Network pharmacology analysis and experimental verification of the antithrombotic active compounds of trichosanthis pericarpium (Gualoupi) in treating coronary heart disease.

ETHNOPHARMACOLOGICAL RELEVANCE: Trichosanthis pericarpium (TP; Gualoupi, pericarps of Trichosanthes kirilowii Maxim) has been used in traditional Chinese medicine (TCM) to reduce heat, resolve phlegm, promote Qi, and clear chest congestion. It is also an essential herbal ingredient in the "Gualou Xiebai" formula first recorded by Zhang Zhongjing (from the Eastern Han Dynasty) in the famous TCM classic "Jin-Guì-Yào-Lüe" for treating chest impediments. According to its traditional description, Gualou Xiebai is indicated for symptoms of chest impediments, which correspond to coronary heart diseases (CHD). AIM OF THE STUDY: This study aimed to identify the antithrombotic compounds in Gualoupi for the treatment of CHD. MATERIALS AND METHODS: A CHD rat model was established with a combination of high-fat diet and isoproterenol hydrochloride (ISO) administration via subcutaneous multi-point injection in the back of the neck. This model was used to evaluate the antithrombotic effect of two mainstream cultivars of TP ("HaiShi GuaLou" and "WanLou") by analyzing the main components and their effects. Network pharmacology, molecular docking-based studies, and a zebrafish (Danio rerio) thrombosis model induced by phenylhydrazine was used to validate the antithrombosis components of TP. RESULTS: TP significantly reduced the body weight of the CHD rats, improved myocardial ischemia, and reduced collagen deposition and fibrosis around the infarcted tissue. It reduced thrombosis in a dose-dependent manner and significantly reduced inflammation and oxidative stress damage. Cynaroside, isoquercitrin, rutin, citrulline, and arginine were identified as candidate active TP compounds with antithrombotic effects. The key potential targets of TP in thrombosis treatment were initially identified by molecular docking-based analysis, which showed that the candidate active compounds have a strong binding affinity to the potential targets (protein kinase C alpha type [PKCα], protein kinase C beta type [PKCß], von Willebrand factor [vWF], and prostaglandin-endoperoxide synthase 1 [PTGS1], fibrinogen alpha [Fga], fibrinogen beta [Fgb], fibrinogen gamma [Fgg], coagulation factor II [F2], and coagulation factor VII [F7]). In addition, the candidate active compounds reduced thrombosis, improved oxidative stress damage, and down-regulated the expression of thrombosis-related genes (PKCα, PKCß, vWF, PTGS1, Fga, Fgb, Fgg, F2, and F7) in the zebrafish model. CONCLUSION: Cynaroside, isoquercitrin, rutin, citrulline, and arginine were identified as the active antithrombotic compounds of TP used to treat CHD. Mechanistically, the active compounds were found to be involved in oxidative stress injury, platelet activation pathway, and complement and coagulation cascade pathways.

Perioperative Treatment with Rivaroxaban and Dabigatran on Changes of Coagulation and Platelet Activation Biomarkers following Left Atrial Appendage Closure.

