Evidence-based management of anticoagulant therapy: Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines

Frequency of prothrombin time-international normalized ratio monitoring and the long-term prognosis in patients with mechanical valve replacement

BACKGROUND

The study aimed to assess the correlation between the monitoring frequency of PT-INR and the long-term prognosis in patients with mechanical heart valve (MHV) replacement after discharge.

METHODS

This single-center, observational study enrolled patients who underwent MHV replacement and discharged from June 2015 to May 2018. Patients or their corresponding family members were followed with a telephone questionnaire survey in July-October 2020. Based on monitoring intervals, patients were divided into frequent monitoring (FM) group (≤ 1 month) and less frequent monitoring (LFM) group (> 1 month). The primary endpoint was the composite of thromboembolic event, major bleeding or all-cause death. The secondary endpoints were thromboembolic event, major bleeding or all-cause death, respectively.

RESULTS

A total of 188 patients were included in the final analysis. The median follow-up duration was 3.6 years (Interquartile range: 2.6 to 4.4 years). 104 (55.3%) patients and 84 (44.7%) patients were classified into the FM group and the LFM group, respectively. The FM group had a significantly lower incidence of the primary endpoint than the LFM group (3.74 vs. 1.16 per 100 patient-years, adjusted HR: 3.31 [95% CI 1.05-10.42, P = 0.041]). Secondary analysis revealed that the risk of thromboembolic events and all-cause death were also reduced in the FM group.

CONCLUSIONS

The management of warfarin treatment in patients after MHV replacement remains challenging. Patients with less frequent monitoring of PT-INR might have worse clinical prognosis than those with frequent PT-INR monitoring.

Managing Anticoagulation and Dual Antiplatelet Therapy in Patients with Active Bleed or Upcoming Procedure: A Scoping Review

Introduction

The aim of this paper is to provide primary care providers and hospitalists with up-to-date guidance surrounding the management of anticoagulation and antiplatelet agents in periprocedural settings and when unexpected bleeding complications arise.

Methods

We searched PubMed, Cochrane CENTRAL, and Web of Science using applicable MeSH terms and keywords. No date limits or filters were applied. Articles cited by recent cardiovascular guidelines were also utilized.

Results

For direct oral anticoagulants (DOACs) and vitamin K agonists (VKAs), a patient's risk for clot and procedural risk of bleeding should be assessed. Generally, patients considered at high risk for venous thromboembolism (VTE) should be bridged, patients at low risk should forgo bridging therapy, and patients in the intermediate range should be evaluated on a case-by-case basis. Emergent anticoagulation reversal treatment is available for both warfarin (i.e., prothrombin complex concentrate, phytonadione) and DOACs (i.e., idarucizumab for dabigatran reversal; andexanet alfa for apixaban and rivaroxaban reversal). DAPT does not need to be held for paracentesis or thoracentesis and is low risk for those needing urgent lumbar punctures. In patients with clinically significant bleeding, those with percutaneous coronary intervention (PCI) performed in the last three months should resume DAPT as soon as the patient is hemodynamically stable, while patients greater than three months out from PCI at high risk of bleed can be de-escalated to single antiplatelet therapy.

Conclusions

Appropriate management of anticoagulation and antiplatelet agents in the periprocedural setting and patients with active bleed remains critical in inpatient management.

Dimethyl fumarate and 4-octyl itaconate are anticoagulants that suppress Tissue Factor in macrophages via inhibition of Type I Interferon

Excessive inflammation-associated coagulation is a feature of infectious diseases, occurring in such conditions as bacterial sepsis and COVID-19. It can lead to disseminated intravascular coagulation, one of the leading causes of mortality worldwide. Recently, type I interferon (IFN) signaling has been shown to be required for tissue factor (TF; gene name F3) release from macrophages, a critical initiator of coagulation, providing an important mechanistic link between innate immunity and coagulation. The mechanism of release involves type I IFN-induced caspase-11 which promotes macrophage pyroptosis. Here we find that F3 is a type I IFN-stimulated gene. Furthermore, F3 induction by lipopolysaccharide (LPS) is inhibited by the anti-inflammatory agents dimethyl fumarate (DMF) and 4-octyl itaconate (4-OI). Mechanistically, inhibition of F3 by DMF and 4-OI involves suppression of Ifnb1 expression. Additionally, they block type I IFN- and caspase-11-mediated macrophage pyroptosis, and subsequent TF release. Thereby, DMF and 4-OI inhibit TF-dependent thrombin generation. In vivo, DMF and 4-OI suppress TF-dependent thrombin generation, pulmonary thromboinflammation, and lethality induced by LPS, E. coli, and S. aureus, with 4-OI additionally attenuating inflammation-associated coagulation in a model of SARS-CoV-2 infection. Our results identify the clinically approved drug DMF and the pre-clinical tool compound 4-OI as anticoagulants that inhibit TF-mediated coagulopathy via inhibition of the macrophage type I IFN-TF axis.

Position statement from the Indian Society of Gastroenterology, Cardiological Society of India, Indian Academy of Neurology and Vascular Society of India on gastrointestinal bleeding and endoscopic procedures in patients on antiplatelet and/or anticoagulant therapy

Antiplatelet and/or anticoagulant agents (collectively known as antithrombotic agents) are used to reduce the risk of thromboembolic events in patients with conditions such as atrial fibrillation, acute coronary syndrome, recurrent stroke prevention, deep vein thrombosis, hypercoagulable states and endoprostheses. Antithrombotic-associated gastrointestinal (GI) bleeding is an increasing burden due to the growing population of advanced age with multiple comorbidities and the expanding indications for the use of antiplatelet agents and anticoagulants. GI bleeding in antithrombotic users is associated with an increase in short-term and long-term mortality. In addition, in recent decades, there has been an exponential increase in the use of diagnostic and therapeutic GI endoscopic procedures. Since endoscopic procedures hold an inherent risk of bleeding that depends on the type of endoscopy and patients' comorbidities, in patients already on antithrombotic therapies, the risk of procedure-related bleeding is further increased. Interrupting or modifying doses of these agents prior to any invasive procedures put these patients at increased risk of thromboembolic events. Although many international GI societies have published guidelines for the management of antithrombotic agents during an event of GI bleeding and during urgent and elective endoscopic procedures, no Indian guidelines exist that cater to Indian gastroenterologists and their patients. In this regard, the Indian Society of Gastroenterology (ISG), in association with the Cardiological Society of India (CSI), Indian Academy of Neurology (IAN) and Vascular Society of India (VSI), have developed a "Guidance Document" for the management of antithrombotic agents during an event of GI bleeding and during urgent and elective endoscopic procedures.

Perioperative Management of Anticoagulant and Antiplatelet Therapy

Anticoagulant and Antiplatelet Drug ManagementManagement of patients on an anticoagulant or antiplatelet drug who require surgery or an invasive procedure is a common clinical problem. Douketis and Spyropoulos provide an evidence-based but practical approach to managing anticoagulants and antiplatelet drugs in the perioperative setting.

Circulating and extracellular vesicle-derived microRNAs as biomarkers in bone-related diseases

MicroRNAs (miRNA) are small non-coding RNA molecules that regulate posttranscriptional gene expression by repressing messengerRNA-targets. MiRNAs are abundant in many cell types and are secreted into extracellular fluids, protected from degradation by packaging in extracellular vesicles. These circulating miRNAs are easily accessible, disease-specific and sensitive to small changes, which makes them ideal biomarkers for diagnostic, prognostic, predictive or monitoring purposes. Specific miRNA signatures can be reflective of disease status and development or indicators of poor treatment response. This is especially important in malignant diseases, as the ease of accessibility of circulating miRNAs circumvents the need for invasive tissue biopsy. In osteogenesis, miRNAs can act either osteo-enhancing or osteo-repressing by targeting key transcription factors and signaling pathways. This review highlights the role of circulating and extracellular vesicle-derived miRNAs as biomarkers in bone-related diseases, with a specific focus on osteoporosis and osteosarcoma. To this end, a comprehensive literature search has been performed. The first part of the review discusses the history and biology of miRNAs, followed by a description of different types of biomarkers and an update of the current knowledge of miRNAs as biomarkers in bone related diseases. Finally, limitations of miRNAs biomarker research and future perspectives will be presented.

