Outcomes of direct oral anticoagulants with aspirin vs warfarin with aspirin: a registry-based cohort study.

Background: For patients anticoagulated with direct oral anticoagulants (DOACs) or warfarin and on aspirin (ASA) for nonvalvular atrial fibrillation and/or venous thromboembolism, it is unclear if bleeding outcomes differ. Objectives: To assess bleeding rates for ASA with DOACs vs warfarin and one another. Methods: Registry-based cohort study of patients followed by a 6-center quality improvement collaborative in Michigan using data from 2009 to 2022. The study included adults on ASA with warfarin or DOACs for atrial fibrillation and/or venous thromboembolism without a recent myocardial infarction or heart valve replacement. Results: After propensity matching by anticoagulant class, we compared 2 groups of 1467 patients followed for a median of 18.0 months. Any bleeding and nonmajor bleeding was increased with DOACs + ASA compared with warfarin + ASA (32.2 vs 27.8 and 27.1 vs 22.9 events/100 patient-years; relative risks [RRs], 1.1 and 1.2; 95% CIs, 1.1-1.2 and 1.1-1.3, respectively). After matching by drug, patients on apixaban + ASA vs warfarin + ASA had more bleeding (31.2 vs 27.8 events/100 patient-years; RR, 1.1; 95% CI, 1.0-1.2) and nonmajor bleeding but less major bleeding (3.8 vs 4.7 events/100 patient-years; RR, 0.8; 95% CI, 0.6-1.0) and emergency room visits for bleeding. Patients on rivaroxaban + ASA vs warfarin + ASA had more bleeding (39.3 vs 26.3 events/100 patient-years, RR, 1.5; 95% CI, 1.3-1.6), nonmajor bleeding, and thrombosis. Patients on apixaban + ASA vs rivaroxaban + ASA had significantly less bleeding (22.5 vs 39.3/100 patient-years; RR, 0.6; 95% CI, 0.5-0.7), nonmajor bleeding, major bleeding (2.1 vs 5.5 events/100 patient-years; RR, 0.4; 95% CI, 0.2-0.6), emergency room visits for bleeding, and thrombotic events. Conclusion: Patients on DOAC + ASA without a recent myocardial infarction or heart valve replacement had more nonmajor bleeding but otherwise similar outcomes compared with warfarin + ASA. Patients treated with rivaroxaban + ASA experienced more adverse clinical events compared with warfarin + ASA or apixaban + ASA.

Effectiveness of Novel Oral Anticoagulants Versus Warfarin in Patients With Atrial Fibrillation: A Systematic Review and Meta-Analysis.

Atrial fibrillation (AF) is a common cardiac arrhythmia associated with an increased risk of stroke and systemic embolism (SE). Anticoagulation therapy, particularly with vitamin K antagonists (VKA) or novel oral anticoagulants (NOACs), is essential for stroke prevention in patients with AF. However, the comparative effectiveness of NOACs and warfarin remains debatable. Of the 34 studies included, 14 studies involving 166,845 patients were included in the meta-analysis and 20 studies were included in the systematic review. Our findings indicate that NOACs were associated with a significantly lesser risk of stroke/SE with a relative risk (RR) of 0.84 and p=0.0005, and all-cause mortality RR=0.88 and p=0.006. There were no significant differences between major bleeding events with an RR of 0.87 and p=0.22, and serious adverse events (SAE) with RR=1.01 and p=0.35, compared to warfarin in patients with AF. Our meta-analysis demonstrates strong evidence for the superiority in reducing stroke/SE and all-cause mortality of NOACs compared to warfarin. However, no significant differences were identified in the bleeding outcomes or SAEs between the two groups.

Warfarin and Polypharmacy Challenges in Sudan: Drug Interactions in Patient Cohort.