Insufficient data exist regarding the investigation of the impact of novel oral anticoagulants (NOACs) on coagulation activation biomarkers in the context of left atrial appendage closure (LAAC) and device-related thrombosis (DRT). The study was designed to investigate the changes and presence of coagulation activation biomarkers between different antithrombotic strategies following LAAC. A total of 120 nonvalvular atrial fibrillation patients intolerant of long-term anticoagulants, who underwent successful WATCHMAN closure implantation, were enrolled (rivaroxaban, n = 82; dabigatran, n = 38). Blood samples were obtained from left atrium (LA) and left atrial appendage (LAA) during the operation and fasting blood samples on the same day of LAAC and 45 days after discharge. The biochemical indicators, thrombin-antithrombin complex (TAT), soluble P-selectin (sP-selectin), von Willebrand factor (vWF), and CD40 ligand (CD40L), were measured by enzyme-linked immunosorbent assay. The primary endpoints of this study were the efficacy and safety characteristics of different antithrombotic strategies, including DRT incidence, stroke or transient ischemic attack, systemic embolism, and clinical major and nonmajor bleeding complications during the follow-up of 180 days. The results revealed that TAT, vWF, sP-selectin, and CD40L levels in vein were significantly reduced by 2.4% (p = 0.043), 5.0% (p < 0.001), 8.7% (p < 0.001), and 2.5% (p = 0.043) from their baseline levels after rivaroxaban treatment. Conversely, no significant changes were detected in the dabigatran group. Furthermore, the plasma levels of platelet activation biomarkers (CD40L and sP-selectin) in both LA and LAA groups were significantly lower after anticoagulation with rivaroxaban, as compared to dabigatran treatment (CD40L: 554.62 ± 155.54 vs. 445.02 ± 130.04 for LA p = 0.0013, 578.51 ± 156.28 vs. 480.13 ± 164.37 for LAA p = 0.0052; sP-selectin: 2849.07 ± 846.69 vs. 2225.54 ± 799.96 for LA p = 0.0105, 2915.52 ± 1402.40 vs. 2203.41 ± 1061.67 for LAA p = 0.0022). Notably, the present study suggests that rivaroxaban may be more effective in the prevention of DRT for patients undergoing LAAC.

Therapeutic effects and molecular mechanisms of natural products in thrombosis.

Thrombotic disorders, such as myocardial infarction and stroke, are the leading cause of death in the global population and have become a health problem worldwide. Drug therapy is one of the main antithrombotic strategies, but antithrombotic drugs are not completely safe, especially the risk of bleeding at therapeutic doses. Recently, natural products have received widespread interest due to their significant efficacy and high safety, and an increasing number of studies have demonstrated their antithrombotic activity. In this review, articles from databases, such as Web of Science, PubMed, and China National Knowledge Infrastructure, were filtered and the relevant information was extracted according to predefined criteria. As a result, more than 100 natural products with significant antithrombotic activity were identified, including flavonoids, phenylpropanoids, quinones, terpenoids, steroids, and alkaloids. These compounds exert antithrombotic effects by inhibiting platelet activation, suppressing the coagulation cascade, and promoting fibrinolysis. In addition, several natural products also inhibit thrombosis by regulating miRNA expression, anti-inflammatory, and other pathways. This review systematically summarizes the natural products with antithrombotic activity, including their therapeutic effects, mechanisms, and clinical applications, aiming to provide a reference for the development of new antithrombotic drugs.

Biomimetic platelet-camouflaged drug-loaded polypyrrole for the precise targeted antithrombotic therapy.

Lower extremity deep venous thrombosis (LEDVT) affects patient's quality of life for a long time, and even causes pulmonary embolism, which threatens human health. Current anticoagulant drugs in clinical treatment are hampered by the risk of bleeding due to poor targeting and low drug penetration. Here, we used platelet (PLT)-like biological targeting to enhance the delivery and accumulation of nanomedicines in thrombus and reduce the risk of bleeding. Meanwhile, the parallel strategy of "thrombus thermal ablation and anticoagulation" was applied to increase the permeability of drugs in thrombus and achieve the optimal antithrombotic effect. Polypyrrole (PPy) and rivaroxban (Riv, an anticoagulant drug) were co-assembled into platelet membrane-coated nanoparticles (NPs), PLT-PPy/Riv NPs, which actively targeted the thrombotic lesion at multiple targets in the platelet membrane and were thermally and drug-specific thrombolysed by 808 nm laser irradiation. The combination therapy resulted in up to 90% thrombolysis in a femoral vein thrombosis model compared to single phototherapy or drug therapy. The results showed that the nanoformulation provided a new direction for remote precise and controlled sustained thrombolysis, which was in line with the trend of nanomedicine towards clinical translation.

Secondary right atrial thrombosis in three dogs: Antithrombotics therapy and echocardiographic follow-up.

Three dogs were diagnosed with right atrial thrombosis, thought to be secondary to systemic diseases. Specifically, two cases had hyperadrenocorticism and one case was diagnosed with pancreatitis with acute renal injury. In all cases, the thrombi were found within the right atrium, necessitating a differentiation from cardiac neoplasia. In all three cases, the structures assumed to be thrombi had irregular margins with interspersed hypoechoic regions, which were later confirmed as thrombi based on the responsiveness to therapy. All three cases were prescribed with the combination of clopidogrel and rivaroxaban.The thrombi gradually disappeared after initiation of the combination therapy. Complete resolution of right atrial thrombosis was noted in each dog treated with clopidogrel and rivaroxaban. This combination therapy appears to be safe and well tolerated. Diligent observation of the echocardiographic findings and clinical course allows the diagnosis of thrombosis.

