treatment of the inflammatory environment within the thrombus, enhancing the antiplatelet aggregation effects and promoting cooperative thrombolysis therapy. When used for thrombotic disorders, our drug delivery system (MCRUA) promotes thrombolysis, suppresses rethrombosis, and enhances biosafety with fewer hemorrhagic side effects.

External validation of the PE-SARD risk score for predicting early bleeding in acute pulmonary embolism in the RIETE Registry

INTRODUCTION

The PE-SARD score (syncope, anemia, renal dysfunction) was developed to predict the risk of major bleeding in the acute phase of pulmonary embolism (PE).

METHODS

We analyzed data from 50,686 patients with acute PE included in the RIETE registry to externally validate the PE-SARD score. We calculated the overall reliability of the PE-SARD score, as well as discrimination and calibration for predicting the risk of major bleeding at 30 days. The performance of PE-SARD was compared to the BACS and PE-CH models.

RESULTS

During the first 30 days, 640 patients (1.3 %) had a major bleeding event. The incidence of major bleeding within 30 days was 0.6 % in the PE-SARD-defined low-risk group, 1.5 % in the intermediate-risk group, and 2.5 % in the high-risk group, for an OR of 2.22 (95 % CI, 2.02-2.43) for the intermediate-risk group (vs low-risk group), and 3.94 for the high-risk group (vs low-risk group). The corresponding sensitivity was 81.1 % (intermediate/high vs low risk), and specificity was 85.9 % (95 % CI, 85.8-86.1) (low/intermediate vs high risk). The applicability of PE-SARD was consistent across clinically relevant patient subgroups and over shorter time periods of follow-up (i.e., 3 and 7 days). The C-index was 0.654 and calibration was excellent. The PE-SARD bleeding score improved the major bleeding risk prediction compared with the BACS and PE-CH scores.

CONCLUSIONS

The PE-SARD score identifies PE patients with a higher risk of bleeding, which could assist providers for potentially adjusting PE management, in a framework of shared decision-making with individual patients.

Thromboembolic Disease

Venous thromboembolism (VTE) encompasses deep vein thrombosis and pulmonary embolism, both of which can present on a spectrum from subtle symptoms to life- and limb-threatening emergencies. Some risk factors for VTE overlap cardiovascular risk factors and statin therapy can somewhat reduce the VTE risk. When presentations are not life-threatening, clinical prediction scores using the Well's criteria are best used to determine diagnostic testing. The mainstay of VTE treatment is anticoagulant therapy, although life- and limb-threatening presentations can also require thrombolytic therapy.

MACHINE LEARNING FOR PREDICTING HEMODYNAMIC DETERIORATION OF PATIENTS WITH INTERMEDIATE-RISK PULMONARY EMBOLISM IN INTENSIVE CARE UNIT

ABSTRACT

Background: Intermediate-risk pulmonary embolism (PE) patients in the intensive care unit (ICU) are at a higher risk of hemodynamic deterioration than those in the general ward. This study aimed to construct a machine learning (ML) model to accurately identify the tendency for hemodynamic deterioration in the ICU patients with intermediate-risk PE. Method: A total of 704 intermediate-risk PE patients from the MIMIC-IV database were retrospectively collected. The primary outcome was defined as hemodynamic deterioration occurring within 30 days after admission to ICU. Four ML algorithms were used to construct models on the basis of all variables from MIMIC IV database with missing values less than 20%. The extreme gradient boosting (XGBoost) model was further simplified for clinical application. The performance of the ML models was evaluated by using the receiver operating characteristic curve, calibration plots, and decision curve analysis. Predictive performance of simplified XGBoost was compared with the simplified Pulmonary Embolism Severity Index score. SHapley Additive explanation (SHAP) was performed on a simplified XGBoost model to calculate the contribution and impact of each feature on the predicted outcome and presents it visually. Results: Among the 704 intermediate-risk PE patients included in this study, 120 patients experienced hemodynamic deterioration within 30 days after admission to the ICU. Simplified XGBoost model demonstrated the best predictive performance with an area under the curve of 0.866 (95% confidence interval, 0.800-0.925), and after recalibrated by isotonic regression, the area under the curve improved to 0.885 (95% confidence interval, 0.822-0.935). Based on the simplified XGBoost model, a web app was developed to identify the tendency for hemodynamic deterioration in ICU patients with intermediate-risk PE. Conclusion: A simplified XGBoost model can accurately predict the occurrence of hemodynamic deterioration for intermediate-risk PE patients in the ICU, assisting clinical workers in providing more personalized management for PE patients in the ICU.

