Pharmacokinetics of single-dose rivaroxaban under fed state in obese vs. non-obese subjects: An open-label controlled clinical trial (RIVOBESE-PK).

The evidence of rivaroxaban's pharmacokinetics in obese compared with non-obese populations remains inconclusive. We aimed to compare the pharmacokinetic profile of rivaroxaban between obese and non-obese populations under fed state. Participants who met the study's eligibility criteria were assigned into one of two groups: obese (body mass index ≥35 kg/m2) or non-obese (body mass index 18.5-24.9 kg/m2). A single dose of rivaroxaban 20 mg was orally administered to each participant. Nine blood samples over 48 h, and multiple urine samples over 18 h were collected and analyzed for rivaroxaban concentration using ultra-performance liquid chromatography coupled with tandem mass detector. Pharmacokinetic parameters were determined using WinNonlin software. Thirty-six participants were recruited into the study. No significant changes were observed between obese and non-obese participants in peak plasma concentration, time to reach peak plasma concentration, area under the plasma concentration-time curve over 48 h or to infinity, elimination rate constant, half-life, apparent volume of distribution, apparent clearance, and fraction of drug excreted unchanged in urine over 18 h. Rivaroxaban's exposure was similar between the obese and non-obese subjects, and there were no significant differences in other pharmacokinetic parameters between the two groups. These results suggest that dose adjustment for rivaroxaban is probably unwarranted in the obese population.

Predictors of adherence to direct oral anticoagulants after cardiovascular or bleeding events in Medicare Advantage Plan enrollees with atrial fibrillation.

BACKGROUND: Direct oral anticoagulants (DOACs) are recommended for patients with atrial fibrillation (AF) given their improved safety profile. Suboptimal adherence to DOACs remains a significant concern among individuals with AF. However, the extent of adherence to DOACs following a cardiovascular or bleeding event has not been fully evaluated. OBJECTIVE: To evaluate the pattern of adherence trajectories of DOACs after a cardiovascular or bleeding event and to investigate the sociodemographic and clinical predictors associated with each adherence trajectory by using claims-based data. METHODS: This retrospective study was conducted among patients with AF prescribed with DOACs (dabigatran/apixaban/rivaroxaban) between July 2016 and December 2017 and who were continuously enrolled in the Texas-based Medicare Advantage Plan. Patients who experienced a cardiovascular or bleeding event while using the DOACs were further included in the analysis. The sample was limited to patients who experienced a clinical event such as a cardiovascular or bleeding event while using the DOACs. The clinical events considered in this study were cardiovascular (stroke, congestive heart failure, myocardial infarction, systemic embolism) and bleeding events. To assess adherence patterns, each patient with a DOAC prescription was followed up for a year after experiencing a clinical event. The monthly adherence to DOACs after these events was evaluated using the proportion of days covered (PDC). A group-based trajectory model incorporated the monthly PDC to classify groups of patients based on their distinct patterns of adherence. Predictors associated with each trajectory were assessed using a multinomial logistic regression model, with the adherent trajectory serving as the reference group in the outcome variable. RESULTS: Among the 694 patients with AF who experienced clinical events after the initiation of DOACs, 3 distinct adherence trajectories were identified: intermediate nonadherent (30.50%), adherent (37.7%), and low adherent (31.8%); the mean PDC was 0.47 for the intermediate nonadherent trajectory, 0.93 for the adherent trajectory, and 0.01 for low adherent trajectory. The low-income subsidy was significantly associated with lower adherence trajectories (odds ratio [OR] = 4.81; 95% CI = 3.07-7.51) and with intermediate nonadherent trajectories (OR = 1.57; 95% CI = 1.06-2.34). Also, nonsteroidal anti-inflammatory drug use was significantly associated with lower adherence trajectories (OR = 5.10; 95% CI = 1.95-13.36) and intermediate nonadherent trajectories (OR = 3.17; 95% CI = 1.26-7.93). Other predictors significantly associated with both nonadherent trajectories are type of DOACs (OR = 0.53; 95% CI = 0.35-0.79), presence of coronary artery disease (OR = 1.89; 95% CI = 1.01-3.55), and having 2 or more clinical events (OR = 1.65; 95% CI = 1.09-2.50). CONCLUSIONS: Predictors identified provide valuable insights into the suboptimal adherence of DOACs among Medicare Advantage Plan enrollees with AF, which can guide the development of targeted interventions to enhance adherence in this high-risk patient population.

Development of immediate-release formulation with reliable absorption of rivaroxaban in various meal regimes.