Ex Vivo Antiplatelet and Thrombolytic Activity of Bioactive Fractions from the New-Fangled Stem Buds of Ficus religiosa L. with Simultaneous GC-MS Examination.

Different parts of Ficus religiosa are the common components of various traditional formulations for the treatment of several blood disorders. The new-fangled stem buds' powder was extracted with 80% ethanol and successively fractionated by chloroform and methanol. Chloroform and methanol fractions of Ficus religiosa (CFFR and MFFR) were tested for antiplatelet, antithrombotic, thrombolytic, and antioxidant activity in ex vivo mode. The MFFR was particularly investigated for GC-MS and toxicity. The antiplatelet activity of the CFFR, MFFR, and standard drug aspirin at 50 µg/mL was 54.32%, 86.61%, and 87.57%, and a significant delay in clot formation was noted. CFFR at different concentrations did not show a significant effect on the delay of clot formation, antiplatelet, and free radical scavenging activity. The most possible marker compounds for antiplatelet and antioxidant activity identified by GC-MS in the MFFR are salicylate derivatives aromatic compounds such as benzeneacetaldehyde (7), phenylmalonic acid (13), and Salicylic acid (14), as well as Benzamides derivatives such as carbobenzyloxy-dl-norvaline (17), 3-acetoxy-2(1H)-pyridone (16), and 3-benzylhexahydropyrrolo [1,2-a] pyrazine-1,4-dione (35). A toxicity study of MFFR did not show any physical indications of toxicity and mortality up to 1500 mg/kg body weight and nontoxic up to 1000 mg/kg, which is promising for the treatment of atherothrombotic diseases.

Effects of intravenous thrombolysis with and without salvianolic acids for injection on the functional recovery of patients with acute ischemic stroke: A systematic review, meta-analysis, and trial sequential analysis.

In patients with acute ischemic stroke (AIS), the effect of salvianolic acids for injection (SAFI) as the secondary treatment after intravenous thrombolysis (IVT) is unclear. We aimed to evaluate the efficacy of SAFI for patients with AIS undergoing IVT. We searched seven electronic databases and two registries from inception to July 24, 2022, for randomized controlled trials (RCTs) assessing the effect of SAFI plus recombinant tissue plasminogen activator (rt-PA) on the functional recovery compared to rt-PA alone in patients with AIS. Two independent authors selected RCTs, extracted data, and assessed the risk of bias. A meta-analysis was conducted. Eight RCTs involving 682 patients with AIS were included. Compared to patients receiving intravenous rt-PA alone, those receiving intravenous rt-PA combined with SAFI had a higher likelihood of achieving favorable functional outcomes at 3 months. In addition, the use of SAFI for 2 weeks was associated with better neurological recovery. The evidence of benefit was confirmed by trial sequential analysis (TSA). The incidence of intracranial hemorrhage did not differ between the two groups. In patients with AIS, intravenous rt-PA combined with SAFI might achieve better functional outcomes. However, further high-quality studies are needed to firmly establish the clinical efficacy of SAFI.

Astaxanthin ameliorates inflammation, oxidative stress, and reproductive outcomes in endometriosis patients undergoing assisted reproduction: A randomized, triple-blind placebo-controlled clinical trial.