Contemporary Antiplatelet and Anticoagulant Therapies for Secondary Stroke Prevention: A Narrative Review of Current Literature and Guidelines

PURPOSE OF REVIEW

Stroke is a leading cause of death and disability worldwide. The annual incidence of new or recurrent stroke is approximately 795,000 cases per year in the United States, of which 87% are ischemic in nature. In addition to the management of modifiable high-risk factors to reduce the risk of recurrent stroke, antithrombotic agents (antiplatelets and anticoagulants) play an important role in secondary stroke prevention. This review will discuss the published literature on the use of antiplatelets and anticoagulants in secondary prevention of acute ischemic stroke and transient ischemic attack (TIA), including their pharmacology, efficacy, and adverse effects. We will also highlight the role of dual antiplatelet therapy (DAPT) in secondary stroke prevention, along with supporting literature.

RECENT FINDINGS

Single antiplatelet therapy (SAPT) with aspirin or clopidogrel reduces the risk of recurrent ischemic stroke in patients with non-cardioembolic ischemic stroke or TIA. However, as shown in recent trials, short-term DAPT with aspirin and clopidogrel or ticagrelor for 21-30 days is more effective than SAPT in patients with minor acute non-cardioembolic stroke or high-risk TIA. Although short-term DAPT is highly effective in preventing recurrent stroke, a more prolonged course can increase bleeding risks without additional benefit. DAPT for 90 days, followed by aspirin monotherapy for patients with large vessel intracranial atherosclerotic disease, is suitable for secondary stroke prevention. However, patients need to be monitored for both minor (e.g., bruising) and major (e.g., intracranial) bleeding complications. Conversely, oral warfarin and newer direct oral anticoagulant (DOACs) such as dabigatran, rivaroxaban, apixaban, and edoxaban are the agents of choice for secondary stroke prevention in patients with non-valvular cardioembolic strokes. DOACs may be preferred over warfarin due to decreased bleeding risks, including ICH, lack of need for international normalized ratio monitoring, no dietary restrictions, and limited drug-drug interactions. The choice between different antiplatelets and anticoagulants for prevention of ischemic stroke depends on the underlying stroke mechanism, cytochrome P450 2C19 polymorphisms, bleeding risk profile, compliance, drug tolerance, and drug resistance. Physicians must carefully weigh each patient's relative benefits and bleeding risks before initiating an antiplatelet/anticoagulant treatment regimen. Further studies are warranted to study the optimal duration of DAPT in symptomatic intracranial atherosclerosis since the benefit is most pronounced in the short term while the bleeding risk remains high during the extended duration of therapy.

A Rare Case of Skin Necrosis Following Extravasation of Prothrombin Complex Concentrate (PCC) Infusion During Warfarin Reversal

Warfarin-induced skin necrosis is a well-documented complication that can occur following commencement of warfarin. However, skin necrosis following extravasation of prothrombin complex concentrate (PCC) infusion is a very rare adverse event that is not commonly documented. This case illustrates the possibility of developing skin necrosis following the administration of an anticoagulation reversal agent rather than from anticoagulation itself. We report a case of a 58-year-old male who developed skin necrosis at the site of PCC infusion in the right upper extremity (RUE) for warfarin reversal of an elevated international normalized ratio (INR). The skin necrosis progressed into a full thickness chemical burn. As a result, the patient underwent allograft followed by split thickness autograft and RECELL placement. This case presentation describes the first reported case of skin necrosis following extravasation of PCC infusion during warfarin reversal.

Thrombin generation in real life bleeding patients on oral anticoagulants reversed (or not) with (activated) prothrombin complex concentrate

BACKGROUND

Bleeding during oral anticoagulant therapy is currently codified by expert guidelines. Monitoring of coagulation during bleeding events is challenging. Our study sought to assess thrombin generation assay (TGA) in direct oral anticoagulant-treated patients without bleeding (WB), bleeding without reversal therapy (BR-), and bleeding with reversal therapy (BR+).

METHODS

We conducted a prospective, monocentric study from June 2015 to June 2018. For all bleeding groups, TGA was evaluated using platelet-poor plasma collected upon arrival at emergency (T0), and 30 min (T1), 6 h (T2) and 24 h (T3) after reversal therapy (if indicated) following activation by tissue factor 5 pM and phospholipids.

RESULTS

Overall, 292 patients participated, including 91 BR+, 94 BR-, and 107 WB patients. At T0, vitamin K antagonist reversed (VKA-BR+) patients experienced a significant decrease in TGA parameters (ETP and peak) compared with VKA without bleeding (VKA-WB). Compared with healthy controls, VKA-BR+ patients reversed by four-factor prothrombin complex concentrate (4F-PCC) displayed comparable TGA 's ETP and peak at T1, T2, and T3, whereas direct anti-Xa BR+ patients reversed by 4F-PCC or activated prothrombin complex concentrate (aPCC) reached thrombin generation parameters that exceeded normal range at T2 and T3.

CONCLUSIONS

In VKA-treated patients reversed by 4F-PCC, TGA parameters were normalized, whereas in rivaroxaban or apixaban-treated patients reversed by 4F-PCC or aPCC, TGA parameters exceeded normal range. Further studies are needed to compare the efficacy and safety of a different dose of reversal therapy and the impact on coagulation parameters.

Novel Antithrombotic Agents in Pregnancy Anticoagulants and Antiplatelet Agents

Increasing rates of thromboembolic complications have required increasing use of anticoagulant and antiplatelet agents during and after pregnancy. Furthermore, thromboembolism is both a cause and a complication of severe maternal morbidity requiring intensive care. As a consequence, almost all patients admitted to intensive care units receive an anticoagulant or an antiplatelet agent (or both) for either treatment or prevention of thromboembolism. In this review, we summarize commonly used anticoagulants and antiplatelet agents and outline the potential role of newly developed (novel) antithrombotic agents for pregnant and postpartum patients.

Rivaroxaban plus aspirin versus acenocoumarol to manage recurrent venous thromboembolic events despite systemic anticoagulation with rivaroxaban

INTRODUCTION

The evaluation and management of patients who sustain recurrent thromboembolic events while taking therapeutic anticoagulation have not been well characterized; moreover, there has been no systematic review or randomized trial focused on treating patients with recurrent deep vein thrombosis (DVT) and pulmonary embolism (PE) during anticoagulant treatment. Therefore, we developed a pilot trial to compare rivaroxaban plus aspirin versus acenocoumarol in patients with recurrent venous thromboembolism despite ongoing anticoagulation with rivaroxaban.

MATERIALS AND METHODS

The study was a multicenter, randomized clinical trial. We randomly assigned patients with objectively documented recurrent venous thromboembolism to receive rivaroxaban (20 mg once a day) plus aspirin (300 mg once a day) or an adjusted dose of acenocoumarol. The study was designed to evaluate the incidence of recurrent thromboembolic events (recurrent ipsilateral or contralateral DVT, PE, ischemic stroke, and myocardial infarction) and hemorrhagic events.

RESULTS

A total of 58 patients were randomized: 28 were allocated to the rivaroxaban plus aspirin group and 30 to the acenocoumarol group. After 90 days of follow-up, three recurrent thromboembolic events (primary outcome) occurred in the acenocoumarol group - two DVTs and one ischemic stroke - and zero events in the rivaroxaban plus aspirin group (risk ratio [RR] 0.15; 95 % confidence interval [CI] 0.008-2.83; P = 0.20). Minor bleeding occurred in five patients in the acenocoumarol group and zero in the rivaroxaban plus aspirin group (RR 0.09; 95 % CI 0.005-1.68; p = 0.10). There was one non-fatal gastrointestinal major bleed in the rivaroxaban plus aspirin group.

CONCLUSIONS

In this pilot study, there were no significant differences in any outcome assessed; however, recurrent thromboembolic events and minor bleeding events occurred numerically less frequently in the rivaroxaban plus aspirin group. These data suggest the need to carry out more extensive randomized studies with sufficient statistical power to clarify these results.

A Systematic Review of Warfarin Use in Post-Bariatric Surgery Patients: Cases Compiled From a Literature Review

OBJECTIVE

The objective of this review was to provide dosing recommendations for percentage change in weekly warfarin dose and rates of thrombotic and bleeding events in patients requiring long-term warfarin therapy after bariatric surgery.

DATA SOURCES

A comprehensive literature search of PubMed (through April 5, 2021), Cochrane Library, and Google Scholar (through April 5, 2021) databases was completed using the keywords warfarin OR vitamin k antagonist AND bariatric surgery.