Laser-assisted permanent greenfield filter removal with ileocaval stent reconstruction following filter thrombosis, a case report

Emerging literature supports removal of chronic indwelling IVC filters when they are contributing to complications for a patient and are no longer indicated. We present an interesting case of an elderly patient who had a history of DVT and underwent spinal surgery, which required cessation of his anticoagulation and placement of an IVC filter pre-operatively. Approximately 15 years later the patient presented to our institution with chronic occlusion of his IVC at the level of his filter which had never been removed, with bilateral lower extremity DVT and symptoms of phlegmasia cerulea dolens. Despite a previous unsuccessful attempt at DVT thrombectomy at an outside institution, interventional radiology was consulted, and he subsequently underwent successful laser sheath assisted removal of his 15-year-old permanent Greenfield filter with bilateral lower extremity DVT thrombectomy and venous stenting with significant improvement in his presenting symptoms. Clinical presentation, diagnostic workup, case findings, and outcomes are described.

Prediction of very early major bleeding risk in acute pulmonary embolism: an independent external validation of the Pulmonary Embolism-Syncope, Anemia, and Renal Dysfunction (PE-SARD) bleeding score

BACKGROUND

The Pulmonary Embolism-Syncope, Anemia, and Renal Dysfunction (PE-SARD) bleeding score was derived to predict very early major bleeding (MB) in patients with acute pulmonary embolism (PE). Before adoption into practice, the score requires external validation in different populations.

OBJECTIVES

We independently validated the PE-SARD score in a prospective multicenter Swiss cohort of 687 patients aged ≥65 years with acute PE.

METHODS

The PE-SARD score uses 3 variables (syncope, anemia, and renal dysfunction) to classify patients into 3 categories of increasing bleeding risk. The outcomes were very early MB at 7 days (primary) and MB at later time points (secondary). We calculated the PE-SARD score for each patient and classified the proportion of patients as being at low, intermediate, and high risk. To assess discrimination and calibration, we calculated the area under the receiver operating characteristic curve and the Hosmer-Lemeshow goodness-of-fit test, respectively.

RESULTS

The prevalence of MB was 2.0% (14/687) at 7 days and 14.0% (96/687) after a median follow-up of 30 months. The PE-SARD score classified 40.2%, 42.2%, and 17.6% of patients as low, intermediate, and high risk for MB, respectively. The frequency of observed very early MB at 7 days was 1.8% in low-, 2.1% in intermediate-, and 2.5% in high-risk patients. The area under the receiver operating characteristic curve was 0.52 (95% CI, 0.48-0.56) at 7 days and increased to 0.60 (95% CI, 0.56-0.64) at the end of follow-up. Score calibration was adequate (p > .05) over the entire follow-up.

CONCLUSION

In our independent validation, the PE-SARD score did not accurately predict very early MB and may not be transportable to older patients with PE.

Machine learning-based models for predicting mortality and acute kidney injury in critical pulmonary embolism

OBJECTIVES

We aimed to use machine learning (ML) algorithms to risk stratify the prognosis of critical pulmonary embolism (PE).

MATERIAL AND METHODS

In total, 1229 patients were obtained from MIMIC-IV database. Main outcomes were set as all-cause mortality within 30 days. Logistic regression (LR) and simplified eXtreme gradient boosting (XGBoost) were applied for model constructions. We chose the final models based on their matching degree with data. To simplify the model and increase its usefulness, finally simplified models were built based on the most important 8 variables. Discrimination and calibration were exploited to evaluate the prediction ability. We stratified the risk groups based on risk estimate deciles.

