Magnetic nanoparticles immobilized thrombin ligand fishing to screen thrombin inhibitors in natural products

In this study, thrombin was immobilized with magnetic particles modified by glutaraldehyde. The changes in secondary structures of immobilized enzyme revealed an increment in conformational rigidity and stability, which can be reflected in temperature and pH stability as well as the tolerance of organic reagents. The optimal reutilization times of magnetic particle immobilized thrombin were 7 times, and the half-life of enzyme activity preserved at room temperature was 5 days, which was 2.5 times higher than that of free enzyme. Ligusticum chuanxiong and Anemarrhenae Rhizoma with high enzyme inhibitory activity were selected for primary screening, and six potential inhibitors of thrombin were identified by HPLC/MS. The results showed that three compounds in Anemarrhenae Rhizoma had better predictive thrombin inhibitory activity. Through the in vitro thrombin activity inhibition experiment, it was also verified that mangiferin and neo-mangiferin had an ideal thrombin activity inhibition effect, which was consistent with the results of molecular docking.

Management of prosthetic valve thrombosis with unfractionated heparin

BACKGROUND

Prosthetic valve thrombosis (PVT) is a severe and life-threatening complication. Surgery and thrombolytic therapy (TT) carry a high risk, and in several circumstances, optimal anticoagulation with unfractionated heparin (UFH) infusion may be an alternative treatment. This study aimed to assess the results of UFH in patients diagnosed with both obstructive and non-obstructive PVT.

METHODS

This observational retrospective study enrolled patients who had contraindications for TT and surgery underwent UFH therapy.

RESULTS

A total of 136 patients were enrolled [male: 55 (40.4%), mean age: 50.3 ± 14.6 years] in the study. In the successful group, 66 patients (48,5%) showed >75% regression in the thrombus burden without facing death or major non-fatal complications.In the unsuccessful group, 56 had less than a 50% reduction in thrombus load and 14 (10.3%) suffered major complications. The presence of obstruction (27.1% vs. 12.1%; p = 0.028), thrombus area 1.1 cm2 vs. 0.8 cm2; p = 0.005] and the duration of UFH treatment (15.1 vs. 11.8 (days); p = 0.005) were significantly higher in the unsuccessful UFH group.In multivariate regression analyses the presence of obstruction (RR: 3.088, p = 0.020), increased thrombus area (RR: 2.400; p = 0.015), and increased duration of UFH therapy (RR: 1.073 95%, p = 0.012) were identified as independent predictive parameters for a failed UFH therapy.

CONCLUSIONS

This study suggests that UFH therapy may be considered a relatively beneficial treatment strategy for some patients with PVT. The most significant factors affecting success are the obstructive nature and area of the thrombus.

Harnessing the potential of de-sulfated heparin for targeted drug delivery: A three-component approach exemplified by conjugation with galactose and paclitaxel

Heparin, an anticoagulant with a century-long history of use, has been investigated over the past decade as a potential drug delivery vehicle. Despite its safety and efficacy, its interactions with many proteins through specific sulfate patterns can complicate drug delivery by mediating diverse biological functions. Here, we present the synthesis of a three-component drug delivery system comprising de-sulfated heparin as the carrier, galactose as the targeting moiety, and paclitaxel as the therapeutic drug. Removal of sulfates eliminated most of its anticoagulant effects in all intermediates. Through coupling with galactose and paclitaxel, the system improved the solubility of the drug and achieved selective targeting and efficient drug delivery to HepG2 cells, a liver carcinoma cell line with high galactose receptor expression. While the three-component system exhibited a slightly higher IC50 value than native paclitaxel, demonstrating its efficacy as a drug carrier, the IC50 value for the normal human liver cell line QSG7701 was significantly higher, indicating its selectivity and safety. Our study introduces a novel approach utilizing desulfated heparin as a carrier, warranting further investigation to unlock its potential in targeted drug delivery strategies.

Nanosensor based approaches for quantitative detection of heparin

Heparin, being a widely employed anticoagulant in numerus clinical complications, requires strict quantification and qualitative screening to ensure the safety of patients from potential threat of thrombocytopenia. However, the intricacy of heparin's chemical structures and low abundance hinders the precise monitoring of its level and quality in clinical settings. Conventional laboratory assays have limitations in sensitivity and specificity, necessitating the development of innovative approaches. In this context, nanosensors emerged as a promising solution due to enhanced sensitivity, selectivity, and ability to detect heparin even at low concentrations. This review delves into a range of sensing approaches including colorimetric, fluorometric, surface-enhanced Raman spectroscopy, and electrochemical techniques using different types of nanomaterials, thus providing insights of its principles, capabilities, and limitations. Moreover, integration of smart-phone with nanosensors for point of care diagnostics has also been explored. Additionally, recent advances in nanopore technologies, artificial intelligence (AI) and machine learning (ML) have been discussed offering specificity against contaminants present in heparin to ensure its quality. By consolidating current knowledge and highlighting the potential of nanosensors, this review aims to contribute to the advancement of efficient, reliable, and economical heparin detection methods providing improved patient care.

Effect of bivalirudin on coagulation in neonatal (cord) and adult human blood in vitro

INTRODUCTION

Bivalirudin is recommended as an alternative to heparin in cardiac surgery with cardiopulmonary bypass. Although it has been used in infants and children for this indication, there is a paucity of data on the pharmacologic effects of bivalirudin in neonates. Given the immaturity of the hemostatic system in neonates, we hypothesized that coagulation responses to bivalirudin in this population would be different than in adults.

METHODS

Blood samples were drawn from placenta-cord units and from healthy adult donors. The study was carried out in two steps. First, bivalirudin was added to cord and adult blood samples at concentrations of 0, 5, 10, 15, and 20 μg/mL. Activated clotting time and thromboelastographic variables were recorded. Next, we used a Chandler loop system to assess the efficacy of bivalirudin in a simple model of cardiopulmonary bypass. The loops were primed with cord or adult blood and were run until thrombus was detected. Plasma bivalirudin concentrations were measured at 1, 15, 30, 45, 60, and 75 min after initiating rotation of the loops using liquid chromatography/mass spectrometry.

RESULTS

Bivalirudin elicited a dose-dependent prolongation inhibition of coagulation in both cord and adult blood samples with greater potency in cord blood in comparison to adult blood (activated clotting time: 627 ± 50 vs. 452 ± 22 s at 15 μg/mL bivalirudin, p < .0001). This relative potency was also demonstrated in the Chandler loop system, but interestingly, cord blood appeared to inactivate bivalirudin more rapidly than adult blood with earlier clotting in loops containing cord blood.

CONCLUSIONS

This study demonstrates that bivalirudin has greater potency in cord blood in vitro than in adult blood. Plasma degradation appears to proceed more rapidly in cord blood than in adults. Both of these findings should be considered when planning dosing regimens in neonatal patients.

Unveiling the Hidden Stroke Threat in Patients With Atrial Fibrillation and Primary Hyperparathyroidism

Recent American College of Cardiology (ACC), American Heart Association (AHA), American College of Clinical Pharmacy (ACCP), and Heart Rhythm Society (HRS) guidelines suggest that patients with atrial fibrillation (AF) at intermediate to low annual risk of ischemic stroke can benefit from consideration of factors that might modify their risk of stroke. The role of nontraditional risk factors, such as primary hyperparathyroidism (PHPT), remains unexplored. In our study, we investigated the potential association between PHPT and the risk of ischemic stroke in patients with AF. Using data from the Nationwide Inpatient Sample Database, a retrospective cohort study focused on the adult population with AF, we stratified the participants based on PHPT presence. Demographic information, co-morbidities, and hospitalization details were extracted using International Classification of Diseases, Tenth revision codes. Propensity score matching was applied, encompassing over 20 confounding variables, including the risk factors outlined in the CHA2DS2-VASc (Congestive heart failure (C), Hypertension (H), Age ≥75 years (A₂), Diabetes Mellitus (D), Stroke/Transient Ischemic Attack (TIA)/Thromboembolism (S₂), Vascular disease (V), Age 65-74 years (A), Sex category [female] (Sc)) score. Multivariate logistic regression analysis was performed after matching to assess the independent impact of PHPT as an ischemic stroke risk factor. A total of 2,051 of the identified 395,249 patients with AF had PHPT. The PHPT group had an average age of 74 years and consisted of more women (66.1% vs 53.0%). After matching, it was observed that the PHPT group had longer hospital stays (5 vs 4 days) and higher hospitalization charges ($45,126 vs $36,644). This group exhibited higher rates of ischemic stroke (6.0% vs 4.4%) and mortality (6.3% vs 4.9%). The adjusted outcomes showed a 1.4-fold increased risk for ischemic stroke and a 1.32-fold increased risk for mortality in the PHPT cohort. The subgroup analysis showed a higher incidence of mortality in men with a high CHA2DS2-VASc score. In conclusion, this study highlights a marked association between PHPT and ischemic stroke in patients with AF, independent of the conventional CHA2DS2-VASc score. The potential mechanisms implicated include vascular changes, cardiac dysfunction, and coagulation cascade alterations. The presence of PHPT should be taken into consideration when deciding the assessment of thromboembolic risk.

