Effectiveness Of Direct Oral Anticoagulants Research Articles

Comparison of apixaban versus aspirin for the prevention of latent bioprosthetic aortic valve thrombosis: study protocol for a prospective randomized trial.

The optimal antithrombotic strategy early after aortic valve replacement surgery with a biological valve remains controversial due to lack of high-quality evidence. Either oral anticoagulants or acetylsalicylic acid should be considered for the first 3 months. Hypo-attenuated leaflet thickening on cardiac computed tomography has been associated with latent bioprosthetic valve thrombosis and may be prevented with anticoagulation. We hypothesize that anticoagulation with apixaban is superior to single antiplatelet therapy with acetylsalicylic acid in reducing hypo-attenuated leaflet thickening of bioprosthetic aortic valve prostheses. In this prospective, open-label, randomized trial, patients undergoing isolated aortic valve replacement surgery with rapid deployment bioprosthetic valves will be randomized. The treatment group will receive 5 mg of apixaban twice a day for the first 3 months and 100 mg of acetylsalicylic acid thereafter. The control group will be administered 100 mg of acetylsalicylic acid once a day, indefinitely. After the 3-month treatment period, a contrast-enhanced electrocardiogram-gated cardiac computed tomography will be performed to identify hypo-attenuated leaflet thickening of the bioprosthetic valve. The primary objective of the study is to assess the impact of apixaban on the prevention of hypo-attenuated leaflet thickening at 3 months. The secondary and exploratory endpoints will be clinical outcomes and safety profiles of the two strategies. Antithrombotic therapy after aortic valve replacement is used to prevent valve thrombosis and systemic thromboembolism. Latent bioprosthetic valve thrombosis is a precursor of clinically significant prosthetic valve dysfunction or thromboembolic events. The hallmark feature of latent bioprosthetic valve thrombosis is hypo-attenuated leaflet thickening on cardiac computed tomography. Subclinical leaflet thrombosis occurs frequently in bioprosthetic aortic valves, more commonly in transcatheter than in surgical valves. There is no evidence on the effect of direct oral anticoagulants on the incidence of hypo-attenuated leaflet thickening after surgical aortic valve replacement with rapid deployment bioprostheses. ClinicalTrials.gov NCT06184113. Registered on December 28, 2023.

Engineering and evaluation of FXa bypassing agents that restore hemostasis following Apixaban associated bleeding

Direct oral anticoagulants (DOACs) targeting activated factor Xa (FXa) are used to prevent or treat thromboembolic disorders. DOACs reversibly bind to FXa and inhibit its enzymatic activity. However, DOAC treatment carries the risk of anticoagulant-associated bleeding. Currently, only one specific agent, andexanet alfa, is approved to reverse the anticoagulant effects of FXa-targeting DOACs (FXaDOACs) and control life-threatening bleeding. However, because of its mechanism of action, andexanet alfa requires a cumbersome dosing schedule, and its use is associated with the risk of thrombosis. Here, we present the computational design, engineering, and evaluation of FXa-variants that exhibit anticoagulation reversal activity in the presence of FXaDOACs. Our designs demonstrate low DOAC binding affinity, retain FXa-enzymatic activity and reduce the DOAC-associated bleeding by restoring hemostasis in mice treated with apixaban. Importantly, the FXaDOACs reversal agents we designed, unlike andexanet alfa, do not inhibit TFPI, and consequently, may have a safer thrombogenic profile.

Risk factors for postgastric endoscopic submucosal dissection bleeding in direct oral anticoagulant users.

Bleeding after endoscopic submucosal dissection (ESD) for gastric tumors in patients taking antithrombotic drugs, in particular direct oral anticoagulants (DOACs), remains unresolved; therefore, we evaluated the risk factors for post-ESD bleeding and drug differences in patients taking DOACs. We included 278 patients taking antithrombotic drugs who underwent gastric ESD between January 2017 and March 2022. Antithrombotic drugs were withdrawn following the 2017 guidelines (Appendix on anticoagulants including DOACs). To further clarify differences in antithrombotic agents' effects, the peri-cancerous mucosa in the resected specimen was pathologically evaluated according to the Updated Sydney System. Multivariate analysis was performed to assess the risk of post-ESD bleeding. The incidence of post-ESD bleeding in patients taking DOACs was 19.6% (10/51). Among patients taking antithrombotic drugs, DOACs were identified as a possible factor involved in post-ESD bleeding (odds ratio [OR] 4.92). Among patients taking DOACs, possible factors included resection length diameter ≥30 mm (OR 3.72), presence of neutrophil infiltration (OR 2.71), lesions occurring in the lower third of stomach (OR 2.34), and preoperative antiplatelet use (OR 2.22). Post-ESD bleeding by DOAC type was 25.0% of patients (4/16) receiving apixaban, in 20.0% (3/15) receiving edoxaban, in 21.4% (3/14) receiving rivaroxaban, and in none of those receiving dabigatran. The administration of DOACs was shown to be a possible factor involved in post-ESD bleeding, and risk factors for patients taking DOACs included neutrophil infiltration. The pharmacological differences in the effects of DOACs contributing to bleeding in gastric ulcers suggest comparatively less bleeding with dabigatran after ESD.