RESULTS

The simplified XGB model performed better in model discrimination, which AUC were 0.82 (95% CI: 0.78-0.87) in the validation cohort, compared with the AUC of simplified LR model (0.75 [95% CI: 0.69-0.80]). And XGB performed better than sPESI in the validation cohort. A new risk-classification based on XGB could accurately predict low-risk of mortality, and had high consistency with acknowledged risk scores.

CONCLUSIONS

ML models can accurately predict the 30-day mortality of critical PE patients, which could further be used to reduce the burden of ICU stay, decrease the mortality and improve the quality of life for critical PE patients.

Updated Renal Dosage Recommendations for Rivaroxaban in Patients Experiencing or at Risk of Thromboembolic Disease

Patients with chronic kidney disease are at an increased risk of venous thromboembolism (VTE). The factor Xa inhibitor rivaroxaban has been shown to provide similar efficacy and a lower risk of bleeding compared with vitamin K antagonists for the treatment and prevention of VTE. Rivaroxaban has been studied in patients with varying degrees of renal impairment, and this review summarizes current knowledge supporting its use in patients with severe renal impairment (creatinine clearance [CrCl] of 15 to < 30 mL/min) for the prevention, treatment, or prophylaxis of VTE. Clinical pharmacology studies have demonstrated an increase in rivaroxaban systemic exposure, factor Xa inhibition, and prothrombin time with decreasing renal function. These changes reach a plateau with comparable increases in exposure among individuals with moderate or severe renal impairment and end-stage renal disease. The clinical development program for the treatment and prevention of VTE as well as prophylaxis of deep vein thrombosis (DVT) following orthopedic surgery excluded patients with CrCl < 30 mL/min; however, a limited number of patients with severe renal impairment were enrolled. Efficacy outcomes in these patients with severe renal impairment were not meaningfully different from those of patients with higher levels of renal function. There was also no increase in the incidence of major bleeding with rivaroxaban in patients with CrCl < 30 mL/min. Taken together, these pharmacological and clinical data suggest that in patients with severe renal impairment, the approved dosages of rivaroxaban can be used in the treatment and prevention of VTE and for prophylaxis of DVT after hip or knee replacement surgery.

Trends in management and outcomes of pulmonary embolism with a multidisciplinary response team

Multidisciplinary pulmonary embolism (PE) response teams have garnered widespread adoption given the complexities of managing acute PE and provide a platform for assessment of trends in therapy and outcomes. We describe temporal trends in PE management and outcomes following the deployment of such a team. All consecutive patients managed by our multidisciplinary PE response team activated by the Emergency Department were included over a 5-year calendar period. We examined temporal trends in management and rates of a composite primary endpoint (all-cause-death, major bleeding, recurrent venous thromboembolism, and readmission) at 30 days and 6 months. We assessed 425 patients between 2015 and 2019. We observed an increase in PE acuity and use of systemic thrombolysis. The primary endpoint at 30 days decreased from 16.3% in 2015 to 7.1% in 2019 (adjusted rate ratio per period, 0.63; 95%CI, 0.47-0.84), driven by a decrease in the adjusted rate of major bleeding. Among 406 patients with complete follow-up, the adjusted rate ratio per year for the primary outcome at 6 months was 0.37 (95%CI, 0.19-0.71), driven by a decrease in all-cause mortality. We observed evidence of temporal changes in clinical presentation, therapeutic strategies, and outcomes for acute PE, in parallel to, but not necessarily because of, the implementation of a multidisciplinary response team. Over time, major bleeding, mortality and readmission rates decreased, despite an increase in PE risk category.

Extended Anticoagulation After Pulmonary Embolism: A Multicenter Observational Cohort Analysis

