Antithrombotic therapy for stable coronary artery disease and atrial fibrillation in patients with and without revascularisation: the AFIRE trial.

BACKGROUND: The Atrial Fibrillation and Ischemic Events with Rivaroxaban in Patients with Stable Coronary Artery Disease (AFIRE) trial demonstrated non-inferior efficacy endpoints for rivaroxaban monotherapy versus combination therapy (rivaroxaban plus a single antiplatelet) and superior safety endpoints in patients with atrial fibrillation and stable coronary artery disease. AIMS: This post hoc analysis investigated whether the AFIRE trial results reflected the presence or absence of prior revascularisation. METHODS: Among 2,215 patients, 1,697 (76.6%) had previously undergone revascularisation, and the remaining 518 (23.4%) had not undergone prior revascularisation. The primary efficacy endpoint was a composite of stroke, systemic embolism, myocardial infarction, unstable angina requiring revascularisation, or death from any cause, while the primary safety endpoint was major bleeding. RESULTS: In 1,697 patients with prior revascularisation, the efficacy and safety endpoints were superior for monotherapy versus combination therapy (efficacy: hazard ratio [HR] 0.62, 95% confidence interval [CI]: 0.45-0.85; p=0.003; safety: HR 0.62, 95% CI: 0.39-0.98; p=0.042). Among 518 without prior revascularisation, there were no significant differences in endpoints (efficacy: HR 1.19, 95% CI: 0.67-2.12; p=0.554; safety: HR 0.47, 95% CI: 0.18-1.26; p=0.134). There was borderline interaction of the efficacy endpoints (p=0.055) between two treatments. The safety benefit of monotherapy on any bleeding was significant in patients without prior revascularisation (HR 0.59, 95% CI: 0.38-0.93; p=0.022). CONCLUSIONS: In high-risk thrombosis patients with a history of prior revascularisation, rivaroxaban monotherapy versus combination therapy demonstrated favourable safety and efficacy outcomes.

Methods, design, and initial results of an angiographic core lab from VOYAGER-PAD.

Background: Anatomy is critical in risk stratification and therapeutic decision making in coronary disease. The relationship between anatomy and outcomes is not well described in PAD. We sought to develop an angiographic core lab within the VOYAGER-PAD trial. The current report describes the methods of creating this core lab, its study population, and baseline anatomic variables. Methods: Patients undergoing lower-extremity revascularization for symptomatic PAD were randomized in VOYAGER-PAD. The median follow up was 2.25 years. Events were adjudicated by a blinded Clinical Endpoint Committee. Angiograms were collected from study participants; those with available angiograms formed this core lab cohort. Angiograms were scored for anatomic and flow characteristics by trained reviewers blinded to treatment. Ten percent of angiograms were evaluated independently by two reviewers; inter-rater agreement was assessed. Clinical characteristics and the treatment effect of rivaroxaban were compared between the core lab cohort and noncore lab participants. Anatomic data by segment were analyzed. Results: Of 6564 participants randomized in VOYAGER-PAD, catheter-based angiograms from 1666 patients were obtained for this core lab. Anatomic and flow characteristics were collected across 16 anatomic segments by 15 reviewers. Concordance between reviewers for anatomic and flow variables across segments was 90.5% (24,417/26,968). Clinical characteristics were similar between patients in the core lab and those not included. The effect of rivaroxaban on the primary efficacy and safety outcomes was also similar. Conclusions: The VOYAGER-PAD angiographic core lab provides an opportunity to correlate PAD anatomy with independently adjudicated outcomes and provide insights into therapy for PAD. (ClinicalTrials.gov Identifier: NCT02504216).

Safety profile of rivaroxaban in first-time users treated for venous thromboembolism in four European countries.

BACKGROUND: The European rivaroxaban post-authorization safety study evaluated bleeding risk among patients initiated on rivaroxaban or vitamin K antagonists for the treatment and secondary prevention of venous thromboembolism in routine clinical practice. METHODS: Cohorts were created using electronic healthcare databases from the UK, the Netherlands, Germany and Sweden. Patients with a first prescription of rivaroxaban or vitamin K antagonist during the period from December 2011 (in the UK, January 2012) to December 2017 (in Germany, December 2016) for venous thromboembolism indication, with no record of atrial fibrillation or recent cancer history, were observed until the occurrence of each safety outcome (hospitalization for intracranial, gastrointestinal, urogenital or other bleeding), death or study end (December 2018; in Germany, December 2017). Crude incidence rates of each outcome per 100 person-years were computed. RESULTS: Overall, 44 737 rivaroxaban and 45 842 vitamin K antagonist patients were enrolled, mean age, 59.9-63.8 years. Incidence rates were similar between rivaroxaban and vitamin K antagonist users with some exceptions, including higher incidence rates for gastrointestinal bleeding in rivaroxaban users than in vitamin K antagonist users. Among rivaroxaban users, mortality and bleeding risk generally increased with age, renal impairment and diabetes. CONCLUSIONS: This study provides further data from routine clinical practice that broadly support safety profile of rivaroxaban for VTE indication and complement findings from previous randomized clinical trials.