The bioavailability of rivaroxaban at the higher doses (15 and 20 mg) is considerably reduced when the drug is administered on an empty stomach. This can lead to inadequate anticoagulant effect, and therefore, it is recommended to use the higher doses at fed state. However, proper posology may represent a barrier for some patients. Therefore, the aim of this study was to evaluate innovative rivaroxaban-containing formulations designed to eliminate the food effect to ensure reliable absorption and thus to improve patient adherence with the treatment. Three prototypes (Cocrystal, HPMCP and Kollidon) with rivaroxaban were developed and their bioavailability and food effect in comparison to the reference product was tested in open label, randomized, single oral dose, crossover studies, where test products were administered under fasting and fed conditions and the reference product was administered under fed conditions. Comparable bioavailability for all tested prototypes both under fed and fasting conditions was demonstrated as the 90% confidence intervals of the geometric mean ratios for area under the concentration-time curve remained within the standard acceptance range of 80.00%-125.00%. An innovative immediate release form of rivaroxaban with no food effect on drug bioavailability has been developed, which may represent an important step toward increasing adherence, improving treatment outcome and reducing health care costs.

Perioperative Management in Patients with Atrial Fibrillation Treated with Non-Vitamin K Antagonist Oral Anticoagulants Undergoing Minor Bleeding Risk Procedure: Rationale and Protocol for the PERIXa Study.

Background: While treatment interruption of non-vitamin K antagonist oral anticoagulants (NOACs) for elective surgery or procedures among patients with atrial fibrillation (AF) is becoming more prevalent, there remains insufficient evidence regarding the optimal perioperative management of NOACs, particularly procedures with minor bleeding risks. Objective: This study aims to evaluate the safety and effectiveness of a simplified, standardized protocol for perioperative management of direct factor Xa inhibitors in patients, with AF undergoing procedures associated with minor bleeding risk. Methods: This multicenter, prospective single-arm registry study plans to enroll patients undergoing procedures with minor bleeding risk who were prescribed direct factor Xa inhibitors for AF. The procedures with minor bleeding risk will include gastrointestinal endoscopy for diagnostic purposes, selected dental procedures, and ocular surgery for cataracts or glaucoma. For apixaban, patients will withhold the last evening dose and resume either from the evening dose of the procedure day or the following morning, depending on the bleeding risk of the patient. For edoxaban or rivaroxaban, patients will withhold only a single dose on the procedure day. The primary outcome is the occurrence of major bleeding events within 30 days. Secondary outcomes include systemic thromboembolism, all-cause mortality, and a composite of major and clinically relevant non-major bleeding events. Conclusion: This study has the potential to generate evidence regarding the safety of perioperative management for patients, with AF undergoing procedures associated with minor bleeding risk. Trial Registration: Clinicaltrials.gov: NCT05801068.

Comparison of Fixed Versus Weight-Based Prothrombin Complex Concentrate Dosing Strategies for Factor Xa Inhibitor Reversal.

Background: Our institution introduced fixed-dose prothrombin complex concentrate (PCC) to streamline order verification and medication administration. Previous studies using fixed-dose PCC for vitamin K antagonist reversal showed comparable efficacy to weight-based dosing. Objective: To compare fixed versus weight-based PCC dosing for reversal of Factor Xa Inhibitor (FXaI) effects. Methods: Retrospective cohort study conducted at a tertiary care academic medical center. Patients who received PCC to reverse the effects of apixaban or rivaroxaban were eligible. Subjects in the fixed-dose group (5000 units or 2000 units) were compared to weight-based PCC (50 units/kg). The primary outcome was time between order entry and medication administration. Secondary outcomes included: average PCC dose, postadministration procedures, achieved hemostasis, 30-day mortality, hospital length of stay, and adverse drug events. Results: 72 patients received fixed-dose PCC and 101 received weight-based PCC. Median time between order entry and administration was 4.5 min shorter in the fixed-dose group compared to weight-based (34.5 vs 39 min, P = .10). In patients who received fixed-dose, 79.2% achieved hemostasis versus 71.3% in the weight-based group (RR = 1.11, 95% CI = 0.94-1.32). There was no difference in the number of subsequent hemorrhage-related surgeries (29.2% vs 36.7%, RR = 0.80, 95% CI = 0.51-1.24) or mortality rate (26.4% vs 35.6%, RR = 0.73, 95% CI = 0.46-1.17). There were zero adverse drug events reported. Rates of thrombosis were 2.8% and < 1% (P = .57) in the fixed and weight-based groups, respectively. Conclusion and Relevance: The fixed-dosing strategy did not reduce time to PCC administration nor impact hemostasis or mortality. These data support that the fixed-dosing method is a viable option.

Assessment of Days Alive Out of Hospital as a Possible End Point in Trials of Stroke Prevention for Atrial Fibrillation: A ROCKET AF Analysis.