Background Pulmonary embolism (PE) has a long-term risk of adverse events, which can be prevented by extended anticoagulation. We compared clinical characteristics and outcomes between patients treated with 2-year extended anticoagulation and those who were not, in a population who had completed an initial phase of 3 to 6 months of anticoagulant therapy after acute PE. Methods and Results Observational cohort analysis of patients with PE who survived an initial phase of 3 to 6 months anticoagulation. Primary efficacy outcome was all-cause death or recurrent venous thromboembolism. Primary safety outcome was major bleeding. In total, 858 (71.5%) patients were treated with and 341 (28.5%) were treated without extended anticoagulant therapy during the active study period. Age <65 years, intermediate-high or high-risk index PE, normal platelet count, and the absence of concomitant antiplatelet treatment were independently associated with the prescription of extended anticoagulation. The mean duration of the active phase was 2.1±0.3 years. The adjusted rate of the primary efficacy outcome was 2.1% in the extended group and 7.7% in the nonextended group (P<0.001) for patients treated with extended anticoagulant therapy. Rate of bleeding were similar between the extended anticoagulant group and the nonextended group. Conclusions Extended oral anticoagulation over 2 and a half years after index PE seems to provide a net clinical benefit compared with no anticoagulation in patients with PE selected to receive extended anticoagulation. Randomized clinical trials are warranted to explore the potential benefit of extended anticoagulation in patients with PE, especially those with transient provoking factors but residual risk.

Significant decrease in plasmad-dimer levels and mean platelet volume after a 3-month treatment with rosuvastatin in patients with venous thromboembolism

BACKGROUND

Inflammation has been considered as a possible mechanism for the initiation and recurrence of venous thromboembolism (VTE). Statins have anti-inflammatory and potential immune-modulatory effects, but their effect on plasmad-dimer levels is controversial.

HYPOTHESIS

In this study, we aimed to evaluate the impact of rosuvastatin on D-dimer and other inflammatory serum markers in VTE patients.

METHODS

We conducted a prospective, randomized study on 228 patients with VTE. Control group received conventional treatment (warfarin or rivaroxaban), whereas rosuvastatin-intervention group received rosuvastatin 10 mg daily, in addition to their conventional treatment for 3 months. Serum markers were extracted from both groups at the baseline and 3 months after the beginning of treatment.

RESULTS

After 3 months, in patients of the intervention group, there was a statistically significant decrease in levels ofd-dimer and mean platelet volume (MPV) but no significant change in neutrophil-to-lymphocyte ratio and platelet-to-lymphocyte ratio.

CONCLUSIONS

Our results showed that a 3-month treatment with 10 mg rosuvastatin daily can significantly decrease the plasma levels ofd-dimer and MPV, which would support a potential role of statins to reduce activated systemic inflammation among VTE patients. Such effects can be used to reduce the rate of recurrent VTE in these patients.

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.

Screening of the Promising Direct Thrombin Inhibitors from Haematophagous Organisms. Part I: Recombinant Analogues and Their Antithrombotic Activity In Vitro

The success in treatment of venous thromboembolism and acute coronary syndromes using direct thrombin inhibitors has stimulated research aimed at finding a new anticoagulant from haematophagous organisms. This study deals with the comparison between hirudin-1 from Hirudomedicinalis(desirudin), being the first-known and most well-studied natural anticoagulant, along with recombinant analogs of haemadin from the leech Haemadipsa sylvestris, variegin from the tick Amblyomma variegatum, and anophelin from Anopheles albimanus. These polypeptides were chosen due to their high specificity and affinity for thrombin, as well as their distinctive inhibitory mechanisms. We have developed a universal scheme for the biotechnological production of these recombinant peptides as pharmaceutical substances. The anticoagulant activities of these peptides were compared using the thrombin amidolytic activity assay and prolongation of coagulation time (thrombin time, prothrombin time, and activated partial thromboplastin time) in mouse and human plasma. The preliminary results obtained suggest haemadin as the closest analog of recombinant hirudin-1, the active substance of the medicinal product Iprivask (Aventis Pharmaceuticals, USA) for the prevention of deep venous thrombosis in patients undergoing elective hip or knee replacement surgery. In contrast, variegin can be regarded as a natural analog of bivalirudin (Angiomax, The Medicines Company), a synthetic hirudin-1 derivative certified for the treatment of patients undergoing percutaneous coronary intervention and of patients with unstable angina pectoris after percutaneous transluminal coronary angioplasty.