Purpose: Warfarin plays an important role in anticoagulation therapy despite the availability of the newest oral anticoagulants, and achieving optimal anticoagulation is challenging due to its narrow therapeutic range and variable dose. This study aimed to highlight polypharmacy and drug interactions in patients receiving warfarin therapy at Medani Heart Centre, Sudan. Methods: This retrospective hospital-based study was conducted from May 2017 to October 2018. Each concurrent medication prescribed for 104 patients was collected and checked for drug-drug interactions using Medscape Reference-Drug Interaction Checker. The data were analysed by using SPSS 20, and descriptive statistics were used. Results: The results revealed that 95.2% of patients had more than three medications in their profile, (3-5), (6-9) and more than 10 medications were prescribed for 40.4%, 44.2% and 10.6% of patients, respectively. A total of 93.3% of patients had drug-drug interactions, as follows: (1-5), (6-10), (11-15), (16-20) and more than 20 drug-drug interactions were found in 31.7%, 32.7%, 19.2%, 5.8% and 3.8% of patients, respectively. A total of 178 warfarin-drug interactions were identified in 88.5% of the patients. The INR ranged between 2 and 2.99 in 13.4% of patients, and INR values below 2 and above 5 were found in 44.2% and 21.2% of patients, respectively. Analgesics (n=54; 30.3%), cardiovascular drugs (n=51; 28.6%), and anticoagulants (n=46; 25.8%) were the most common drug classes that interact with warfarin. Significant and serious types of interactions with warfarin were found in 51% and 37.5% of patients, respectively. Conclusion: This study highlights the complexity of managing warfarin therapy amid prevalent polypharmacy. A substantial majority of patients experienced multiple drug interactions. The identification of significant and serious interactions emphasizes the need for vigilant management strategies, including improved communication among healthcare professionals and targeted education for both providers and patients, to enhance the safety and efficacy of warfarin therapy.

Efficacy and safety of direct oral anticoagulants versus warfarin in the treatment of cerebral venous sinus thrombosis.

BACKGROUND: Given the evolving application and promising outcomes of direct oral anticoagulants (DOACs) in various thromboembolic conditions, we aimed to compare the efficacy and safety of DOACs with warfarin in the post-acute treatment of cerebral venous sinus thrombosis (CVST) using clinical and radiological parameters. METHODS: A total of 140 CVST patients were enrolled, with 95 receiving warfarin and 45 receiving DOACs as post-acute treatment. Clinical and imaging parameters of the patients in follow-up visits were investigated, including the last modified Rankin Scale (mRS), venous thromboembolic events, CVST recurrence, mortality rate, recanalization status, and hemorrhagic events, to compare the efficacy and safety of treatment between the two groups. RESULTS: At baseline, patients' assessments using two prognostic scores, ISCVT-RS and IN-REvASC, revealed that there was no statistically significant difference in the distribution of prognostic risk categories between the warfarin and DOACs groups. Following acute therapy, patients in the warfarin and DOACs groups were followed up for the median of 359 and 325 days, respectively. Analysis to compare the efficacy of warfarin and DOACs revealed no significant difference in last mRS scores, CVST recurrence rate, venous thromboembolic events, and recanalization status between the two groups. Additionally, there was no statistically significant difference in the risk of hemorrhagic events between warfarin and DOACs groups. CONCLUSION: Our findings show that DOACs have comparable safety and efficacy in the post-acute treatment of CVST patients; however, large-scale randomized controlled trials are required to validate our findings.

Exploring factors associated with bleeding events after open heart surgery in patients on dialysis - effects of the presence or absence of warfarin therapy.

BACKGROUND: Perioperative management of patients on dialysis is critical for controlling bleeding and thrombotic risk, in addition to infection control. Postoperative anticoagulation is often difficult to control, and different institutions have different policies. Therefore, in this study, we aimed to investigate factors associated with postoperative bleeding events and whether warfarin (WF) therapy affects the incidence of postoperative bleeding events, total mortality, and stroke. METHODS: Patients who were admitted to the cardiovascular surgery department and underwent valve replacement or plasty were included, and those who underwent mechanical valve introduction were excluded. Thirty-nine patients were included in the study. The primary endpoint was to identify factors associated with the composite endpoint of postoperative bleeding events, and the secondary endpoint was to determine the effect size of WF therapy on postoperative bleeding events, all-cause mortality, and stroke and the strength of association between the crossed endpoints. The strength of the association between the crossed items was examined. RESULTS: Low body weight (p = 0.038) was identified as a factor associated with the primary endpoint of postoperative bleeding events. The secondary endpoint of whether or not patients received WF therapy was largely unrelated to bleeding events, all-cause mortality, and postoperative stroke up to 90 days after surgery. CONCLUSIONS: Preliminary studies suggest that low body weight is a risk factor for postoperative bleeding events in patients on dialysis, although further exploration of other factors will be necessary with the accumulation of similar cases.