Clinical guideline on reversal of direct oral anticoagulants in patients with life threatening bleeding

BACKGROUND

Anticoagulation is essential for the treatment and prevention of thromboembolic events. Current guidelines recommend direct oral anticoagulants (DOACs) over vitamin K antagonists in DOAC-eligible patients. The major complication of anticoagulation is serious or life-threatening haemorrhage, which may necessitate prompt haemostatic intervention. Reversal of DOACs may also be required for patients in need of urgent invasive procedures. This guideline from the European Society of Anaesthesiology and Intensive Care (ESAIC) aims to provide evidence-based recommendations and suggestions on how to manage patients on DOACs undergoing urgent or emergency procedures including the treatment of DOAC-induced bleeding.

DESIGN

A systematic literature search was performed, examining four drug comparators (dabigatran, rivaroxaban, apixaban, edoxaban) and clinical scenarios ranging from planned to emergency surgery with the outcomes of mortality, haematoma growth and thromboembolic complications. The GRADE (Grading of Recommendations, Assessment, Development and Evaluation) methodology was used to assess the methodological quality of the included studies. Consensus on the wording of the recommendations was achieved by a Delphi process.

RESULTS

So far, no results from prospective randomised trials comparing two active comparators (e.g. a direct reversal agent and an unspecific haemostatic agent such as prothrombin complex concentrate: PCC) have been published yet and the majority of publications were uncontrolled and observational studies. Thus, the certainty of evidence was assessed to be either low or very low (GRADE C). Thirty-five recommendations and clinical practice statements were developed. During the Delphi process, strong consensus (>90% agreement) was achieved in 97.1% of recommendations and consensus (75 to 90% agreement) in 2.9%.

DISCUSSION

DOAC-specific coagulation monitoring may help in patients at risk for elevated DOAC levels, whereas global coagulation tests are not recommended to exclude clinically relevant DOAC levels. In urgent clinical situations, haemostatic treatment using either the direct reversal or nonspecific haemostatic agents should be started without waiting for DOAC level monitoring. DOAC levels above 50 ng ml-1 may be considered clinically relevant necessitating haemostatic treatment before urgent or emergency procedures. Before cardiac surgery under activated factor Xa (FXa) inhibitors, the use of andexanet alfa is not recommended because of inhibition of unfractionated heparin, which is needed for extracorporeal circulation. In the situation of DOAC overdose without bleeding, no haemostatic intervention is suggested, instead measures to eliminate the DOACs should be taken. Due to the lack of published results from comparative prospective, randomised studies, the superiority of reversal treatment strategy vs. a nonspecific haemostatic treatment is unclear for most urgent and emergency procedures and bleeding. Due to the paucity of clinical data, no recommendations for the use of recombinant activated factor VII as a nonspecific haemostatic agent can be given.

CONCLUSION

In the clinical scenarios of DOAC intake before urgent procedures and DOAC-induced bleeding, practitioners should evaluate the risk of bleeding of the procedure and the severity of the DOAC-induced bleeding before initiating treatment. Optimal reversal strategy remains to be determined in future trials for most clinical settings.

Safety and Efficacy of Enoxaparin During Low-Risk Elective Percutaneous Coronary Intervention

Intravenous unfractionated heparin (UFH) is the most frequently used anticoagulant for percutaneous coronary intervention (PCI). Intravenous enoxaparin, a low-molecular-weight heparin, has superior pharmacokinetic and pharmacodynamic properties compared with UFH. Multiple trials have shown enoxaparin to be safe and effective in PCI. However, there has not been a contemporary study evaluating its safety and efficacy. To assess its efficacy and safety, intravenous enoxaparin during PCI through radial artery access was evaluated in PCI patients from January 2015 to December 2019. Outcomes included procedural success, all-cause mortality, ischemic complications, and bleeding complications from the time of the procedure until hospital discharge. A total of 1019 consecutive eligible patients were identified. Median age was 63 years, and 70% were men. The indication for PCI was stable and unstable angina in two-thirds of cases (77%). Few patients had myocardial infarction (MI) (2.2%) as the indication for intervention. The procedure was successful in 98.2% of cases. There were no deaths. Procedural MI occurred in 0.3% of patients. Acute stent thrombosis occurred in 0.4%. Urgent revascularization and stroke occurred in 0.1% each. Small wrist hematomas occurred in 0.3% and all were managed conservatively. There was one radial artery pseudoaneurysm. There were no cases of major bleeding. In conclusion, this single-center study showed that intravenous enoxaparin is a reasonable alternative anticoagulant for use in low-risk and elective non-MI PCI through radial artery access.

Use of anticoagulants to improve pregnancy outcomes in couples positive for M2 haplotype: A systematic review

BACKGROUND

Placental mediated pregnancy complications (PMPC) are common, often recurring, and pose a significant health risk to mother and fetus. Evidence suggests that the hypercoagulable state associated with many PMPC, could reflect reduced expression of Annexin 5 (ANXA5), a naturally occurring anticoagulant protein in placental tissue. The ANXA5 M2 haplotype is a genetic variant, which results in reduced expression of ANXA5 protein. M2 haplotype carrier couples may therefore be at increased risk of PMPC. Evidence regarding the effectiveness of anticoagulation to prevent PMPC is inconsistent. Furthermore, studies have not selected or stratified for M2 haplotype carriers, in whom there is a predisposition to hypercoagulability, to assess the effectiveness of anticoagulation, which may vary from those without the M2 haplotype.

OBJECTIVES AND RATIONALE

The aim of this study was to systematically review the current evidence to assess whether anticoagulant treatment improves pregnancy outcomes in couples positive for M2 haplotype.

SEARCH METHODS

The review was registered on PROSPERO (CRD42022343943). A comprehensive literature search was performed using MEDLINE, Embase and Cochrane collaboration databases from inception to January 2023. Two reviewers assessed the articles for eligibility and extracted the data simultaneously. Primary outcome was successful pregnancy and live birth. Secondary outcomes included PMPC (implantation failure, miscarriage, pre-eclampsia, preterm birth and fetal growth restriction).

OUTCOMES

From a pool of 410 references, 10 were selected for full text review, of which three studies (a post hoc analysis of a randomised controlled trial, cohort study and a case report) were included in this review. Included studies comprised of 223 individuals, 129 of whom who received anticoagulation treatment after testing positive for M2 haplotype. The studies collectively showed an improvement in pregnancy outcomes in M2 haplotype positive individuals however, given the heterogeneity of studies, it was not possible to conduct a meta-analysis and draw firm conclusions.

WIDER IMPLICATIONS

Current evidence is limited, such that the value of screening couples for the M2 haplotype to select or stratify for treatment with prophylactic anticoagulation remains unknown. Thus, further studies including well designed, large, multi-centre randomised controlled trials are required to assess whether anticoagulation treatment will be effective in improving pregnancy outcomes in M2 haplotype couples.

[BLITZ-AF Cancer study: an international observational research project on patients with atrial fibrillation and cancer]

BACKGROUND

Cancer is an important condition associated with the development of atrial fibrillation (AF). The objectives of the BLITZ-AF Cancer study were to collect real-life information on the clinical profile and use of antithrombotic drugs in patients with AF and cancer to improve clinical management, as well as the evaluation of the association between different antithrombotic treatments (or their absence) and the main clinical events.

METHODS

European multinational, multicenter, prospective, non-interventional study conducted in patients with AF (electrocardiographically confirmed) and cancer occurring within 3 years. The CHA2DS2-VASc and the HAS-BLED scores were calculated in all enrolled patients.

RESULTS

From June 2019 to July 2021, 1514 patients were enrolled, 36.5% women, from 112 cardiology departments in 6 European countries (Italy, Belgium, the Netherlands, Spain, Portugal and Ireland). Italy enrolled 971 patients in 77 centers. Average age of patients was 74 ± 9 years, of which 20.9% affected by heart failure, 18.1% by ischemic heart disease, 9.8% by peripheral arterial disease and 38.5% by valvular diseases; 41.5% of patients had a CHA2DS2-VASc score ≥4. The most represented cancer sites were lung (14.9%), colorectal tract (14.1%), prostate (8.8%), or non-Hodgkin's lymphoma (8.1%). Before enrollment, 16.6% of patients were not taking antithrombotic therapy, while 22.7% were on therapy with antiplatelet agents and/or low molecular weight heparin. After enrollment these percentages decreased to 7.7% and 16.6%, respectively and, at the same time, the percentage of patients on direct oral anticoagulant (DOAC) therapy increased from 48.4% to 68.4%, also to the detriment of those on vitamin K antagonist therapy.