BACKGROUND: Days alive out of hospital (DAOH) is an objective and patient-centered net benefit end point. There are no assessments of DAOH in clinical trials of interventions for atrial fibrillation (AF), and it is not known whether this end point is of clinical utility in these populations. METHODS AND RESULTS: ROCKET AF (Rivaroxaban Once Daily Oral Direct Factor Xa Inhibition Compared With Vitamin K Antagonism for Prevention of Stroke and Embolism Trial in Atrial Fibrillation) was an international double-blind, double-dummy randomized clinical trial that compared rivaroxaban with warfarin in patients with atrial fibrillation at increased risk for stroke. We assessed DAOH using investigator-reported event data for up to 12 months after randomization in ROCKET AF. We assessed DAOH overall, by treatment group, and by subgroup, including age, sex, and comorbidities, using Poisson regression. The mean±SD number of days dead was 7.3±41.2, days hospitalized was 1.2±7.2, and mean DAOH was 350.7±56.2, with notable left skew. Patients with comorbidities had fewer DAOH overall. There were no differences in DAOH by treatment arm, with mean DAOH of 350.6±56.5 for those randomized to rivaroxaban and 350.7±55.8 for those randomized to warfarin (P=0.86). A sensitivity analysis found no difference in DAOH not disabled with rivaroxaban versus warfarin (DAOH not disabled, 349.2±59.5 days and 349.1 days±59.3 days, respectively, P=0.88). CONCLUSIONS: DAOH did not identify a treatment difference between patients randomized to rivaroxaban versus warfarin. This may be driven in part by the low overall event rates in atrial fibrillation anticoagulation trials, which leads to substantial left skew in measures of DAOH.

Comparative Bleeding Risk of Brand Vs Generic Rivaroxaban in Elderly Inpatients with Atrial Fibrillation.

Objective: Atrial fibrillation (AF) is the most common abnormal heart rhythm in elderly patients. Rivaroxaban has been widely used for stroke prevention. The anticoagulant response to rivaroxaban increases with age, which may make elderly patients susceptible to adverse outcomes resulting from small differences in bioavailability between generic and brand products. Methods: We designed a cohort study of ≥65-year-old inpatients with AF. Sociodemographic and laboratory measures of qualified patients who received brand or generic rivaroxaban for at least 72 hours at the study hospital from January 2021 to June 2023 were collected retrospectively. The primary outcome was the incidence of bleeding. Results: A total of 1008 qualifying patients were included for analysis, with 626 (62.1%) receiving brand rivaroxaban and 382 (37.9%) receiving generic rivaroxaban. After propensity score matching and weighting to account for confounders, the odds ratios comparing brand vs generic rivaroxaban (95% confidence intervals) for the bleeding was 1.15 (0.72-1.82). Results from subgroup analyses of patients with age ≥85, HAS-BLED score ≥ 3, containment of antiplatelet drugs, and female patients were consistent with the primary analysis. Conclusion: It provides evidence regarding the clinical safety outcome of generic rivaroxaban in the elderly AF population that may be particularly susceptible to adverse outcomes resulting from small allowable differences in pharmacokinetics.

Effect of different oral anticoagulants on cognitive function in patients with atrial fibrillation: A Bayesian network meta-analysis.

BACKGROUND: Atrial fibrillation (AF) is 1 of the most common types of arrhythmias. At present, the treatment for patients with AF mainly includes oral anticoagulants (OACs). Studies have shown that OACs are associated with cognitive decline in patients with atrial fibrillation; however, there is a lack of relevant evidence. This study used Bayesian network meta-analysis (NMA) to investigate the effects of different oral anticoagulants on cognitive decline in patients with AF. METHODS: We systematically searched for clinical studies on oral anticoagulants in patients with AF in PubMed, Web of Science, Embase, and the Cochrane Library as of July 3, 2023. Cochrane's randomized controlled trial bias risk assessment tool and the Newcastle-Ottawa Scale were used to assess the bias risk of the included studies. The main outcome measure was decreased cognitive functioning. RESULTS: Ten studies were included, including 2 RCTs and 7 RCSs, including 882,847 patients with AF. Five oral anticoagulants and 2 anticoagulants were included: VKAs (especially warfarin), Dabigatran, Edoxaban, Rivaroxaban, Apixaban, and Aspirin, Clopidogrel. The results of the mesh meta-analysis showed that VKAs were superior to warfarin in reducing the risk of cognitive decline in patients with AF (OR = -1.19, 95% CI (-2.35, -0.06), P < .05) (Table 5). The top 3 drugs in terms of the probability of reducing the incidence of cognitive impairment in patients with AF with different oral anticoagulants were VKAs (87%), rivaroxaban (62.2%), and dabigatran (60.8%). CONCLUSION: Based on the results of this study, VKAs may be the best intervention measure for reducing the risk of cognitive decline in patients with AF. Owing to the limitations of this study, more high-quality randomized controlled trials with large sample sizes and multiple centers are required to provide more evidence.

Appropriateness of prescribing profiles and intake adherence to non-vitamin K antagonist oral anticoagulants in patients with atrial fibrillation: analysis of a retrospective longitudinal study using real-world data from Northern Portugal (AF-React Study).

