Direct factor Xa inhibitors and the risk of cancer and cancer mortality: A Danish population-based cohort study.

BACKGROUND: Preclinical animal studies have suggested that myeloid cell-synthesized coagulation factor X dampens antitumor immunity and that rivaroxaban, a direct factor Xa inhibitor, can be used to promote tumor immunity. This study was aimed at assessing whether patients with atrial fibrillation taking direct factor Xa inhibitors have lower risk of cancer and cancer-related mortality than patients taking the direct thrombin inhibitor dabigatran. METHODS AND FINDINGS: This nationwide population-based cohort study in Denmark included adult patients with atrial fibrillation and without a history of cancer, who started taking a factor Xa inhibitor or dabigatran between 2011 and 2015. Data on medical history, outcomes, and drug use were acquired through Danish healthcare registries. The primary outcome was any cancer. Secondary outcomes were cancer-related mortality and all-cause mortality. Outcome events were assessed during 5 years of follow-up in an intention-to-treat analysis. The propensity score-based inverse probability of treatment weighting was used to compute cumulative incidence and subdistribution hazard ratios (SHRs) and corresponding 95% confidence intervals (CIs), with death as a competing event. Propensity scores were estimated using logistic regression and including in the model sex, age group at index date, comorbidities, and use of comedications. A total of 11,742 patients with atrial fibrillation starting a factor Xa inhibitor and 11,970 patients starting dabigatran were included. Mean age was 75.2 years (standard deviation [SD] 11.2) in the factor Xa cohort and 71.7 years (SD 11.1) in the dabigatran cohort. On the basis of the propensity score-weighted models, after 5 years of follow-up, no substantial difference in the cumulative incidence of cancer was observed between the factor Xa inhibitor (2,157/23,711; 9.11%, 95% CI [8.61%,9.63%]) and dabigatran (2,294/23,715; 9.68%, 95% CI [9.14%,10.25%]) groups (SHR 0.94, 95% CI [0.89,1.00], P value 0.0357). We observed no difference in cancer-related mortality (factor Xa inhibitors cohort 1,028/23,711; 4.33%, 95% CI [4.02%,4.68%]. Dabigatran cohort 1,001/23,715; 4.22%, 95% CI [3.83%,4.66%]; SHR 1.03, 95% CI [0.94,1.12]), but all-cause mortality was higher in the factor Xa inhibitor cohort (factor Xa inhibitors cohort 7,416/23,711; 31.31%, 95% CI [30.37%,32.29%]. Dabigatran cohort 6,531/23,715; 27.56%, 95% CI [26.69%,28.45%]; HR 1.17, 95% CI [1.13,1.21]). The main limitations of the study were the possibility of residual confounding and the short follow-up period. CONCLUSIONS: In this population based cohort study, factor Xa inhibitor use was not associated with an overall lower incidence of cancer or cancer-related mortality when compared to dabigatran. We did observe an increase in all-cause mortality in the factor Xa inhibitor cohort.

Bivalirudin versus heparin in patients with or without bail-out GPI use: a pre-specified subgroup analysis from the BRIGHT-4 trial.

BACKGROUND: Conflicting results comparing bivalirudin versus heparin anticoagulation in patients with ST-segment elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (PCI), in part due to the confounding effect of glycoprotein IIb/IIIa inhibitors (GPI). The aim of the study was to compare the safety and effectiveness of bivalirudin plus a post-PCI high-dose infusion vs heparin with or without bail-out GPI use. METHODS: We conducted a pre-specified subgroup analysis from the BRIGHT-4 trial that randomized 6016 STEMI patients who underwent primary PCI to receive either bivalirudin plus a post-PCI high-dose infusion for 2-4 h or heparin monotherapy. GPI use was only reserved as bail-out therapy for procedural thrombotic complications. The primary outcome was a composite of all-cause death or Bleeding Academic Research Consortium (BARC) types 3-5 bleeding at 30 days. RESULTS: A total of 5250 (87.4%) patients received treatment without GPI while 758 (12.6%) received bail-out GPI. Bail-out GPI use was associated with an increased risk of the primary outcome compared to non-GPI use (5.28% vs. 3.41%; adjusted hazard ratio (aHR), 1.62; 95% confidence interval (CI), 1.13-2.33; P = 0.009) and all-cause death (5.01% vs. 3.12%; aHR, 1.74; 95% CI, 1.20-2.52; P = 0.004) but not in the risk of BARC types 3-5 bleeding (0.53% vs. 0.48%; aHR, 0.90; 95% CI, 0.31-2.66; P = 0.85). Among patients without GPI use, bivalirudin was associated with lower rates of the primary outcome (2.63% vs. 4.21%; aHR, 0.55; 95% CI, 0.39-0.77; P = 0.0005), all-cause death (2.52% vs. 3.74%; aHR, 0.58; 95% CI, 0.41-0.83; P = 0.003), and BARC types 3-5 bleeding (0.15% vs. 0.81%; aHR, 0.19; 95% CI, 0.06-0.57; P = 0.003) compared with heparin. However, among patients requiring bail-out GPI, there were no significant differences observed in the rates of the primary outcome (5.76% vs. 4.87%; aHR, 0.77; 95% CI, 0.36-1.66; P = 0.50; Pinteraction = 0.07) or its individual components between bivalirudin and heparin groups. CONCLUSIONS: Bivalirudin plus a post-PCI high-dose infusion was associated with significantly reduced 30-day composite rate of all-cause death or BARC types 3-5 bleeding compared with heparin monotherapy in STEMI patients undergoing primary PCI without GPI use. However, these benefits might be less pronounced in patients requiring bail-out GPI due to thrombotic complications during primary PCI. TRIAL REGISTRATION: ClinicalTrials.gov NCT03822975.