CONCLUSIONS

The BLITZ-AF Cancer study, which enrolled patients diagnosed with AF and cancer, highlights that the use of DOACs by cardiologists in this clinical context has increased, even though the guidelines on AF do not give accurate indications about oral anticoagulant therapy in patients with cancer.

Initial results of transcatheter modification of left atrial appendage by obliteration with device in patients with nonvalvular atrial fibrillation: Real-world data from the TERMINATOR registry

BACKGROUND

Percutaneous left atrial appendage closure (LAAC) has increased for those who need alternative to long-term anticoagulation with non-valvular atrial fibrillation (NVAF).

METHODS AND RESULTS

From September 2019, after initiating WATCHMAN (Boston Scientific, Maple Grove, MN, USA) device implantation, we established Transcatheter Modification of Left Atrial Appendage by Obliteration with Device in Patients from the NVAF (TERMINATOR) registry. Utilizing 729 patients' data until January 2022, we analyzed percutaneous LAAC data regarding this real-world multicenter prospective registry. A total of 729 patients were enrolled. Average age was 74.9 years and 28.5 % were female. Paroxysmal AF was 37.9 % with average CHADS2 3.2, CHA2DS2-VASc 4.7, and HAS-BLED score of 3.4. WATCHMAN implantation was successful in 99.0 %. All-cause deaths were 3.2 %, and 1.2 % cardiovascular or unexplained deaths occurred during follow-up [median 222, interquartile range (IQR: 93-464) days]. Stroke occurred in 2.2 %, and the composite endpoint which included cardiovascular or unexplained death, stroke, and systemic embolism were counted as 3.4 % [median 221, (IQR: 93-464) days]. Major bleeding defined as BARC type 3 or 5 was seen in 3.7 %, and there was 8.6 % of all bleeding events in total [median 219, (IQR: 93-464) days].

CONCLUSIONS

These preliminary data demonstrated percutaneous LAAC with WATCHMAN device might have a potential to reduce stroke and bleeding events for patients with NVAF. Further investigation is mandatory to confirm the long-term results of this strategy using this transcatheter local therapy instead of life-long systemic anticoagulation.

A case of pulmonary visceral subpleural hematoma treated by hematoma evacuation during care of post-cardiopulmonary resuscitation

BACKGROUND

The occurrence of pulmonary visceral subpleural hematoma during care of post-cardiopulmonary resuscitation including chest compressions and anticoagulant and antiplatelet therapies is extremely rare. Also, there are few reports of treatment of visceral subpleural hematoma, most of which are treated by lung resection. Here we describe a rare case that pulmonary visceral subpleural hematoma arose during post-cardiopulmonary resuscitation care and was treated by hematoma evacuation.

CASE PRESENTATION

A 58-year-old male with no smoking history and, past medical histories of rheumatoid arthritis, chronic atrial fibrillation, hypertension, diabetes, and dyslipidemia developed ventricular fibrillation due to myocardial infarction and fainted. He received bystander cardiopulmonary resuscitation and defibrillation by the ambulance crew and had return of spontaneous circulation. After transfer to our hospital, the patient underwent percutaneous catheter intervention and stenting with a diagnosis of myocardial infarction, followed by anticoagulant and antiplatelet therapies. On the 8th hospital day, chest radiography suggested right lower lobe pneumonia, and subsequent chest computed tomography revealed pulmonary hematoma in the visceral subpleural area from S6 to S10. Since no improvement was observed in hypoxemia, treatment was considered necessary. First, an attempt at computed tomography-guided drainage of hematoma was made, but insertion of the Pig-tail catheter was difficult due to hardness of the hematoma. Next, evacuation of hematoma was performed on the 13th hospital day. The hematoma was located in the visceral subpleural area and was removed by incising the pleura. TachoSil Tissue Sealing sheet and Polyglycoal acid sheet were applied to the sites of air leakage and oozing after hematoma evacuation. No re-bleeding or air leakage was observed after the treatment, and the patient was discharged on the 26th hospital day after an uneventful course.

CONCLUSIONS

Pulmonary visceral subpleural hematoma may occur during post-cardiopulmonary resuscitation care, including chest compressions and anticoagulant and antiplatelet therapies. In our case, CT-guided puncture and drainage was difficult and surgical treatment by incision of the visceral pleura and hematoma evacuation alone was done successfully.

Patterns of comorbidities in patients with atrial fibrillation and impact on management and long-term prognosis: an analysis from the Prospective Global GLORIA-AF Registry

BACKGROUND

Clinical complexity, as the interaction between ageing, frailty, multimorbidity and polypharmacy, is an increasing concern in patients with AF. There remains uncertainty regarding how combinations of comorbidities influence management and prognosis of patients with atrial fibrillation (AF). We aimed to identify phenotypes of AF patients according to comorbidities and to assess associations between comorbidity patterns, drug use and risk of major outcomes.

METHODS

From the prospective GLORIA-AF Registry, we performed a latent class analysis based on 18 diseases, encompassing cardiovascular, metabolic, respiratory and other conditions; we then analysed the association between phenotypes of patients and (i) treatments received and (ii) the risk of major outcomes. Primary outcome was the composite of all-cause death and major adverse cardiovascular events (MACE). Secondary exploratory outcomes were also analysed.

RESULTS

32,560 AF patients (mean age 70.0 ± 10.5 years, 45.4% females) were included. We identified 6 phenotypes: (i) low complexity (39.2% of patients); (ii) cardiovascular (CV) risk factors (28.2%); (iii) atherosclerotic (10.2%); (iv) thromboembolic (8.1%); (v) cardiometabolic (7.6%) and (vi) high complexity (6.6%). Higher use of oral anticoagulants was found in more complex groups, with highest magnitude observed for the cardiometabolic and high complexity phenotypes (odds ratio and 95% confidence interval CI): 1.76 [1.49-2.09] and 1.57 [1.35-1.81], respectively); similar results were observed for beta-blockers and verapamil or diltiazem. We found higher risk of the primary outcome in all phenotypes, except the CV risk factor one, with highest risk observed for the cardiometabolic and high complexity groups (hazard ratio and 95%CI: 1.37 [1.13-1.67] and 1.47 [1.24-1.75], respectively).

CONCLUSIONS

Comorbidities influence management and long-term prognosis of patients with AF. Patients with complex phenotypes may require comprehensive and holistic approaches to improve their prognosis.

Effect of Aspirin Versus Low-Molecular-Weight Heparin Thromboprophylaxis on Medication Satisfaction and Out-of-Pocket Costs: A Secondary Analysis of a Randomized Clinical Trial

BACKGROUND

Current guidelines recommend low-molecular-weight heparin for thromboprophylaxis after orthopaedic trauma. However, recent evidence suggests that aspirin is similar in efficacy and safety. To understand patients' experiences with these medications, we compared patients' satisfaction and out-of-pocket costs after thromboprophylaxis with aspirin versus low-molecular-weight heparin.

METHODS

This study was a secondary analysis of the PREVENTion of CLots in Orthopaedic Trauma (PREVENT CLOT) trial, conducted at 21 trauma centers in the U.S. and Canada. We included adult patients with an operatively treated extremity fracture or a pelvic or acetabular fracture. Patients were randomly assigned to receive 30 mg of low-molecular-weight heparin (enoxaparin) twice daily or 81 mg of aspirin twice daily for thromboprophylaxis. The duration of the thromboprophylaxis, including post-discharge prescription, was based on hospital protocols. The study outcomes included patient satisfaction with and out-of-pocket costs for their thromboprophylactic medication measured on ordinal scales.

RESULTS

The trial enrolled 12,211 patients (mean age and standard deviation [SD], 45 ± 18 years; 62% male), 9725 of whom completed the question regarding their satisfaction with the medication and 6723 of whom reported their out-of-pocket costs. The odds of greater satisfaction were 2.6 times higher for patients assigned to aspirin than those assigned to low-molecular-weight heparin (odds ratio [OR]: 2.59; 95% confidence interval [CI]: 2.39 to 2.80; p < 0.001). Overall, the odds of incurring any out-of-pocket costs for thromboprophylaxis medication were 51% higher for patients assigned to aspirin compared with low-molecular-weight heparin (OR: 1.51; 95% CI: 1.37 to 1.66; p < 0.001). However, patients assigned to aspirin had substantially lower odds of out-of-pocket costs of at least $25 (OR: 0.15; 95% CI: 0.12 to 0.18; p < 0.001).

CONCLUSIONS

Use of aspirin substantially improved patients' satisfaction with their medication after orthopaedic trauma. While aspirin use increased the odds of incurring any out-of-pocket costs, it protected against costs of ≥$25, potentially improving health equity for thromboprophylaxis.