Purpose: In a randomized, triple-blind, placebo-controlled clinical trial (RCT) including 50 infertile women with endometriosis candidate for assisted reproductive techniques (ART), we studied the effect of Astaxanthin (AST) on pro-inflammatory cytokines, oxidative stress (OS) markers, and early pregnancy outcomes. Methods: Before and after 12 weeks of AST treatment (6 mg per day), blood serum and follicular fluid (FF) samples were collected from 50 infertile women with endometriosis stage III/IV undergoing ART. Pro-inflammatory cytokines (IL-1ß, IL-6, and TNF-α) and OS markers (malondialdehyde [MDA], superoxide dismutase [SOD], catalase [CAT], and total antioxidant capacity [TAC]) were measured in the serum and FF. ART outcomes were also compared between the groups. Results: Increased serum levels of TAC (398.661 ± 57.686 vs. 364.746 ± 51.569; P = 0.004) and SOD (13.458 ± 7.276 vs. 9.040 ± 5.155; P = 0.010) were observed after AST therapy in the treatment group. Furthermore, serum MDA (14.619 ± 2.505 vs. 15.939 ± 1.512; P = 0.031) decreased significantly following antioxidant treatment. In addition, significantly lower serum levels of IL-1ß (4.515 ± 0.907 vs. 6.8760 ± 0.8478; P = 0.000), IL-6 (5.516 ± 0.646 vs. 5.0543 ± 0.709; P = 0.024) and TNF-α (2.520 ± 0.525 vs. 2.968 ± 0.548; P = 0.038) were observed after AST treatment. In addition, AST supplementation led to an improved number of oocytes retrieved (14.60 ± 7.79 vs. 9.84 ± 6.44; P = 0.043), number of mature (MII) oocytes (10.48 ± 6.665 vs. 6.72 ± 4.3; P = 0.041), and high-quality embryos (4.52 ± 2.41 vs. 2.72 ± 2.40; P = 0.024). Conclusion: AST pretreatment can modulate inflammation and OS in endometriosis-induced infertile patients. ART outcomes also improved after 12 weeks of AST therapy. Our results suggest that AST can be a potential therapeutic target for infertile patients with endometriosis undergoing ART.

[Proposal for a diagnostic and therapeutic care pathway of the Piedmont Region on lipid-lowering and antithrombotic treatment in patients with peripheral arterial disease]. / Proposta di percorso diagnostico-terapeutico assistenziale della Regione Piemonte sulla terapia ipolipemizzante ed antitrombotica in pazienti con malattia delle arterie periferiche.

The aim of this paper is to present the diagnostic and therapeutic care pathway on peripheral arterial disease, recently developed in the Piedmont Region, Italy. It proposes a combined approach between the cardiologist and vascular surgeon for optimizing the treatment of patients with peripheral artery disease, which includes the most recently approved antithrombotic and lipid-lowering drugs. The goal is to promote a greater awareness on peripheral vascular disease, in order to implement its treatment patterns and consequently to perform an effective secondary cardiovascular prevention.

Structural insights into thrombolytic activity of destabilase from medicinal leech.

Destabilase from the medical leech Hirudo medicinalis belongs to the family of i-type lysozymes. It has two different enzymatic activities: microbial cell walls destruction (muramidase activity), and dissolution of the stabilized fibrin (isopeptidase activity). Both activities are known to be inhibited by sodium chloride at near physiological concentrations, but the structural basis remains unknown. Here we present two crystal structures of destabilase, including a 1.1 Å-resolution structure in complex with sodium ion. Our structures reveal the location of sodium ion between Glu34/Asp46 residues, which were previously recognized as a glycosidase active site. While sodium coordination with these amino acids may explain inhibition of the muramidase activity, its influence on previously suggested Ser49/Lys58 isopeptidase activity dyad is unclear. We revise the Ser49/Lys58 hypothesis and compare sequences of i-type lysozymes with confirmed destabilase activity. We suggest that the general base for the isopeptidase activity is His112 rather than Lys58. pKa calculations of these amino acids, assessed through the 1 µs molecular dynamics simulation, confirm the hypothesis. Our findings highlight the ambiguity of destabilase catalytic residues identification and build foundations for further research of structure-activity relationship of isopeptidase activity as well as structure-based protein design for potential anticoagulant drug development.

Antithrombotic therapy and cardiovascular outcomes after transcatheter aortic valve implantation in patients without indications for chronic oral anticoagulation: a systematic review and network meta-analysis of randomized controlled trials.