Efficacy and Safety of Direct Oral Anticoagulants versus Warfarin in Obese Patients (BMI ≥ 30 kg/m2) with Atrial Fibrillation or Venous Thromboembolism: An Updated Systematic Review and Meta-Analysis.

Background: Real-world data show limited utilization of direct oral anticoagulants (DOACs) in obese patients (body mass index [BMI] ≥ 30 kg/m2) due to concerns regarding their efficacy and safety in this demographic. Aim: This review aimed to consolidate current evidence on the efficacy and safety of DOACs versus warfarin in obese patients with non-valvular atrial fibrillation (AF) or venous thromboembolism (VTE). The primary efficacy outcome assessed a composite of all-cause mortality, stroke, systemic embolism (SE), and myocardial infarction (MI). Methods: A systematic search was conducted in MEDLINE, SCOPUS, and Cochrane databases from inception to December 28, 2023. Data were synthesized using random-effects meta-analysis. Results: A total of 35 studies involving 434,320 participants were analyzed. DOAC use was associated with a significant reduction in the risk of the composite outcome (RR = 0.80, 95% CI [0.65, 0.98], I2 = 95%), hemorrhagic stroke (RR = 0.58, 95% CI [0.38, 0.88], I2 = 92%), major bleeding (RR = 0.76, 95% CI [0.63, 0.92], I2 = 94%), gastrointestinal bleeding (RR = 0.59, 95% CI [0.49, 0.72], I2 = 88%), and intracranial bleeding (RR = 0.45, 95% CI [0.34, 0.60], I2 = 44%) compared to warfarin. A non-significant benefit of DOACs was observed for all-cause mortality, MI, the composite of stroke or SE, ischemic stroke, SE, VTE, and minor bleeding compared to warfarin. Subgroup analysis indicated no significant effect modification based on the indication for anticoagulation or study design. Conclusions: DOACs demonstrated a favorable efficacy and safety profile in obese individuals compared to warfarin.

Comparative effectiveness among thromboprophylaxis strategies after the Fontan operation: A systematic review and network meta-analysis.

INTRODUCTION: A variety of thromboprophylaxis regimens have been administered in patients following the Fontan procedure. However, consensus guidelines regarding the optimal thromboprophylaxis strategy have not yet been developed. METHOD: A network meta-analysis was conducted to evaluate the comparative effectiveness among available thromboprophylaxis regimens and major bleeding events associated with these regimens. RESULTS: A total of 28 comparative studies with 4430 Fontan patients were included. The incidence of thromboembolic events (TE) was significantly lower in individuals who underwent thromboprophylaxis compared to those who did not. Compared to a no-treatment strategy, nonvitamin K oral anticoagulants (NOACs) showed the largest treatment effect for preventing TE (OR = 0.08, 95 % CI 0.03 to 0.21), followed by warfarin (OR = 0.16, 95 % CI 0.10 to 0.27), and aspirin (OR = 0.23, 95 % CI 0.14 to 0.38). Indeed, NOACs were significantly more effective than aspirin in preventing TE (OR = 0.35, 95 % CI 0.14 to 0.84). Aspirin was associated with the lowest occurrence of major bleeding events, followed by NOACs, no medication, and warfarin. NOACs were shown to possess a highly favorable overall profile. CONCLUSION: Prescribing thromboprophylaxis drugs, either antiplatelets or anticoagulants, may be more effective in preventing TE after the Fontan operation than not doing so. Among the included regimens, NOACs demonstrated significantly greater efficacy than aspirin; however, they did not show statistically significant superiority over warfarin. Aspirin exhibited lower rates of major bleeding compared to both NOACs and warfarin. Overall, NOACs tended to offer the most advantageous balance of efficacy and safety. However, the findings should be interpreted considering the certainty and limitations of the evidence, including potential residual confounding in observational studies.

Warfarin-related nephropathy: unveiling the hidden dangers of anticoagulation.

Warfarin-related nephropathy (WRN) is defined as acute kidney injury subsequent to excessive anticoagulation with warfarin. Patients with mechanical prosthetic valves require long-term anticoagulant therapy. Nonetheless, warfarin remains the sole available option for anticoagulant therapy. Consequently, patients with mechanical prosthetic valves constitute a special group among the entire anticoagulant population. The present study recorded two cases of patients who had undergone mechanical prosthetic valve surgery and were receiving warfarin therapy. They presented to the hospital with gross hematuria and progressive creatinine levels. Notably, their international normalized ratio (INR) did not exceed three. Subsequent renal biopsies confirmed WRN with IgA nephropathy. The two patients continued to receive warfarin as anticoagulation therapy and were prescribed oral corticosteroids and cyclophosphamide, which resulted in improved renal function during the follow-up. Based on a review of all relevant literature and the present study, we proposed a new challenge: must elevated INR levels be one of the criteria for clinical diagnosis of WRN? Perhaps some inspiration can be drawn from the present article.