Coagulation Tests and Reversal Agents in Patients Treated with Oral Anticoagulants: The Challenging Scenarios of Life-Threatening Bleeding and Unplanned Invasive Procedures.

In clinical practice, the number of patients treated with direct oral anticoagulants (DOACs) has consistently increased over the years. Since anticoagulant therapy has been associated with an annual incidence of major bleeding (MB) events of approximately 2% to 3.5%, it is of paramount importance to understand how to manage anticoagulated patients with major or life-threatening bleeding. A considerable number of these patients' conditions necessitate hospitalization, and the administration of reversal agents may be imperative to manage and control bleeding episodes effectively. Importantly, effective strategies for reversing the anticoagulant effects of DOACs have been well recognized. Specifically, idarucizumab has obtained regulatory approval for the reversal of dabigatran, and andexanet alfa has recently been approved for reversing the effects of apixaban or rivaroxaban in patients experiencing life-threatening or uncontrolled bleeding events. Moreover, continuous endeavors are being made to develop supplementary reversal agents. In emergency scenarios where specific reversal agents might not be accessible, non-specific hemostatic agents such as prothrombin complex concentrate can be utilized to neutralize the anticoagulant effects of DOACs. However, it is paramount to emphasize that specific reversal agents, characterized by their efficacy and safety, should be the preferred choice when suitable. Moreover, it is worth noting that adherence to the guidelines for the reversal agents is poor, and there is a notable gap between international recommendations and actual clinical practices in this regard. This narrative review aims to provide physicians with a practical approach to managing specific reversal agents.

Effectiveness and safety of direct oral anticoagulants among patients with non-valvular atrial fibrillation and liver disease: A multinational cohort study

Background and aimsThe effects of direct oral anticoagulants (DOACs) in patients with non-valvular atrial fibrillation (NVAF) and liver disease remain poorly understood. Our multinational cohort study assessed the effectiveness and safety of DOACs in this high-risk population. MethodsWe assembled two population-based cohorts in United Kingdom and in Québec of NVAF patients with liver disease initiating DOACs or vitamin K antagonists (VKAs) between 2011 and 2020. Using an as-treated exposure definition, we compared DOACs to VKAs and apixaban to rivaroxaban. After inverse probability of treatment weighting, Cox proportional hazards models estimated site-specific hazard ratios (HRs) and 95 % confidence intervals (CIs) of ischemic stroke and major bleeding. Site-specific estimates were pooled using random-effects models. Analyses were repeated among NVAF patients with cirrhosis. ResultsThere were 11,881 NVAF patients with liver disease (2683 with cirrhosis). Among those, 8815 initiated DOACs (4414 apixaban, 2497 rivaroxaban) and 3696 VKAs. The HRs (95 % CIs) for DOACs compared to VKAs were 1.01 (0.76–1.34) for ischemic stroke and 0.87 (0.77–0.99) for major bleeding. Results were consistent among patients with cirrhosis. The HRs (95 % CIs) for apixaban compared to rivaroxaban were 0.85 (0.60–1.20) for ischemic stroke and 0.80 (0.68–0.95) for major bleeding. This decreased bleeding risk was not observed among patients with cirrhosis (HR, 1.01; 95 % CI 0.72–1.43). ConclusionsAmong NVAF patients with liver disease, DOACs were as effective and slightly safer than VKAs, and apixaban was as effective but safer than rivaroxaban. The safety benefit with apixaban was not present among patients with cirrhosis.

Pearls and Pitfalls in the Measurement of Direct Oral Anticoagulants.