[Mid-term analysis of prospective cohort study of rivaroxaban in preventing CRT in breast cancer].

Objective: To explore the efficacy and safety of Rivaroxaban in preventing catheter related thrombosis (CRT) in patients with breast cancer who are undergoing central venous catheter chemotherapy, and provide basis for making standardized prevention and treatment strategies. Methods: In this research, a prospective cohort study was adopted, and breast cancer patients who received central venous catheter chemotherapy in Sanhuan Cancer Hospital during September 2020 to March 2022 were selected as a treatment group to take the rivaroxaban anticoagulation therapy with 10 mg.po.qd for one month. The control group got no preventive anticoagulation therapy. Vascular ultrasound examination was taken to confirm the occurrence of CRT, and a chi-square test was done for comparison the disparity between the groups. Logistic regression was applied to analyze the univariate and multivariate factors for the formation of CRT. Results: In the research, a total of 235 patients were selected, and there were a total of 19 035 days of catheterization with 81 days of catheterization on average. While in the control group, the incidence of CRT was 28.0% (33/118), the incidence of CRT in the treatment group was 20.5% (24/117), the difference was no significant (P=0.183). Subgroup analysis results showed that the peripherally inserted central catheter (PICC) was performed in 165 cases with the CRT incidence of 18.2% (30/165) and thrombosis was mostly seen around axillary vein, accounting for 63.3%. Subclavian vein catheterization was performed in 63 cases with the CRT incidence of 39.7% (25/63), and thrombosis was mostly seen around subclavian vein, accounting for 88.0% (22/25). Implantable venous access port was implanted in 7 cases around subclavian vein and internal jugular vein with the CRT incidence of 28.6% (2/7). The patients who developed CRT within 30 days after catheterization accounted for 54.4% (31/57), 22.8% (13/57) in a period during 30 days and 60 days) and 22.8% (13/57) in a period during 60 days and 180 days). The diagnosed CRT patients had been treated with rivaroxaban 15 mg.bid.po for 3 months. During the 3 months, 100.0% of the thrombosis waned, 71.9% (41/57) of the thrombosis waned within 30 days, 19.3% (11/57) in a period during 30 and 60days and 8.8% (5/57) in a period during 60 days and 90 days. Univariate and multivariate analysis indicated that the risk of CRT in subclavian vein catheterization was higher than that in PICC, respectively (OR=2.898, 95% CI:1.386-6.056 P=0.005), and the type of catheterization was an independent factor for the formation of thrombosis. Safety analysis result showed that in the prevention of CRT, rivaroxaban treatment did not induce drug-related bleeding, liver function damage, bone marrow suppression or any other side effects. While CRT diagnosed patients were treated with anticoagulation, they kept the central venous catheter, and the infusion was smooth. These patients all finished the anti-tumor treatment as planned, and no abnormalities like new thrombosis or pulmonary embolism were observed. Conclusions: In the mid-term analysis, the proportion of Rivaroxaban in preventing anticoagulant CRT decreases, but it don't reach statistical significance. The sample size should be further increased for observation. Rivaroxaban is proved effective and very safe in the treatment of CRT, and does not affect the concurrent chemotherapy. Medical personnel should carry out the policy of "early prevention, early detection and early treatment" for CRT so as to improve the patients' quality of life.

Perioperative Treatment with Rivaroxaban and Dabigatran on Changes of Coagulation and Platelet Activation Biomarkers following Left Atrial Appendage Closure.