Direct oral anticoagulants vs Vitamin-K antagonists in solid organ transplant recipients: A systematic review and meta-analysis.

Objective: Oure review aimed to examine evidence on the safety and efficacy of direct oral anticoagulants (DOAC) vs Vitamin K antagonists (VKA) in patients with solid organ transplants. Methods: PubMed, Embase, and Web of Science libraries were searched from inception to 25th November 2023 for all studies comparing DOAC with VKA in solid organ recipients. Results: Nine studies were included with patients who had undergone kidney, heart, or liver transplants. Meta-analysis showed that patients receiving DOAC had a significantly reduced risk of composite bleeding as compared to those with VKA (RR: 0.45 95% CI: 0.30, 0.68 I2=25%). However, the risk of major bleeding was not significantly different between the two groups (RR: 0.76 95% CI: 0.40, 1.42 I2=37%). Pooled analysis showed that the risk of VTE (RR: 0.90 95% CI: 0.72, 1.13 I2=0%) and ischemic stroke (RR: 0.87 95% CI: 0.39, 1.94 I2=12%) was not significantly different between DOAC and VKA groups. Conclusion: Limited data shows that DOAC are safe and effective in patients with solid organ transplants. The overall risk of bleeding may be reduced with the use of DOAC. There is a need for randomized controlled trials comparing DOAC and VKA in such patients to obtain high-quality evidence.

The comparative efficacy and safety of factor Xa inhibitors and warfarin for primary thromboprophylaxis in multiple myeloma patients undergoing immunomodulatory therapy.

There are limited data on the optimal choice of anticoagulation in multiple myeloma (MM) patients receiving immunomodulatory drugs (IMiDs). We conducted a propensity score-matched cohort study using the TriNetX database to compare the efficacy and safety of factor Xa inhibitors and warfarin in this patient population. Compared to warfarin, factor Xa inhibitors had a similar risk of deep vein thrombosis (hazard ratio [HR]: 1.11 [95% CI: 0.50-2.46]) or pulmonary embolism (HR: 1.08 [95% CI: 0.59-2.00]). There were no differences in the risk of gastrointestinal or intracranial bleeding. Factor Xa inhibitor-treated patients had lower all-cause mortality (HR: 0.56 [95% CI: 0.36-0.86]) compared with warfarin. These data suggest that factor Xa inhibitors had similar safety and efficacy compared with warfarin for MM patients on IMiDs.

Effective Non-invasive Treatment of Lingual Hematoma in an End-Stage Renal Disease (ESRD) Patient on Rivaroxaban: A Case Report.

Lingual hematoma is a rare, life-threatening condition that can obstruct the airway. We report a 73-year-old male with end-stage renal disease (ESRD) who developed lingual hematoma while on rivaroxaban. He presented with odynophagia and significant tongue swelling. Treatment with vitamin K, dexamethasone, tranexamic acid, and prothrombin complex concentrate led to rapid improvement without the need for intubation. This case highlights the importance of prompt medical management to prevent airway obstruction in similar patients.

Psychological Status and Warfarin Therapy in Patients after Valve Replacement during the COVID-19 Pandemic: A Cross-sectional Study.