Due to their widespread use, testing for direct oral anticoagulants (DOACs) has become urgent in certain clinical situations. Screening based on widely available, rapid, and simple hemostasis assays such as prothrombin time, activated partial thromboplastin time, or even diluted Russel Viper venom time may provide sufficient evidence of "over-coagulation" and could be used "in small/peripheral/spoke laboratories" as an emergency strategy, but is not thought to be reliable for driving clinical decision making. Given their good correlation with plasma concentration, urine dipsticks may be considered a valuable alternative for emergency screening, although their performance is dependent on renal function, may vary depending on the time since the last urination, and there may be problems of interfacing with the laboratory/hospital information system. Separation methods based on liquid chromatography and mass spectrometry may be clinically questionable, since they measure the concentration rather than the actual inhibitory effect of DOACs, are relatively expensive, cumbersome and time consuming, and therefore seem unsuitable for most conditions requiring urgent clinical decision making. A proposed approach therefore involves establishing a network of routine clinical laboratories, designating a reference center where DOAC tests could be available 24/7, establishing a clear diagnostic care pathway for ordering the tests from the laboratory and standard operating procedures for performing them, the use of the diluted thrombin time for dabigatran and anti-FXa assays (drug-calibrated) for rivaroxaban, apixaban, and edoxaban, as well as providing expert advice throughout the testing process, from ordering to interpretation of results.

Retrospective, multicenter analysis of the safety and effectiveness of direct oral anticoagulants for the treatment of venous thromboembolism in obesity.

Direct oral anticoagulants (DOACs) are the preferred treatment for venous thromboembolism (VTE). However, DOAC use in patients with a BMI greater than 40kg/m2 has not been well studied despite the growing prevalence of obesity, and current literature is often underpowered. This multicenter, retrospective, observational study evaluated patients 18 years and older who received DOACs for acute VTE treatment. Patients receiving DOACs for recurrent VTE or for failure of another agent were excluded. The primary efficacy outcome was recurrent VTE and the primary safety outcome was major bleeding within 12 months (or one month after stopping anticoagulation therapy). A propensity score analysis was performed to balance patient characteristics and evaluate the primary endpoints by BMI group. Time-to-event outcomes were analyzed using weighted Kaplan-Meier curves. There were 165 patients with a BMI of at least 40kg/m2 and 320 patients with a BMI less than 40kg/m2. The majority received apixaban (373, 77%). Recurrent VTE occurred in 5 (3.0%) and 13 (4.1%) of patients in the higher and lower BMI groups, respectively (adjusted OR: 0.66; 95% CI: 0.16-2.69). Major bleeding occurred in 5 (3.0%) and 15 (4.7%) of patients in the higher and lower BMI groups, respectively (adjusted OR: 1.19; 95% CI: 0.36-3.92). There was no significant difference in VTE recurrence or major bleeding related to BMI among patients treated with DOACs. This study showed that DOACs may be a safe and effective VTE treatment option in patients with obesity.

Effect of direct oral anticoagulants on bleeding during and after cataract surgery

PurposeTo assess the risk for intraoperative and postoperative ocular bleeding associated with direct oral anticoagulant treatment in patients undergoing phacoemulsification surgery.MethodsConsecutive patients had phacoemulsification and intraocular lens implantation while taking uninterrupted direct oral anticoagulants (dabigatran, rivaroxaban, or apixaban). Gender and age-matched patients without antithrombotic therapy were used as the control group. Patients were examined one week postoperatively. Intraoperative and postoperative hemorrhagic and non-hemorrhagic complications were assessed.ResultsForty patients (56 eyes) on direct oral anticoagulants and 120 patients (172 eyes) without anticoagulation, at a mean age of 77 years, had phacoemulsification. There was no significant difference between the groups in the rate of intraoperative and postoperative bleeding. One eye (1.8%) in the treatment group and 3 eyes (1.7%) in the control group had hyphema (p = 0.72). No patient had thromboembolic event during or after surgery.ConclusionsCataract surgery was safely performed while continuing direct oral anticoagulation.

Efficacy and Safety of Direct Oral Anticoagulants in Cerebral Venous Thrombosis: Meta-Analysis of Randomized Clinical Trials.