Insufficient data exist regarding the investigation of the impact of novel oral anticoagulants (NOACs) on coagulation activation biomarkers in the context of left atrial appendage closure (LAAC) and device-related thrombosis (DRT). The study was designed to investigate the changes and presence of coagulation activation biomarkers between different antithrombotic strategies following LAAC. A total of 120 nonvalvular atrial fibrillation patients intolerant of long-term anticoagulants, who underwent successful WATCHMAN closure implantation, were enrolled (rivaroxaban, n = 82; dabigatran, n = 38). Blood samples were obtained from left atrium (LA) and left atrial appendage (LAA) during the operation and fasting blood samples on the same day of LAAC and 45 days after discharge. The biochemical indicators, thrombin-antithrombin complex (TAT), soluble P-selectin (sP-selectin), von Willebrand factor (vWF), and CD40 ligand (CD40L), were measured by enzyme-linked immunosorbent assay. The primary endpoints of this study were the efficacy and safety characteristics of different antithrombotic strategies, including DRT incidence, stroke or transient ischemic attack, systemic embolism, and clinical major and nonmajor bleeding complications during the follow-up of 180 days. The results revealed that TAT, vWF, sP-selectin, and CD40L levels in vein were significantly reduced by 2.4% (p = 0.043), 5.0% (p < 0.001), 8.7% (p < 0.001), and 2.5% (p = 0.043) from their baseline levels after rivaroxaban treatment. Conversely, no significant changes were detected in the dabigatran group. Furthermore, the plasma levels of platelet activation biomarkers (CD40L and sP-selectin) in both LA and LAA groups were significantly lower after anticoagulation with rivaroxaban, as compared to dabigatran treatment (CD40L: 554.62 ± 155.54 vs. 445.02 ± 130.04 for LA p = 0.0013, 578.51 ± 156.28 vs. 480.13 ± 164.37 for LAA p = 0.0052; sP-selectin: 2849.07 ± 846.69 vs. 2225.54 ± 799.96 for LA p = 0.0105, 2915.52 ± 1402.40 vs. 2203.41 ± 1061.67 for LAA p = 0.0022). Notably, the present study suggests that rivaroxaban may be more effective in the prevention of DRT for patients undergoing LAAC.

Crushing tablets or sprinkling capsules: Implications for clinical strategy and study performance based on BE studies of rivaroxaban and deferasirox.

Administration of oral medicinal products as crushed tablets or open capsules is an important delivery option for patients suffering from dysphagia. To obtain full interchangeability of generics with the original products, demonstration of bioequivalence (BE) between both products administered as crushed tablets/open capsules was required for poorly soluble product by European Medicines Agency (EMA) at the time of development of our rivaroxaban and deferasirox generic products. We present the results of two BE studies with modified administration of these products, which compared relative bioavailability between generic and reference products. In the rivaroxaban study, the test product was administered as a capsule sprinkled on and mixed with applesauce, whereas the reference tablet was crushed and administered with applesauce under fed conditions. In the deferasirox study, both treatments were administered as crushed tablets under fasting conditions. Both studies applied a two-way crossover design and were conducted after a single-dose in healthy volunteers. The 90% confidence interval of the geometric mean ratio area under the analyte concentration versus time curve, from time zero to the time of the last measurable analyte concentration and maximum measured analyte concentration over the sampling period of the test to reference ratio were 103.36-110.37% and 97.98-108.45% for rivaroxaban, respectively, and 96.69-107.29% and 94.19-109.45% for deferasirox, respectively. Thus, the BE criteria (80.00-125.00%) were met in both studies which demonstrated that bioavailability was not affected when the test and reference products were administered in the form of crushed tablet/open capsule. These results support the argument of redundancy of crushed product studies for poorly soluble drugs, which is in line with the currently revised position of the EMA on this topic.

Impact of very low dose rivaroxaban in addition to dual antiplatelet therapy on endogenous fibrinolysis in acute coronary syndrome: The VaLiDate-R study.