Practice patterns and outcomes of direct oral anticoagulant use in myeloproliferative neoplasm patients

Myeloproliferative neoplasms (MPNs) are characterized by an increased risk of thrombosis and bleeding. Vitamin K antagonists (VKAs) are the historic anticoagulant recommended for use in MPNs. Direct oral anticoagulants (DOACs) are being increasingly used in general and cancer populations. However, DOAC safety and efficacy in MPN patients remains unclear. We characterized real-world practice patterns of DOAC use in MPN patients and evaluated thrombosis and bleeding risk. We conducted a retrospective cohort study of 133 MPN patients prescribed DOACs for venous thromboembolism (VTE), atrial fibrillation, or arterial thromboembolism (ATE). Practice patterns including duration of anticoagulation, dosing, and concomitant use of antiplatelet/cytoreductive agents, were heterogeneous among MPN patients. The 1-year cumulative incidence of thrombosis and bleeding on DOAC was 5.5% (1.5–9.5%) and 12.3% (6.4–18.2%) respectively. In comparison, reported bleeding rates in MPN patients on DOAC and VKAs are 1–3%. On multivariable analysis, prior history of thrombosis, use of dabigatran or edoxaban, and younger age were significantly associated with a higher risk of recurrent thrombosis, while leukocytosis was associated with a higher risk of bleeding on DOAC. The higher-than-expected bleeding rate found in our study indicates the continued need for rigorous evaluation of DOACs in this population.

Available Bleeding Scoring Systems Poorly Predict Major Bleeding in the Acute Phase of Pulmonary Embolism

We aimed to compare six available bleeding scores, in a real-life cohort, for prediction of major bleeding in the early phase of pulmonary embolism (PE). We recorded in-hospital characteristics of 2754 PE patients in a prospective observational multicenter cohort contributing 18,028 person-days follow-up. The VTE-BLEED (Venous Thrombo-Embolism Bleed), RIETE (Registro informatizado de la enfermedad tromboembólica en España; Computerized Registry of Patients with Venous Thromboembolism), ORBIT (Outcomes Registry for Better Informed Treatment), HEMORR₂HAGES (Hepatic or Renal Disease, Ethanol Abuse, Malignancy, Older Age, Reduced Platelet Count or Function, Re-Bleeding, Hypertension, Anemia, Genetic Factors, Excessive Fall Risk and Stroke), ATRIA (Anticoagulation and Risk Factors in Atrial Fibrillation), and HAS-BLED (Hypertension, Abnormal Renal/Liver Function, Stroke, Bleeding History or Predisposition, Labile International Normalized Ratio, Elderly, Drugs/Alcohol) scores were assessed at baseline. International Society on Thrombosis and Haemostasis (ISTH)-defined bleeding events were independently adjudicated. Accuracy of the overall original 3-level and newly defined optimal 2-level outcome of the scores were evaluated and compared. We observed 82 first early major bleedings (3.0% (95% CI, 2.4–3.7)). The predictive power of bleeding scores was poor (Harrel’s C-index from 0.57 to 0.69). The RIETE score had numerically higher model fit and discrimination capacity but without reaching statistical significance versus the ORBIT, HEMORR₂HAGES, and ATRIA scores. The VTE-BLEED and HAS-BLED scores had significantly lower C-index, integrated discrimination improvement, and net reclassification improvement compared to the others. The rate of observed early major bleeding in score-defined low-risk patients was high, between 15% and 34%. Current available scoring systems have insufficient accuracy to predict early major bleeding in patients with acute PE. The development of acute-PE-specific risk scores is needed to optimally target bleeding prevention strategies.

An Original Risk Score to Predict Early Major Bleeding in Acute Pulmonary Embolism: The Syncope, Anemia, Renal Dysfunction (PE-SARD) Bleeding Score

BACKGROUND

Improved prediction of the risk of early major bleeding in pulmonary embolism (PE) is needed to optimize acute management.

RESEARCH QUESTION

Does a simple scoring system predict early major bleeding in acute PE patients, identifying patients with either high or low probability of early major bleeding?

STUDY DESIGN AND METHODS

From a multicenter prospective registry including 2,754 patients, we performed post hoc multivariable logistic regression analysis to build a risk score to predict early (up to hospital discharge) major bleeding events. We validated the endpoint model internally, using bootstrapping in the derivation dataset by sampling with replacement for 500 iterations. Performances of this novel score were compared with that of the VTE-BLEED, RIETE, and BACS models.