Current guidelines recommend the standard-of-care anticoagulation (vitamin K antagonists or low-molecular-weight heparin) in patients with cerebral venous thrombosis (CVT). Herein, we performed a meta-analysis of randomized clinical trials (RCTs) to assess the efficacy and safety of direct oral anticoagulants (DOACs) compared with the current standard of care in patients with CVT. We systematically searched the PubMed and Embase databases up to December 2023 to identify clinical trials on the effect of DOACs in patients with CVT. A Mantel-Haenszel fixed effects model was applied, and the effect measures were expressed as the absolute risk differences (RDs) and 95% confidence intervals (CIs). A total of 4 RCTs involving 270 participants were included. In the pooled analysis, DOACs and standard of care had low incidence rates of recurrent VTE and all-cause death, and similar rates of any recanalization (78.2% vs 83.2%; RD = -4%, 95%CI:-14% to 5%) and complete recanalization (60.9% vs 69.4%; RD = -7%, 95%CI:-24% to 10%). Compared with the standard of care, DOACs had non-significant reductions in the rates of major bleeding (1.2% vs 2.4%; RD = -1%, 95%CI: -6% to 3%), intracranial hemorrhage (1.9% vs 3.6%; RD = -2%, 95%CI:-7% to 3%), clinically relevant non-major bleeding (3.8% vs 7.4%; RD = -4%, 95%CI:-9% to 2%), and any bleeding (17.3% vs 21.4%; RD = -4%, 95%CI:-16% to 8%) in patients with CVT. DOACs and standard of care showed similar efficacy and safety profiles for the treatment of CVT. DOACs might be safe and a convenient alternative to vitamin K antagonists for thromboprophylaxis in patients with CVT.

Effect of Direct Oral Anticoagulants in Patients with Splanchnic Vein Thrombosis: A Systematic Reviews and Meta-Analysis.

Since several studies have examined the use of direct oral anticoagulants (DOACs) in treating patients with splanchnic vein thrombosis (SVT), we conducted a meta-analyses to assess the safety and efficacy of DOACs compared to vitamin K antagonists (VKAs) in this population. We conducted a comprehensive search using the PubMed, Embase, and Cochrane Library databases until June 2024. We used odds ratios (ORs) and 95% confidence intervals (CIs) as the effect measures to compare DOACs with VKAs. A total of 9 observational studies were included. The pooled analysis revealed that a trend towards higher complete recanalization rates with DOACs (71.4%) compared to VKAs (55.3%), though not statistically significant (OR 1.95; 95%CI 0.70 to 5.44). For SVT extension, a significant effect was observed favoring DOACs (OR 0.12; 95%CI 0.03 to 0.54). No significant differences were found in other efficacy outcomes or safety outcomes, except for major bleeding, which was significantly lower with DOACs (OR 0.27; 95%CI 0.13 to 0.56). DOACs are superior to VKAs in SVT extension and major bleeding, suggesting that DOACs may be a favorable treatment option in the treatment of SVT.

Use of Direct-Acting Oral Anticoagulants in Patients With Atrial Fibrillation and Significant Tricuspid Regurgitation.

There are limited data on the efficacy and safety of direct oral anticoagulants (DOACs) in patients with atrial fibrillation with significant tricuspid regurgitation (TR), which can lead to hepatic dysfunction and intestinal malabsorption. We aimed to compare the efficacy and safety of DOACs and warfarin for patients with atrial fibrillation with significant (moderate to severe) TR. A total of 1215 patients with significant TR and atrial fibrillation who were treated with warfarin (N=491) or DOACs (N=724) were retrospectively analyzed. The primary outcomes were ischemic stroke, systemic embolic events, and hospitalization for major bleeding. The secondary outcomes were intracranial hemorrhage, hospitalization for gastrointestinal bleeding, all-cause mortality, and a composite outcome. The median follow-up duration was 2.4 years. In the inverse probability treatment weighting-adjusted cohort, DOACs and warfarin had a similar risk for ischemic stroke and systemic embolic events (adjusted hazard ratio [aHR], 0.95 [95% CI, 0.67-1.36]; P=0.79) and major bleeding (aHR, 0.78 [95% CI, 0.57-1.06]; P=0.11). For the secondary outcomes, relative to warfarin, DOACs had a lower risk of intracranial hemorrhage and the composite outcome, and a comparable risk for gastrointestinal bleeding and all-cause mortality. In the subgroup analysis, the effects of DOACs on ischemic stroke and systemic embolic events were comparable to the effects ofwarfarin, even in patients with inferior vena cava plethora (increased right atrial pressure) or severe TR. In this study, relative to warfarin, DOACs demonstrated comparable efficacy for ischemic stroke and systemic embolic events and major bleeding, with a lower intracranial hemorrhage risk in patients with significant TR and atrial fibrillation, indicating their effectiveness and safety.

Direct Oral Anticoagulants in Special Patient Populations.