OBJECTIVE: The standardization of warfarin anticoagulant therapy is the key to lifelong treatment for patients after heart valve replacement. The present study explored the possible risk factors for anxiety and depression during the coronavirus disease 2019 (COVID-19) pandemic and analyzed the influence of psychological state on medication safety. METHODS: Eligible patients received a web-based questionnaire survey via the Wenjuanxing platform during outpatient visits. Depression was evaluated by the Self-Rating Depression Scale (SDS). Anxiety was evaluated by the Self-Rating Anxiety Scale (SAS). Medication adherence was evaluated by the Morisky scale. RESULTS: A total of 309 patients (aged 52.2±11.4 years) were included in the present study. The SDS score of all included patients was 36.9±9.4 points, of which 11 (3.6%) patients were diagnosed as having depression. The SAS score of all included patients was 43.1±9.3 points, of which 71 (23%) patients were diagnosed as having anxiety. Seven patients (2.3%) had both anxiety and depression. Logistic regression analysis revealed that only monthly income was an independent influencing factor for depression. Regarding anxiety, patients who underwent repeated operations had a 2.264-fold greater risk, and patients who received combination medication had a 2.140-fold greater risk. More bleeding events and coagulation disorders could be observed in patients with anxiety, depression or both. When anxiety occurred, patients showed worse medication adherence. However, depression had no significant effect on medication adherence. CONCLUSION: During the COVID-19 pandemic, the detection rate of mental illnesses such as anxiety and depression was high, which seriously affected the medication safety of warfarin. Analysis of its influencing factors will provide a reference for further standardized regulation of warfarin anticoagulant therapy after valve replacement.

Adherence to oral anticoagulants in patients with non-valvular atrial fibrillation: the role of patients' characteristics and out-of-pocket payments.

BACKGROUND: Recent practice guidelines favor direct oral anticoagulants (DOACs) over warfarin for primary stroke prevention in patients with non-valvular atrial fibrillation (NVAF). However, challenges persist in Iraq's private pharmaceutical sector. DOACs have been sold at high and inconsistent retail prices and lack insurance coverage, leading to significant out-of-pocket (OOP) costs. The objective of this study is to investigate the impact of OOP costs on oral anticoagulants (OAC) adherence among NVAF patients. RESEARCH DESIGN AND METHODS: This multicenter cross-sectional study interviewed 359 eligible patients attending three private cardiology clinics within Iraq's southern region from December 2022 to February 2023. The 8-item Morisky Adherence Scale evaluated patient adherence. Statistical analyses, including descriptive analysis, ANOVA, and chi-square. p < 0.05 was considered statistically significant. RESULTS: The most frequently prescribed OAC were DOACs (62.8%). Patient adherence level to OAC was chiefly medium (54.6%) with no significant difference in adherence based on OAC type. Patient adherence was significantly associated with monthly income (p = 0.001), number of daily pills (p = 0.006), and OACs' average monthly cost (p = 0.011). CONCLUSION: Addressing the issue of cost-related non-adherence to OACs requires multiple actions. These include ensuring comprehensive health insurance coverage for OACs, increasing the use of affordable generic alternatives, and establishing effective cost-related discussions between healthcare providers and patients.

Effect of direct oral anticoagulant therapy on pulmonary artery clot dissolution in intermediate high-risk pulmonary thromboembolism.

BACKGROUND: Direct oral anticoagulants are the established drugs for treating pulmonary thromboembolism. The advantage of direct oral anticoagulants over conventional therapy for clot lysis and right ventricular unloading in the acute phase remains unclear. This study aimed to evaluate the effect of acute treatment with direct oral anticoagulants on clot dissolution and right ventricular unloading in intermediate high-risk pulmonary thromboembolism. METHODS: Thirty patients with intermediate high-risk pulmonary thromboembolism admitted between November 2012 and December 2018 were included; 21 and 9 were treated with direct oral anticoagulants and conventional therapy, respectively. We compared the efficacy of clot dissolution and right ventricular unloading for intermediate high-risk pulmonary thromboembolism between direct oral anticoagulant and conventional therapy in the acute phase. Efficacy was assessed by computed tomography obstruction index, right/left ventricular ratio, and brain natriuretic peptide levels between baseline and at discharge. RESULTS: Computed tomography obstruction index, right ventricular/left ventricular ratio, and brain natriuretic peptide levels were significantly lower at discharge than at admission in both groups. The rate of improvement in computed tomography obstruction index was significantly higher in the direct oral anticoagulant therapy group than in the conventional therapy group (64 ± 15% vs. 47 ± 16%; p = 0.01). There were no significant differences in the rate of improvement in right ventricular/ left ventricular ratio and brain natriuretic peptide levels between the two groups. CONCLUSIONS: Compared with conventional therapy, direct oral anticoagulants significantly reduced pulmonary artery clot burden conventional therapy in the acute treatment of intermediate high-risk pulmonary thromboembolism.

Long-term discontinuation of warfarin in a patient with HeartMate 3 left ventricular assist device without thromboembolic events.