RESULTS

Multivariable regression identified three predictors for the occurrence of 82 major bleeds (3.0%; 95% CI, 2.39%-3.72%): Syncope (+1.5); Anemia, defined as hemoglobin <12 g/dL (+2.5); and Renal Dysfunction, defined as glomerular filtration rate <60 mL/min (+1 point) (SARD). The PE-SARD bleeding score was calculated by summing all the components. Overall, 52.2% (95% CI; 50.29%-54.11%) of patients were classified as low bleeding-risk (score, 0 point), 35.2% (95% CI, 33.39%-37.04%) intermediate-risk (score, 1-2.5 points), and 12.6% (95% CI, 9.30%-16.56%) high-risk (score >2.5 points). Observed bleeding rates increased with increasing risk group, from 0.97% (95% CI, 0.53%-1.62%) in the low-risk to 8.93% (95% CI, 6.15%-12.44%) in the high-risk group. C-index was 0.74 (95% CI, 0.73-0.76) and Brier score 0.028 in the derivation cohort. Similar values were calculated from internal bootstrapping. Performance of the PE-SARD score was better than that observed with the VTE-BLEED, RIETE, and BACS scores, leading to a high proportion of bleeding-risk reclassification in patients who bled and those who did not.

INTERPRETATION

The PE-SARD bleeding risk score is an original, user-friendly score to estimate risk of early major bleeding in patients with acute PE.

Running Promotes Transformation of Brain Astrocytes Into Neuroprotective Reactive Astrocytes and Synaptic Formation by Targeting Gpc6 Through the STAT3 Pathway

Ischemic stroke is caused by cerebral ischemia upon the blockage of an artery, which results in a high disability rate. Little is known regarding the mechanism of astrocyte function in cerebral ischemia. We aimed to determine the effects of running on the transformation of astrocytes, and subsequent synapse formation. A study of middle cerebral artery occlusion (MCAO) after running in vivo showed that running can promote the transformation of astrocytes toward the neuroprotective phenotype. Our findings of oxygen-glucose deprived astrocytes in vitro after running revealed that these astrocytes transformed into the neuroprotective phenotype, and that the expression of STAT3 and Gpc6 was increased. We confirmed that mechanistically, running can target Gpc6 through the STAT3 pathway and then regulate the number of synapses. We concluded that running promotes synapse proliferation by polarizing astrocytes toward the neuroprotective phenotype and ultimately leads to nerve regeneration.

Impact of Preinjury Antithrombotic Therapy on 30-Day Mortality in Older Patients Hospitalized With Traumatic Brain Injury (TBI)

Objective: Elderly patients are frequently in need of antithrombotic therapy for reducing thrombotic events. The association between antithrombotic drugs and survival after traumatic brain injury (TBI) is, nevertheless, unclear.

Methods: This retrospective study included patients ≥65 years admitted to a Norwegian Level 1 trauma center with TBI identified on cerebral computed tomography (cerebral-CT) during 2014–2019. Preinjury use of antiplatelets and anticoagulants was compared to the prescription rate in the general Norwegian population. The primary outcome was 30-day mortality. Uni- and multivariate logistic regression analyses estimated the association between the use of antithrombotic drugs and mortality.

Results: The study includes 832 consecutive TBI patients ≥65 years. The median age was 76 years, 58% were males, 51% had moderate or severe TBI, and 39% had multiple traumas. Preinjury use of antithrombotics was registered in 471/832 (55.6%) patients; antiplatelet therapy alone in 268, anticoagulant therapy alone in 172, and combined antiplatelet and anticoagulant therapy in 31. Antiplatelet use did not differ between the study cohort and the general Norwegian population ≥65 years (31 vs. 31%, p = 0.87). Anticoagulant therapy was used more commonly in the study cohort than in the general Norwegian population (24 vs. 19%, p = 0.04). Combined use of antiplatelet and anticoagulant therapy was significantly associated with 30-day mortality, while preinjury antiplatelet or anticoagulation treatment alone was not. No difference in 30-day mortality between patients using VKA, DOACs, or LMWH was encountered.