Anticoagulants are a cornerstone of treatment in atrial fibrillation. Nowadays, direct oral anticoagulants (DOACs) are extensively used for this condition in developed countries. However, DOAC treatment may be inappropriate in certain patient populations, such as: patients with chronic kidney disease in whom DOAC concentrations may be dangerously elevated; frail elderly patients with an increased risk of falls; patients with significant drug-drug interactions (DDI) affecting either DOAC concentration or effect; patients at the extremes of body mass in whom an "abnormal" volume of distribution may result in inappropriate drug concentrations; patients with recurrent stroke reflecting an unusually high thromboembolic tendency; and, lastly, patients who experience major hemorrhage on an anticoagulant and in whom continued anticoagulation is deemed necessary. Herein we provide a fictional case-based approach to review the recommendations for the use of DOACs in these special patient populations.

Effectiveness and safety of apixaban and rivaroxaban vs warfarin in patients with atrial fibrillation and chronic kidney disease.

Randomized controlled trials (RCTs) of direct oral anticoagulants (DOACs) included a low proportion of atrial fibrillation (AF) patients with chronic kidney disease (CKD), and suggested that DOACs are safe and effective in patients with mild-to-moderate CKD. In a metanalysis of RCTs and observational studies, DOACs were associated with better efficacy (vs warfarin) in early CKD and had similar efficacy and safety profiles in patients with stages IV-V CKD. But few studies have provided data on the safety and effectiveness of each DOAC vs warfarin in patients with stage III CKD. The effectiveness and safety of DOACs in those patients are still subject to debate. To assess and compare the effectiveness and safety of apixaban and rivaroxaban vs warfarin in this patient population. A cohort of patients with an inpatient or outpatient code for AF and stage III CKD who were newly prescribed apixaban and rivaroxaban was created using the administrative databases from the Quebec province of Canada between 2013 and 2017. The primary effectiveness outcome was a composite of ischemic stroke, systemic embolism, and death, whereas the primary safety outcome was a composite of major bleeding within a year of DOAC vs warfarin initiation. Treatment groups were compared in an under-treatment analysis using inverse probability of treatment weighting and Cox proportional hazards. A total of 8899 included patients filled out a new oral anticoagulation therapy claim; 3335 for warfarin and 5564 for DOACs. Compared with warfarin, 15 mg and 20 mg rivaroxaban presented a similar effectiveness and safety composite risk. Apixaban 5.0 mg was associated with a lower effectiveness composite risk [Hazard ratio (HR) 0.76; 95% confidence interval (CI): 0.65-0.88] and a similar safety risk (HR 0.94; 95%CI: 0.66-1.35). Apixaban 2.5 mg was associated with a similar effectiveness composite (HR 1.00; 95%CI: 0.79-1.26) and a lower safety risk (HR 0.65; 95%CI: 0.43-0.99. Although, apixaban 5.0 mg was associated with a better effectiveness (HR 0.76; 95%CI: 0.65-0.88), but a similar safety risk profile (HR 0.94; 95%CI: 0.66-1.35). The observed improvement in the effectiveness composite for apixaban 5.0 mg was driven by a reduction in mortality (HR 0.61; 95%CI: 0.43-0.88). In comparison with warfarin, rivaroxaban and apixaban appear to be effective and safe in AF patients with stage III CKD.

Efficacy and Safety of Direct Oral Anticoagulants in Pediatric Venous Thromboembolism: A Systematic Review and Meta-Analysis.

To assess the efficacy and safety of direct oral anticoagulants (DOACs) in comparison to standard-of-care (SOC) anticoagulants in the management and prophylaxis of thromboembolic events in pediatric populations. A comprehensive search of electronic databases was conducted to identify relevant studies published between January 1, 2015, and December 18, 2022. A meta-analysis was undertaken to evaluate the effect of DOACs on clinically significant endpoints, employing trial-level data with harmonized endpoint definitions. The primary outcome was venous thromboembolism (VTE). Odds ratios (ORs) with 95% confidence intervals (CIs) were calculated. The study was registered with INPLASY (2022120065). Three studies encompassing 934 subjects were included. The incidence of VTE was reduced in patients administered DOACs compared to those on SOC anticoagulants (OR 0.41 [95% CI 0.19-0.93], I²=0%, P = 0.03). No significant differences were observed between the DOAC and SOC groups in all-cause mortality (OR 0.50 [95% CI 0.07-3.59], I²=0%, P = 0.35) or serious adverse events (OR 0.75 [95% CI 0.50-1.12], I²=0%, P = 0.16). The risk of major bleeding (OR 0.50 [95% CI 0.13-1.87], I²=44%, P = 0.30) and clinically relevant non-major bleeding (OR 1.23 [95% CI 0.50-3.00], I²=0%, P = 0.65) exhibited no significant differences between the groups. DOACs are associated with a reduced risk of VTE in pediatric patients without increasing the risk of bleeding, all-cause mortality, or serious adverse events when compared to SOC anticoagulants. DOACs may be an alternative for the treatment and prevention of thromboembolic events in the pediatrics.