The Effect of ABCB1 and CES1 Polymorphisms on Plasma Levels of Dabigatran and Risk of Hemorrhagic Complications in Ischemic Stroke Patients.

BACKGROUND: Dabigatran directly inhibits thrombin and is used in primary and secondary stroke prevention in individuals with nonvalvular atrial fibrillation. The prodrug dabigatran etexilate is absorbed by enteral P-glycoprotein (ABCB1) and then activated by hepatic and intestinal carboxylesterases (CES1) to produce active metabolites. Variations in dabigatran metabolism because of genetics may affect concentration levels and clinical outcomes. STUDY QUESTION: We conducted a study to assess how polymorphisms in the CES1 (rs2244613) and ABCB1 (rs4148738) genes affect the through plasma level (c min ) of dabigatran and its correlation to clinical outcomes. STUDY DESIGN: Retrospective multicentric study of consecutive patients on dabigatran therapy. Examination of CES1 rs2244613 and ABCB1 rs4148738 polymorphisms, c min 12 hours after administration, clinical follow-up (ischemic stroke, major or clinically relevant hemorrhage, myocardial infarction, other thromboembolism, and death). MEASURES AND OUTCOMES: A total of 432 patients received treatment for an average of 19.78 months (SD of 20.165). The sex distribution of the patients was 56.5% male, and the average age was 67.56 years (SD of 14.7). The ABCB1 variant genotype was present in 67.8% of patients, whereas 37.5% carried the CES1 polymorphism. RESULTS: Compared with wild-type patients, patients with the CES1 variant had significantly lower dabigatran plasma levels (with a mean difference of 16.986; 95% confidence interval, 5.794-28.178 ng/mL, P = 0.003). We also found a significant risk of major bleeding in patients carrying the ABCB1 rs4148738 allele (hazard ratio = 1.99, confidence interval 95% 1.10 to 3.59, P = 0.024). CONCLUSIONS: The CES1 variant genotype rs2244613 is closely linked with reduced c min of dabigatran. Carriers of the ABCB1 rs4148738 polymorphism exhibit a tendency toward higher plasma levels of dabigatran, which leads to a significantly increased risk of bleeding.

Efficacy and safety of dabigatran and rivaroxaban in atrial fibrillation patients with impaired liver function: a multicenter retrospective cohort study.

BACKGROUND: The efficacy and safety of direct oral anticoagulants (DOACs) in atrial fibrillation (AF) patients with impaired liver function (ILF) have not been sufficiently studied. The aim of this study was to evaluate the efficacy and safety of DOACs for stroke prevention in patients with AF and ILF. METHOD: This study was based on data from 15 centers in China, including 4,982 AF patients. The patients were divided into 2 subgroups based on their liver function status: patients with normal liver function (NLF)(n = 4213) and patients with ILF (n = 769). Logistic regression analysis was used to investigate the risk of total bleeding, major bleeding, thromboembolism, and all-cause deaths in AF patients with NLF and ILF after taking dabigatran or rivaroxaban, respectively. RESULTS: Among AF patients treated with dabigatran or rivaroxaban, patients with ILF were associated with significantly higher major bleeding, compared with NLF patients (aOR: 4.797; 95% CI: 2.224-10.256; P < 0.001). In patients with NLF, dabigatran (n = 2011) had considerably lower risk of total bleeding than rivaroxaban (n = 2202) (aOR: 1.23; 95% CI: 1.002-1.513; P = 0.049). In patients with ILF, dabigatran (n = 321) significantly favored lower risks of major bleeding compared with rivaroxaban(n = 448) (aOR: 5.484; 95% CI: 1.508-35.269; P = 0.026). CONCLUSION: After using dabigatran or rivaroxaban, patients with ILF had remarkably increased risk of major bleeding compared with patients with NLF. In AF patients with NLF, dabigatran had the distinct strength of significantly reduced risk of total bleeding compared with rivaroxaban. In patients with AF and ILF, dabigatran use was associated with lower risk for major bleeding compared with rivaroxaban.

Comparison of warfarin, rivaroxaban, and dabigatran for effectiveness and safety in atrial fibrillation patients with different CHA2DS2-VASc scores: a retrospective cohort study.