AIMS: As the antithrombotic regimen that may best prevent ischaemic complications along with the lowest bleeding risk offset following transcatheter aortic valve implantation (TAVI) remains unclear, we aimed to compare the safety and efficacy of antithrombotic regimens in patients without having an indication for chronic oral anticoagulation. METHODS AND RESULTS: We conducted a PROSPERO-registered (CRD42021247924) systematic review and network meta-analysis of randomized controlled trials evaluating post-TAVI antithrombotic regimens up to April 2022. We estimated the relative risk (RR) and 95% confidence intervals (95% CIs) using a random-effects model in a frequentist pairwise and network metanalytic approach. We included seven studies comprising 4006 patients with a mean weighted follow-up of 12.9 months. Risk of all-cause death was significantly reduced with dual antiplatelet therapy (DAPT) compared with low-dose rivaroxaban + 3-month single antiplatelet therapy (SAPT) (RR 0.60, 95% CI 0.41-0.88), while no significant reduction was observed with SAPT vs. DAPT (RR 1.02, 95% CI 0.67-1.58) and SAPT and DAPT compared with apixaban or edoxaban (RR 0.60, 95% CI 0.32-1.14 and RR 0.59, 95% CI 0.34-1.02, respectively). SAPT was associated with a significant reduction of life-threatening, disabling, or major bleeding compared with DAPT (RR 0.45, 95% CI 0.29-0.70), apixaban or edoxaban alone (RR 0.45, 95% CI 0.25-0.79), and low-dose rivaroxaban + 3-month SAPT (RR 0.30, 95% CI 0.16-0.57). There were no differences between the various regimens with respect to myocardial infarction, stroke, or systemic embolism. CONCLUSION: Following TAVI in patients without an indication for chronic oral anticoagulant, SAPT more than halved the risk of bleeding compared with DAPT and direct oral anticoagulant-based regimens without significant ischaemic offset.

Exploring the mechanism of the antithrombotic effects of Pueraria lobata and Pueraria lobata var. thomsonii based on network pharmacology.

ETHNOPHARMACOLOGICAL RELEVANCE: Pueraria lobata (Willd.) Ohwi and Pueraria lobata var. thomsonii (Benth.) Maesen are nutritious medicine food homology plants that are widely used in the food and health products industry and are excellent natural materials for the development of new health foods, with great potential for domestic and foreign markets. Clinically, P. lobata and P. thomsonii are used to treat coronary heart disease, atherosclerosis, cerebral infarction and other cardiovascular diseases, and antithrombotic actions may be their core effect in the treatment of thrombotic diseases. However, the underlying mechanisms of the antithrombotic properties of P. lobata and P. thomsonii have not been clarified. METHODS: First, P. lobata and P. thomsonii were identified by high-performance liquid chromatography (HPLC). An arteriovenous bypass thrombosis rat model was established. Thrombus dry‒wet weight, platelet accumulation rate and the four coagulation indices, including activated partial thromboplastin time (APTT), prothrombin time (PT), thrombin time (TT) and fibrinogen (FIB), were detected in plasma to manifest the P. lobata and P. thomsonii antithrombotic function. Network pharmacology and molecular docking methods were used to obtain key targets and verify reliability. David 6.8 was used for GO and KEGG analyses to explore pathways and potential targets for P. lobata and P. thomsonii antithrombotic functions. Prostaglandin I2 (PGI2), thromboxane A2 (TXA2), cyclooxygenase 2 (COX-2), myeloperoxidase (MPO) and endothelial nitric oxide synthase (eNOS) were tested by enzyme-linked immunosorbent assay (ELISA). RESULTS: The results indicated that P. lobata and P. thomsonii can reduce thrombus dry‒wet weight and platelet accumulation in rats and inhibit TT, APTT, FIB, and PT. A comprehensive network pharmacology approach successfully identified 9 active ingredients in P. lobata and P. thomsonii. The main active ingredients include polyphenols, amino acids and flavonoids. A total of 15 antithrombotic function targets were obtained, including 3 key targets (PTGS2, NOS3, MPO). Pathway analysis showed 10 significant related pathways and 29 biological processes. P. lobata and P. thomsonii inhibited platelet aggregation by upregulating PGI2 and downregulating TXA2, inhibited PTGS2 to reduce inflammation, and increased the level of eNOS to promote vasodilation. In addition, P. lobata and P. thomsonii alleviated oxidative stress by increasing SOD levels and significantly decreasing MDA contents. CONCLUSION: The results of the study further clarify the antithrombotic mechanism of action of P. lobata and P. thomsonii, which provides a scientific basis for the development of new drugs for thrombogenic diseases and lays the foundation for the development of P. lobata and P. thomsonii herbal resources and P. lobata and P. thomsonii health products.