LEVEL OF EVIDENCE

Therapeutic Level II . See Instructions for Authors for a complete description of levels of evidence.

Smaller nadroparin dose reductions required for patients with renal impairment: A multicenter cohort study

BACKGROUND

Guidelines advise 50 % and 25 % dose reduction of the therapeutic nadroparin dose (86 IU/kg) in patients with eGFR 15-29 and 30-60 ml/min respectively. For monitoring, peak anti-Xa levels are suggested. Data lack whether this results in therapeutic anti-Xa levels or in anti-Xa levels that are comparable to those of patients without renal impairment.

AIMS

To determine dose ranges in patients with renal impairment that result in therapeutic anti-Xa levels and to determine the percentage of the 86 IU/kg dose that results in anti-Xa levels normally occurring in patients without renal impairment.

METHODS

A retrospective cohort study was conducted in five hospitals. Patients ≥18 years of age, with an eGFR ≥ 15 ml/min were included. The first correctly sampled peak (i.e. 3-5 h after ≥ third administration, regardless of dose per patient) was included. Simulated prediction models were developed using multiple linear regression.

RESULTS

770 patients were included. eGFR and hospital affected the association between dose and anti-Xa level. The doses for peak anti-Xa levels of 0.75 IU/ml differed substantially between hospitals and ranged from 55 to 91, 65-359 and 68-168 IU/kg in eGFR 15-29, 30-60 and > 60 ml/min/1.73m2, respectively. In eGFR 15-29 and 30-60 ml/min/1.73m2, doses of 75 % and 91 % of 86 IU/kg respectively, were needed for anti-Xa levels normally occurring in patients with eGFR > 60 ml/min.

CONCLUSION

We advise against anti-Xa based dose-adjustments as long as anti-Xa assays between laboratories are not harmonized and an anti-Xa target range is not validated. A better approach might be to target levels similar to eGFR > 60 ml/min/1.73m2, which are achieved by smaller dose reductions.

Real-world experience with edoxaban for anticoagulation in children at risk for coronary artery thrombosis

BACKGROUND

Direct oral anticoagulants have the potential to improve care in children requiring chronic anticoagulation. Edoxaban has favourable pharmacokinetics that could benefit younger patients but data on long-term safety and efficacy for specific paediatric indications are lacking.

STUDY AIMS

We present a single-centre experience using edoxaban in children who require chronic anticoagulation for large coronary artery aneurysms secondary to Kawasaki disease.

METHODS

Weight-based dosing of once-daily oral edoxaban was offered as alternative to standard anticoagulation for patients aged 1-18 years. Chart review was performed for a median follow-up period of 49 months on edoxaban. Steady-state pharmacokinetics and pharmacodynamics of edoxaban were also explored.

RESULTS

Sixteen patients on chronic therapy with edoxaban were included. No major bleeding events were reported. Two patients experienced coronary artery thrombosis after 23 and 38 months on edoxaban, 7 and 11 years after diagnosed with Kawasaki disease, respectively. This predicts 70% event-free rate at 12 years from diagnosis. Area under the curve estimates over the dosing interval of 24 hours were similar to those reported in adults.

CONCLUSIONS

Edoxaban use is feasible and well-tolerated for long-term use in paediatric population. We suggest appropriate exposure using weight-based once-daily dosing strategy that may be comparable to standard-of-care anticoagulation in prevention of coronary artery thrombosis. Larger studies are needed to evaluate long-term safety and efficacy of edoxaban in this population.

Extended Post Discharge Prophylaxis for Venous Thromboembolism Prevention After Bariatric Surgery

PURPOSE

The utility of routine post-discharge VTE prophylaxis after bariatric surgery remains a matter of debate. While inpatient chemical prophylaxis decreases the risk of fatal pulmonary embolism, most thromboembolic events occur after discharge and carry high morbidity and mortality. To address this risk, apixaban was introduced as extended prophylaxis for 30 days after surgery.

MATERIALS AND METHODS

The study ranges between 1/2014 and 7/2022. Apixaban was incorporated as routine extended prophylaxis protocol in 05/2017 and is dosed at 2.5 mg BID for 30 days. There were two study groups: those who received apixaban on discharge (n = 1443; 60%) and those who did not (n = 953; 40%). Patients with concern for postoperative bleeding (hypotension, unexplained tachycardia with hematocrit drop > 6%, hematocrit drop > 9%), or on preoperative anticoagulant/antiplatelet therapy (except aspirin), were not discharged on apixaban. Post-discharge VTE, readmission, transfusion, and reoperation rates were compared between groups.

RESULTS

There were 2396 consecutive primary bariatric operations: sleeve gastrectomy (1949; 81%), Roux-en-Y gastric bypass (419; 18%), and duodenal switch (28; 1%). There were no post-discharge VTEs in patients treated with apixaban vs. five (0.5%) VTEs in patients who did not receive treatment; p = 0.02. There was a higher incidence in post-discharge bleeding events in the apixaban group (0.5 vs 0.3%; p = 0.75), mostly requiring readmission for monitoring without intervention or transfusion. In the apixaban group, one patient underwent EGD for bleeding while another required blood transfusion; there were no reoperations for bleeding.

CONCLUSION

There were no post-discharge VTEs in patients who received apixaban. Treatment was associated with a higher risk of self-resolving bleeding events. This study adds to the increasing body of evidence supporting the benefit of routine, extended oral chemoprophylaxis after bariatric surgery.

The effect of off-label use of reduced-dose direct oral anticoagulants therapy in the treatment of pulmonary embolism comparable to standard-dose therapy

Direct oral anticoagulants (DOACs) have been shown to be effective and safe in preventing pulmonary embolism recurrence. In this single-center retrospective observational study, we aimed to evaluate the efficacy and safety of reduced-dose DOACs in 86 consecutive patients with acute pulmonary embolism. Patients were divided into standard-dose and reduced-dose DOACs groups. Initial clot volume did not significantly differ between the two groups (standard-dose DOACs vs. reduced-dose DOACs, 18.8 [Q1-Q3 7.3-30.8] mL vs. 10.0 [Q1-Q3 3.2-27.9] mL, p = 0.1). Follow-up computed tomography (CT) within 30 days showed a higher rate of clot volume reduction or disappearance in the standard-dose group compared to the reduced-dose group (standard-dose DOACs vs. reduced-dose DOACs, 81.6% vs. 53.9%, p = 0.02). However, at the final follow-up CT, there was no significant difference in clot volume change between the two groups (standard-dose DOACs vs. reduced-dose DOACs, 91.5% vs. 82.0%, p = 0.19). Major bleeding occurred in two patients in the standard-dose group (4.3%) and three patients in the reduced-dose DOACs group (7.7%) (p = 0.5). In conclusion, while standard-dose DOACs demonstrated superior efficacy in early clot reduction, reduced doses of apixaban and edoxaban showed comparable efficacy and safety profiles in long-term treatment of acute pulmonary embolism in certain patients.

Cerebral Small Vessel Disease Burden for Bleeding Risk during Antithrombotic Therapy: Bleeding with Antithrombotic Therapy 2 Study

OBJECTIVE

This study was undertaken to determine the excess risk of antithrombotic-related bleeding due to cerebral small vessel disease (SVD) burden.

METHODS

In this observational, prospective cohort study, patients with cerebrovascular or cardiovascular diseases taking oral antithrombotic agents were enrolled from 52 hospitals across Japan between 2016 and 2019. Baseline multimodal magnetic resonance imaging acquired under prespecified conditions was assessed by a central diagnostic radiology committee to calculate total SVD score. The primary outcome was major bleeding. Secondary outcomes included bleeding at each site and ischemic events.

RESULTS

Of the analyzed 5,250 patients (1,736 women; median age = 73 years, 9,933 patient-years of follow-up), antiplatelets and anticoagulants were administered at baseline in 3,948 and 1,565, respectively. Median SVD score was 2 (interquartile range = 1-3). Incidence rate of major bleeding was 0.39 (per 100 patinet-years) in score 0, 0.56 in score 1, 0.91 in score 2, 1.35 in score 3, and 2.24 in score 4 (adjusted hazard ratio [aHR] for score 4 vs 0 = 5.47, 95% confidence interval [CI] = 2.26-13.23), that of intracranial hemorrhage was 0.11, 0.33, 0.58, 0.99, and 1.06, respectively (aHR = 9.29, 95% CI = 1.99-43.35), and that of ischemic event was 1.82, 2.27, 3.04, 3.91, and 4.07, respectively (aHR = 1.76, 95% CI = 1.08-2.86). In addition, extracranial major bleeding (aHR = 3.43, 95% CI = 1.13-10.38) and gastrointestinal bleeding (aHR = 2.54, 95% CI = 1.02-6.35) significantly increased in SVD score 4 compared to score 0.

