Severe Bleeding Risk of Direct Oral Anticoagulants Versus Vitamin K Antagonists for Stroke Prevention and Treatment in Patients with Atrial Fibrillation: A Systematic Review and Network Meta-Analysis.

PURPOSE: We aimed to determine the safety of direct oral anticoagulants (DOACs) for stroke prevention and treatment in patients with atrial fibrillation (AF). METHODS: A systematic search of four databases (PubMed, EMBASE, Web of Science, and Cochrane Library) was performed to identify randomized controlled trials (RCTs) reporting severe bleeding events in patients taking DOACs or vitamin K antagonists (VKAs). In this frequency-based network meta-analysis, odds ratios and 95% confidence intervals were used for reporting. Based on the surface under the cumulative ranking curves (SUCRA), the relative ranking probability of each group was generated. RESULTS: Twenty-three RCTs met the inclusion criteria, and a total of 87,616 patients were enrolled. The bleeding safety of DOACs for stroke prevention and treatment in patients with AF was ranked from highest to lowest as follows: fatal bleeding: edoxaban (SUCRA,80.2), rivaroxaban (SUCRA,68.3), apixaban (SUCRA,48.5), dabigatran (SUCRA,40.0), VKAs (SUCRA,12.9); major bleeding: dabigatran (SUCRA,74.0), apixaban (SUCRA,71.5), edoxaban (SUCRA,66.5), rivaroxaban (SUCRA,22.7), VKAs (SUCRA,15.4); gastrointestinal bleeding: apixaban (SUCRA,55.9), VKAs (SUCRA,53.7), edoxaban (SUCRA,50.5), rivaroxaban (SUCRA,50.4), dabigatran (SUCRA,39.5); intracranial hemorrhage: dabigatran (SUCRA,84.6), edoxaban (SUCRA,74.1), apixaban (SUCRA,65.8), rivaroxaban (SUCRA,24.4), VKAs (SUCRA,1.1). CONCLUSION: Based on current evidence, for stroke prevention and treatment in patients with AF, the most safe DOAC is edoxaban in terms of fatal bleeding; dabigatran in terms of major bleeding and intracranial hemorrhage and apixaban in terms of gastrointestinal bleeding. However, given the nature of indirect comparisons, more high-quality evidence from head-to-head comparisons is still needed to confirm them.

The Bridge Between Ischemic Stroke and Gut Microbes: Short-Chain Fatty Acids.

Short-chain fatty acids (SCFAs) are monocarboxylates produced by the gut microbiota (GM) and result from the interaction between diet and GM. An increasing number of studies about the microbiota-gut-brain axis (MGBA) indicated that SCFAs may be a crucial mediator in the MGBA, but their roles have not been fully clarified. In addition, there are few studies directly exploring the role of SCFAs as a potential regulator of microbial targeted interventions in ischemic stroke, especially for clinical studies. This review summarizes the recent studies concerning the relationship between ischemic stroke and GM and outlines the role of SCFAs as a bridge between them. The potential mechanisms by which SCFAs affect ischemic stroke are described. Finally, the beneficial effects of SFCAs-mediated therapeutic measures such as diet, dietary supplements (e.g., probiotics and prebiotics), fecal microbiota transplantation, and drugs on ischemic brain injury are also discussed.

Effects and Mechanism of Action of Panax notoginseng Saponins on the Pharmacokinetics of Warfarin.