STUDY SELECTION AND DATA EXTRACTION

Retrospective studies and matched-cohort studies evaluating preoperative and postoperative use of warfarin after bariatric surgery for obesity were considered. Weekly dose defined as sum of daily doses of warfarin for 7 consecutive days was a required outcome to be considered in this review. Patients were excluded from review if post-operative dosage change was not reported.

DATA SYNTHESIS

Six studies were included with a total of 160 patients who met the criteria. A decrease in average warfarin dose was seen in all studies, with the largest decrease occurring at 1 month postsurgery followed by an upward trend toward baseline about 90 days postsurgery. While thrombotic events were observed in none of the patients, there was an increased risk of bleeding in patients, particularly in those who underwent roux-en-y gastric bypass (RYGB) surgery.

RELEVANCE TO PATIENT CARE AND CLINICAL PRACTICE

The study provides a specific warfarin dosing titration regimen, as well as embolic and bleed risk in post-bariatric surgery population.

CONCLUSIONS

Clinicians may consider lowering warfarin weekly dose by about 25% immediately postsurgery, with doses approaching closer to baseline about 90 days postsurgery.

Use of SAMe-TT2R2 in a racially diverse anticoagulation clinic: prediction of optimal anticoagulation

The SAMe-TT₂R₂ score predicts optimal long-term oral Vitamin K Antagonist (VKA) anticoagulation for homogenous Caucasian and homogenous Asian populations for non-valvular atrial fibrillation but at different score thresholds. The score that predicts optimal VKA anticoagulation in significantly diverse populations for multiple indications for systemic anticoagulation has not been reported. We determined whether optimal VKA anticoagulation is predicted by SAMe-TT₂R₂ score in a diverse inner-city population for non-valvular atrial fibrillation (NVAF), unprovoked venous and pulmonary thromboembolic disease (VTE), mechanical prosthetic heart valves and all other indications. All patients on long term VKA's that attended an inner-city anticoagulation clinic between February 2016 and October 2017 were included in this study. Eligible patients were grouped according to oral anticoagulation indication: (1) NVAF, (2) VTE, (3) prosthetic valves and (4) other indications. Each patient's SAMe-TT₂R₂ score and percent time of INR in the therapeutic range (TTR) was calculated with optimal international normalized ratio (INR) control defined as TTR ≥ 65%. The correlation between SAMe-TT₂R₂ score and TTR was determined by logistic regression for each oral anticoagulant indication. Receiver operating characteristic curves were then used to identify the best cutoff for prediction of ≥ 65% TTR. Of 316 patients meeting study criteria, 54% were non-Caucasian and there was a significant negative correlation between the SAMe-TT₂R₂ score and TTR (coefficient - 0.35, P < 0.0001) for all patients. A SAMe-TT₂R₂ score < 4 was identified as the best threshold for predicting optimal TTR (Youden's J-statistics = 0.238) with accuracy and positive likelihood ratio of 63.4% and 1.73, respectively. The SAMe-TT₂R₂ score predicts optimal VKA anticoagulation for systemic anticoagulation for multiple indications in a diverse urban population at a higher score than the original report for non-valvular atrial fibrillation of a cohort where < 10% non-Caucasians.

Outcomes of 4-factor Prothrombin Complex Concentrate in Patients With Liver Disease and Nonvitamin K Antagonist-Related Coagulopathy: A Retrospective Study

The administration of 4-factor prothrombin complex concentrate (4F-PCC) has expanded beyond its Food and Drug Administration (FDA)-approved indication for the emergent reversal of vitamin K antagonists (VKAs). Therefore, this study aimed to evaluate the risks and benefits associated with the expanded use of 4F-PCC. We conducted a single-center retrospective review of 4F-PCC administrations at our university hospital. Of the 159 patients who received 4F-PCC, 76% (n = 121) and 24% (n = 38) received it for the FDA-approved indication in the vitamin K-related coagulopathy (VKA) group and for expanded use in the nonvitamin K-related coagulopathy (nVKA) group, respectively. The expanded use of 4F-PCC was associated with a less robust reduction in the international normalized ratio (INR) (INR of -0.7 ± 1.3 vs INR of -1.6 ± 1.8, P = .002), and fewer patients in the nVKA group achieved a postadministration INR of less than1.5 (11% vs 79%, P = .001) than those in the VKA group. Furthermore, the 30-day mortality rate was significantly higher in the nVKA cohort than in the VKA cohort (42% vs 20%, P = .04). Notably, based on our data, underlying differences in the patient's comorbidities, particularly advanced liver disease, may have contributed to the observed outcome variations, including mortality rate. Therefore, factors, including comorbidities and the underlying etiology of coagulopathy, should be considered when deciding on the expanded use of 4F-PCC. Further research is needed to better understand the potential risks and benefits of 4F-PCC in expanded use scenarios, and the clinical decision to use 4F-PCC outside its FDA-approved indication should be made carefully, considering this information.

Low molecular weight heparin in COVID-19: benefits and concerns

Since its emergence, the COVID-19 pandemic had a dramatic impact on the public health worldwide and it scarred the medical, economical, and social determinants of health. Even after the significant vaccination advances, the disease of SARS-CoV-2 can manifest in severe presentations with life-threatening thromboembolic and multi-organ complications leading to notable morbidity and mortality. Clinicians and researchers are on continuous pursuit of investigating different approaches in the attempt to prevent the infection and minimize its severity. Although the COVID-19's pathophysiology remains relatively unclear, it is well established now that coagulopathy, systemic thrombotic propensity, and a robust immunoinflammatory response are some of the most important determinants of its morbidity and mortality. Accordingly, research efforts have focused on addressing the inflammatory and hematological cascades using available agents to avoid thromboembolic events. Several studies and investigators have emphasized the importance of Low molecular weight heparin (LMWH), namely, Lovenox, in addressing these sequelae of the COVID-19 disease, either prophylactically or therapeutically. This review explores the benefits and concerns of employing LMWH, a widely used anticoagulant, in COVID-19 disease. It delves into Enoxaparin as a molecule, along with its pharmacology, mechanism of action, and clinical uses. It also reviews the current high-quality clinical evidence that highlight the role of enoxaparin in SARS-CoV-2 infection.

Potential Diagnostic and Monitoring Biomarkers of Obstructive Sleep Apnea-Umbrella Review of Meta-Analyses

Obstructive sleep apnea (OSA) is a prevalent, underdiagnosed disease that imposes a significant impact on the health and wellbeing of patients and a financial burden on individuals, their families, and society. Development of new methods of testing other than an overnight sleep study, such as measurement of serum or plasma biomarkers, may provide an easier diagnostic process to identify patients with OSA and allow earlier initiation of treatment, which might prevent serious comorbidities. We conducted a systematic review and quality assessment of available meta-analyses regarding potential diagnostic and monitoring biomarkers of obstructive sleep apnea. A total of 14 sets of candidate biomarkers displayed differences in levels or concentrations in OSA patients compared to non-OSA controls, and decreased after OSA treatment: CRP, IL-6, TNF-α, Il-8, HCY, ICAM-1, VCAM-1, VEGF, TC, LDLc, HDLc, TG, leptin, MDA, ALT, AST, IGF-1, adiponectin, and cortisol. This review summarizes the evidence for OSA-associated potential biomarkers and demonstrates that the quality of available studies, as measured by AMSTAR2, is often low and associated with a high risk of bias.