OBJECTIVES: This study aimed to assess the appropriateness of prescribing profiles and intake adherence to non-vitamin K antagonist oral anticoagulants (NOACs) in patients with atrial fibrillation (AF). DESIGN: Retrospective longitudinal study. SETTING: The study was conducted in the Regional Health Administration of Northern Portugal. PARTICIPANTS: The authors selected a database of 21 854 patients with prescriptions for NOACs between January 2016 and December 2018 and were classified with AF until December 2018. OUTCOME MEASURES: The appropriate dosage of NOAC for patients with AF divided into three categories: contraindicated, inconsistent and consistent, based on the 2020 European Society of Cardiology guidelines for AF. RESULTS: Dabigatran had a lower percentage of guideline-consistent doses (n=1657, 50.1%) than other drugs such as rivaroxaban (n=4737, 81.6%), apixaban (n=3830, 78.7%) and edoxaban (n=436, 82.1%). Most patients with an inconsistent dose were prescribed a lower dose than recommended based on their glomerular filtration rate (GFR). Among patients younger than 75 years with GFR >60 mL/min, 59.8% (n=10 028) had an adequate GFR range, while 27.8% (n=7166) of GFR measurements from patients older than 75 years old and 29.4% (n=913) of GFR measurements from patients younger than 75 years with GFR <60 mL/min were within an adequate time range. Adherence to NOACs varied across different drugs, with 59.1% (n=540) adhering to edoxaban, 56.3% (n=5443) to rivaroxaban, 55.3% (n=3143) to dabigatran and 53.3% (n=4211) to apixaban. CONCLUSIONS: Dabigatran had the lowest percentage of guideline-consistent doses. Patients younger than 75 years with GFR >60 mL/min had the highest percentage with an adequate GFR range, while other groups who require closer GFR monitoring had lower percentages within an adequate GFR range. Adherence to NOACs differed among different drugs, with greater adherence to treatment with edoxaban and less adherence to apixaban.

Prophylaxis of microvascular thrombosis using direct oral anticoagulants (DOAC) in microvascular free tissue transplantation - a pilot study.

INTRODUCTION: We conducted this pilot study to assess direct oral anticoagulants (DOACs) in the prevention of microvascular thrombosis. MATERIALS AND METHODS: Five patients undergoing microvascular free tissue transplantation received rivaroxaban or apixaban (depending on their home medication). We compared this group to 19 patients who received enoxaparin subcutaneously. We evaluated the rate of graft loss due to microvascular thrombosis and the number of transfusions administered intra- and postoperatively. RESULTS: There was no graft loss due to microvascular thrombosis in either of the groups. There was no significant difference in the number of intraoperative (study group mean 1.00 (SE 0.32) vs. control group mean 1.11 (SE 0.59); p = 0.876) and postoperative (study group mean 1.2 (SE 0.37) vs. control group mean 1.74 (SE 0.34); p = 0.310) red blood cell transfusions. CONCLUSION: Based on our results in this pilot study, DOACs can be used with microvascular flaps. Further studies with larger sample sizes should be performed to find an optimal medication regimen both for patients already taking DOACs and perhaps even for those not taking DOACs.

A real-world study of different doses of rivaroxaban in patients with nonvalvular atrial fibrillation.

To explore the anticoagulant effect and safety of utilizing different doses of rivaroxaban for the treatment of patients with atrial fibrillation (AF) in the real world. A retrospective case-control analysis was performed by applying the hospital database, and 3595 patients with non-valvular atrial fibrillation (NVAF) who were hospitalized and taking rivaroxaban at Wuhan Asia Heart Hospital and Wuhan Asia General Hospital from March 2018 to December 2021 were included in the study, and were divided into the rivaroxaban 10 mg and 15 mg groups according to the daily prescribed dose, of which 443 cases were in the 10 mg group and 3152 cases were in the 15 mg group. The patients were followed up regularly, and the incidence of thrombotic events, bleeding events and all-cause deaths were recorded and compared between the 2 groups, and logistic regression was applied to analyze the influencing factors for the occurrence of adverse events. Comparison of the incidence of thrombosis, bleeding and all-cause death between the 2 groups of patients showed that the 10 mg group was higher than the 15 mg group, but the difference was not statistically significant (χ2 = 0.36, 3.26, 1.99, all P > .05); the incidence of total adverse events between the 2 groups of patients was higher in the 10 mg group than in the 15 mg group, with a statistically significant difference (χ2 = 4.53, P = .033); multifactorial logistic regression results showed that age [OR (95% CI) = 1.02 (1.00-1.04)], diabetes mellitus [OR (95% CI) = 1.69 (1.09-2.62)], D-dimer level [OR (95% CI) = 1.06 (1.00-1.11)] and persistent AF [OR (95% CI) = 1.54 (1.03-2.31)] were risk factors for adverse events (P < .05). In the real world, Asian clinicians recommend rivaroxaban 10 mg once daily for NVAF patients for a variety of reasons; however, this dose is not superior or even inferior to the 15 mg group in terms of effectiveness and safety. Advanced age, elevated D-dimer levels, history of diabetes mellitus, and persistent AF are risk factors for adverse events, and the optimal dosage of rivaroxaban or optimal anticoagulation strategy for Asian patients with nonvalvular AF requires further study.