Antithrombotic potential of Lippia alba: A mechanistic approach.

ETHNOPHARMACOLOGICAL RELEVANCE: Lippia alba (Mill.) N.E.Br. ex Britton & P. Wilson is traditionally used in Brazil as an adjunct in the relief of mild anxiety, as an antispasmodic, and as an antidyspeptic. This medicinal species was included in the Phytotherapeutic Form of the Brazilian Pharmacopeia 2nd edition (2021) and has already been described as the most used medicinal plant in a study with patients from an Anticoagulation Clinic in Brazil. Meanwhile, no studies were found that support the safety of the use of L. alba in patients using anticoagulants, a drug with several safety limitations. AIM OF THE STUDY: Provide scientific evidence to ensure the safety of the concomitant use of L. alba and warfarin and support the management of these patients by evaluating its in vitro anticoagulant effect and chemical composition. And, as a timely complementation, evaluate the potential of this medicinal species in the development of new antithrombotics. METHODS: The chemical profile of L. alba derivatives was analyzed by chromatographic methods such as Ultra-Performance Liquid Chromatography (UPLC) coupled with electrospray ionization mass spectrometry (ESI-MS), qualitative UPLC using Diode-Array Detection, and Thin Layer Chromatography. The anticoagulant activity was evaluated by the innovative Thrombin Generation Assay by Calibrated Automated Thrombogram method and using traditional coagulometric tests: prothrombin time, activated partial thromboplastin time, and plasma fibrinogen measurement. RESULTS: Extracts and fractions prolonged the coagulation time in all the tests and reduced thrombin formation in thrombin generation assay. Coagulation times with the addition of ethanloic extract (2.26 mg/mL) was 17.78s, 46.43s and 14.25s respectively in prothrombin time, activated partial thromboplastin time and fibrinogren plasma measurement. In thrombin generation test, this same extract showed ETP as 323 nM/min compared to control (815 nM/min) with high tissue factor and 582 nM/min compared to control (1147 nM/min) using low tissue factor. Presence of flavonoids, phenylpropanoids, and triterpenes were confirmed by chromatographic methods and 13 compounds were identified by UPLC-ESI-MS. Based on these results and on the scientific literature, it is possible to propose that phenylpropanoids and flavonoids are related to the anticoagulant activity observed. CONCLUSION: The results demonstrate the in vitro anticoagulant activity of L. alba, probably due to the activation of intrinsic and extrinsic pathways. It is concluded, then, that there is a potential for interaction, which needs to be further studied, between L. alba and warfarin. Also, this medicinal species shows a great potential for use in the development of new antithrombotics.

Moving from traditional to more advanced treatments in stroke care is cost-effective: A case study from Greece.

OBJECTIVES: Stroke is the most common cause of disability in high-income countries. Several countries offer a limited range of advanced treatments with implications for outcomes, disability and costs. This study estimates the burden of disability that could have been avoided through the transition from traditional (no intravenous thrombolytic therapy (IVT), or endovascular thrombectomy (EVT)) to modern stroke treatments (treatment in stroke units, IVT and EVT). We perform a cost-effectiveness analysis comparing best practice with traditional stroke care, using Greece as a case study. MATERIALS AND METHODS: A Markov model was used to calculate costs and Quality Adjusted Life Years (QALYs) for each treatment strategy, using a lifetime horizon. Data for model inputs were derived from meta-analyses of trials, and national and international cost databases. Sensitivity analyses were also performed to address potential uncertainty and test the robustness of the findings. RESULTS: Incremental effectiveness comprised 0.22 QALYs per patient and year. Best practice was cost-effective for more than 90% of all iterations (ICER for the baseline scenario: €2,109.25/QALY). Sensitivity analysis demonstrated that the findings remain robust. Considering the stroke incidence in Greece, the annual additional cost to implement best practice was calculated to be between 0.07%-0.15% of the total health expenditure. CONCLUSION: Best practice stroke treatment was cost-effective and affordable in a case study based on Greece. The results could be leveraged by including effects of preventive policies and rehabilitation. They also highlight the importance of adopting modern treatment strategies from a cost-effectiveness perspective, apart from the improved clinical outcomes.