BACKGROUND: Impaired endogenous fibrinolysis is adverse cardiovascular risk factor in acute coronary syndrome (ACS) patients. Addition of very low dose rivaroxaban (VLDR) to dual antiplatelet therapy (DAPT) reduces cardiovascular events but increases bleeding. OBJECTIVE: We aimed to assess whether addition of VLDR to DAPT can enhance endogenous fibrinolysis. METHODS: In a prospective, open-label trial, we assessed endogenous fibrinolysis in whole blood, in 549 patients with ACS using the Global Thrombosis Test (GTT) and Thromboelastography (TEG). Patients (n = 180) who demonstrated impaired endogenous fibrinolysis (lysis time [LT] >2000s with the GTT) were randomised 1:1:1 to (i) clopidogrel 75 mg daily; (ii) clopidogrel 75 mg daily plus rivaroxaban 2.5 mg twice daily; or (iii) ticagrelor 90 mg twice daily, for 30 days, in addition to aspirin. Fibrinolytic status was assessed at 0, 2, 4 and 8 weeks. The primary outcome was the change in LT from admission to week 4. We also measured thrombotic occlusion time (OT) at high shear, and rivaroxaban level. RESULTS: There was no difference between the groups with respect to LT or clot lysis with TEG, and no change in these parameters compared to baseline during study drug allocation. In the rivaroxaban plus clopidogrel group, OT was prolonged compared to the other groups, although rivaroxaban levels were low, suggesting non-compliance. CONCLUSION: Addition of rivaroxaban 2.5 mg twice daily to DAPT does not affect endogenous fibrinolysis of thrombus formed at either high or low shear. Further studies are needed to determine whether higher doses of rivaroxaban can favourably modulate fibrinolysis. CONDENSED ABSTRACT: Impaired endogenous fibrinolysis is a strong risk factor in ACS. We aimed to assess whether adding very low dose rivaroxaban (VLDR) to DAPT can enhance fibrinolysis. Fibrin and clot lysis were assessed in whole blood. ACS patients with impaired fibrinolysis were randomised 1:1:1 to clopidogrel 75 mg daily; clopidogrel 75 mg plus VLDR; or ticagrelor 90 mg twice daily, in addition to aspirin. At 30-days, there was no difference in lysis time between the groups, nor change from baseline. VLDR does not improve fibrinolysis at high or low shear. Further studies are needed to determine whether alternative antithrombotic regimens can enhance endogenous fibrinolysis.

Toward Genetic Testing of Rivaroxaban? Insights from a Systematic Review on the Role of Genetic Polymorphism in Rivaroxaban Therapy.

BACKGROUND: Investigations into the rivaroxaban response from the perspective of genetic variation have been relatively recent and wide in scope, whereas there is no consensus on the necessity of genetic testing of rivaroxaban. Thus, this systematic review aims to thoroughly evaluate the relationship between genetic polymorphisms and rivaroxaban outcomes. METHODS: The PubMed, Embase, Cochrane Central Register of Controlled Trials (CENTRAL), and Chinese databases were searched to 23 October 2022. We included cohort studies reporting the pharmacogenetic correlation of rivaroxaban. Outcomes measured included efficacy (all-cause mortality, thromboembolic events and coagulation-related tests), safety (major bleeding, clinically relevant non-major bleeding [CRNMB] and any hemorrhage), and pharmacokinetic outcomes. A narrative synthesis was performed to summarize findings from individual studies according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses and the reporting guideline for Synthesis Without Meta-Analysis. RESULTS: A total of 12 studies published between 2019 and 2022 involving 1364 patients were included. Ten, one, and six studies focused on the ABCB1, ABCG2, and CYP gene polymorphisms, respectively. Pharmacokinetic outcomes accounted for the majority of the outcomes reported (n = 11), followed by efficacy (n = 5) [including prothrombin time (PT) or international normalized ratio (n = 3), platelet inhibition rate (PIR) or platelet reactivity units (PRUs; n = 1), thromboembolic events (n = 1)], and safety (n = 5) [including major bleeding (n = 2), CRNMB (n = 2), any hemorrhage (n = 1)]. For ABCB1 gene polymorphism, the relationship between PT and ABCB1 rs1045642 was inconsistent across studies, however there was no pharmacogenetic relationship with other efficacy outcomes. Safety associations were found in ABCB1 rs4148738 and major bleeding, ABCB1 rs4148738 and CRNMB, ABCB1 rs1045642 and CRNMB, and ABCB1 rs2032582 and hemorrhage. Pharmacokinetic results were inconsistent among studies. For ABCG2 gene polymorphism, no correlation was observed between ABCG2 rs2231142 and dose-adjusted trough concentration (Cmin/D). For CYP gene polymorphisms, PIR or PRUs have a relationship with CYP2C19 rs12248560, however bleeding or pharmacokinetic effects did not show similar results. CONCLUSIONS: Currently available data are insufficient to confirm the relationship between clinical or pharmacokinetic outcomes of rivaroxaban and gene polymorphisms. Proactive strategies are advised as a priority in clinical practice rather than detection of SNP genotyping. CLINICAL TRIALS REGISTRATION: PROSPERO registration number CRD42022347907.

Clot time ratio (CTR) and treatment outcomes in Apixaban-treated atrial fibrillation patients.