BACKGROUND: This retrospective cohort study aims to compare the effectiveness and safety of warfarin, rivaroxaban, and dabigatran in atrial fibrillation (AF) patients with different CHA2DS2-VASc scores in northern China. METHODS: A retrospective cohort study was performed to evaluate anticoagulation in AF patients at the second affiliated hospital of Harbin Medical University from September 2018 to August 2019. Patients included in this study (n = 806) received warfarin (n = 300), or rivaroxaban (n = 203), or dabigatran (n = 303). Baseline characteristics and follow-up data including adherence, bleeding events and ischemic stroke (IS) events were collected. RESULTS: Patients receiving rivaroxaban (73.9%) or dabigatran (73.6%) showed better adherence than those receiving warfarin (56.7%). Compared with warfarin-treated patients, dabigatran-treated patients had lower incidence of bleeding events (10.9% vs 19.3%, χ2 = 8.385, P = 0.004) and rivaroxaban-treated patients had lower incidence of major adverse cardiovascular events (7.4% vs 13.7%, χ2 = 4.822, P = 0.028). We classified patients into three groups based on CHA2DS2-VASc score (0-1, 2-3, ≥ 4). In dabigatran intervention, incidence of bleeding events was higher in patients with score 0-1 (20.0%) than those with score 2-3 (7.9%, χ2 = 5.772, P = 0.016) or score ≥ 4 (8.6%, χ2 = 4.682, P = 0.030). Patients with score 0-1 in warfarin or rivaroxaban therapy had a similar but not significant increase of bleeding compared with patients with score 2-3 or score ≥ 4, respectively. During the follow-up, 33 of 806 patients experienced IS and more than half (19, 57.6%) were patients with score ≥ 4. Comparing patients with score 0-1 and 2-3, the latter had an significant reduction of IS in patients prescribed warfarin and non-significant reduction in rivaroxaban and dabigatran therapy. CONCLUSION: Compared with warfarin therapy, patients with different CHA2DS2-VASc scores receiving either rivaroxaban or dabigatran were associated with higher persistence. AF patients with score ≥ 4 were more likely to experience IS events while hemorrhagic tendency preferred patients with low score 0-1.

In DVT, oral DTIs and factor Xa inhibitors reduce major bleeding but not recurrent VTE vs. conventional anticoagulants.

SOURCE CITATION: Wang X, Ma Y, Hui X, et al. Oral direct thrombin inhibitors or oral factor Xa inhibitors versus conventional anticoagulants for the treatment of deep vein thrombosis. Cochrane Database Syst Rev. 2023;4:CD010956. 37058421.

Bivalirudin as a substitute for heparin in neurointervention for patients with heparin-induced thrombocytopenia.

OBJECTIVES: Heparin-induced thrombocytopenia is a known complication of heparin exposure with potentially life-threatening sequelae. Direct thrombin inhibitors can be substituted for heparin in patients with heparin-induced thrombocytopenia that require anticoagulation. However, the use of direct thrombin inhibitors as a substitute for heparin has not been widely reported in the neuroendovascular literature. MATERIALS AND METHODS: Here we report the first use of the direct thrombin inhibitor bivalirudin in a neuroendovascular procedure as a substitute for heparin in a patient with a ruptured pseudoaneurysm and heparin-induced thrombocytopenia, and review the literature on the use of bivalirudin and argatroban for such patients. RESULTS: Bivalirudin was safely and effectively used in the case reported, with no thrombotic or hemorrhagic complications. Our literature review revealed a paucity of studies on the use of heparin alternatives, including bivalirudin, in neuroendovascular procedures in patients with heparin-induced thrombocytopenia. CONCLUSIONS: Heparin-induced thrombocytopenia is an important iatrogenic disease process in patients undergoing neuroendovascular procedures, and developing protocols to diagnose and manage heparin-induced thrombocytopenia is important for healthcare systems. While further research needs to be done to establish the full range of anticoagulation options to substitute for heparin, our case indicates bivalirudin as a potential candidate.

The contact activation inhibitor AB023 in heparin-free hemodialysis: results of a randomized phase 2 clinical trial.

End-stage renal disease (ESRD) patients on chronic hemodialysis have repeated blood exposure to artificial surfaces that can trigger clot formation within the hemodialysis circuit. Dialyzer clotting can lead to anemia despite erythropoietin and iron supplementation. Unfractionated heparin prevents clotting during hemodialysis, but it is not tolerated by all patients. Although heparin-free dialysis is performed, intradialytic blood entrapment can be problematic. To address this issue, we performed a randomized, double-blind, phase 2 study comparing AB023, a unique antibody that binds factor XI (FXI) and blocks its activation by activated FXII, but not by thrombin, to placebo in 24 patients with ESRD undergoing heparin-free hemodialysis. Patients were randomized to receive a single predialysis dose of AB023 (0.25 or 0.5 mg/kg) or placebo in a 2:1 ratio, and safety and preliminary efficacy were compared with placebo and observations made prior to dosing within each treatment arm. AB023 administration was not associated with impaired hemostasis or other drug-related adverse events. Occlusive events requiring hemodialysis circuit exchange were less frequent and levels of thrombin-antithrombin complexes and C-reactive protein were lower after AB023 administration compared with data collected prior to dosing. AB023 also reduced potassium and iron entrapment in the dialyzers, consistent with less blood accumulation within the dialyzers. We conclude that despite the small sample size, inhibition of contact activation-induced coagulation with AB023 was well tolerated and reduced clotting within the dialyzer. This trial was registered at www.clinicaltrials.gov as #NCT03612856.