INTERPRETATION

Total SVD score was predictive for intracranial hemorrhage and probably for extracranial bleeding, suggesting the broader clinical relevance of cerebral SVD as a marker for safe implementation of antithrombotic therapy. ANN NEUROL 2024;95:774-787.

Current and potentially novel antithrombotic treatment in acute ischemic stroke

Acute ischemic stroke (AIS) is the most common type of stroke and requires immediate reperfusion. Current acute reperfusion therapies comprise the administration of intravenous thrombolysis and/or endovascular thrombectomy. Although these acute reperfusion therapies are increasingly successful, optimized secondary antithrombotic treatment remains warranted, specifically to reduce the risk of major bleeding complications. In the development of AIS, coagulation and platelet activation play crucial roles by driving occlusive clot formation. Recent studies implicated that the intrinsic route of coagulation plays a more prominent role in this development, however, this is not fully understood yet. Next to the acute treatments, antithrombotic therapy, consisting of anticoagulants and/or antiplatelet therapy, is successfully used for primary and secondary prevention of AIS but at the cost of increased bleeding complications. Therefore, better understanding the interplay between the different pathways involved in the pathophysiology of AIS might provide new insights that could lead to novel treatment strategies. This narrative review focuses on the processes of platelet activation and coagulation in AIS, and the most common antithrombotic agents in primary and secondary prevention of AIS. Furthermore, we provide an overview of promising novel antithrombotic agents that could be used to improve in both acute treatment and stroke prevention.

Is a minimum duration of 5 days of unfractionated heparin infusion necessary before transition to oral anticoagulation in cerebral venous thrombosis? a retrospective chart review

In managing cerebral venous sinus thrombosis (CVT), the standard approach has been administering parenteral anticoagulation for at least five days, despite limited supporting evidence. This study aimed to determine the optimal duration of parenteral anticoagulation for CVT patients and its potential impact on their functional outcomes upon discharge. This retrospective observational cohort study was conducted across multiple healthcare centers and included adult CVT patients who received varying durations of parenteral anticoagulation: less than 5 days (n = 25) or 5 days or more (n = 16). The primary focus was on the duration of acute anticoagulation treatment, with secondary endpoints including hospital stay length and functional outcomes. The study found that a shorter duration of anticoagulation treatment (< 5 days) was linked to more favorable outcomes, as measured by the modified Rankin Scale (mRS) (68% vs. 25%, RR = 0.37, CI 0.15-0.90, p = 0.007). However, regression analysis showed non statistically significant associations for all variables except gender. Female patients were significantly more likely to receive a shorter duration of anticoagulation (Odds Ratio: 2.6, 95% CI: 2.2-3.1, P-Value: <0.001). These findings suggest a potential connection between shorter anticoagulation duration (< 5 days) and improved CVT patient outcomes, as indicated by their mRS scores at discharge. The observed relationship between female gender and shorter anticoagulation duration warrants further exploration. Nevertheless, caution is necessary when interpreting these findings due to the small sample size and specific patient characteristics. Further research in a larger and more diverse cohort is essential to validate these results and understand their implications fully.

Risk Stratification for Supratherapeutic Peak Anti-Xa Levels in Adult Patients on Therapeutic Enoxaparin

BACKGROUND

The American Society of Hematology Guidelines for the management of venous thromboembolism recommend against the use of anti-Xa monitoring for assessing enoxaparin dosing based on a low level of evidence associating supratherapeutic levels with an increased risk of bleeding. However, institutions still utilize anti-Xa levels in select patient populations with altered volume of distribution and/or excretion to monitor and adjust therapy.

OBJECTIVE

The primary objective of this study was to identify risk factors associated with supratherapeutic peak anti-Xa levels (≥1.10 IU/mL) for patients receiving therapeutic enoxaparin.

METHODS

This was a retrospective single-center study performed at an academic tertiary care hospital. Patients who received enoxaparin at 1 mg/kg twice daily and peak anti-Xa monitoring were separated into supratherapeutic and therapeutic/subtherapeutic cohorts.

RESULTS

A total of 436 patients were screened, and 215 were included, with a mean age of 62 years. There were 108 in the therapeutic/subtherapeutic cohort and 107 in the supratherapeutic cohort. Acute kidney injury (AKI), body mass index (BMI), weight, female sex, intensive care unit (ICU) service, Sequential Organ Failure Assessment (SOFA) score ≥4, and creatinine clearance at the time of peak anti-Xa level collection were associated with supratherapeutic anti-Xa levels in univariate models. Adjusted logistic regression models were created and identified BMI in the 30 to 34.9 kg/m2 (odds ratio [OR] 4.35; 95% confidence interval [CI] 1.70-11.13, P < 0.005) and ≥35 kg/m2 (OR 6.75; 95% CI 3.05-14.94, P < 0.005) and AKI (OR 2.62; 95% CI 1.04-6.62, P = 0.042) as significant risk factors for supratherapeutic anti-Xa levels.

CONCLUSION AND RELEVANCE

Our study identified BMI ≥ 30 kg/m2, AKI, female sex, ICU service, SOFA score ≥4, and creatinine clearance as risk factors for supratherapeutic anti-Xa levels in patients receiving 1 mg/kg twice daily dosing of enoxaparin. Further research should be done to provide evidence for the association between anti-Xa levels and bleeding risk.

Inpatient thrombophilia workup; does hematology consult prevent unnecessary testing?

Hypercoagulable disorders are best described as a group of acquired and hereditary conditions that increase the risk for the development of thrombi within veins or arteries. In the setting of an unprovoked venous thromboembolism, common practice in the inpatient setting has been further investigation via a thrombophilia workup to establish an underlying cause. Current Hematology-Oncology guidelines argue against inpatient workup as the results rarely influence inpatient management. Following American Society of Hematology guidelines (Middledorp), the current study found that only 15% (11/72) of patients met appropriate criteria for thrombophilia testing. There was no relationship between appropriate thrombophilia testing and diagnosis of thrombophilia or initiation of anticoagulation. There was a relationship between appropriate thrombophilia testing and Hematology-Oncology consultation. This demonstrates the need for expert consultation if thrombophilia testing is being considered. The current study provides more evidence that a strong recommendation against inpatient testing should be made as testing does not aid in diagnosis or change management and is an overutilization of healthcare resources.

Timing of Major Postoperative Bleeding Among Patients Undergoing Surgery

Importance

Although major bleeding is among the most common and prognostically important perioperative complications, the relative timing of bleeding events is not well established. This information is critical for preventing bleeding complications and for informing the timing of pharmacologic thromboprophylaxis.

Objective

To determine the timing of postoperative bleeding among patients undergoing surgery for up to 30 days after surgery.

Design, Setting, and Participants

This is a secondary analysis of a prospective cohort study. Patients aged 45 years or older who underwent inpatient noncardiac surgery were recruited in 14 countries between 2007 and 2013, with follow-up until December 2014. Data analysis was performed from June to July 2023.

Exposure

Noncardiac surgery requiring overnight hospital admission.

Main Outcomes and Measures

The primary outcome (postoperative major bleeding) was a composite of the timing of the following bleeding outcomes: (1) bleeding leading to transfusion, (2) bleeding leading to a postoperative hemoglobin level less than 7 g/dL, (3) bleeding leading to death, and (4) bleeding associated with reintervention. Each of the components of the composite primary outcome (1-4) and bleeding independently associated with mortality after noncardiac surgery, which was defined as a composite of outcomes 1 to 3, were secondary outcomes.

Results

Among 39 813 patients (median [IQR] age, 63.0 [54.8-72.5] years; 19 793 women [49.7%]), there were 5340 major bleeding events (primary outcome) in 4638 patients (11.6%) within the first 30 days after surgery. Of these events, 42.7% (95% CI, 40.9%-44.6%) occurred within 24 hours after surgery, 77.7% (95% CI, 75.8%-79.5%) by postoperative day 7, 88.3% (95% CI, 86.5%-90.2%) by postoperative day 14, and 94.6% (95% CI, 92.7%-96.5%) by postoperative day 21. Within 48 hours of surgery, 56.2% of major bleeding events, 56.2% of bleeding leading to transfusion, 56.1% of bleeding independently associated with mortality after noncardiac surgery, 51.8% of bleeding associated with hemoglobin less than 7 g/dL, and 51.8% of bleeding associated with reintervention had occurred.

Conclusions and Relevance

In this cohort study, of the major postoperative bleeding events in the first 30 days, more than three-quarters occurred during the first postoperative week. These findings are useful for researchers for the planning future clinical research and for clinicians in prevention of bleeding-related surgical complications and in decision-making regarding starting of pharmacologic thromboprophylaxis after surgery.