Inhalation of Low Molecular Weight Heparins as Prophylaxis against SARS-CoV-2

New SARS-CoV-2 variants of concern and waning immunity demonstrate the need for a quick and simple prophylactic agent to prevent infection. Low molecular weight heparins (LMWH) are potent inhibitors of SARS-CoV-2 binding and infection in vitro. The airways are a major route for infection and therefore inhaled LMWH could be a prophylactic treatment against SARS-CoV-2. We investigated the efficacy of in vivo inhalation of LMWH in humans to prevent SARS-CoV-2 attachment to nasal epithelial cells in a single-center, open-label intervention study. Volunteers received enoxaparin in the right and a placebo (NaCl 0.9%) in the left nostril using a nebulizer. After application, nasal epithelial cells were retrieved with a brush for ex-vivo exposure to either SARS-CoV-2 pseudovirus or an authentic SARS-CoV-2 isolate and virus attachment as determined. LMWH inhalation significantly reduced attachment of SARS-CoV-2 pseudovirus as well as authentic SARS-CoV-2 to human nasal cells. Moreover, in vivo inhalation was as efficient as in vitro LMWH application. Cell phenotyping revealed no differences between placebo and treatment groups and no adverse events were observed in the study participants. Our data strongly suggested that inhalation of LMWH was effective to prevent SARS-CoV-2 attachment and subsequent infection. LMWH is ubiquitously available, affordable, and easy to apply, making them suitable candidates for prophylactic treatment against SARS-CoV-2. IMPORTANCE New SARS-CoV-2 variants of concern and waning immunity demonstrate the need for a quick and simple agent to prevent infection. Low molecular weight heparins (LMWH) have been shown to inhibit SARS-CoV-2 in experimental settings. The airways are a major route for SARS-CoV-2 infection and inhaled LMWH could be a prophylactic treatment. We investigated the efficacy of inhalation of the LMWH enoxaparin in humans to prevent SARS-CoV-2 attachment because this is a prerequisite for infection. Volunteers received enoxaparin in the right and a placebo in the left nostril using a nebulizer. Subsequently, nasal epithelial cells were retrieved with a brush and exposed to SARS-CoV-2. LMWH inhalation significantly reduced the binding of SARS-Cov-2 to human nasal cells. Cell phenotyping revealed no differences between placebo and treatment groups and no adverse events were observed in the participants. Our data indicated that LMWH can be used to block SARS-CoV-2 attachment to nasal cells. LMWH was ubiquitously available, affordable, and easily applicable, making them excellent candidates for prophylactic treatment against SARS-CoV-2.

Aptamers Regulating the Hemostasis System

The hemostasis system is a complex structure that includes the fibrinolysis system, and Yes this is correct coagulation and anticoagulation parts. Due to the multicomponent nature, it becomes relevant to study the key changes in the functioning of signaling pathways, and develop new diagnostic methods and modern drugs with high selectivity. One of the ways to solve this problem is the development of molecular recognition elements capable of blocking one of the hemostasis systems and/or activating another. Aptamers can serve as ligands for targeting specific clinical needs, promising anticoagulants with minor side effects and significant biological activity. Aptamers with several clotting factors and platelet proteins are used for the treatment of thrombosis. This review is focused on the aptamers used for the correction of the hemostasis system, and their structural and functional features. G-rich nucleic acid aptamers, mostly versatile G-quadruplexes, recognize different components of the hemostasis system and are capable of correcting the functioning.

Safety and efficacy of using portable coagulation monitor for INR examination after left-sided mechanical prosthetic valve replacement

BACKGROUND

Time in therapeutic range (TTR) is an index to assess the effectiveness of anticoagulation and is important to predict the risk of bleeding and thrombosis in patients taking warfarin. In recent years, the portable coagulation monitor, a point-of-care testing device for patients to perform self-management international normalized ratio (INR) examination, has provided an opportunity to improve the quality of oral warfarin treatment. In this study, we applied TTR to evaluate the safety and efficacy of the portable coagulation monitor for patients with oral anticoagulant warfarin after left-sided mechanical prosthetic valve (MPV) replacement.

METHODS

It is a single-centre cohort study. From September 2019 to June 2021, a total of 243 patients who returned to our institution for outpatient clinic revisit at 3 months after left-sided MPV replacement, met the inclusion criteria and agreed to be followed up were included. Self-management group used portable coagulation monitor for INR examination, and patients in the conventional group had their INR monitored in routine outpatient visits. Clinical data of the patients would be recorded for the next 12 months, and results were compared between the two groups to assess the effect of the coagulation monitor on TTR and complications related to bleeding and thrombosis in patients with left-sided MPV replacement.

RESULTS

A total of 212 individuals provided complete and validated INR data spanning of 1 year. Those who applied the portable coagulation monitor had higher TTR values and larger number of tests for INR. No significant differences were seen between the two groups in postoperative bleeding and thromboembolic complications, but portable coagulation monitor showed a trend toward fewer bleeding events.

CONCLUSION

Portable devices for coagulation monitoring are safe and can achieve a higher TTR. Patients who use the portable coagulation monitor for home INR self-management can achieve a safe and effective warfarin therapy.

Predictors of Recurrent Venous Thrombosis After Cerebral Venous Thrombosis: Analysis of the ACTION-CVT Study

BACKGROUND AND OBJECTIVE

Cerebral venous thrombosis (CVT) is a rare cause of stroke carrying a nearly 4% risk of recurrence after 1 year. There are limited data on predictors of recurrent venous thrombosis in patients with CVT. In this study, we aim to identify those predictors.

METHODS

This is a secondary analysis of the ACTION-CVT study which is a multicenter international study of consecutive patients hospitalized with a diagnosis of CVT over a 6-year period. Patients with cancer-associated CVT, CVT during pregnancy, or CVT in the setting of known antiphospholipid antibody syndrome were excluded per the ACTION-CVT protocol. The study outcome was recurrent venous thrombosis defined as recurrent venous thromboembolism (VTE) or de novo CVT. We compared characteristics between patients with vs without recurrent venous thrombosis during follow-up and performed adjusted Cox regression analyses to determine important predictors of recurrent venous thrombosis.

RESULTS

Nine hundred forty-seven patients were included with a mean age of 45.2 years, 63.9% were women, and 83.6% had at least 3 months of follow-up. During a median follow-up of 308 (interquartile range 120-700) days, there were 5.05 recurrent venous thromboses (37 VTE and 24 de novo CVT) per 100 patient-years. Predictors of recurrent venous thrombosis were Black race (adjusted hazard ratio [aHR] 2.13, 95% CI 1.14-3.98, p = 0.018), history of VTE (aHR 3.40, 95% CI 1.80-6.42, p < 0.001), and the presence of one or more positive antiphospholipid antibodies (aHR 3.85, 95% CI 1.97-7.50, p < 0.001). Sensitivity analyses including events only occurring on oral anticoagulation yielded similar findings.

DISCUSSION

Black race, history of VTE, and the presence of one or more antiphospholipid antibodies are associated with recurrent venous thrombosis among patients with CVT. Future studies are needed to validate our findings to better understand mechanisms and treatment strategies in patients with CVT.

Low dose versus standard dose rituximab for the treatment of antiphospholipid syndrome: A pilot study from a tertiary medical center

BACKGROUND

To investigate the therapeutic effects and safety of low-dose and standard-dose rituximab (RTX) in the treatment of antiphospholipid syndrome (APS).

METHODS

In this real-world study, we included 22 consecutive patients with APS who received RTX. Standard dose (SD) was defined as an overall dosage of RTX ≥ 1000mg in the induction period, and low dose (LD) was defined as an overall dosage of RTX <1000mg.

RESULTS

Of included patients, 1 patients died, 2 patients withdrew and 19 patients completed 6-month follow-up. Nine patients received SD-RTX and 13 patients received LD-RTX, and elder patients [LD-RTX vs. SD-RTX: (49.1 ± 15.5) vs. (35.8 ± 12.3) years, p = 0.044] and patients with later-onset [LD-RTX vs. SD-RTX: (46.8 ± 16.3) vs. (31.3 ± 13.6) years, p = 0.029] were more frequently included in LD-RTX than SD-RTX. Following 6 month RTX treatment, 8 patients (42.1%) achieved complete remission, 8 patients (42.1%) achieved partial remission and 3 patients (15.8%) showed no remission. The titers of anticardiolipin antibodies [baseline vs. 6 months: 30.8 (10.7, 90) vs. 19.5 (2.45, 69.10) U/L, p = 0.023] and the levels of erythrocyte sedimentation rate [baseline vs. 6 months: 29 (6, 63) vs. '6 (3, 14) mm/h, p = 0.021] exhibited a significantly decrease in all APS patients. Remission rate and titers of anti-β2-glycoprotein I and lupus anticoagulant did not differ significantly between two groups.

CONCLUSION

RTX might be a safe and effective option for patients with APS, and low dose confers equal efficacy as standard dose. Further cohort studies are needed to confirm our findings.

Appendix to the Society of Interventional Radiology Consensus Guidelines for the Periprocedural Management of Thrombotic and Bleeding Risk in Patients Undergoing Percutaneous Image-Guided Interventions: Pediatric Considerations

PURPOSE

To provide guidance on the use of anticoagulant and antithrombotic agents in pediatric patients undergoing interventional radiology procedures.