Association of direct oral anticoagulant and delayed bleeding with pharmacokinetics after endoscopic submucosal dissection

Pharmacokinetic parameters, such as drug plasma level at trough, time to maximum plasma concentration (Tmax), and coagulation factor Xa (FXa) activity generally predict factors for the anticoagulant effects of direct oral anticoagulants (DOACs). Although GI bleeding is a major adverse event after endoscopic submucosal dissection (ESD), little is known about the association between post-ESD bleeding in patients taking DOACs and the pharmacologic parameters. This study aimed to evaluate pharmacologic risk factors for post-ESD bleeding in patients taking DOACs. We prospectively evaluated the incidence of post-ESD bleeding in patients taking DOACs between April 2018 and May 2022 at 21 Japanese institutions and investigated the association with post-ESD bleeding and pharmacologic factors, including plasma concentration and FXa activity at trough and Tmax. The incidence of post-ESD bleeding was 12.8% (14 of 109; 95% confidence interval [CI], 7.2-20.6). Although plasma DOAC concentration and plasma level/dose ratio at trough and Tmax varied widely among individuals, a significant correlation with plasma concentration and FXa activity was observed (apixaban: correlation coefficient, -0.893; P< .001). On multivariate analysis, risk factors for post-ESD bleeding in patients taking DOACs were higher age (odds ratio [OR], 1.192; 95% CI, 1.020-1.392; P= .027) and high anticoagulant ability analyzed by FXa activity at trough and Tmax (OR, 6.056; 95% CI, 1.094-33.529; P= .039). The incidence of post-ESD bleeding in patients taking DOACs was high, especially in older patients and with high anticoagulant effects of DOACs. Measurement of pharmacokinetic parameters of DOACs may be useful in identifying patients at higher risk of post-ESD bleeding.

Effectiveness and safety of oral anticoagulant therapy in a real-world cohort with atrial fibrillation: The SIESTA-A study protocol.

Oral anticoagulants (OACs) are first-line drugs for stroke prevention in patients with atrial fibrillation (AF). The introduction of new lines of therapy with direct oral anticoagulants (DOACs) has led to a decreased use of vitamin K antagonists (VKAs). Comparative analyses of DOACs in clinical trials are scarce and the comparator has mostly been warfarin. Their impact on health outcomes in observational studies has not always been consistent. The aim of this study is to evaluate the effectiveness and safety of DOACs and VKAs in patients with AF using Real-World Data (RWD). Population-based retrospective cohort study using RWD from actual practice. Period: January 2012-December 2020. Inclusion criteria: patients with AF who had not taken OACs in the previous 12 months. Exclusion criteria: <40 years, with severe mitral stenosis, or valvular heart disease or aortic and/or mitral valve procedures. Data source: The Andalusian Population Health Database, Spain. Outcome measures: a) Effectiveness: ischaemic stroke, transient ischaemic attack, systemic and pulmonary embolism, and death; b) Safety: gastrointestinal and intracranial haemorrhaging; Independent variables: age, sex, comorbidities, medication and health resource use, CHA2DS2-VASC, HAS-BLED, and analytical tests. Statistical analysis: crude incidence analysis, survival models, Kaplan-Meier, Cox regression analysis adjusted for possible confounding and paired analysis by propensity score matching.

DOACs or warfarin use in morbidly obese patients (BMI &amp;gt; 40 kg/m2) on anticoagulant therapy? : a systematic review and meta-analysis