Risk factors for thrombosis and spontaneous echocardiographic contrast with sludge in atrial fibrillation patients treated with oral anticoagulants before electrical cardioversion.

BACKGROUND: Knowledge of thrombosis (T) risk predictors and transesophageal echocardiography (TEE) are important tools in appropriate qualification of patients for safe electrical cardioversion. AIMS: We aimed to investigate predictors of T and spontaneous echocardiographic contrast (SEC) with sludge in the left atrium (LA) and appendage (LAA) in atrial fibrillation (AF) patients on oral anticoagulation. METHODS: The study included 300 patients with AF lasting >48 hours. Two hundred and nineteen patients were treated with oral anticoagulants (OACs) (study group, rivaroxaban: 104 [47.5%], apixaban: 52 [23.7%], dabigatran: 23 [11.5%], VKAs: 40 [18.3%]). Eighty-one consecutive patients with AF lasting >48 hours and not treated with OACs constituted the control group. Before electrical cardioversion, all patients underwent transthoracic echocardiography and TEE. RESULTS: TEE revealed T in the LAA in 4.7% of cases. The number of patients with T or SEC4+ with sludge in the OAC and control groups was similar, 5.9% vs. 1.2% and 16.4% vs. 16.0%, respectively. The risk of SEC4+/T in patients treated with OACs was lowest in those taking rivaroxaban (odds ratio [OR], 0.42; 95% confidence interval [CI], 0.21-0.87; P = 0.027) and highest in those receiving VKAs (OR, 2.49; 95% CI, 1.15-5.39; P = 0.018). Multivariable analysis showed independent prognostic factors for SEC 4+/T: female sex (OR, 3.800; 95% CI, 1.592-9.072; P = 0.003), left ventricular ejection fraction (OR, 0.932; 95% CI, 0.890-0.957; P <0.001), and minimum LAA flow velocity (LAAfly min) (OR, 0.895; 95% CI, 0.841-0.954; P <0.001). CONCLUSIONS: Female sex, transthoracic echocardiography, and TEE results should be taken into account in assessing the risk of T/SEC with sludge in LA/LAA patients with AF.

Net clinical benefit of extended dual pathway inhibition according to baseline risk in patients with chronic coronary syndrome: a COMPASS substudy.

AIMS: Guidelines recommend extended dual pathway inhibition (DPI) with aspirin and rivaroxaban in patients with chronic coronary syndrome (CCS) at high ischaemic risk. The CHADS-P2A2RC score improves risk prediction and enables antithrombotic treatment allocation in these patients. This study evaluated the net clinical benefit of DPI treatment according to baseline risk as classified by the CHADS-P2A2RC score in patients with CCS included in the COMPASS (Cardiovascular Outcomes for People Using Anticoagulation Strategies) trial. METHODS AND RESULTS: COMPASS patients with CCS (n = 14 670), randomized to aspirin alone or DPI, were stratified according to cardiovascular risk using the CHADS-P2A2RC score. Endpoints were major adverse cardiovascular events (MACE), all-cause death, fatal/critical organ bleeding, and composite adverse events (MACE and bleeding). Net clinical benefit was the 30-month risk difference of MACE and bleeding. Thirty-month incidences of MACE [7.9% vs. 3.9%, hazard ratio (HR) 2.01, 95% confidence interval (CI) 1.83-2.18] and fatal/critical organ bleeding (1.2% vs. 0.8%, HR 1.49, 95% CI 1.06-1.92) were higher in high-risk (CHADS-P2A2RC ≥ 4) than in low/moderate-risk (CHADS-P2A2RC < 4) patients. DPI reduced MACE (low/moderate risk: HR 0.62, 95% CI 0.47-0.82; high risk: HR 0.82, 95% CI 0.68-0.99, P for interaction 0.09) and all-cause death (low/moderate risk: HR 0.65, 95% CI 0.46-0.91; high risk: HR 0.81, 95% CI 0.65-1.00, P for interaction 0.29), without substantially increasing fatal/critical organ bleeding (low/moderate risk: HR 1.35, 95% CI 0.72-2.53; high risk: HR 1.18, 95% CI 0.73-1.90, P for interaction 0.73). DPI provided net clinical benefit of similar magnitude in low/moderate-risk (-1.81%, 95% CI -3.00 to -0.62) and high-risk (-1.96%, 95% CI -3.60 to -0.33) CCS patients. CONCLUSION: As classified by the CHADS-P2A2RC score, low/moderate- and high-risk patients with CCS derived similar net clinical benefit and reduction in all-cause death from DPI treatment.