MATERIALS AND METHODS

A multidisciplinary writing group conducted a comprehensive literature search to identify studies on the topic of interest. Recommendations were developed for procedural risk and medication dosage and withholding. A modified Delphi technique was used to achieve consensus agreement on the recommendations.

RESULTS

A total of 24 studies, including systematic reviews and meta-analyses, randomized controlled trials, and prospective and retrospective cohort studies, were identified as relevant. The expert writing group agreed on procedural risk categorization, laboratory testing thresholds, and medication dosage and withholding recommendations specific to pediatric practice. They additionally described the nuances of anticoagulation in clinical conditions specific to pediatrics.

CONCLUSIONS

The Society of Interventional Radiology recommends following the guidance provided in the document when developing multidisciplinary management protocols for anticoagulation and antithrombotic treatment in pediatric patients undergoing interventional radiology procedures.

Perioperative Management of Antithrombotic Therapy: An American College of Chest Physicians Clinical Practice Guideline

BACKGROUND

The American College of Chest Physicians Clinical Practice Guideline on the Perioperative Management of Antithrombotic Therapy addresses 43 Patients-Interventions-Comparators-Outcomes (PICO) questions related to the perioperative management of patients who are receiving long-term oral anticoagulant or antiplatelet therapy and require an elective surgery/procedure. This guideline is separated into four broad categories, encompassing the management of patients who are receiving: (1) a vitamin K antagonist (VKA), mainly warfarin; (2) if receiving a VKA, the use of perioperative heparin bridging, typically with a low-molecular-weight heparin; (3) a direct oral anticoagulant (DOAC); and (4) an antiplatelet drug.

METHODS

Strong or conditional practice recommendations are generated based on high, moderate, low, and very low certainty of evidence using the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) methodology for clinical practice guidelines.

RESULTS

A multidisciplinary panel generated 44 guideline recommendations for the perioperative management of VKAs, heparin bridging, DOACs, and antiplatelet drugs, of which two are strong recommendations: (1) against the use of heparin bridging in patients with atrial fibrillation; and (2) continuation of VKA therapy in patients having a pacemaker or internal cardiac defibrillator implantation. There are separate recommendations on the perioperative management of patients who are undergoing minor procedures, comprising dental, dermatologic, ophthalmologic, pacemaker/internal cardiac defibrillator implantation, and GI (endoscopic) procedures.

CONCLUSIONS

Substantial new evidence has emerged since the 2012 iteration of these guidelines, especially to inform best practices for the perioperative management of patients who are receiving a VKA and may require heparin bridging, for the perioperative management of patients who are receiving a DOAC, and for patients who are receiving one or more antiplatelet drugs. Despite this new knowledge, uncertainty remains as to best practices for the majority of perioperative management questions.

Warfarin Overdose in an Adolescent Not Dependent on Anticoagulation: Reversal Strategy and Kinetics

INTRODUCTION

Warfarin induces coagulopathy. Guidelines protocolize reversal of supratherapeutic international normalized ratio (INR) in patients dependent on anticoagulation, but practices vary for reversing warfarin-induced coagulopathy after overdose in non-warfarin-dependent patients.

CASE REPORT

This is the report of a 15-year-old female who ingested her father's warfarin (100-200 mg) in a self-harm attempt. At hour 24 post-ingestion, her INR was 2.00 and she was admitted for monitoring. Reversal of coagulopathy was initially deferred pending the INR trend. The INR was 5.10 at hour 60 and 2.5 mg oral vitamin K1 (VK1) was given. At hour 85, the INR peaked at 6.67 and she received a second oral dose of 2.5 mg VK1. On day 8, she was medically cleared with an INR of 1.31. On day 11, she developed lower abdominal pain and diarrhea. Imaging revealed a duodenal hematoma, and symptoms improved spontaneously. She was again medically cleared 13 days post-ingestion. Her serum warfarin concentration peaked at 19 mcg/mL at hour 46. Serial warfarin concentrations were obtained, demonstrating first-order elimination kinetics and a 30-hour half-life.

CONCLUSION

A restrictive approach to coagulopathy reversal in non-warfarin-dependent patients with intentional warfarin overdose may result in worsening coagulopathy, bleeding, and lengthy hospital stay. Given the risk for significant, prolonged coagulopathy, these patients should be treated early with VK1, with subsequent serial INR monitoring and probable additional VK1 dosing. Delayed peak warfarin concentrations support consideration of gastrointestinal decontamination in late presenters.

Current Definitions and Clinical Implications of Biomarkers in Graft-versus-Host Disease

Hematopoietic cell transplantation (HCT) is a potentially curative treatment for many hematologic and nonhematologic disorders. Graft-versus-host-disease (GVHD) in its acute or chronic form remains the most important nonrelapse post-HCT complication. Biomarkers offer objective, unbiased information on systemic disorders, and significant attention has focused on identifying biomarkers for GVHD. Ideally, a GVHD biomarker is actionable, with the results of biomarker testing used to guide clinical management of disease and clinical trial design. Although many GVHD biomarkers have been identified, none have been properly qualified for clinical use. The National Institutes of Health (NIH) and Food and Drug Administration (FDA) have provided biomarker subtype definitions; however, confusion remains about the proper definition and application of these subtypes in the HCT field. The 2014 NIH consensus development project provided a framework for the development of biomarkers for clinical practice. This review aims to clarify the biomarker subtype definitions and reemphasize the developmental framework. Armed with this knowledge, clinicians can properly translate GVHD biomarkers for clinical use.

Warfarin anticoagulation management during the COVID-19 pandemic: The role of internet clinic and machine learning

Background: Patients who received warfarin require constant monitoring by hospital staff. However, social distancing and stay-at-home orders, which were universally adopted strategies to avoid the spread of COVID-19, led to unprecedented challenges. This study aimed to optimize warfarin treatment during the COVID-19 pandemic by determining the role of the Internet clinic and developing a machine learning (ML) model to predict anticoagulation quality.

Methods: This retrospective study enrolled patients who received warfarin treatment in the hospital anticoagulation clinic (HAC) and “Internet + Anticoagulation clinic” (IAC) of the Nanjing Drum Tower Hospital between January 2020 and September 2021. The primary outcome was the anticoagulation quality of patients, which was evaluated by both the time in therapeutic range (TTR) and international normalized ratio (INR) variability. Anticoagulation quality and incidence of adverse events were compared between HAC and IAC. Furthermore, five ML algorithms were used to develop the anticoagulation quality prediction model, and the SHAP method was introduced to rank the feature importance.

Results: Totally, 241 patients were included, comprising 145 patients in the HAC group and 96 patients in the IAC group. In the HAC group and IAC group, 73.1 and 69.8% (p = 0.576) of patients achieved good anticoagulation quality, with the average TTR being 79.9 ± 20.0% and 80.6 ± 21.1%, respectively. There was no significant difference in the incidence of adverse events between the two groups. Evaluating the five ML models using the test set, the accuracy of the XGBoost model was 0.767, and the area under the receiver operating characteristic curve was 0.808, which showed the best performance. The results of the SHAP method revealed that age, education, hypertension, aspirin, and amiodarone were the top five important features associated with poor anticoagulation quality.

Conclusion: The IAC contributed to a novel management method for patients who received warfarin during the COVID-19 pandemic, as effective as HAC and with a low risk of virus transmission. The XGBoost model could accurately select patients at a high risk of poor anticoagulation quality, who could benefit from active intervention.

Massive warfarin overdose management in an adolescent patient

INTRODUCTION

Warfarin is a widely used oral anticoagulant with established reversal guidelines in the setting of a supratherapeutic international normalized ratio (INR). Limited literature exists on managing acute warfarin overdoses in patients who are not chronically anticoagulated.

CASE

A 15-year-old male, with no indication for anticoagulation, presented to a pediatric emergency department after an acute 1,000 mg warfarin ingestion. He had no significant complaints upon presentation aside from a mild intermittent headache. His past medical history was significant for anxiety, depression, Tourette syndrome, attention deficit hyperactivity disorder, and polysubstance misuse. Computed tomography of his head was unremarkable and serum acetaminophen, salicylate, and ethanol concentrations were negative. Approximately 16 h post-ingestion, his INR was 1.9 with an increase to 3.3 by 26 h. The regional poison center was consulted and recommended, consistent with the CHEST guidelines, holding treatment with vitamin K until INR was >10 or if signs or symptoms of bleeding occurred. The patient was admitted for monitoring and by hospital day (HD) #4, his INR had risen to >11.8 at which point oral vitamin K 10 mg was administered. On HD #7, the patient was deemed stable for transfer to inpatient psychiatry after repeat INRs of 2.9 and 3.4.