Impact of coronary artery disease on clinical outcomes after TAVR: Insights from the BRAVO-3 randomized trial.

OBJECTIVE: To determine the prognostic impact of coronary artery disease (CAD) in patients randomized to bivalirudin or unfractionated heparin (UFH) during transcatheter aortic valve replacement (TAVR). BACKGROUND: CAD is a common comorbidity among patients undergoing TAVR and studies provide conflicting data on its prognostic impact. METHODS: The Bivalirudin on Aortic Valve Intervention Outcomes-3 (BRAVO-3) randomized trial compared the use of bivalirudin versus UFH in 802 high-surgical risk patients undergoing transfemoral TAVR for severe symptomatic aortic stenosis. Patients were stratified according to the presence or absence of history of CAD as well as periprocedural anticoagulation. The coprimary endpoints were net adverse cardiac events (NACE; a composite of all-cause mortality, myocardial infarction, stroke, or major bleeding) and major Bleeding Academic Research Consortium (BARC) bleeding ≥3b at 30 days postprocedure. RESULTS: Among 801 patients, 437 (54.6%) had history of CAD of whom 223 (51.0%) received bivalirudin. There were no significant differences in NACE (adjusted odds ratio [OR]: 1.04; 95% confidence interval [CI]: 0.69-1.58) or BARC ≥ 3b bleeding (adjusted OR: 0.84; 95% CI: 0.51-1.39) in patients with vs without CAD at 30 days. Among CAD patients, periprocedural use of bivalirudin was associated with similar NACE (OR: 0.80; 95% CI: 0.47-1.35) and BARC ≥ 3b bleeding (OR: 0.64; 95% CI: 0.33-1.25) compared with UFH, irrespective of history of CAD (p-interaction = 0.959 for NACE; p-interaction = 0.479 for major bleeding). CONCLUSION: CAD was not associated with a higher short-term risk of NACE or major bleeding after TAVR. Periprocedural anticoagulation with bivalirudin did not show any advantage over UFH in patients with and without CAD.

Evaluation of acquired antithrombin deficiency in paediatric patients supported on extracorporeal membrane oxygenation.

AIMS: There remains a paucity of literature regarding best practice for antithrombin (AT) monitoring, dosing and dose-response in paediatric extracorporeal membrane oxygenation (ECMO) patients. METHODS: We conducted a retrospective cohort study at a quaternary care paediatric intensive care unit in all patients <18 years of age supported on ECMO from 1 June 2011 to 30 April 2020. Adverse events and outcomes were characterized for all ECMO runs. AT activity and replacement were characterized and compared between two clinical protocols. AT activities measured post- vs. pre-AT replacement were compared in order to characterize a dose-response relationship. RESULTS: The final cohort included 191 patients with 201 ECMO runs and 2028 AT activity measurements. The median AT activity was 65% (interquartile range [IQR], 51-82) and 879 (43.3%) measurements met the criteria of deficient. The overall median AT dose and increase in AT activity were 50.6 units/kg/dose (IQR, 39.5-67.2) and 23.5% (IQR, 9.8-36.0), respectively. In the protocol that restricted AT activity measurements to clinical scenarios concerning for heparin resistance, there was significantly higher dosing in conjunction with significantly fewer overall administrations. Approximately one third of AT activity remained deficient after repletion. There was no difference in mechanical complications, reasons for discontinuation of ECMO support, time on ECMO or survival between protocols. CONCLUSIONS: There was a high prevalence of AT deficiency in paediatric ECMO patients. An AT replacement protocol based on evaluating heparin resistance is associated with fewer AT administrations, with similar circuit and patient outcomes. Further data are needed to identify optimal dosing strategies.

The Rise and Fall of Antithrombin Supplementation in Cardiac Surgery.

Various cohort studies, both retrospective and prospective, showed that low antithrombin levels after cardiac surgery (at the arrival in the intensive care unit and during the next days) were associated with a number of adverse outcomes, including surgical reexploration and thromboembolic events, eventually leading to prolonged stay in the intensive care. Values lower than 58% to 64% of antithrombin activity were indicative of this higher morbidity with good sensitivity and specificity. The scenario generated the hypothesis that low antithrombin levels needed to be corrected by supplementation to improve postoperative outcome. However, randomized controlled studies run to test this idea failed to demonstrate any benefit of antithrombin supplementation, showing no effects on outcome, neither as preemptive preoperative strategy nor for treating postoperative low antithrombin values. In addition, randomized trials highlighted that those patients who received antithrombin experienced significantly higher incidence of acute kidney injury with a pooled odds ratio of 4.41 (95% CI, 1.90-10.23; P = .001). A strongly decreased thrombin activity after antithrombin correction may eventually affect the efficiency of the glomerular filtration and cause the deterioration of kidney function, but underlying biological mechanisms remain unclear. In conclusion, low levels of antithrombin activity after cardiac surgery should be considered as a marker of greater severity of the patient's conditions and/or of the complexity of the surgical procedure. There are no indications for antithrombin supplementation in cardiac surgery unless for correcting heparin resistance.