Abstract Introduction Current guidelines and consensus statements have advised against the use of direct oral anticoagulants (DOACs) for morbidly obese patients (BMI &amp;gt; 40 kg/m2), indicating warfarin as the first-line treatment. Purpose Our aim was to systematically review and examine the effectiveness and safety of DOACs compared to warfarin in patients with BMI &amp;gt; 40 kg/m2 and atrial fibrillation (AF) or venous thromboembolism (VTE). Methods This study was conducted according to the PRISMA guidelines. We systematically searched PubMed, SCOPUS, and Cochrane databases from their inception to February 23, 2023, for studies comparing the effectiveness and safety of DOACs and Warfarin in extremely obese patients. The primary outcome was the incidence of the composite endpoint (stroke, systemic embolism, myocardial infarction, or all-cause mortality), ii) stroke/systematic embolism (SE) and, iii) VTE. Secondary endpoints referred to major and minor bleeding events. Results This meta-analysis comprised 16 studies and 114,999 morbidly obese patients with AF or VTE on oral anticoagulation therapy (48,937 on DOACs vs. 65,080 on Warfarin). The DOAC use was significantly associated with lower all-cause mortality and major bleeding rates compared to the warfarin group [risk ratio= 0.66; 95% confidence interval: 0.53, 0.81; p = 0.03; I2 = 60%, RR: 0.78 (95% CI: 0.6-1.01, p &amp;lt;0.01, I2 = 85%)]. Although the rates of composite endpoint, stroke/SE and VTE were lower in the DOAC group, no statistically significant difference was observed [RR: 0.88 (95% CI: 0.7-1.12, p &amp;lt;0.01, I2 = 86%), RR: 0.92; (95% CI: 0.63-1.35, p &amp;lt;0.01, I2 = 86%), RR: 0.72; (95% CI: 0.46-1.15, p &amp;lt;0.01, I2 = 91%)], indicating no-superiority of Warfarin compared to DOAC use. The rates of minor bleeding events, hemorrhagic stroke and ischemic stroke were lower in the DOAC compared to warfarin groups [RR: 0.78 (95% CI: 0.56-1.10, p &amp;lt;0.01, I2 = 80%), RR: 0.56 (95% CI: 0.26-1.21, p &amp;lt;0.01, I2 = 86%), RR: 0.87; (95% CI: 0.6-1.24, p &amp;lt;0.01, I2 = 81%)]. The same trend favoring DOACs over Warfarin in all the assessed endpoints was observed in the subgroup analysis when results adjusted for the anticoagulation indication (AF or VTE). Conclusions Our findings are of paramount importance indicating, firstly, the non-superiority of Warfarin compared to DOAC use, and secondly, a significantly better profile of DOACs in terms of safety and effectiveness in morbidly obese patients with BMI &amp;gt; 40 kg/m2 in all the assessed endpoints. The findings may aid in the endeavor to enhance the upcoming recommendations for the management of this subgroup.

Usefulness of low-dose direct oral anticoagulants for peripheral deep vein thrombosis of the lower extremities in cancer patients with cancer bleeding lesions

Abstract Background Venous thromboembolism (VTE) is a frequent complication in cancer patients. VTE is often detected as asymptomatic peripheral deep vein thrombosis (DVT). Standard doses of anticoagulants are generally considered difficult to administer in cancer patients due to the high risk of bleeding. However, it has been reported that peripheral DVT worsening to proximal DVT in cancer patients due to increased coagulation tendency, and some strategy for peripheral DVT is required. And the adverse bleeding effects of DOACs have been reported to be dose-dependent. Purpose The aim of this study was to determine the optimal treatment strategy of peripheral DVT in patients with bleeding cancer lesions. In order to do this we compared no anticoagulation, low-dose direct oral anticoagulants (DOACs) and standard-dose DOACs in patients with and without bleeding cancer lesions. Methods A total of 224 consecutive patients with peripheral DVT of the lower extremities (excluding pulmonary thromboembolism or proximal DVT) were included from April 2019 to March 2020. Of these, 172 patients could be followed up by repeated ultrasound examinations for up to 2 years. We investigated retrospectively the change in ultrasound findings between first and second examinations (median interval 44 days). 163 patients were studied, excluding 9 patients who used warfarin or heparin. In 119 of these DOACs were applied, and 44 were without anticoagulation. If the treatment procedure had changed between the first and second ultrasound examinations main treatment procedure was selected and categorized. Results All the patients of low-dose and standard-dose DOACs groups had no major bleeding during follow up period. In the group with cancer bleeding lesion (n=45) there were 12 patients (70.1%) worsening DVT in the group without anticoagulation, 1 patient (4.3%) in the low-dose DOACs and 0 (0%) in the standard-dose DOACs group. There was significant worsening of DVT in the no anticoagulant group compared with low-dose DOACs (P&amp;lt;0.0001), but no significant difference between low-dose DOACs and standard-dose DOACs (P=0.63) in the group with bleeding (see Figure 1). In the group without cancer bleeding (n=118), worsening of DVT occurred in 16 patients (59.3%) without anticoagulation, in 6 patients (16.7%) with low-dose DOACs and in 4 patients (7.3%) with standard-dose DOACs. There was significant worsening of DVT in the no anticoagulant group compared with low-dose DOACs (P&amp;lt;0.0001), but no significant difference between the low-dose and standard-dose DOACs (P=0.16) in the group without bleeding (see Figure 2). Conclusion Low-dose DOACs were found to be as effective as standard-dose DOACs in treating peripheral DVT in cancer patients, with or without bleeding of the cancer lesion. Peripheral DVT treatment with low-dose DOACs can reduce worsening of DVT and should be one of the supportive treatments for the completion of cancer management.DVT in 3 groups with cancer bleedingDVT in 3 groups without cancer bleeding