There are clinical situations where information about the anticoagulant effects of Apixaban could be useful. Specialised methods for measuring Apixaban concentrations are not available at all medical laboratories while methods for measuring the functional effects of Apixaban, using clot time ratio (CTR), can be performed in most medical laboratories around the clock using well-established measurement procedures. The aim of this study was to investigate CTR in trough and peak samples during Apixaban treatment of atrial fibrillation and to correlate the findings to bleeds and thrombotic events. Three trough- and three peak samples from 61 patients (31 on Apixaban 5 mg twice daily and 30 on Apixaban 2.5 mg twice daily) were analysed with MRX PT DOAC. Patients were followed for 30 + /-15 months, and bleeds and thrombotic events were documented. The effect of Apixaban could be measured with MRX PT DOAC and there was a statistically significant difference between CTR in trough samples compared to peak samples (p < 0.001). A total of 21 patients suffered bleeds during follow-up; two patients suffered major bleeds, and 19 suffered minor bleeds. Patients with major bleeds had both mean peak- and mean trough CTR above the respective first to third quartile (Q1-Q3) range. Four patients suffered thromboembolic events. Generally, the peak CTRs were below or in the lower end of the peak Q1-Q3 for these patients. The new test MRX PT DOAC can be used to measure the effect of Apixaban during the treatment of atrial fibrillation. High mean peak- and mean trough CTR were seen in 2 patients with major bleeds, and low peak CTR was seen in 4 patients with thromboembolic events.

Probe Substrate Dependencies in CYP3A4 Allosteric Inhibition: A Novel Molecular Mechanism Involving F-F' Loop Perturbations.

The biochemical basis for substrate dependences in apparent inhibition constant values (Ki) remains unknown. Our study aims to elucidate plausible structural determinants underpinning these observations. In vitro steady-state inhibition assays conducted using human recombinant CYP3A4 enzyme and testosterone substrate revealed that fibroblast growth factor receptor (FGFR) inhibitors erdafitinib and pemigatinib noncompetitively inhibited CYP3A4 with apparent Ki values of 10.2 ± 1.1 and 3.3 ± 0.9 µM, respectively. However, when rivaroxaban was adopted as the probe substrate, there were 2.0- and 3.2-fold decreases in its apparent Ki values. To glean mechanistic insights into this phenomenon, erdafitinib and pemigatinib were docked to allosteric sites in CYP3A4. Subsequently, molecular dynamics (MD) simulations of apo- and holo-CYP3A4 were conducted to investigate the structural changes induced. Comparative structural analyses of representative MD frames extracted by hierarchical clustering revealed that the allosteric inhibition of CYP3A4 by erdafitinib and pemigatinib did not substantially modulate its active site characteristics. In contrast, we discovered that allosteric binding of the FGFR inhibitors reduces the structural flexibility of the F-F' loop region, an important gating mechanism to regulate access of the substrate to the catalytic heme. We surmised that the increased rigidity of the F-F' loop engenders a more constrained entrance to the CYP3A4 active site, which in turn impedes access to the larger rivaroxaban molecule to a greater extent than testosterone and culminates in more potent inhibition of its CYP3A4-mediated metabolism. Our findings suggest a potential mechanism to rationalize probe substrate dependencies in Ki arising from the allosteric noncompetitive inhibition of CYP3A4.

Real-world experience of direct oral anticoagulant use in a single pediatric center.

BACKGROUND: Pediatric venous thromboembolism has increased by 130%-200%, specifically in hospitalized children, and direct oral anticoagulants (DOACs) offer several therapeutic advantages. METHODS: This study aims to evaluate the real-world epidemiological and outcome data from a retrospective review of pediatric patients treated with DOACs from January 1, 2013 to December 31, 2022. In this single-center, IRB-approved study, 65 patients were identified and analyzed using SPSS statistical software, and a descriptive statistical analysis was conducted. RESULTS: Of the 65 patients, 37% were on apixaban, 61.5% were on rivaroxaban, and 1.5% were on dabigatran. Per the 2023 ISTH outcome definitions, one (2%) patient had a major bleeding episode, six (9%) had clinically relevant non-major bleeding, three (5%) patients had patient-important heavy menstrual bleeding (HMB), and one (1.5%) patient had minor bleeding. Seven (19%) of 37 postmenarchal patients had evidence of HMB. Six (9.2%) patients had recurrent venous thromboembolism while on a DOAC (one was on apixaban, and five were on rivaroxaban) and were transitioned to other forms of anticoagulation. CONCLUSION: Thus, bleeding rates after DOAC therapy are comparable to previous DOAC trials, as well as other anticoagulants in pediatrics. HMB is an important outcome measure and should continue to be investigated. This study reports a higher rate of recurrent thrombosis (9.2%) compared to other trials. However, this observation may be attributed to patients who had ongoing risk factors, as well as a longer duration of study follow-up. Additional multicentered outcome studies evaluating DOAC use in children are needed to determine long-term recurrence and HMB risks.