The Pharmacogenetic Variability Associated with the Pharmacokinetics and Pharmacodynamics of Rivaroxaban in Healthy Chinese Subjects: A National Multicenter Exploratory Study.

PURPOSE: This study aimed to explore the pharmacogenetic variability associated with the pharmacokinetics (PK) and pharmacodynamics (PD) of rivaroxaban in healthy Chinese subjects. METHODS: This was a multicenter study that included 304 healthy adults aged 18 to 45 years with unknown genotypes. All participants were administered a single dose of rivaroxaban at 10 mg, 15 mg, or 20 mg. PK and PD parameters were measured, and exome-wide association analysis was conducted. FINDINGS: Sixteen SNPs located on 11 genes influenced the AUC0-t. Among these, the 3 most influential genes were MiR516A2, PARP14, and MIR618. Thirty-six SNPs from 28 genes were associated with the PD of rivaroxaban. The 3 most influential genes were PKNOX2, BRD3, and APOL4 for anti-Xa activity, and GRIP2, PLCE1, and MLX for diluted prothrombin time (dPT). Among them, BRD3 played an important role in both the PK and PD of rivaroxaban. Anti-Xa activity (ng/mL) differed significantly among subjects with BRD3 rs467387: 145.1 ± 55.5 versus 139.9 ± 65.1 versus 164.0 ± 68.6 for GG, GA, and AA carriers, respectively (P = 0.0002). IMPLICATIONS: This study found that that the regulation of the BRD3 gene might affect the PK and PD of rivaroxaban, suggesting that it should be studied as a new pharmacologic target. The correlation between this gene locus and clinical outcomes has yet to be verified in patients undergoing clinical treatment.

Comparative Safety and Effectiveness of Reduced Doses of Direct Acting Oral Anticoagulants for Stroke Prevention in Atrial Fibrillation.

BACKGROUND: This Nordic observational cohort study aims to assess the effectiveness and safety of reduced-dose direct-acting oral anticoagulants (DOACs) dabigatran, rivaroxaban, and apixaban compared to standard warfarin for stroke prevention in nonvalvular atrial fibrillation. METHODS: The study, utilizing nationwide administrative databases from Denmark, Sweden, Norway, and Finland, spanned from January 1, 2011 to December 31, 2018 (2017 for Sweden). The cohort included 26,883 patients initiating reduced-dose DOACs and 108,014 comparable warfarin patients. Effectiveness was measured by the composite endpoint of ischemic stroke and systemic embolism, while safety was assessed through intracranial hemorrhage. RESULTS: The meta-analysis across countries revealed similar or lower incidences of ischemic stroke and systemic embolism in patients on reduced-dose DOACs compared to standard warfarin (rivaroxaban: HR 0.93, dabigatran: HR 0.88, apixaban: HR 0.79). Incidences within warfarin groups ranged from 2.16 to 3.71 per 100 person-years, comparable to DOAC recipients. Intracranial hemorrhage rates were generally low, ranging from 0.16 to 1.85 per 100 person-years. In comparison with warfarin patients, meta-analyses yielded HRs for rivaroxaban (1.41), dabigatran (0.35), and apixaban (0.72). CONCLUSIONS: In this study, atrial fibrillation patients initiating reduced-dose rivaroxaban and dabigatran exhibited incidences of ischemic stroke and systemic embolism similar to warfarin, and for apixaban, even lower. Rates of intracranial hemorrhage were comparable to or lower for patients on DOACs compared to warfarin.

Time Course of the Interaction Between Oral Short-Term Ritonavir Therapy with Three Factor Xa Inhibitors and the Activity of CYP2D6, CYP2C19, and CYP3A4 in Healthy Volunteers.

BACKGROUND: We investigated the effect of a 5-day low-dose ritonavir therapy, as it is used in the treatment of COVID-19 with nirmatrelvir/ritonavir, on the pharmacokinetics of three factor Xa inhibitors (FXaI). Concurrently, the time course of the activities of the cytochromes P450 (CYP) 3A4, 2C19, and 2D6 was assessed. METHODS: In an open-label, fixed sequence clinical trial, the effect and duration of a 5-day oral ritonavir (100 mg twice daily) treatment on the pharmacokinetics of three oral microdosed FXaI (rivaroxaban 25 µg, apixaban 25 µg, and edoxaban 50 µg) and microdosed probe drugs (midazolam 25 µg, yohimbine 50 µg, and omeprazole 100 µg) was evaluated in eight healthy volunteers. The plasma concentrations of all drugs were quantified using validated liquid chromatography-tandem mass spectrometry (LC-MS/MS) methods and pharmacokinetics were analysed using non-compartmental analyses. RESULTS: Ritonavir increased the exposure of apixaban, edoxaban, and rivaroxaban, but to a different extent the observed area under the plasma concentration-time curve (geometric mean ratio 1.29, 1.46, and 1.87, respectively). A strong CYP3A4 inhibition (geometric mean ratio > 10), a moderate CYP2C19 induction 2 days after ritonavir (0.64), and no alteration of CYP2D6 were observed. A CYP3A4 recovery half-life of 2.3 days was determined. CONCLUSION: This trial with three microdosed FXaI suggests that at most the rivaroxaban dose should be reduced during short-term ritonavir, and only in patients receiving high maintenance doses. Thorough time series analyses demonstrated differential effects on three different drug-metabolising enzymes over time with immediate profound inhibition of CYP3A4 and only slow recovery after discontinuation. CLINICAL TRIAL REGISTRATION: EudraCT number: 2021-006643-39.