DISCUSSION

Case reports have demonstrated early administration of vitamin K can temporarily lower INR and prevent detection of rebound. The CHEST warfarin reversal guidelines describe the risks and benefits with respect to bleeding and thrombosis in the non-intentional overdose patient. Application and extrapolation of these guidelines to acute overdose in patients who lack an indication for anticoagulation may or may not be warranted.

CONCLUSION

While established clinical guidance exists on reversing a supratherapeutic INR in patients chronically anticoagulated with warfarin, the risks and benefits of extrapolating this approach are unclear in those who lack an indication for anticoagulation.

Comparison between rivaroxaban versus enoxaparin for venous thromboembolism prophylaxis following spine surgeries, a randomized clinical trial

BACKGROUND

Enoxaparin is currently used for VTE prophylaxis. Rivaroxaban is more cost-effective and is as potent as enoxaparin in VTE prophylaxis.

METHODS

The study was held at Al-Zahra and Kashani university hospitals in Isfahan, Iran, from January 2019 to October 2020. Two hundred ninety-six patients requiring instrumented spine surgery were enrolled; 23 were excluded (lack of consent/interfering medical situations). They were randomized into the groups of rivaroxaban (case, n = 137) and enoxaparin receiving (control, n = 136). Medical data were recorded and 244 patients (case = 123, control = 121) were analyzed value < 0.05 was meaningful.

RESULTS

150 patients were males, and 94 were females. The mean age was 52.09 ± 12.6 years. Postoperative drain volume was higher in rivaroxaban received patients than in enoxaparin (p = 0.02). Post-operation epidural hematoma was detected in 3 patients in the case and 1 in the control group, which was not meaningful(p = 0.622). All of them were evacuated surgically. POH was associated with cervical canal stenosis surgery, existing comorbidities, and new medical events. New medical events were associated with postoperative wound dehiscence (p = 0.001). Short and long-term postoperative outcomes were similar in both groups. The mean follow-up duration was 25.8 ± 7.5 months.

CONCLUSION

Rivaroxaban is as effective as enoxaparin in venous thromboembolic event prophylaxis. Regarding postoperative epidural hematoma, statistical analysis showed equal safety of both drugs. Still, the authors would like to recommend more discretion in rivaroxaban administration in cervical spine laminectomy until future studies are conducted.

Prothrombin Complex Concentrate vs Plasma for Post-Cardiopulmonary Bypass Coagulopathy and Bleeding: A Randomized Clinical Trial

Importance

Post-cardiopulmonary bypass (CPB) coagulopathy and bleeding are among the most common reasons for blood product transfusion in surgical practices. Current retrospective data suggest lower transfusion rates and blood loss in patients receiving prothrombin complex concentrate (PCC) compared with plasma after cardiac surgery.

Objective

To analyze perioperative bleeding and transfusion outcomes in patients undergoing cardiac surgery who develop microvascular bleeding and receive treatment with either PCC or plasma.

Design, Setting, and Participants

A single-institution, prospective, randomized clinical trial performed at a high-volume cardiac surgical center. Patients were aged 18 years or older and undergoing cardiac surgery with CPB. Patients undergoing complex cardiac surgical procedures (eg, aortic replacement surgery, multiple procedures, or repeated sternotomy) were preferentially targeted for enrollment. During the study period, 756 patients were approached for enrollment, and 553 patients were randomized. Of the 553 randomized patients, 100 patients met criteria for study intervention.

Interventions

Patients with excessive microvascular bleeding, a prothombin time (PT) greater than 16.6 seconds, and an international normalized ratio (INR) greater than 1.6 were randomized to receive treatment with either PCC or plasma. The PCC dose was 15 IU/kg or closest standardized dose; the plasma dose was a suggested volume of 10 to 15 mL/kg rounded to the nearest unit.

Main Outcomes and Measures

The primary outcome was postoperative bleeding (chest tube output) from the initial postsurgical intensive care unit admission through midnight on postoperative day 1. Secondary outcomes were PT/INR, rates of intraoperative red blood cell (RBC) transfusion after treatment, avoidance of allogeneic transfusion from the intraoperative period to the end of postoperative day 1, postoperative bleeding, and adverse events.

Results

One hundred patients (mean [SD] age, 66.8 [13.7] years; 61 [61.0%] male; and 1 [1.0%] Black, 1 [1.0%] Hispanic, and 98 [98.0%] White) received the study intervention (49 plasma and 51 PCC). There was no significant difference in chest tube output between the plasma and PCC groups (median [IQR], 1022 [799-1575] mL vs 937 [708-1443] mL). After treatment, patients in the PCC arm had a greater improvement in PT (effect estimate, -1.37 seconds [95% CI, -1.91 to -0.84]; P < .001) and INR (effect estimate, -0.12 [95% CI, -0.16 to -0.07]; P < .001). Fewer patients in the PCC group required intraoperative RBC transfusion after treatment (7 of 51 patients [13.7%] vs 15 of 49 patients [30.6%]; P = .04); total intraoperative transfusion rates were not significantly different between groups. Seven (13.7%) of 51 patients receiving PCCs avoided allogeneic transfusion from the intraoperative period to the end of postoperative day 1 vs none of those receiving plasma. There were no significant differences in postoperative bleeding, transfusions, or adverse events.

Conclusions and Relevance

The results of this study suggest a similar overall safety and efficacy profile for PCCs compared with plasma in this clinical context, with fewer posttreatment intraoperative RBC transfusions, improved PT/INR correction, and higher likelihood of allogeneic transfusion avoidance in patients receiving PCCs.

Trial Registration

ClinicalTrials.gov Identifier: NCT02557672.

Challenging clinical scenarios for therapeutic anticoagulation: A practical approach

Therapeutic anticoagulation remains a fundamental backbone in the treatment and prevention of venous thromboembolism. However, while modern therapies are increasingly safe, anticoagulation is not without risks, particularly in those at high risk for or with recent bleeding. When weighing concurrent risks and benefits in each challenging clinical scenario, an individualized assessment of the risk and acuity of bleeding should be balanced by the indication for anticoagulation. Addressing modifiable risk factors and routine re-evaluation of any changes in this balance is critical. This review outlines available data and current guidelines for the management of anticoagulation in high-risk populations, including those with thrombocytopenia, elderly and high-fall risk, inherited bleeding disorders, and in acute coronary syndrome. We also examine management after clinically significant bleeding episodes, including intracranial hemorrhage, gastrointestinal bleeding, hemoptysis, retroperitoneal bleeding, hematuria, and abnormal uterine bleeding. The aim is to provide a comprehensive review of available literature to guide clinicians in providing optimal, safe, and individualized care for patients in these challenging scenarios.

Measuring Mobile Phone Application Usability for Anticoagulation from the Perspective of Patients, Caregivers, and Healthcare Professionals

Oral anticoagulants (OAC) are recommended for preventing stroke and systemic embolism in atrial fibrillation. Proper use is imperative for maximizing anticoagulation therapy's effectiveness and safety. In preparation for the implementation of a smartphone-based SmartMed app (application) aiming to promote patient self-management, medication adherence, and data collection for patients on anticoagulation therapy, its usability assessment can ensure the value of OAC app development and adoption. We evaluated the SmartMed app's usability using the System Usability Scale (SUS) and the app-specific domain of the Mobile App Rating Scale (MARS) for its perceived impact on taking OAC regularly. We recruited 25 OAC users and their home caregivers and 59 healthcare professionals, including pharmacists, nurses, and cardiac surgeons from one medical center and one regional hospital in Taiwan. All participants (n = 84) thought the SmartMed app was useful, with mean SUS and MARS scores of 81.49 (±14.42) and 4.65 (±0.49), respectively. Usability evaluation revealed that fewer experiences with smartphone apps and different healthcare professionals (pharmacists versus nurses or cardiac surgeons) were associated with lower SUS scores and perceived impact. Throughout the evaluation process, the SmartMed app's design was considered helpful from multiple stakeholders' perspectives. Further ongoing mobile technology supports are necessary to establish the SmartMed app's effectiveness.