Exploring the Fibrin(ogen)olytic, Anticoagulant, and Antithrombotic Activities of Natural Cysteine Protease (Ficin) with the κ-Carrageenan-Induced Rat Tail Thrombosis Model.

Although fibrinolytic enzymes and thrombolytic agents help in cardiovascular disease treatment, those currently available have several side effects. This warrants the search for safer alternatives. Several natural cysteine protease preparations are used in traditional medicine to improve platelet aggregation and thrombosis-related diseases. Hence, this study aimed to investigate the effect of ficin, a natural cysteine protease, on fibrin(ogen) and blood coagulation. The optimal pH (pH 7) and temperature (37 °C) for proteolytic activity were determined using the azocasein method. Fibrinogen action and fibrinolytic activity were measured both electrophoretically and by the fibrin plate assay. The effect of ficin on blood coagulation was studied by conventional coagulation tests: prothrombin time (PT), activated partial thromboplastin time (aPTT), blood clot lysis assay, and the κ-carrageenan thrombosis model. The Aα, Bß, and γ bands of fibrinogen are readily cleaved by ficin, and we also observed a significant increase in PT and aPTT. Further, the mean length of the infarcted regions in the tails of Sprague-Dawley rats was shorter in rats administered 10 U/mL of ficin than in control rats. These findings suggest that natural cysteine protease, ficin contains novel fibrin and fibrinogenolytic enzymes and can be used for preventing and/or treating thrombosis-associated cardiovascular disorders.

Antithrombin supplementation for prevention of vascular thrombosis after pediatric liver transplantation.

AIMS: After liver transplantation (LT), synthesis of coagulation factors by the graft recovers faster for pro thrombotic than anti thrombotic factors, resulting in a potential pro thrombotic imbalance. We studied the thrombotic and hemorrhagic complications in our pediatric LT series, providing supplementation of fresh frozen plasma (FFP) and/or antithrombin (AT) in the prophylactic antithrombotic regimen. METHODS: This was a retrospective observational single center study. All isolated pediatric LTs performed between 1/11/2009 and 31/12/2019 (n = 181) were included. Postoperatively, in addition to low molecular weight heparin, 22 patients (12%) received FFP (10 ml/kg twice daily for 10 days), 27 patients (15%) were given FFP (reduced duration) and AT (50-100 IU/kg/day if AT activity remained <70%), and 132 (73%) received AT only. Complications, outcome, and coagulation profiles in postoperative days 0-10 were analyzed. RESULTS: In all three treatment groups, AT activity normalized by day 4 while prothrombin remained <70% of normal until day 9. Hepatic artery thrombosis (HAT), portal vein thrombosis (PVT), and hemorrhagic complications occurred in 2.8%, 3.3%, and 3.9% of LTs. One- and 5-year patient and graft survival were 88% (±2.4% Standard Error) and 84% (±2.5%), and 86% (±2.6%) and 84% (±2.7%), respectively, without difference between groups. HAT were associated with low AT on days 0 and 1, and PVT with low AT on day 0. CONCLUSIONS: Low antithrombin activity after LT was associated with postoperative thromboses. FFP and/or AT supplementation allowed early normalization of AT activity, while thrombotic or hemorrhagic complications were rare, suggesting efficient and safe management of post-LT coagulopathy.

Rivaroxaban Monotherapy vs Combination Therapy With Antiplatelets on Total Thrombotic and Bleeding Events in Atrial Fibrillation With Stable Coronary Artery Disease: A Post Hoc Secondary Analysis of the AFIRE Trial.