The gold standard therapy for end-stage heart failure is cardiac transplantation. However, in the face of a donor shortage, a mechanical assist device such as the left ventricular assist device HeartMate 3 (Abbott Laboratories, Abbott Park, IL, USA) serves as bridging therapy to transplantation and/or destination therapy. Current guidelines recommend anticoagulation with a vitamin K antagonist in combination with low-dose aspirin. We herein report a challenging anticoagulation regimen in a patient with a HeartMate 3 in whom systemic anticoagulation with warfarin was not feasible for 4 years because of low compatibility and a rare X-factor deficiency. This is a rare hematological disorder, estimated to affect approximately 1 in every 500,000 to 1,000,000 people in the general population. The patient finally received a modified anticoagulation regimen involving the combination of rivaroxaban and clopidogrel without warfarin. Under this regimen, the patient remained free of thromboembolic complications for 4 years with in situ placement of the left ventricular assist device. This case illustrates that under specific circumstances, long-term absence of warfarin therapy is feasible in patients with a HeartMate 3.

A rodent and tick bait for controlling white-footed mice (Peromyscus leucopus) and blacklegged ticks (Ixodes scapularis), the respective pathogen host and vector of the Lyme disease spirochetes.

A promising alternative approach to conventional vector and rodent control practices is the use of a bait containing a rodenticide and acaricide in controlling vectors and pathogen reservoirs concurrently. In the United States, Lyme disease continues to be the most prevalent vector-borne disease with approximately 500,000 Lyme disease cases estimated each year. Previous research has demonstrated the usefulness of a low dose fipronil bait in controlling Ixodes scapularis larvae feeding on white-footed mice. However, considering white-footed mice can be an unwanted species because of their association with tick-borne disease and hantaviruses, a combination rodent and tick bait (RTB) might provide a useful alternative to encourage additional community participation in integrated tick management (ITM) efforts. The purpose of this research was to evaluate the use of RTB (0.025 % warfarin, 0.005 % fipronil) in controlling white-footed mice and I. scapularis larvae. Studies were designed in part based on Environmental Protection Agency (EPA) guidelines. A laboratory choice test was conducted to evaluate the use of RTB in controlling white-footed mice over 15-day exposure when they were exposed to an alternative diet. Mice were observed every day for mortality and signs of warfarin toxicity. A simulated field test was conducted to evaluate the use of RTB, presented in the presence of an alternative diet, in controlling I. scapularis parasitizing white-footed mice over 4-day exposure. Mice were fitted with capsules and manually infested with I. scapularis larvae. The inside of each capsule was observed to evaluate tick attachment. Replete larvae detaching from each mouse were collected. Blood was collected from all treatment group mice via cardiac puncture to determine the fipronil sulfone concentration in plasma for each animal. Results indicated that RTB would be adequately consumed in the presence of an alternative diet under laboratory and simulated field conditions. Treatment with RTB resulted in 100 % mortality of white-footed mice during 15-day exposure and prevented 100 % larvae from feeding to repletion during 4-day exposure. All mice succumbing to RTB showed signs of warfarin toxicity. All mice parasitized with ticks that were exposed to RTB had fipronil sulfone detectable in plasma, with even the lowest concentration detected (8.1 parts per billion) controlling 100 % parasitizing I. scapularis larvae. The results suggest that RTB could be a useful means of rodent and tick control for use in ITM programs.

Time-in-therapeutic-range defined warfarin and direct oral anticoagulants in atrial fibrillation: a Nationwide Cohort Study.