BACKGROUD: The interactions between Chinese herbs and drugs pose a great challenge to the combined clinical application of Chinese herbs and drugs. Chinese medicinal products contain complex pharmacologically active components that may influence the in vivo processes of drugs in a variety of ways. In China, drugs based on Panax ginseng total saponins (PNS) are often combined with warfarin for the treatment of cardiovascular diseases. OBJECTIVES: To assess the effects of Panax notoginseng saponins (PNS) on the pharmacokinetics of warfarin and its mechanism. METHOD: Blood was collected for the determination of the prothrombin time (PT) and international normalized ratio (INR) from rats treated with warfarin alone or with warfarin + PNS. The plasma concentration of warfarin was determined by high-performance liquid chromatography. Western blot was used to detect the expression of cytochrome P450 (CYP) enzymes. RESULTS: When warfarin and PNS were co-administered, the PT and INR increased compared to when warfarin was given alone. 72 hours after administration, compared to the warfarin alone group, the warfarin + low-dose PNS, warfarin + medium-dose PNS, and warfarin + high-dose PNS groups showed 110%, 122%, and 126% increases in PT, respectively (all P < 0.05), as well as 111%, 124%, and 128% increases in INR (all P < 0.05). Compared with the warfarin alone group, the clearance rate (CL/F) of warfarin in the warfarin + low-dose PNS, warfarin + medium-dose PNS, and warfarin + high-dose PNS groups was 10% (P > 0.05), 23% (P < 0.05), and 33% (P < 0.05) lower, respectively, while the systemic exposure (area under the concentration-time curve, AUC0-t) increased by 106% (P > 0.05), 119% (P < 0.05), and 134% (P < 0.05), respectively, and the blood concentration of warfarin incresed by 112%, 113%, and 114%, respectively (all P > 0.05). After combined treatment of HepG2 cells with warfarin + PNS, CYP1A2 expression was upregulated (P < 0.05) and CYP3A4 was downregulated (P < 0.05) but there was no effect on CYP2C9. In animal experiments, PNS had different effect on the expression of CYP1A2 in different doses. While a low dose of PNS resulted in downregulated CYP1A2 expression (P < 0.05), a medium dose resulted in upregulation (P < 0.05), and CYP1A2 expression was not significantly affected by a high dose of PNS (P > 0.05). Meanwhile, PNS at all doses downregulated the expression of CYP3A4 (P < 0.05) but had no effect on the expression of CYP2C9 (P > 0.05). CONCLUSION: PNS can increase the blood concentration of warfarin, as well as the exposure time, and it can enhance the anticoagulant effect of warfarin by inhibiting the expression of the liver enzyme CYP3A4.

Editor's Choice - Severe Bleeding Risks of Direct Oral Anticoagulants in the Prevention and Treatment of Venous Thromboembolism: A Network Meta-Analysis of Randomised Controlled Trials.

OBJECTIVE: The aim of this study was to determine the severe bleeding safety of direct oral anticoagulants (DOACs) for the prevention and treatment of venous thromboembolism (VTE). METHODS: PubMed, EMBASE, Web of Science, and the Cochrane Library databases were searched up to 6 January 2021. The incidence of severe bleeding (major, gastrointestinal [GI], intracranial, and fatal) was investigated. Using frequentist network meta-analysis, interventions that were not compared directly could be compared indirectly by the 95% confidence interval (CI), making the search results more intuitive. Based on surface under the cumulative ranking curves (SUCRA), the relative ranking probability of each group was generated. RESULTS: Thirty-one randomised controlled trials (76 641 patients) were included. For the treatment of VTE, the risk of major bleeding with apixaban was significantly lower than dabigatran (odds ratio [OR] 2.10, 95% CI 1.07 - 4.12) and edoxaban (OR 2.64, 95% CI 1.36 - 5.15). The safety of the drugs was ranked from highest to lowest as follows: major bleeding: apixaban (SUCRA 98.0), rivaroxaban (SUCRA 69.6), dabigatran (SUCRA 50.7), edoxaban (SUCRA 26.5), and vitamin K antagonists (VKAs; SUCRA 5.1); GI bleeding: apixaban (SUCRA 80.7), rivaroxaban (SUCRA 66.8), edoxaban (SUCRA 62.3), VKAs (SUCRA 34.4), and dabigatran (SUCRA 5.8); intracranial bleeding: rivaroxaban (SUCRA 74.4), edoxaban (SUCRA 70.4), dabigatran (SUCRA 58.2), apixaban (SUCRA 44.4), and VKAs (SUCRA 5.6); fatal bleeding: edoxaban (SUCRA 82.7), rivaroxaban (SUCRA 59.2), dabigatran (SUCRA 48.6), apixaban (SUCRA 43.0), and VKAs (SUCRA 16.3). For the prevention of VTE, the risk of major bleeding with apixaban was significantly lower than rivaroxaban (OR 2.14, 95% CI 1.02 - 4.52). Among the four types of bleeding, apixaban had the lowest bleeding risk among DOACs (major bleeding: SUCRA 81.6; GI bleeding: SUCRA 75.4; intracranial bleeding: SUCRA 64.1; fatal bleeding: SUCRA 73.6). CONCLUSIONS: For the treatment of VTE, in terms of major bleeding and GI bleeding, apixaban had the lowest bleeding risk; in terms of intracranial bleeding, rivaroxaban had the lowest bleeding risk; in terms of fatal bleeding, edoxaban had the lowest bleeding risk. For the prevention of VTE, apixaban had the lowest bleeding risk.