Comparison of direct oral anticoagulants and warfarin in chronic limb-threatening ischemia.

OBJECTIVE: The role of direct oral anticoagulants (DOACs) in chronic limb-threatening ischemia after revascularization is unknown. Current evidence-based guidelines do not provide clear guidance on the role of anticoagulation or the selection of anticoagulant. Current practice is highly varied and based on provider and patient preference. The purpose of this study was to measure the impact of different anticoagulants on the incidence of major adverse limb events (MALEs) after revascularization for chronic limb-threatening ischemia, major adverse cardiovascular events (MACEs), all-cause mortality, and hospitalization for major bleeding events. METHODS: This was a single-center, observational, retrospective cohort study. Subjects were eligible if they were 18 years or older; underwent endovascular or open revascularization for chronic limb-threatening ischemia, rest pain, or tissue loss; and were subsequently prescribed apixaban, rivaroxaban, or warfarin. The primary end point was the incidence of MALEs, including above-ankle amputation or major index-limb reintervention, within 1 year of index event. Secondary end points included the rate of all-cause mortality, MACEs, and incidence of International Society on Thrombosis and Haemostasis (ISTH) major bleeding. RESULTS: From January 1, 2017, to September 20, 2022, 141 patients met the inclusion and exclusion criteria and were reviewed. The median age was 67 years, with 92 patients prescribed apixaban or rivaroxaban and 49 patients prescribed warfarin. Of these, 42 patients were prescribed triple antithrombotic therapy, 88 dual antithrombotic therapy, and 13 anticoagulant monotherapy. The primary outcome of 1-year MALEs occurred in 36.7% of the warfarin group and 33.7% of the DOAC group (relative risk [RR], 1.09; 95% CI, 0.53-2.25; P = .72). Secondary outcomes of 1-year MACEs (10.2% vs 4.3%; RR, 2.35; 95% CI, 0.60-9.18; P = .18) and 1-year all-cause mortality (26.5% vs 16.3%; RR, 1.63; 95% CI, 0.70-3.78; P = .15) did not differ between the groups. The secondary safety outcome of 1-year ISTH major bleeding occurred in 16.3% of the warfarin group and 4.3% of the DOAC group (RR, 3.76; 95% CI, 1.07-13.19; P = .015). CONCLUSIONS: In patients with chronic limb-threatening ischemia who were revascularized and prescribed anticoagulation with apixaban, rivaroxaban, or warfarin on discharge, no difference in MALEs, MACEs, or all-cause mortality was found. However, 1-year admissions for ISTH major bleeding were significantly higher among patients prescribed warfarin. A randomized trial may confirm these findings.

Routine extended (30 days) chemoprophylaxis for patients undergoing laparoscopic sleeve gastrectomy may reduce Portomesenteric vein thrombosis rates.

BACKGROUND: Venous thromboembolism (VTE), including Portomesenteric vein thrombosis (PMVT), is a major complication of sleeve gastrectomy (SG). We changed our practice in July 2021 to routinely discharge all SG patients postoperatively with extended chemoprophylaxis for 30 days. OBJECTIVES: Evaluate the efficacy and safety of routine extended chemoprophylaxis compared to 2 prior timeframes using selective extended chemoprophylaxis. SETTING: University Hospital. METHODS: Between 2012-2018, SG patients were discharged on extended chemoprophylaxis for patients deemed "high-risk" for VTE, including patients with body mass index (BMI) >50, and previous VTE. Between 2018-2021, extended chemoprophylaxis was broadened to include patients with positive preoperative thrombophilia panels (including Factor VIII). After 2021, all SG were routinely discharged on extended chemoprophylaxis. The typical regimen was 30 days Lovenox BID (40-mg twice daily for BMI> 40, 60-mg twice daily for BMI >60). Outcomes evaluated were rate of VTE/PMVT and postoperative bleed, including delayed bleed. RESULTS: A total of 8864 patients underwent SG. Average age and BMI were 37.5 years and 43.0 kg/m2, respectively. The overall incidence of PMVT was 33/8864 (.37%). Converting from selective extended chemoprophylaxis (Group 1) to routine extended chemoprophylaxis (Group 3) decreased the rate of PMVT from .55% to .21% (P = .13). There was a significantly higher overall bleeding rate (.85%), including delayed bleeds (.34%) in the routine extended chemoprophylaxis patients (P < .05). These bleeds were mainly managed nonoperatively. CONCLUSIONS: Routine extended (30 day) chemoprophylaxis for all SG may reduce PMVT rate but lead to a higher bleeding rate post-operatively. The vast majority of the increased bleeds are delayed and can be managed non-operatively.