Abstract 12293: Subclinical Leaflet Thrombus on Transcatheter Heart Valve in Patients With Severe Aortic Stenosis and Atrial Fibrillation

Background: Subclinical leaflet thrombosis is one of transcatheter heart valve (THV) failure that should be avoided after transcatheter aortic valve implantation (TAVI). Although the effectiveness of direct oral anticoagulants (DOACs) on subclinical leaflet thrombosis has been demonstrated, there is insufficiently established evidence for post-TAVI antithrombotic therapy. The aim of this study was to clarify the formation process of subclinical leaflet thrombosis on THV and thrombogenicity during the perioperative period of TAVI. Methods: This multicenter, prospective, single-arm interventional study enrolled 26 patients with atrial fibrillation treated with edoxaban and severe aortic valve stenosis who underwent TAVI between September 2018 and September 2022. After exclusion, 24 patients were finally analyzed. We investigated changes in maximal leaflet thickness detected by contrast-enhanced computed tomography between 1 week and 3 months after TAVI and measured the thrombogenicity by Total Thrombus-formation Analysis System (T-TAS) and flow stagnation volume by computational fluid dynamics (CFD). Results: Of all, subclinical leaflet thrombosis was observed in 16.7% at 1 week, but decreased to 5.9% at 3 months after TAVI. There was no significant difference in maximum leaflet thickness between 1 week and 3 months, however, patients with subclinical leaflet thrombosis at 1 week had a significantly greater difference in that thickness compared to those without thrombosis. Thrombogenicity assessed by T-TAS and platelet count decreased markedly at 1 week and tended to improve at 3 months. Simple liner regression analysis showed that stagnation volume was positively associated with an increase in maximum leaflet thickness, and low-dose edoxaban was associated with a high risk of increased leaflet thickness at chronic phase. Conclusions: This study showed that course of leaflet thrombus formation in neo-sinus of THV and dynamic fluctuation of thrombogenicity in the acute phase after TAVI. These findings were merely hypotheses generation and thus necessitate future hypothesis testing with large sample sizes.

Abstract 17888: Apixaban versus Vitamin K Antagonists for Left Ventricular Thrombus: A Systematic Review and Meta-Analysis

Introduction: Left ventricular thrombus (LVT), a major complication following acute myocardial infarction, significantly contributes to the increased risk of stroke and systemic embolism. Although vitamin K antagonists (VKAs) are the first-line treatment for LVT, direct oral anticoagulants (DOACs) have emerged as a potential alternative. However, the comparative effectiveness and safety of DOACs and VKAs for LVT treatment remain uncertain. Research question: Is apixaban therapy more effective and safer than VKA therapy for LVT? Aim: To assess the efficacy and safety of apixaban compared with VKAs therapy in patients with LVT. Methods: We systematically searched PubMed, Embase, and Cochrane databases for studies comparing the efficacy and safety of apixaban versus VKAs. We applied the random-effects model to calculate odds ratios (OR) and the corresponding 95% confidence interval. Heterogeneity was assessed using I 2 statistics. All calculations and graphics were performed using R (version 4.2.3). Results: Three randomized clinical trials (RCTs) were included, with 109 patients assigned to either apixaban (56 patients) or VKAs (53 patients). Compared to VKAs, apixaban showed no significant impact on thrombus resolution (OR 0.69; 95% CI 0.11-4.50; p=0.70; I 2 =0%), stroke reduction (OR 0.91; 95% CI 0.09-9.38; p=0.93; I 2 =1%), clinically relevant bleeding (OR 0.21; 95% CI 0.02-1.99; p=0.17; I 2 =0%), or all-cause mortality (OR 0.65; 95% CI 0.11-3.78; p=0.63; I 2 =8%). Conclusions: Apixaban therapy showed similar efficacy and safety to VKAs for LVT. These findings support the use of apixaban as an alternative to VKAs in LVT treatment.