BACKGROUND: Little is known how individual time-in-therapeutic-range (TTR) impacts the effectiveness and safety of warfarin therapy compared to direct oral anticoagulants (DOACs) in patients with atrial fibrillation (AF). OBJECTIVE: To compare the effectiveness and safety of standard dose DOACs to warfarin in patients with AF, while categorizing warfarin treated patients into quartiles based on their individual TTR. MATERIALS AND METHODS: We conducted a nationwide study including all patients with new-onset AF between 2011 and 2018 in Finland. Hazard ratios (HR) were calculated using Cox regression analysis with the inverse probability of treatment weighted method to assess the risks of ischaemic stroke (IS), intracranial haemorrhage (ICH) and mortality for users of apixaban (n = 12,426), dabigatran (n = 4545), rivaroxaban (n = 12,950) and warfarin (n = 43,548). RESULTS: The median TTR for warfarin users was 72%. Compared to the second best TTR quartile (reference), the risk of IS was higher in the two poorest TTR quartiles, and lower in the best TTR quartile and on rivaroxaban [2.35 (95% confidence interval, 1.85-2.85), 1.44 (1.18-1.75), 0.60 (0.47-0.77) and 0.72 (0.56-0.92)]. These differences were non-significant for apixaban and dabigatran. HR of ICH was 6.38 (4.88-8.35) and 1.87 (1.41-2.49) in the two poorest TTR groups, 1.44 (1.02-1.93) on rivaroxaban, and 0.58 (0.40-0.85) in the best TTR group compared to the reference group. Mortality was higher in the two poorest TTR groups and lowest in the best TTR group. CONCLUSIONS: The outcome was unsatisfactory in the two lowest TTR quartiles - in half of the patients treated with warfarin. The differences between the high TTR groups and standard dose DOACs were absent or modest.

Meta-analysis evaluating apixaban in patients with atrial fibrillation and end-stage renal disease requiring dialysis.

Background: Warfarin is considered the primary oral anticoagulant for patients with atrial fibrillation and end-stage renal disease (ESRD) requiring dialysis. Although warfarin can offer significant stroke prevention in this population, the accompanying major bleeding risks make warfarin nearly prohibitive. Apixaban was shown to be superior to warfarin in preventing stroke or systemic embolism, with a lower risk of bleeding and mortality in a large, randomized trial of individuals with mostly normal renal function but none with ESRD. Methods: We systematically reviewed evidence comparing apixaban versus warfarin for atrial fibrillation in this population, and evaluated outcomes of stroke or systemic embolism, and major bleeding using random-effects models. The main safety outcome was major bleeding, and the main effectiveness outcome was stroke or systemic embolism. Results: We found five observational studies of 10 036 patients (2638 receiving apixaban, and 7398 receiving warfarin) meeting inclusion criteria. Pooled analysis demonstrated a significant reduction in major bleeding with apixaban as compared to warfarin (odds ratio [OR] 0.51, 95% confidence interval [CI] 0.42-0.61; p < .0001). Apixaban was also associated with a reduction in intracranial bleeding (OR 0.58, 95% CI 0.37-0.92; p = .02) and in gastrointestinal bleeding (OR 0.61, 95% CI 0.51-0.73; p < .0001). Furthermore, apixaban was associated with a reduction in stroke/systemic embolism (OR 0.64, 95% CI 0.50-0.82; p < .0001). Conclusion: Apixaban was associated with superior outcomes and reduced adverse events compared to warfarin in observational studies of patients with atrial fibrillation on dialysis. Randomized controlled studies are needed to confirm these findings.

Post-Discharge Treatment Patterns among Patients Treated with Apixaban or Warfarin during Hospitalization for Venous Thromboembolism (VTE).

Background: Oral anticoagulants (OACs), such as apixaban and warfarin, are indicated for reducing the risk of recurrent venous thromboembolism (VTE) and are often initiated in the hospital. The aim of this study was to evaluate OAC continuity from inpatient to outpatient settings and the risk of recurrent VTE among patients with an initial event. Methods: This retrospective cohort study utilized hospital charge data and medical and prescription claims from 1 July 2016 to 31 December 2022 to identify adults treated with apixaban or warfarin while hospitalized for VTE. Patients were followed to assess switching or discontinuation post-discharge and the risk of recurrent VTE. The index date was the date of the first apixaban or warfarin claim within 30 days post-discharge. Results: Of the 19,303 eligible patients hospitalized with VTE, 85% (n = 16,401) were treated with apixaban and 15% (n = 2902) received warfarin. After discharge, approximately 70% had ≥1 fill for their respective apixaban or warfarin therapy. The cumulative incidence of discontinuation over the 6 months following index was 50.5% and 52.2% for the apixaban and warfarin cohorts, respectively; the cumulative incidence of switching was 6.0% and 20.9%, respectively. The incidence rates of recurrent VTE were 1.2 and 2.5 per 100 person-years for the apixaban and warfarin cohorts, respectively. Conclusions: The majority of patients continued their apixaban or warfarin therapy following hospital discharge; however, a considerable proportion either switched or discontinued OAC upon transitioning from inpatient care. Among those who continued therapy, discontinuation, switch, and recurrent VTE occurred less often with apixaban vs. warfarin.