Impact of dabigatran dose on drug levels in asian patients with atrial fibrillation or venous thromboembolism: evidence from pharmacological to clinical outcomes.

Dabigatran is commonly used in atrial fibrillation (AF) or venous thromboembolism (VTE). However, there was limited data on dabigatran levels in Asian patients. This study aimed to investigate plasma levels of dabigatran 110 mg (D110) or 150 mg (D150) twice daily and their impact on clinical outcomes in Thai patients. This was a prospective cohort study including patients who were diagnosed with AF or VTE and were prescribed either D110 or D150. Plasma dabigatran levels were measured using the diluted thrombin time method. All patients were observed for bleeding and thrombotic complications for 12 months after enrollment. Ninety patients were included in the study (45 in the D110 group and 45 in the D150 group). For the D110 group, there was no significant difference in trough and peak levels in patients with creatinine clearance (CrCl) < 50 ml/min compared to those with CrCl ≥ 50 ml/min. For the D150 group, patients with CrCl < 50 ml/min had significantly higher trough and peak levels compared to those with CrCl ≥ 50 ml/min (P = 0.016 for trough, P = 0.005 for peak). Multivariate regression analysis showed females and low CrCl were independent risk factors for high dabigatran levels. Most patients (83.33%) who experienced bleeding complications had peak levels within the expected range. D150 was associated with higher plasma dabigatran levels, especially in those with impaired renal function.

Oral direct thrombin inhibitors or oral factor Xa inhibitors versus conventional anticoagulants for the treatment of deep vein thrombosis.

BACKGROUND: Deep vein thrombosis (DVT) is a condition in which a clot forms in the deep veins, most commonly of the leg. It occurs in approximately one in 1000 people. If left untreated, the clot can travel up to the lungs and cause a potentially life-threatening pulmonary embolism (PE). Previously, a DVT was treated with the anticoagulants heparin and vitamin K antagonists. However, two forms of direct oral anticoagulants (DOACs) have been developed: oral direct thrombin inhibitors (DTIs) and oral factor Xa inhibitors, which have characteristics that may be favourable compared to conventional treatment, including oral administration, a predictable effect, lack of frequent monitoring or dose adjustment and few known drug interactions. DOACs are now commonly being used for treating DVT: recent guidelines recommended DOACs over conventional anticoagulants for both DVT and PE treatment. This Cochrane Review was first published in 2015. It was the first systematic review to measure the effectiveness and safety of these drugs in the treatment of DVT. This is an update of the 2015 review.  OBJECTIVES: To assess the effectiveness and safety of oral DTIs and oral factor Xa inhibitors versus conventional anticoagulants for the long-term treatment of DVT. SEARCH METHODS: The Cochrane Vascular Information Specialist searched the Cochrane Vascular Specialised Register, CENTRAL, MEDLINE, Embase and CINAHL databases and the World Health Organization International Clinical Trials Registry Platform and ClinicalTrials.gov trials registers to 1 March 2022. SELECTION CRITERIA: We included randomised controlled trials (RCTs) in which people with a DVT, confirmed by standard imaging techniques, were allocated to receive an oral DTI or an oral factor Xa inhibitor compared with conventional anticoagulation or compared with each other for the treatment of DVT.  DATA COLLECTION AND ANALYSIS: We used standard Cochrane methods. Our primary outcomes were recurrent venous thromboembolism (VTE), recurrent DVT and PE. Secondary outcomes included all-cause mortality, major bleeding, post-thrombotic syndrome (PTS) and quality of life (QoL). We used GRADE to assess the certainty of evidence for each outcome. MAIN RESULTS: We identified 10 new studies with 2950 participants for this update. In total, we included 21 RCTs involving 30,895 participants. Three studies investigated oral DTIs (two dabigatran and one ximelagatran), 17 investigated oral factor Xa inhibitors (eight rivaroxaban, five apixaban and four edoxaban) and one three-arm trial investigated both a DTI (dabigatran) and factor Xa inhibitor (rivaroxaban). Overall, the studies were of good methodological quality. Meta-analysis comparing DTIs to conventional anticoagulation showed no clear difference in the rate of recurrent VTE (odds ratio (OR) 1.17, 95% confidence interval (CI) 0.83 to 1.65; 3 studies, 5994 participants; moderate-certainty evidence), recurrent DVT (OR 1.11, 95% CI 0.74 to 1.66; 3 studies, 5994 participants; moderate-certainty evidence), fatal PE (OR 1.32, 95% CI 0.29 to 6.02; 3 studies, 5994 participants; moderate-certainty evidence), non-fatal PE (OR 1.29, 95% CI 0.64 to 2.59; 3 studies, 5994 participants; moderate-certainty evidence) or all-cause mortality (OR 0.66, 95% CI 0.41 to 1.08; 1 study, 2489 participants; moderate-certainty evidence). DTIs reduced the rate of major bleeding (OR 0.58, 95% CI 0.38 to 0.89; 3 studies, 5994 participants; high-certainty evidence).   For oral factor Xa inhibitors compared with conventional anticoagulation, meta-analysis demonstrated no clear difference in recurrent VTE (OR 0.85, 95% CI 0.71 to 1.01; 13 studies, 17,505 participants; moderate-certainty evidence), recurrent DVT (OR 0.70, 95% CI 0.49 to 1.01; 9 studies, 16,439 participants; moderate-certainty evidence), fatal PE (OR 1.18, 95% CI 0.69 to 2.02; 6 studies, 15,082 participants; moderate-certainty evidence), non-fatal PE (OR 0.93, 95% CI 0.68 to 1.27; 7 studies, 15,166 participants; moderate-certainty evidence) or all-cause mortality (OR 0.87, 95% CI 0.67 to 1.14; 9 studies, 10,770 participants; moderate-certainty evidence). Meta-analysis showed a reduced rate of major bleeding with oral factor Xa inhibitors compared with conventional anticoagulation (OR 0.63, 95% CI 0.45 to 0.89; 17 studies, 18,066 participants; high-certainty evidence).  AUTHORS' CONCLUSIONS: The current review suggests that DOACs may be superior to conventional therapy in terms of safety (major bleeding), and are probably equivalent in terms of efficacy. There is probably little or no difference between DOACs and conventional anticoagulation in the prevention of recurrent VTE, recurrent DVT, pulmonary embolism and all-cause mortality. DOACs reduced the rate of major bleeding compared to conventional anticoagulation. The certainty of evidence was moderate or high.