Warfarin Reversal With Four-Factor Prothrombin Complex Concentrate for Left Ventricular Assist Device Conversion Surgery Monitored by TEG6s: A Case Report

Left ventricular assist devices (LVADs) require careful therapeutic anticoagulation with warfarin to prevent pump thrombosis. However, the best method to reverse warfarin for elective LVAD conversion surgery with massive bleeding remains unclear. We report the case of a 39-year-old Japanese man who was administered a four-factor prothrombin complex concentrate (4F-PCC) as warfarin reversal when he underwent conversion surgery from paracorporeal LVAD to implantable LVAD. 4F-PCC with co-administration of vitamin K reduced the international normalized ratio and R time in TEG6s (Haemonetics Corporation, USA) immediately. The effect was prolonged, and good hemostasis was achieved. 4F-PCC with vitamin K provided good hemostasis in our patient; therefore, 4F-PCC could be a useful tool for elective LVAD conversion surgery with expected massive bleeding and requiring immediate warfarin reversal.

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

Background

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

Aim

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

Methods

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

Results

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

Conclusions

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

Coordination of Oral Anticoagulant Care at Hospital Discharge (COACHeD): protocol for a pilot randomised controlled trial

Background

Oral anticoagulants (OACs) are commonly prescribed, have well-documented benefits for important clinical outcomes but have serious harms as well. Rates of OAC-related adverse events including thromboembolic and hemorrhagic events are especially high shortly after hospital discharge. Expert OAC management involving virtual care is a research priority given its potential to reach remote communities in a more feasible, timely, and less costly way than in-person care. Our objective is to test whether a focused, expert medication management intervention using a mix of in-person consultation and virtual care follow-up, is feasible and effective in preventing anticoagulation-related adverse events, for patients transitioning from hospital to home.

Methods and analysis

A randomized, parallel, multicenter design enrolling consenting adult patients or the caregivers of cognitively impaired patients about to be discharged from medical wards with a discharge prescription for an OAC. The interdisciplinary multimodal intervention is led by a clinical pharmacologist and includes a detailed discharge medication reconciliation and management plan focused on oral anticoagulants at hospital discharge; a circle of care handover and coordination with patient, hospital team and community providers; and early post-discharge follow-up virtual medication check-up visits at 24 h, 1 week, and 1 month. The control group will receive usual care plus encouragement to use the Thrombosis Canada website.

The primary feasibility outcomes include recruitment rate, participant retention rates, trial resources management, and the secondary clinical outcomes include adverse anticoagulant safety events composite (AASE), coordination and continuity of care, medication-related problems, quality of life, and healthcare resource utilization. Follow-up is 3 months.

Discussion

This pilot RCT tests whether there is sufficient feasibility and merit in coordinating oral anticoagulant care early post-hospital discharge to warrant a full sized RCT.

Trial registration

NCT02777047.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40814-022-01130-z.

Emergent Reversal of Antithrombotics and Treatment of Life-Threatening Bleeding from Coagulopathies: A Clinical Review

BACKGROUND

Reversal of antithrombotic agents and treatment of life-threatening bleeding episodes from coagulopathies can be a stressful scenario for clinicians, especially when the selection of treatment options should occur quickly. Understanding the options available for these agents requires emergency physicians to be familiar with the current data surrounding new therapies and dosing strategies for the treatment of bleeding from reversible and nonreversible antithrombotics and coagulopathic conditions.

OBJECTIVE

To provide quick resource guides for the reversal of major or life-threatening bleeding caused by antithrombotic agents or in the setting of coagulopathies.

METHODS

A literature search for articles published through September 2021 related to antithrombotic reversal and treatment of acute bleeding from coagulopathies was conducted using the PubMed clinical database. Selected articles were used to generate 5 guidance tables in this clinical review.

DISCUSSION

Four guidance tables for how to treat major or life-threatening bleeding from antithrombotic agents and 1 table for how to manage life-threatening bleeding for coagulopathies are presented as a quick reference tool for the emergency physician. Additional information on upcoming reversal agents and possible treatment options are provided herein.

CONCLUSIONS

In this clinical review, a series of 5 tables were created to provide quick and comprehensive guidance for the emergency physician when treating major or life-threatening bleeding caused by antithrombotic agents or coagulopathies. © 2022 Elsevier Inc.

Optimal quality of vitamin K antagonist therapy in Japanese patients with venous thromboembolism

BACKGROUND

Vitamin K antagonist (VKA) remains an essential option for venous thromboembolism (VTE), although direct oral anticoagulants have become available. However, there is a paucity of data on the optimal intensity and quality of control for VKA in Japanese.

METHODS

The COMMAND VTE Registry is a multicenter registry enrolling consecutive 3027 patients with acute symptomatic VTE among 29 centers in Japan. The current study population consisted of 1938 patients who received VKA with prothrombin time-international normalized ratio (PT-INR) measurement >5 times. The primary outcome measure was a composite of symptomatic VTE recurrence or major bleeding at 1 year. The presumed optimal quality of VKA therapy was defined as the combination of PT-INR range and time in therapeutic range (TTR) with the numerically lowest event rate.

RESULTS

The group with TTR ≥70 % based on PT-INR range ≥1.5 and <2.0 showed the lowest cumulative incidence rate. The cumulative 1-year incidence and the adjusted risk for the primary outcome measure were significantly lower in the optimal quality group than in the non-optimal quality group (5.2 % vs. 11.7 %, p = 0.001, and HR 0.49, 95%CI 0.28-0.81). Similarly, the cumulative 1-year incidences of a recurrent VTE, major bleeding, and all-cause death were significantly lower in the optimal quality group (recurrent VTE: 2.5 % vs. 6.0 %, p = 0.02; major bleeding: 2.8 % vs. 7.0 %, p = 0.008; and all-cause death: 2.8 % vs. 12.6 %, p < 0.0001). The lower risk of the optimal quality group relative to non-optimal quality group for the clinical outcomes was consistent regardless of the etiology of VTE (active cancer, transient risk factor, and unprovoked).

CONCLUSIONS

The current VTE registry showed the optimal intensity of VKA therapy was target PT-INR range ≥1.5 and <2.0, which could support the current Japanese guideline recommendation, and the good quality of control for VKA therapy of TTR ≥70 % was independently associated with better outcomes.

Optimizing the dynamic treatment regime of in-hospital warfarin anticoagulation in patients after surgical valve replacement using reinforcement learning

OBJECTIVE

Warfarin anticoagulation management requires sequential decision-making to adjust dosages based on patients' evolving states continuously. We aimed to leverage reinforcement learning (RL) to optimize the dynamic in-hospital warfarin dosing in patients after surgical valve replacement (SVR).

MATERIALS AND METHODS

10 408 SVR cases with warfarin dosage-response data were retrospectively collected to develop and test an RL algorithm that can continuously recommend daily warfarin doses based on patients' evolving multidimensional states. The RL algorithm was compared with clinicians' actual practice and other machine learning and clinical decision rule-based algorithms. The primary outcome was the ratio of patients without in-hospital INRs >3.0 and the INR at discharge within the target range (1.8-2.5) (excellent responders). The secondary outcomes were the safety responder ratio (no INRs >3.0) and the target responder ratio (the discharge INR within 1.8-2.5).

RESULTS

In the test set (n = 1260), the excellent responder ratio under clinicians' guidance was significantly lower than the RL algorithm: 41.6% versus 80.8% (relative risk [RR], 0.51; 95% confidence interval [CI], 0.48-0.55), also the safety responder ratio: 83.1% versus 99.5% (RR, 0.83; 95% CI, 0.81-0.86), and the target responder ratio: 49.7% versus 81.1% (RR, 0.61; 95% CI, 0.58-0.65). The RL algorithms performed significantly better than all the other algorithms. Compared with clinicians' actual practice, the RL-optimized INR trajectory reached and maintained within the target range significantly faster and longer.

DISCUSSION

RL could offer interactive, practical clinical decision support for sequential decision-making tasks and is potentially adaptable for varied clinical scenarios. Prospective validation is needed.

CONCLUSION

An RL algorithm significantly optimized the post-operation warfarin anticoagulation quality compared with clinicians' actual practice, suggesting its potential for challenging sequential decision-making tasks.