Conclusions: In this cohort, neither antiplatelet nor anticoagulant therapy alone was associated with increased 30-day mortality. Anticoagulant use was more prevalent among TBI patients than the general population, suggesting that anticoagulation might contribute to the initiation of intracranial bleeding after blunt head trauma. Combined antiplatelet and anticoagulant therapy posed increased risk of 30-day mortality.

Massive Pulmonary Embolism and Deep Vein Thrombosis in COVID-19 Pneumonia: Two Case Reports

Coronavirus disease 2019 (COVID-19) is known to cause a severe acute respiratory syndrome with increased morbidity and mortality due to multiorgan involvement. COVID-19 is associated with an increased risk of venous thromboembolism (VTE), ranging from asymptomatic to potentially fatal presentations. Predictors of VTE in COVID-19 are not fully defined, and the role of anticoagulation in these patients is debatable. Here we discuss two cases of COVID-19, who initially presented with mild COVID-19 symptoms and later with potentially fatal VTE within 30 days of initial presentation. The first case is of a 42-year-old gentleman with a history of sarcoidosis and a recent diagnosis of COVID-19 pneumonia who was in isolation at home and presented with syncope and worsening shortness of breath. He was hemodynamically unstable and resuscitated with fluid management in the emergency department. The chest angiogram imaging studies showed massive pulmonary embolism with right heart strain, which was confirmed with bedside point-of-care ultrasound. The patient deteriorated clinically and received an intravenous tissue plasminogen activator in the emergency. He was discharged home under stable condition on oral anticoagulation. The second patient is a 63-year-old gentleman with chronic obstructive pulmonary disease, obesity, sleep apnea, and a recent diagnosis of COVID-19 pneumonia, which was complicated with an ischemic stroke, who presented with worsening complaints of shortness of breath and palpitation. The chest angiogram imaging showed bilateral pulmonary embolism. An echocardiogram showed mild right heart strain. The lower extremity duplex ultrasound showed bilateral deep vein thrombosis. The patient underwent catheter-directed thrombolysis and discharged on oral anticoagulation. There is a need to develop stronger predictors to provide thromboprophylaxis in COVID-19 pneumonia to prevent life-threatening VTE.

The current place of direct oral anticoagulants in the prevention/treatment of venous thromboembolism

Venous thromboembolism (VTE; includes deep venous thrombosis, DVT, and pulmonary embolism, PE) represents the third most common acute cardiovascular syndrome. Contemporary VTE management comprises primary prevention in high-risk patients, treatment of established VTE, and prevention of its recurrence (secondary prevention). Anticoagulants are the basis of VTE pharmacological prophylaxis and treatment. For several decades, parenteral (heparin and low-molecular-weight heparins, LMWHs) and oral anticoagulants (vitamin K antagonists, VKAs) have been the cornerstone of VTE prevention/treatment. The introduction of direct oral anticoagulants (DOACs: thrombin inhibitor dabigatran and Xa inhibitors rivaroxaban, apixaban, edoxaban, and betrixaban) markedly improved the management of VTE by overcoming many disadvantages of conventional anticoagulants. For primary VTE prevention in patients after total hip/knee arthroplasty, rivaroxaban, apixaban, and dabigatran are preferred over LMWHs, due to comparable efficacy and safety, but favourable acceptability (avoided everyday injections). In other high-risk populations (other surgical patients, acutely ill medical patients), LMWHs are still the recommended option. Betrixaban is currently the only DOAC approved for VTE prophylaxis in medically ill patients during and after hospitalization. For acute VTE treatment and secondary prevention, DOACs (rivaroxaban, apixaban, edoxaban, and dabigatran) are recommended as the first-line therapy in the general population. DOACs proved to be similarly effective but safer than VKAs. In some specific populations, DOACs also seem to be advantageous over conventional treatment (patients with renal impairment, elderly, long-term secondary prevention in cancer patients). Currently, there is no data from randomized head-to-head comparative studies between the DOAC classes or representatives so the choice is made mainly according to patient characteristics and pharmacokinetic properties of the drug.