Pharmacokinetics, pharmacodynamics, and safety of frunexian in healthy Chinese volunteer adults: A randomized dose-escalation phase I study

The purpose of this study was to evaluate the safety, pharmacokinetics (PK), and pharmacodynamics (PD) of frunexian (formerly known as EP-7041 and HSK36273) injection, a small molecule inhibitor of activated coagulation factor XI (FXIa), in healthy Chinese adult volunteers. This study was a randomized, placebo- and positive-controlled, sequential, ascending-dose (0.3/0.6/1.0/1.5/2.25 mg/kg/h) study of 5-day continuous intravenous infusions of frunexian. Frunexian administration exhibited an acceptable safety profile with no bleeding events. Steady state was rapidly reached with a median time ranging from 1.02 to 1.50 h. The mean half-life ranged from 1.15 to 1.43 h. Frunexian plasma concentration at a steady state and area under the concentration-time curve exhibited dose-proportional increases. The dose-escalation study of frunexian demonstrated its progressively enhanced capacities to prolong activated partial thromboplastin time (aPTT) and inhibit FXIa activity. The correlations between PK and PD biomarkers (aPTT/baseline and FXI clotting activity/baseline) were described by the two Emax models, with the EC50 values of 8940 and 1300 ng/mL, respectively. Frunexian exhibits good safety and PK/PD properties, suggesting it is a promising candidate for anticoagulant drug.

Risk of venous thromboembolism in pregnant patients with active malignancy: A systematic review and meta-analysis

INTRODUCTION

Cancer currently occurs in about 1 in 1000 pregnancies. Both active malignancy and pregnancy are individual risk factors for venous thromboembolism (VTE). The purpose of this systematic review/meta-analysis was to evaluate the rate of VTE in pregnant patients with active malignancy compared with pregnant patients without malignancy.

MATERIAL AND METHODS

Embase, Medline/PubMed, Cochrane Database, and clinicaltrial.gov were search by a trained librarian from inception until June 2021, and limited to English and French language human studies using keywords related to pregnancy, neoplasm, and thrombosis. This study was prospectively registered with PROSPERO (CRD42021245886). Title, abstract, and full-text review was performed using the Covidence data management system. Two authors reviewed the studies independently. Of the 3821 articles screened, seven cohort studies were included that reported VTE rate in patients with active malignancy in pregnancy.

RESULTS

A total of 5928 individuals had active malignancy and pregnancy. Active malignancy in pregnancy significantly increased the odds of a VTE (odds ratio [OR] 6.8, 95% confidence interval [CI] 3.8-12.1). Specifically, patients with thyroid (OR 2.7, 95% CI 1.3-6.3), cervix (OR 6.6, 95% CI 2.4-18.0), or other gynecological (OR 10.6, 95% CI 4.4-25.8) cancers; Hodgkin's lymphoma (OR 8.7, 95% CI 3.3-23.4); or acute leukemia (OR 17.1, 95% CI 10.9-26.8) all had increased odds, whereas those with brain cancer (OR 6.1, 95% CI 0.4-98.2), breast cancer (OR 2.5, 95% CI 0.3-17.4), malignant melanoma (OR 5.5, 95% CI 0.3-88.1), or non-Hodgkin's lymphoma (OR 3.2, 95% CI 0.8-12.9) malignancies did not have statistically significant increased odds for VTE. No studies reported whether prophylactic anticoagulation was used during pregnancy in this population; nor did they report timing in pregnancy of the VTE. The absolute risk for VTE in those with active malignancy was 0.9% compared with 0.2% in those without active malignancy in pregnancy.

CONCLUSIONS

Pregnancy with active malignancy confers a significant increased risk for VTE compared with pregnancy alone. Given this finding, prophylactic anticoagulation during pregnancy and postpartum could be considered in this patient population. Data are underpowered to make firm recommendations per cancer type.

Intimate partner violence as a risk factor for venous thromboembolism in women on combined oral contraceptives: An international matched case-control study

BACKGROUND

Intimate partner violence (IPV) targeting women is probably underestimated during a woman's lifetime. Venous thromboembolism (VTE) is a multifactorial disease associated with haemostasis-activating conditions. Minor injuries can trigger VTE.

OBJECTIVES

We aimed to look for an association between VTE and IPV in women taking combined oral contraceptives (COCs) METHODS: We performed a multicentric, international, matched case-control study. Patients were women with a first VTE associated with COC intake. Controls were women taking COCs undergoing regular gynaecological check-ups. Patients and Controls were matched for country, age, length of COC intake and type (997 pairs). IPV was evaluated using the WAST self-administrated questionnaire.

RESULTS

IPV, defined as a WAST score value at least 5, was diagnosed in 33 Controls (3.3 %) and 109 patients (10.9 %), conditional odds ratio (OR): 3.586, 95 % confidence interval (2.404-5.549), p < 0.0001. After multivariate analysis, the adjusted OR was 3.720 (2.438-5.677), p < 0.0001. Sensitivity analysis using increasing WAST score thresholds confirmed the association.

CONCLUSIONS

A first VTE in women taking COCs is associated with IPV. This association can have strong human consequences but also raises significant medical issues, for instance on the haemorrhagic risk of anticoagulant treatments in abused women. Pathophysiological studies are warranted.

Direct oral anticoagulants in skin surgery: a systematic review of their complications and recommendations for perioperative management

INTRODUCTION

Many patients undergoing cutaneous surgery are prescribed at least one anticoagulant or antiplatelet agent. With the recent emergence of direct oral anticoagulants (DOACs), there is a deficit of knowledge regarding optimal perioperative management. This review aims to evaluate the evidence and risk surrounding management of DOACs in patients undergoing skin surgeries.

METHODS

Systematic review of EMBASE, Scopus, and PubMed, with inclusion of studies that detailed perioperative management of DOACs in those undergoing skin surgery. Primary outcome measures were perioperative hemorrhagic and thromboembolic complications.

RESULTS

Seven thousand seven hundred and forty-one abstracts were identified, with 13 articles meeting inclusion criteria. Two studies investigated complication risk associated with DOAC continuation in skin surgery and found an average rate of hemorrhagic complications of 1.74%. Two studies evaluated complications associated with DOAC cessation prior to skin surgery, with a pooled thromboembolic complication rate of 0.15%. Articles comparing continuation and cessation discovered no decreased risk of bleeding with DOAC cessation prior to surgery (P = 0.93). Seven of the 13 articles compared complications in a control vs a DOAC group undergoing cutaneous procedures. Evidence was conflicting but may have suggested a small increase in bleeding risk in those on DOAC therapy.

CONCLUSION

Optimal management of anticoagulants perioperatively is difficult because of conflicting information, complicated by advent of novel agents. Risk of hemorrhagic complications with both continuation and interruption of DOAC therapy was low. Perioperative DOAC management can be guided by procedural bleeding and patient clotting risk and can often be continued in minor dermatologic procedures.

[Geriatric patient with neurological symptoms and prolonged aPTT]

A 73-year-old man with dementia was referred to our clinic with hypernatremia and volume depletion. New-onset neurogenic dysphagia was likely the reason for both. The patient had chronic embolic strokes on the computed tomography (CT) images. Documentation from previous hospitalizations in different hospitals revealed a repeatedly prolonged activated partial thromboplastin time (aPTT); 5 years prior, antiphospholipid antibody syndrome had already been suspected, but the necessary workup was never completed. We diagnosed the patient with primary antiphospholipid antibody syndrome and initiated therapy with vitamin K antagonists (phenprocoumon) and aspirin.

Age-related variation in coagulation factors in non-valvular atrial fibrillation patients receiving direct oral anticoagulants

Age is a significant risk factor for ischemic stroke. However, the influence of aging on coagulation parameters in non-valvular atrial fibrillation (NVAF) patients treated with direct oral anticoagulants (DOACs) remains unclear. A total of 775 samples were collected from 224 NVAF patients receiving apixaban, edoxaban or rivaroxaban. The samples were categorized into three age groups: (i) ≤ 64 years, (ii) 65-74 years, and (iii) ≥ 75 years (apixaban: N = 48, 108, 119; edoxaban: N = 63, 68, 126; rivaroxaban: N = 115, 90, 38, respectively). Coagulation parameters including fibrinogen (Fbg), factor II, factor V, factor VII, factor X, and D-dimer, were compared between the three age groups for each drug. The slopes in the correlation between drug concentrations and modified diluted prothrombin time (mdPT) were also assessed. Fbg and factor V increased with age, while factor II and factor X decreased. Factor VII and D-dimer showed no significant differences across age categories. The slope in response to drug concentrations was similar between the age groups. In NVAF patients treated with apixaban, edoxaban and rivaroxaban, some coagulation parameters exhibited age-related variation. However, the response of mdPT to drug concentration was consistent across age categories.