Patrones y resultados del cambio de anticoagulantes orales directos en la fibrilación auricular no valvular: experiencia en la práctica clínica en España / Patterns and outcomes of switching direct oral anticoagulants in non-valvular atrial fibrillation: A real-world experience from Spain

Objetivos El objetivo consistía en evaluar un programa de gestión de anticoagulantes orales directos (ACOD) en pacientes con fibrilación auricular no valvular (FANV) según sus perfiles, idoneidad de la dosis, patrones de cambio de tratamiento, efectividad y seguridad Se trató de un estudio observacional, prospectivo y longitudinal en una cohorte de pacientes atendidos en la práctica clínica cotidiana en un hospital regional español con un plan de seguimiento de 3 años para pacientes que iniciaron el tratamiento con dabigatrán, rivaroxabán o apixabán entre enero de 2012 y diciembre de 2016. Métodos Se analizaron 490 episodios de tratamiento (apixabán 2,5mg, 9,4%; apixabán 5mg, 21,4%; dabigatrán 75mg, 0,6%; dabigatrán 110mg, 12,4%; dabigatrán 150mg, 19,8%; rivaroxabán 15mg, 17,8%; rivaroxabán 20mg, 18,6%) en 445 pacientes. En el 13,6% de los pacientes tratados con dabigatrán, el 9,7% de los tratados con rivaroxabán y el 3,9% de los tratados con apixabán se cambió a otros ACOD o se modificó la dosis. Resultados El ACOD al que se cambió con mayor frecuencia fue el apixabán. Los motivos más frecuentes para cambiar de tratamiento fueron toxicidad (23,8%), hemorragia (21,4%) y deterioro renal (16,7%). En el 23,8% de los episodios se constató una inadecuación de la dosis. Las tasas de ictus y accidentes isquémicos transitorios (AIT) fueron de 1,64 y 0,54 eventos/100 años/paciente, respectivamente, mientras que las de hemorragias importantes, no importantes, pero clínicamente relevantes (NICR) e intracraneales fueron de 2,4, 5 y 0,5 eventos/100 años/paciente, respectivamente. Las hemorragias digestivas y genitourinarias fueron el tipo más frecuente de eventos hemorrágicos. En el análisis multifactorial, el ictus previo y la edad fueron factores predictivos independientes de ictus/AIT. El uso concomitante de antiagregantes plaquetarios, el sexo masculino y la edad fueron factores predictivos independientes de eventos hemorrágicos (AU)

Aims The aim is to evaluate a management program for direct oral anticoagulants (DOACs) in non-valvular atrial fibrillation (NVAF) patients according to their profiles, appropriateness of dosing, patterns of crossover, effectiveness and safety. This is an observational and longitudinal prospective study in a cohort of patients attended in daily clinical practice in a regional hospital in Spain with 3-year a follow-up plan for patients initiating dabigatran, rivaroxaban or apixaban between Jan/2012 and Dec/2016. Methods We analyzed 490 episodes of treatment (apixaban 2.5, 9.4%; apixaban 5, 21.4%; dabigatran 75, 0.6%; dabigatran 110, 12.4%; dabigatran 150, 19.8%; rivaroxaban 15, 17.8% and rivaroxaban 20, 18.6%) in 445 patients. 13.6% of patients on dabigatran, 9.7% on rivaroxaban, and 3.9% on apixaban switched to other DOACs or changed dosing. Results Apixaban was the most frequent DOAC switched to. The most frequent reasons for switching were toxicity (23.8%), bleeding (21.4%) and renal deterioration (16.7%). Inappropriateness of dose was found in 23.8% of episodes. Rates of stroke/transient ischemic attack (TIA) were 1.64/0.54 events/100 patients-years, while rates of major, clinically relevant non-major (CRNM) bleeding and intracranial bleeding were 2.4, 5, and 0.5 events/100 patients-years. Gastrointestinal and genitourinary bleeding were the most common type of bleeding events (BE). On multivariable analysis, prior stroke and age were independent predictors of stroke/TIA. Concurrent platelet inhibitors, male gender and age were independent predictors of BE. Conclusion This study complements the scant data available on the use of DOACs in NVAF patients in Spain, confirming a good safety and effectiveness profil (AU)