Prevalence and risk factors for cerebral microbleeds in elderly Chinese patients with arteriosclerotic cardiovascular diseases: A single-center study.

OBJECTIVES: People with arteriosclerotic cardiovascular diseases (ASCVD) frequently use antithrombotic agents and statins. The objective of the study was to explore the prevalence and risk factors of cerebral microbleeds (CMBs) in elderly (≥ 65 years old) Chinese people with ASCVD. MATERIALS AND METHODS: We prospectively included 755 eligible participants with complete MRI data, and CMBs were discerned on the SWI sequence. Multivariate logistic regression was performed to analyze risk factors associated with CMBs. RESULTS: The average age was 74.9 ± 9.5 years, and the prevalence of CMBs was 37.9% (286/755). Of those with CMBs, 65.0% (186/286) had strictly lobar CMBs, 35.0% (100/286) had deep or infratentorial CMBs with or without lobar CMBs. We divided CMBs into two groups according to their locations, lobar CMBs group (strictly lobar CMBs) and deep CMBs group (with or without lobar CMBs). Age per 10 years (odds ratio (OR) 1.42, 95% confidence interval (CI) 1.17-1.72, p < 0.001), statin use (OR 1.54, 95% CI 1.05-2.26, p = 0.03), and lacunes (OR 1.70, 95% CI 1.09-2.68, p = 0.02) were associated with any CMBs. Age per 10 years (OR 1.33, 95% CI 1.10-1.63, p < 0.001), statin use (OR 1.67, 95% CI 1.12-2.50, p = 0.01), and white matter hyperintensities (OR 1.71, 95% CI 1.17-2.51, p < 0.01) were associated with lobar CMBs. Only lacunes were associated with deep CMBs (OR 3.29, 95% CI 1.85-5.87, p < 0.001). CONCLUSIONS: In elderly people with risk factors of ASCVD, antithrombotic drug use was not associated with any CMBs, lobar CMBs, or deep CMBs. Statin use was correlated with lobar CMBs but not deep CMBs.

Effectiveness and Safety of Dabigatran Reversal with Idarucizumab in the Taiwanese Population: A Comparison Based on Eligibility for Inclusion in Clinical Trials.