[Choice of the prosthetic valve in patients aged between 55 and 70 years]

About 280 000 heart valve replacements are performed worldwide every year. Since the first prosthetic valve implantation in 1952 there have been notable developments. There are a lot of types of prosthetic valves that can be summarized into two categories: biological prosthetic valves or mechanical prosthetic valves. Biological prostheses, made of bovine or porcine pericardium, homografts, or autografts, degenerate over time becoming dysfunctional. Mechanical prostheses have a potentially unlimited lifespan but require oral anticoagulation which can affect patients' quality of life. Generally, biological prostheses are particularly suitable for elderly patients while mechanical prostheses for young people, with some distinctions. For example, in case of age <60 years, in the presence of preoperative oral anticoagulant therapy, metabolic syndrome, hemodialysis or hyperparathyroidism, a mechanical valve is the preference. The choice of the prosthesis in patients aged between 55 and 70 years is particularly challenging because the advantages and disadvantages of the two categories of prosthesis overlap in middle-aged patients. The choice of the prosthesis should be made after discussion with the surgeon, according to the patient's preferences, and keeping in mind the pros and cons of biological and mechanical prostheses.

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

Background

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

Objectives

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

Design

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

Setting

NHS hospitals, with primary data collection at four sites.

Participants

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

Interventions

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

Main outcome measures

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

Results

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

Limitations

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

Conclusions

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

Future work

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

Study registration

This study is registered as PROSPERO CRD42020165778 and Researchregistry5216.

Funding

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

Safety of dry needling in stroke patients: a scoping review

INTRODUCTION

Spasticity is a common problem in stroke patients. Treatments of spasticity often have side effects or are insufficiently effective. Dry needling (DN) has been proposed as a potential additional option to consider in the multimodal treatment of post-stroke spasticity, although questions about its safety remain. The goal of this study is to assess the safety of DN in stroke patients.

EVIDENCE ACQUISITION

A systematic search in Medline, Embase, The Cochrane Library, Web of Science, CIHNAL and PEDro was conducted in June 2023. Two reviewers independently screened abstracts according to the eligibility criteria.

EVIDENCE SYNTHESIS

Twenty-five articles were included in this review. Only six studies reported adverse events, all of which were considered minor. None of the included studies reported any serious adverse events. In four of the included studies anticoagulants were regarded as contra-indicative for DN. Anticoagulants were not mentioned in the other included studies.

CONCLUSIONS

There is a paucity of literature concerning the safety of DN in stroke patients. This review is the first to investigate the safety of DN in stroke patients and based on the results there is insufficient evidence regarding the safety of DN in stroke patients.

CLINICAL REHABILITATION IMPACT

Although DN could be a promising treatment in post-stroke spasticity, further research is indicated to investigate its mechanism of action and its effect on outcome. However, before conducting large clinical trials to assess outcome parameters, the safety of DN in stroke patients must be further investigated.

Small Bowel Obstruction Secondary to a Spontaneous Intramural Jejunal Hematoma

N/a.

Thrombosis prophylaxis following trauma

PURPOSE OF REVIEW

This review explores the persistent occurrence of venous thromboembolic events (VTE) in major trauma patients despite standard thrombosis prophylaxis with low-molecular-weight heparin (LMWH) or unfractionated heparin (UFH). It investigates the inadequacies of standard pharmacologic prophylaxis and proposes alternative approaches not covered in current trauma guidelines.

RECENT FINDINGS

Recent studies highlight the effectiveness of monitoring and adjusting subcutaneous LMWH doses based on anti-Xa levels for the purpose of reducing VTE in trauma patients. The need for dose adaptation arises due to factors like fluctuating organ function, varying antithrombin levels, interaction with plasma proteins, and altered bioavailability influenced by oedema or vasopressor use. Additionally, promising alternatives such as intravenous LMWH, UFH, and argatroban have shown success in intensive care settings.

SUMMARY

The standard dosing of subcutaneous LMWH is often insufficient for effective thrombosis prophylaxis in trauma patients. A more personalised approach, adjusting doses based on specific effect levels like anti-Xa or choosing an alternative mode of anticoagulation, could reduce the risk of insufficient prophylaxis and subsequent VTE.

Dual antithrombotic therapy dose-dependently alters hemostatic plug structure and function

BACKGROUND

Antithrombotic medications carry an inherent risk of bleeding, which may be exacerbated when anticoagulant and antiplatelet therapeutics are combined. Prior studies have shown different effects of antiplatelet vs anticoagulant drugs on the structure and function of hemostatic plugs in vivo.

OBJECTIVES

We examined whether dual antithrombotic treatment consisting of combined antiplatelet and anticoagulant therapeutics alters hemostatic plug structure and function differently from treatment with either therapeutic alone.

METHODS

Mice were treated with the P2Y12 antagonist clopidogrel and the factor Xa inhibitor rivaroxaban across a range of doses, either alone or in combination. The hemostatic response was assessed using a mouse jugular vein puncture injury model. Platelet accumulation and fibrin deposition were evaluated using quantitative multiphoton fluorescence microscopy, and bleeding times were recorded.

RESULTS

Mice treated with clopidogrel alone exhibited a decrease in platelet accumulation at the site of injury, with prolonged bleeding times only at the highest doses of clopidogrel used. Mice treated with rivaroxaban alone instead showed a reduction in fibrin deposition with no impact on bleeding. Mice treated with both clopidogrel and rivaroxaban exhibited platelet and fibrin accumulation that was similar to that with either drug given alone; however, dual antithrombotic therapy resulted in impaired hemostasis at doses that had no impact on bleeding when given in isolation.

CONCLUSION

Combined administration of antiplatelet and anticoagulant therapeutics exacerbates bleeding as compared to that with either drug alone, potentially via combined loss of both adenosine 5'-diphosphate- and thrombin-mediated platelet activation. These findings enhance our understanding of the bleeding risk associated with dual antithrombotic therapy.

The Complex Role of Thrombin in Cancer and Metastasis: Focus on Interactions with the Immune System

Thrombin, a pleiotropic enzyme involved in coagulation, plays a crucial role in both procoagulant and anticoagulant pathways. Thrombin converts fibrinogen into fibrin, initiates platelet activation, and promotes clot formation. Thrombin also activates anticoagulant pathways, indirectly inhibiting factors involved in coagulation. Tissue factor triggers thrombin generation, and the overexpression of thrombin in various cancers suggests that it is involved in tumor growth, angiogenesis, and metastasis. Increased thrombin generation has been observed in cancer patients, especially those with metastases. Thrombin exerts its effects through protease-activated receptors (PARs), particularly PAR-1 and PAR-2, which are involved in cancer progression, angiogenesis, and immunological responses. Thrombin-mediated signaling promotes angiogenesis by activating endothelial cells and platelets, thereby releasing proangiogenic factors. These functions of thrombin are well recognized and have been widely described. However, in recent years, intriguing new findings concerning the association between thrombin activity and cancer development have come to light, which justifies a review of this research. In particular, there is evidence that thrombin-mediated events interact with the immune system, and may regulate its response to tumor growth. It is also worth reevaluating the impact of thrombin on thrombocytes in conjunction with its multifaceted influence on tumor progression. Understanding the role of thrombin/PAR-mediated signaling in cancer and immunological responses is crucial, particularly in the context of developing immunotherapies. In this systematic review, we focus on the impact of the thrombin-related immune system response on cancer progression.

Validation of the IMPEDE VTE score for prediction of venous thromboembolism in Chinese patients with multiple myeloma: A single-center retrospective cohort study

Multiple myeloma (MM) significantly increases the risk of venous thromboembolism (VTE) within 6 months of treatment initiation. The IMPEDE VTE score is a VTE risk prediction model which is recently incorporated into the National Comprehensive Cancer Network (NCCN) guidelines, but it lacks validation among Asians, including Chinese MM patients. We performed a retrospective chart review of 405 Chinese with newly diagnosed MM who started therapy at Beijing Jishuitan Hospital between April 2013 to October 2022. The 6-month cumulative incidence of VTE was 3.8 % (95 % CI:1.6-7.6), 8.6 % (95 % CI: 5.3-21.9) and 40.5 % (95 % CI: 24.9-55.7) in the low-, intermediate- and high-risk groups (P < 0.001), respectively. The C-statistic of the IMPEDE VTE scores for predicting VTE within 6 months of treatment initiation was 0.74 (95 % CI: 0.65-0.83). Of note, in this single-center cohort study, we propose that the anticoagulant LMWH may be more effective than the antiplatelet aspirin in potentially preventing VTE in newly diagnosed MM patients. Our findings suggest that the IMPEDE VTE score is a valid evidence-based risk stratification tool in Chinese patients with newly diagnosed MM.

Should recommended laboratory-test cut-offs allowing surgery be followed for proximal femoral fractures in patients on direct oral anticoagulant therapy?