Importance: Appropriate regimens of antithrombotic therapy for patients with atrial fibrillation (AF) and coronary artery disease (CAD) have not yet been established. Objective: To compare the total number of thrombotic and/or bleeding events between rivaroxaban monotherapy and combined rivaroxaban and antiplatelet therapy in such patients. Design, Setting, and Participants: This was a post hoc secondary analysis of the Atrial Fibrillation and Ischemic Events With Rivaroxaban in Patients With Stable Coronary Artery Disease (AFIRE) open-label, randomized clinical trial. This multicenter analysis was conducted from February 23, 2015, to July 31, 2018. Patients with AF and stable CAD who had undergone percutaneous coronary intervention or coronary artery bypass grafting 1 or more years earlier or who had angiographically confirmed CAD not requiring revascularization were enrolled. Data were analyzed from September 1, 2020, to March 26, 2021. Interventions: Rivaroxaban monotherapy or combined rivaroxaban and antiplatelet therapy. Main Outcomes and Measures: The total incidence of thrombotic, bleeding, and fatal events was compared between the groups. Cox regression analyses were used to estimate the risk of subsequent events in the 2 groups, with the status of thrombotic or bleeding events that had occurred by the time of death used as a time-dependent variable. Results: A total of 2215 patients (mean [SD] age, 74 [8.2] years; 1751 men [79.1%]) were included in the modified intention-to-treat analysis. The total event rates for the rivaroxaban monotherapy group (1107 [50.0%]) and the combination-therapy group (1108 [50.0%]) were 12.2% (135 of 1107) and 19.2% (213 of 1108), respectively, during a median follow-up of 24.1 (IQR, 17.3-31.5) months. The mortality rate was 3.7% (41 of 1107) in the monotherapy group and 6.6% (73 of 1108) in the combination-therapy group. Rivaroxaban monotherapy was associated with a lower risk of total events compared with combination therapy (hazard ratio, 0.62; 95% CI, 0.48-0.80; P < .001). Monotherapy was an independent factor associated with a lower risk of subsequent events compared with combination therapy. The mortality risk after a bleeding event (monotherapy, 75% [6 of 8]; combination therapy, 62.1% [18 of 29]) was higher than that after a thrombotic event (monotherapy, 25% [2 of 8]; combination therapy, 37.9% [11 of 29]). Conclusions and Relevance: Rivaroxaban monotherapy was associated with lower risks of total thrombotic and/or bleeding events than combination therapy in patients with AF and stable CAD. Tapered antithrombotic therapy with a sole anticoagulant should be considered in these patients. Trial Registration: ClinicalTrials.gov Identifier: NCT02642419.

Comparison of Managing Factor Xa Inhibitor to Unfractionated Heparin Transitions by aPTT Versus a Treatment Guideline Utilizing Heparin Anti-Xa Levels.

BACKGROUND: There are inadequate data on the optimal strategy for transitioning factor Xa inhibitors (FXai; apixaban, rivaroxaban) to unfractionated heparin (UFH) infusions. OBJECTIVE: In patients transitioning from an FXai to an UFH infusion, this study compared the safety and efficacy of monitoring UFH infusions using an activated partial thromboplastin time (aPTT) titration scale versus utilizing an UFH-calibrated anti-Xa titration scale aided by a novel institutional guideline. METHODS: A retrospective cohort analysis was conducted on adult patients transitioning from an FXai to an UFH infusion at 2 medical centers from June 1, 2018, to November 1, 2020. One institution utilized aPTT while the other institution primarily used UFH-calibrated anti-Xa. The primary endpoint was a composite of death, major bleeding, or new thrombosis during the hospitalization with a planned noninferiority analysis. Secondary outcomes were also collected including the amount and duration of UFH administered between cohorts. RESULTS: The incidence rate of the primary composite endpoint was 6.3% in the anti-Xa group and 11% in the aPTT group (P < 0.001 for noninferiority, P = 0.138 for superiority) meeting noninferiority criteria. No statistical differences were seen in new thrombosis, major bleeding, or any bleeding. CONCLUSION AND RELEVANCE: This represents the first report of a comparison between aPTT versus anti-Xa monitoring in relation to clinical outcomes for patients transitioning from an FXai to an UFH infusion. A transition guideline primarily utilizing an UFH-calibrated anti-Xa assay appears to be a safe alternative to aPTT monitoring and can aid facilities in the management of patients during these complex transitions.