Innate immune signaling and immunothrombosis: New insights and therapeutic opportunities

Activation of the coagulation cascade is a critical, evolutionarily conserved mechanism that maintains hemostasis by rapidly forming blood clots in response to blood-borne infections and damaged blood vessels. Coagulation is a key component of innate immunity since it prevents bacterial dissemination and can provoke inflammation. The term immunothrombosis describes the process by which the innate immune response drives aberrant coagulation, which can result in a lethal condition termed disseminated intravascular coagulation, often seen in sepsis. In this review, we describe the recently uncovered molecular mechanisms underlying inflammasome- and STING-driven immunothrombosis induced by bacterial and viral infections, culminating in tissue factor (TF) activation and release. Current anticoagulant therapeutics, while effective, are associated with a life-threatening bleeding risk, requiring the urgent development of new treatments. Targeting immunothrombosis may provide a safer option. Thus, we highlight preclinical tools which target TF and/or block canonical (NLRP3) or noncanonical (caspase-11) inflammasome activation as well as STING-driven TF release and discuss clinically approved drugs which block key immunothrombotic processes and, therefore, may be redeployed as safer anticoagulants.

Qualidade da Anticoagulação Oral em Pacientes com Fibrilação Atrial em um Hospital Terciário no Brasil

Fundamento

A fibrilação atrial (FA) afeta de 0,5% a 2,0% da população geral e geralmente está associada a doenças estruturais cardíacas, comprometimento hemodinâmico e complicações tromboembólicas. A anticoagulação oral previne eventos tromboembólicos e é monitorada pela razão normalizada internacional (RNI).

Objetivos

Avaliar a estabilidade do RNI em pacientes com FA não valvar tratados com anticoagulante varfarina, avaliar complicações tromboembólicas ou hemorrágicas e identificar o grupo com risco mais alto de eventos tromboembólicos ou hemorrágicos.

Métodos

Dados de prontuários médicos de 203 pacientes atendidos em um hospital terciário no Brasil foram analisados e o tempo de intervalo terapêutico (TTR) foi calculado usando-se o método Rosendaal. Em seguida possíveis fatores que influenciam o TTR foram analisados e a relação entre TTR e eventos tromboembólicos ou hemorrágicos foi calculada. O nível de significância foi 5%.

Resultados

O TTR médio foi 52,2%. Pacientes com instabilidade de RNI na fase de adaptação tinham um TTR médio mais baixo (46,8%) do que aqueles sem instabilidade (53,9%). Entre os pacientes estudados, 6,9% sofreram eventos hemorrágicos e 8,4% tiveram um acidente vascular cerebral. O grupo com risco mais alto de acidente vascular cerebral e sangramento era composto de pacientes com instabilidade de RNI na fase de adaptação.

Conclusões

A qualidade da anticoagulação nesse hospital terciário no Brasil é semelhante à de centros de países em desenvolvimento. Pacientes com instabilidade de RNI maior na fase de adaptação evoluíram para um TTR médio mais baixo durante o acompanhamento, tinham uma chance de acidente vascular cerebral 4,94 vezes maior e uma chance de sangramento 3,35 vezes maior. Portanto, para esse grupo de pacientes, individualizar a escolha de tratamento anticoagulante seria recomendado, considerando-se a relação custo-benefício.

Intracoronary thrombus visualized by optical coherence tomography in a patient with antiphospholipid syndrome

A patient with a history of deep venous thrombosis on warfarin underwent coronary angiography and was found to have a red intracoronary thrombus in the mid left anterior descending artery by optical coherence tomography. Percutaneous coronary intervention was successfully performed. On discharge, the patient continued triple therapy with aspirin, clopidogrel, and apixaban for 30 days then discontinued aspirin. A hypercoagulable work up was notable for antiphospholipid syndrome and lifelong anticoagulation was recommended. The patient continued apixaban twice daily given recurrent thrombosis while on warfarin and was event free at 6-month follow up.

A Review of Direct-acting Oral Anticoagulants and Their Use in Solid Organ Transplantation

Direct-acting oral anticoagulant (DOAC) use has increased dramatically since their introduction because of the growing evidence of proven efficacy and enhanced safety compared with warfarin and the low-molecular-weight heparins in the general population. Unfortunately, there is a dearth of quality data regarding the safety and efficacy of the DOACs in patients awaiting organ transplant and those who received a solid organ transplant. This review aims to evaluate the available literature and considerations regarding anticoagulation use in transplant recipients, focusing on preoperative, perioperative, and postoperative DOAC use.

Drug Interactions Affecting Oral Anticoagulant Use

Oral anticoagulants (OACs) are medications commonly used in patients with atrial fibrillation and other cardiovascular conditions. Both warfarin and direct oral anticoagulants are susceptible to drug-drug interactions (DDIs). DDIs are an important cause of adverse drug reactions and exact a large toll on the health care system. DDI for warfarin mainly involve moderate to strong inhibitors/inducers of cytochrome P450 (CYP) 2C9, which is responsible for the elimination of the more potent S-isomer of warfarin. However, inhibitor/inducers of CYP3A4 and CYP1A2 may also cause DDI with warfarin. Recognition of these precipitating agents along with increased frequency of monitoring when these agents are initiated or discontinued will minimize the impact of warfarin DDI. Direct oral anticoagulants are mainly affected by medications strongly affecting the permeability glycoprotein (P-gp), and to a lesser extent, strong CYP3A4 inhibitors/inducers. Dabigatran and edoxaban are affected by P-gp modulation. Strong inducers of CYP3A4 or P-gp should be avoided in all patients taking direct oral anticoagulant unless previously proven to be otherwise safe. Simultaneous strong CYP3A4 and P-gp inhibitors should be avoided in patients taking apixaban and rivaroxaban. Concomitant antiplatelet/anticoagulant use confers additive risk for bleeding, but their combination is unavoidable in many cases. Minimizing duration of concomitant anticoagulant/antiplatelet therapy as indicated by evidence-based clinical guidelines is the best way to reduce the risk of bleeding.

Prophylaxis for Venous Thromboembolic Events in Elective Total Hip and Total Knee Arthroplasty

Venous thromboembolism (VTE) is a serious complication after major orthopaedic operations, such as a total hip (THA) and knee (TKA) arthroplasty. Therefore, perioperative VTE prophylaxis is recommended; a multitude of modern options are available, including both pharmacologic (aspirin, unfractionated and lowmolecular-weight heparin, vitamin K antagonists, and novel oral anticoagulants) and/or mechanical interventions (early mobilization, graduated compression stockings, intermittent pneumatic compression devices, and venous foot pumps). However, because of the abundance of these possibilities, it is crucial to understand the benefits and drawbacks of each VTE prophylaxis option to ensure that the optimal treatment plan is developed for each patient. The American College of Chest Physicians (AACP) and the American Academy of Orthopaedic Surgeons (AAOS) have both published individual guidelines on VTE prophylaxis regimens, alongside numerous studies evaluating the efficacy and outcomes of the different prophylaxis modalities. The purpose of this review is to provide a summary of the evidence on VTE prophylaxis after elective total hip and knee arthroplasty based on current guidelines and highlight the major concerns and potential complications.

Effects of Silicone Mattress Combined with Hydrocolloid Dressing on Pressure Ulcers and Phlebitis in ICU Patients with Liver Failure

Objective

This study was aimed at clarifying the application effect of silicone mattress combined with hydrocolloid dressing in ICU patients with liver failure.

Methods

A total of 86 patients with liver failure admitted to the intensive care unit (ICU) of the Fifth Medical Center of Chinese PLA General Hospital from September 2018 to September 2020 were selected as the research subjects. Patients treated with conventional sponge mattress and routine nursing care were included in group A (n = 43), and those treated with silicone mattress combined with hydrocolloid dressing were included in group B (n = 43). The incidence of pressure ulcers and phlebitis, the scores of Visual Analogue Scale (VAS) and Pittsburgh Sleep Quality Index (PSQI), and the nursing satisfaction were observed and compared between the two groups.

Results

The incidence of pressure ulcers in group B (6.98%) was lower than that in group A (25.58%). The incidence of phlebitis in group B was lower than that in group A (20.93% vs. 53.49%). The VAS score of group B was 2.16 ± 0.38, which was lower than that of group A (4.86 ± 1.09). The PSQI score of group B was lower than that of group A (9.74 ± 2.76 vs. 14.84 ± 3.95). A higher nursing satisfaction was determined in group B compared with group A (93.02% vs. 76.74%).

Conclusions

Silicone mattress combined with hydrocolloid dressing can reduce the incidence of pressure ulcers and phlebitis in ICU patients with liver failure, reduce complications, and improve nursing satisfaction, which is worthy of clinical promotion.