BACKGROUND

Proximal femoral fractures (PFFs) in elderly patients must receive prompt surgical treatment. Optimal PFF-surgery timing in patients on direct oral anticoagulant (DOA) therapy is a specific but common clinical issue. Recommendations exist about the anti-Xa or anti-IIa levels and creatinine clearance values required to allow surgery. The objectives of this study in patients older than 75 years who required PFF surgery were to evaluate bleeding when the recommendations were versus were not applied and to assess concordance between DOA-activity-assay results and creatinine clearance used to help determine the wait to surgery.

HYPOTHESIS

Peri-operative bleeding is more marked when surgery is performed while the DOA is still active.

PATIENTS AND METHODS

This single-centre, retrospective, comparative, observational study included 87 patients older than 75 years who required arthroplasty or intra-medullary nailing for PFF and were taking DOA therapy. Surgery was performed after versus before the laboratory-test results fell below the recommended cut-offs in 68 patients (Rec+ group) versus 19 patients (Rec- group), respectively. The study outcomes were blood loss estimated using the Mercuriali's formula and the proportion of patients requiring post-operative blood transfusions.

RESULTS

Mean blood loss was 287.1mL in the Rec+ group and 411.7mL in the Rec- group (p=0.12). Blood transfusions were required by a post-operative haemoglobin level below 0.8g/dL in 11 (16.2%) Rec+ patients and 6 (31.6%) Rec- patients (p=0.2). Concordance was poor between DOA activity and creatinine clearance (Cohen's κ, 0.16; p=0.146).

DISCUSSION

Peri-operative bleeding was not significantly more severe when PFF surgery was performed while DOA therapy was still active. These data suggest that PFF surgery within 48h may be appropriate in patients older than 75 years on DOA therapy.

LEVEL OF EVIDENCE

IV; retrospective single-centre study.

Apixaban-Associated Intracranial Hemorrhage in a Patient With Elevated International Normalized Ratio

Apixaban has been associated with prolongation of the international normalized ratio (INR), but data surrounding the extent of elevation and its clinical significance are limited. Due to interaction between apixaban and the prothrombin assay, elevations in INR in patients receiving apixaban are common and not always grounds for concern. However, in high risk patients, elevations can represent a need for closer monitoring. This case summarizes an 82-year-old woman with a history of atrial fibrillation and left middle cerebral artery strokes with no residual deficits. She presented with right-sided hemiparesis and aphasia and underwent a mechanical thrombectomy with TICI 2b recanalization of a left M1 occlusion. Post-thrombectomy, she was found to have a left atrial thrombus and 10 days later was started on apixaban 5 mg twice daily. On the fourth day of apixaban therapy, she experienced an INR increase to 2.3, prompting initiation of a vitamin K challenge for nutritional deficiency. Despite initial improvement, her INR increased to 2.7 a week after apixaban was initiated, coinciding with a decline in mental status and an apixaban peak level of 435.6 ng/mL (reference range 91-321 ng/mL). A computed tomography (CT) scan of her head showed new intracranial hemorrhage in the area of her previous infarction, prompting apixaban reversal with andexanet alfa. Unfortunately, the patient expired. This case report highlights the importance and difficulty in performing therapeutic drug monitoring in patients receiving oral anti-factor Xa inhibitors, revealing a downside to administration of high-risk medications that do not have readily available monitoring.

Anti-factor Xa as the preferred assay to monitor heparin for the treatment of pulmonary embolism

INTRODUCTION

The mainstay of acute pulmonary embolism (PE) treatment is anticoagulation. Timely anticoagulation correlates with decreased PE-associated mortality, but the ability to achieve a therapeutic activated partial thromboplastin time (aPTT) with unfractionated heparin (UFH) remains limited. Although some institutions have switched to a more accurate and reproducible test to assess for heparin's effectiveness, the anti-factor Xa (antiXa) assay, data correlating a timely therapeutic antiXa to PE-associated clinical outcomes remains scarce. We evaluated time to a therapeutic antiXa using intravenous heparin after PE response team (PERT) activation and assessed clinical outcomes including bleeding and recurrent thromboembolic events.

METHODS

This was a retrospective cohort study at NYU Langone Health. All adult patients ≥18 years with a confirmed PE started on IV UFH with >2 antiXa levels were included. Patients were excluded if they received thrombolysis or alternative anticoagulation. The primary endpoint was the time to a therapeutic antiXa level of 0.3-0.7 units/mL. Secondary outcomes included recurrent thromboembolism, bleeding and PE-associated mortality within 3 months.

RESULTS

A total of 330 patients with a PERT consult were identified with 192 patients included. The majority of PEs were classified as sub massive (64.6%) with 87% of patients receiving a bolus of 80 units/kg of UFH prior to starting an infusion at 18 units/kg/hour. The median time to the first therapeutic antiXa was 9.13 hours with 93% of the cohort sustaining therapeutic anticoagulation at 48 hours. Recurrent thromboembolism, bleeding and mortality occurred in 1%, 5% and 6.2%, respectively. Upon univariate analysis, a first antiXa <0.3 units/ml was associated with an increased risk of mortality [27.78% (5/18) vs 8.05% (14/174), p = 0.021].

CONCLUSION

We observed a low incidence of recurrent thromboembolism or PE-associated mortality utilizing an antiXa titrated UFH protocol. The use of an antiXa based heparin assay to guide heparin dosing and monitoring allows for timely and sustained therapeutic anticoagulation for treatment of PE.

Antithrombotic therapy for stable coronary artery disease and atrial fibrillation in patients with and without revascularisation: the AFIRE trial

BACKGROUND

The Atrial Fibrillation and Ischemic Events with Rivaroxaban in Patients with Stable Coronary Artery Disease (AFIRE) trial demonstrated non-inferior efficacy endpoints for rivaroxaban monotherapy versus combination therapy (rivaroxaban plus a single antiplatelet) and superior safety endpoints in patients with atrial fibrillation and stable coronary artery disease.

AIMS

This post hoc analysis investigated whether the AFIRE trial results reflected the presence or absence of prior revascularisation.

METHODS

Among 2,215 patients, 1,697 (76.6%) had previously undergone revascularisation, and the remaining 518 (23.4%) had not undergone prior revascularisation. The primary efficacy endpoint was a composite of stroke, systemic embolism, myocardial infarction, unstable angina requiring revascularisation, or death from any cause, while the primary safety endpoint was major bleeding.

RESULTS

In 1,697 patients with prior revascularisation, the efficacy and safety endpoints were superior for monotherapy versus combination therapy (efficacy: hazard ratio [HR] 0.62, 95% confidence interval [CI]: 0.45-0.85; p=0.003; safety: HR 0.62, 95% CI: 0.39-0.98; p=0.042). Among 518 without prior revascularisation, there were no significant differences in endpoints (efficacy: HR 1.19, 95% CI: 0.67-2.12; p=0.554; safety: HR 0.47, 95% CI: 0.18-1.26; p=0.134). There was borderline interaction of the efficacy endpoints (p=0.055) between two treatments. The safety benefit of monotherapy on any bleeding was significant in patients without prior revascularisation (HR 0.59, 95% CI: 0.38-0.93; p=0.022).

CONCLUSIONS

In high-risk thrombosis patients with a history of prior revascularisation, rivaroxaban monotherapy versus combination therapy demonstrated favourable safety and efficacy outcomes.

Thrombomodulin: a multifunctional receptor modulating the endothelial quiescence

Thrombomodulin (TM) is a type 1 receptor best known for its function as an anticoagulant cofactor for thrombin activation of protein C on the surface of vascular endothelial cells. In addition to its anticoagulant cofactor function, TM also regulates fibrinolysis, complement, and inflammatory pathways. TM is a multidomain receptor protein with a lectin-like domain at its N-terminus that has been shown to exhibit direct anti-inflammatory functions. This domain is followed by 6 epidermal growth factor-like domains that support the interaction of TM with thrombin. The interaction inhibits the procoagulant function of thrombin and enables the protease to regulate the anticoagulant and fibrinolytic pathways by activating protein C and thrombin-activatable fibrinolysis inhibitor. TM has a Thr/Ser-rich region immediately above the membrane surface that harbors chondroitin sulfate glycosaminoglycans, and this region is followed by a single-spanning transmembrane and a C-terminal cytoplasmic domain. The structure and physiological function of the extracellular domains of TM have been extensively studied, and numerous excellent review articles have been published. However, the physiological function of the cytoplasmic domain of TM has remained poorly understood. Recent data from our laboratory suggest that intracellular signaling by the cytoplasmic domain of TM plays key roles in maintaining quiescence by modulating phosphatase and tensin homolog signaling in endothelial cells. This article briefly reviews the structure and function of extracellular domains of TM and focuses on the mechanism and possible physiological importance of the cytoplasmic domain of TM in modulating phosphatase and tensin homolog signaling in endothelial cells.