Background and Objectives: The effectiveness and safety of idarucizumab for the reversal of the effects of dabigatran have been proven. However, there remains a paucity of literature comprehensively investigating outcomes in real-world patients. This is especially true when comparing patients who were eligible for inclusion in the RE-VERSE AD trial with patients who were ineligible. As the prescription of dabigatran has become increasingly popular, the generalizability of the results to real-world populations has come into question due to the broad variability of real-world patients receiving dabigatran. Our study aimed to identify all patients who were prescribed idarucizumab and examined how effectiveness and safety varied among those patients who were eligible and ineligible for the trial. Materials and Methods: This retrospective cohort study analyzed the largest medical database in Taiwan. We enrolled all patients who were prescribed and received idarucizumab from when it became available in Taiwan up until May 2021. A Total of 32 patients were included and analyzed, and they were further divided into subgroups based on their eligibility for inclusion in the RE-VERSE AD trial. Multiple outcomes were evaluated, including successful hemostasis rate, complete reversal efficacy of idarucizumab, 90-day thromboembolic events, intra-hospital mortality, and adverse event rate. Results: In our study, we found that 34.4% of real-world cases of idarucizumab use were ineligible for the RE-VERSE AD trials. The eligible group had higher successful hemostasis rates (95.2% vs. 80%) and anticoagulant effect reversal rates compared to the ineligible group (73.3% vs. 0%). The mortality rates were 9.5%, compared to 27.3% in the ineligible group. Few adverse effects (n = 3) and 90-day thromboembolic events (n = 1) were observed in either group. Among the ineligible cases, all acute ischemic stroke patients (n = 5) received definite, timely treatments without complications. Conclusions: Our study demonstrated the real-world effectiveness and safety of idarucizumab infusion for trial-eligible patients and all acute ischemic stroke patients. However, although it seems to be effective and safe, idarucizumab appears to be less effective in other trial-ineligible patients. Despite this result, our study provides further evidence for extending the applicability of idarucizumab in real-world scenarios. Our study suggests that idarucizumab can be a safe and effective option for reversing the anticoagulant effect of dabigatran, particularly for eligible patients.

Reversing dabigatran effect with idarucizumab to enable intravenous thrombolysis in patients with acute ischaemic stroke - a single centre experience.

INTRODUCTION: Our study analysed the safety and effectiveness of idarucizumab in enabling intravenous thrombolysis (IVT) in dabigatran-treated patients with acute ischaemic stroke (AIS). CLINICAL RATIONALE FOR THE STUDY: New oral anticoagulants (NOAC), including dabigatran, are the first-choice treatment option for preventing ischaemic stroke in patients with non-valvular atrial fibrillation (AF). However, a significant percentage of AF patients develops AIS despite NOAC treatment. According to current guidelines, treatment with IVT is contraindicated in patients who have received NOAC within the last 48 hours. Idarucizumab is a fragment of a monoclonal antibody that reverses the anticoagulation effect of dabigatran. The latest research shows that it can enable safe and successful IVT in patients with recent dabigatran intake, but more data is needed to confirm the safety and effectiveness of such treatment. MATERIAL AND METHODS: Our study included dabigatran-treated patients who received idarucizumab to allow AIS treatment with IVT in the University Hospital in Kraków (Poland) from December 2018 to June 2023. We gathered data on their past medical history, stroke severity, course of treatment and outcomes as defined by modified Rankin Scale (mRS) and National Institutes of Health Stroke Scale (NIHSS) scores at discharge. A good functional outcome was defined as mRS 0-2 points at discharge. RESULTS: This observational study included 19 patients (13 male and six female) with a median age of 74 (IQR = 13) years. In all patients (100%), the reason for dabigatran treatment was AF. A good functional outcome after treatment (mRS 0-2) was achieved in 68.4% of patients, but mRS was already ≥ 3 points before stroke onset in three (15.8%) patients. Haemorrhagic transformation of stroke occurred in three (15.8%) patients, including symptomatic intracranial haemorrhage in two (10.5%). The mortality rate was 5.3%. CONCLUSIONS AND CLINICAL IMPLICATIONS: Our study results are in line with previous research on this topic, showing that IVT after idarucizumab can be successfully administered and is reasonably safe in dabigatran-treated patients with AIS.

A survey on thromboprophylaxis and coagulation assessment in children and young adults with acute lymphoblastic leukaemia (ALL) in the Nordic and Baltic countries: Different practices of assessment and management.

Patients undergoing treatment for acute lymphoblastic leukaemia (ALL) are at risk of coagulopathy, especially thromboembolism. We conducted a survey on practices in the assessment and management of coagulopathy during the new ALLTogether protocol in 29 (17 paediatric, 12 adult) Nordic and Baltic cancer centres. While 92% of adult centres used thromboprophylaxis with low-molecular-weight heparin, no paediatric centre did. Almost all providers performed baseline coagulation studies, but only 59% continued the assessment. Fibrinogen replacement was conducted in 59%, and antithrombin replacement in 28% of the centres. The survey highlights the need for guidelines in the management of coagulopathy during ALL therapy.

Dabigatran for Prevention of Stroke after Embolic Stroke of Undetermined Source.

BACKGROUND: Cryptogenic strokes constitute 20 to 30% of ischemic strokes, and most cryptogenic strokes are considered to be embolic and of undetermined source. An earlier randomized trial showed that rivaroxaban is no more effective than aspirin in preventing recurrent stroke after a presumed embolic stroke from an undetermined source. Whether dabigatran would be effective in preventing recurrent strokes after this type of stroke was unclear. METHODS: We conducted a multicenter, randomized, double-blind trial of dabigatran at a dose of 150 mg or 110 mg twice daily as compared with aspirin at a dose of 100 mg once daily in patients who had had an embolic stroke of undetermined source. The primary outcome was recurrent stroke. The primary safety outcome was major bleeding. RESULTS: A total of 5390 patients were enrolled at 564 sites and were randomly assigned to receive dabigatran (2695 patients) or aspirin (2695 patients). During a median follow-up of 19 months, recurrent strokes occurred in 177 patients (6.6%) in the dabigatran group (4.1% per year) and in 207 patients (7.7%) in the aspirin group (4.8% per year) (hazard ratio, 0.85; 95% confidence interval [CI], 0.69 to 1.03; P = 0.10). Ischemic strokes occurred in 172 patients (4.0% per year) and 203 patients (4.7% per year), respectively (hazard ratio, 0.84; 95% CI, 0.68 to 1.03). Major bleeding occurred in 77 patients (1.7% per year) in the dabigatran group and in 64 patients (1.4% per year) in the aspirin group (hazard ratio, 1.19; 95% CI, 0.85 to 1.66). Clinically relevant nonmajor bleeding occurred in 70 patients (1.6% per year) and 41 patients (0.9% per year), respectively. CONCLUSIONS: In patients with a recent history of embolic stroke of undetermined source, dabigatran was not superior to aspirin in preventing recurrent stroke. The incidence of major bleeding was not greater in the dabigatran group than in the aspirin group, but there were more clinically relevant nonmajor bleeding events in the dabigatran group. (Funded by Boehringer Ingelheim; RE-SPECT ESUS ClinicalTrials.gov number, NCT02239120.).

Short-Term Cessation of Dabigatran Causes a Paradoxical Prothrombotic State.

OBJECTIVE: It is unclear if stopping treatment with dabigatran, a new oral anticoagulant (NOAC), induces a paradoxical rebound prothrombotic state. We investigated if short-term (1-3 days) dabigatran cessation is associated with a higher thrombus volume than expected from a simple reversal of the anticoagulant effect. METHODS: Ten-week-old C57Bl/6 mice (n = 338) received one of the following oral treatments: phosphate-buffered saline (PBS), dabigatran for 7 days with or without 1 to 4 day cessation, and aspirin in either a single dose or daily for 7 days. Some of the animals that ceased dabigatran for 1 to 3 days received single-dose aspirin. Thereafter, we induced FeCl3 -mediated carotid thrombosis in 130 mice, after which we performed micro computed tomography thrombus imaging. The other 208 mice underwent coagulation assays or platelet function tests. As an explorative pilot study, we reviewed the medical records of 18 consecutive patients with NOAC cessation-related cerebral infarction in a large acute stroke cohort. RESULTS: We observed a ~ 40% higher volume of carotid thrombus after dabigatran cessation at 1 to 3 days than after vehicle treatment and showed that this effect could be prevented by single-dose aspirin pretreatment. Dabigatran cessation unduly increased platelet aggregability for 2 days after drug cessation, an effect mediated through thrombin or arachidonic acid, which effect was significantly attenuated by single-dose aspirin pretreatment. In patients, short-term (≤ 3 days) cessation of NOAC therapy, compared with longer-term (≥ 5 days) cessation, tended to be associated with relatively high stroke severity. INTERPRETATION: We provide the first preclinical evidence that a rebound prothrombotic state follows short-term cessation of dabigatran therapy. ANN NEUROL 2021;89:444-458.

A systematic review and meta-analysis of dabigatran peak and trough concentration in adults.

Dabigatran etexilate is an oral direct thrombin inhibitor used in preventing thromboembolism in patients with atrial fibrillation and several other conditions. Routine dabigatran concentration monitoring is not recommended in clinical practice; however, measurement of dabigatran concentration may be required in several conditions. This study aims to pool the peak and trough dabigatran concentration from real-world studies. A systematic review was performed to identify studies that measured the peak and trough dabigatran concentrations. Observational studies reporting dabigatran peak or trough concentrations and patients' clinical characteristics of either sex, age or weight were included. Random-effect meta-analyses and metaregression were conducted to pool dabigatran concentrations and to identify the correlation between factors affecting dabigatran concentrations. Fifteen studies with a total of 1226 patients were included. The pooled peak dabigatran concentration was 133 ng/mL (95% CI: 113-154, I2  = 86%, n = 655), while the pooled dabigatran trough concentration was 80 ng/mL (95% CI: 69-91, I2  = 93%, n = 1010). Metaregression analyses suggested that age is significantly correlated to trough concentration, while body weight and creatinine clearance significantly correlated to peak concentration. Subgroup results revealed that dabigatran concentration when measured with liquid chromatography-tandem mass spectrometry was higher than haemoclot thrombin inhibitor assay. Several guidelines have proposed dabigatran concentrations target range and the pooled dabigatran concentrations were in line with the suggested range. Further studies to correlate dabigatran concentrations and clinical outcomes is warranted to improve the safety and efficacy monitoring of dabigatran therapy.