Challenges and lessons learned from a long-term postauthorisation safety study programme of rivaroxaban in Europe.

OBJECTIVES: To describe opportunities and challenges experienced from the four pharmacoepidemiological database studies included in the rivaroxaban post authorisation safety study (PASS) programme and propose ways to maximise the value of population-based observational research when addressing regulatory requirements. DESIGN: PASS programme of rivaroxaban carried out as part of the regulatory postapproval commitment to the European Medicines Agency. SETTING: Clinical practice in Germany, the Netherlands, Sweden and the UK (electronic health records)-undertaken by pharmacoepidemiology research teams using country-specific databases with different coding structures. PARTICIPANTS: 355 152 patients prescribed rivaroxaban and 338 199 patients prescribed vitamin K antagonists. RESULTS: Two major challenges that were encountered throughout the lengthy PASS programme were related to: (1) finalising country-tailored study designs before the extent of rivaroxaban uptake was known, and (2) new research questions that arose during the programme (eg, those relating to an evolving prescribing landscape). RECOMMENDATIONS: We advocate the following strategies to help address these major challenges (should they arise in any future PASS): conducting studies based on a common data model that enable the same analytical tools to be applied when using different databases; maintaining early, clear, continuous communication with the regulator (including discussing the potential benefit of studying drug use as a precursor to planning a safety study); consideration of adaptive designs whenever uncertainty exists and following an initial period of data collection; and setting milestones for the review of study objectives.

Comparison of High- and Low-Dose Rivaroxaban Regimens in Elderly East Asian Patients With Atrial Fibrillation.

BACKGROUND: In the Rivaroxaban Once-daily oral direct factor Xa inhibition Compared with vitamin K antagonism for prevention of stroke and Embolism Trial in Atrial Fibrillation (ROCKET AF) trial, rivaroxaban 20 mg was the on-label dose, and the dose-reduction criterion for rivaroxaban was a creatinine clearance of < 50 mL/min. Some Asian countries are using reduced doses label according to the J-ROCKET AF trial. The aim of this study was to assess the safety and efficacy of a high-dose rivaroxaban regimen (HDRR, 20/15 mg) and low-dose rivaroxaban regimen (LDRR, 15/10 mg) among elderly East Asian patients with atrial fibrillation (AF) in real-world practice. METHODS: This study was a multicenter, prospective, non-interventional observational study designed to evaluate the efficacy and safety of rivaroxaban in AF patients > 65 years of age with or without renal impairment. RESULTS: A total of 1,093 patients (mean age, 72.8 ± 5.8 years; 686 [62.9%] men) were included in the analysis, with 493 patients allocated to the HDRR group and 598 patients allocated to the LDRR group. A total of 765 patients received 15 mg of rivaroxaban (203 in the HDRR group and 562 in the LDRR group). There were no significant differences in the incidence rates of major bleeding (adjusted hazard ratio [HR], 0.64; 95% confidential interval [CI], 0.21-1.93), stroke (adjusted HR, 3.21; 95% CI, 0.54-19.03), and composite outcomes (adjusted HR, 1.13; 95% CI, 0.47-2.69) between the HDRR and LDRR groups. CONCLUSION: This study revealed the safety and effectiveness of either dose regimen of rivaroxaban in an Asian population for stroke prevention of AF. Considerable numbers of patients are receiving LDRR therapy in real-world practice in Asia. Both regimens were safe and effective for these patients. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT04096547.

Comparative effectiveness of factor Xa non-vitamin K antagonist oral anticoagulants versus phenprocoumon in patients with non-valvular atrial fibrillation.

BACKGROUND: Non-vitamin K antagonist oral anticoagulants (NOACs) have largely supplanted vitamin K antagonists (VKAs) for oral anticoagulation in non-valvular atrial fibrillation (NVAF). However, data on the real-world effectiveness of NOACs vs. phenprocoumon, a VKA widely used in Germany, are limited. The RELOADED study aimed to compare effectiveness of factor Xa NOACs and phenprocoumon in NVAF in clinical practice. METHODS: Patients who started on a factor Xa NOAC or phenprocoumon for NVAF during the study period were enrolled from the Institute for Applied Healthcare Research Berlin. Patients were followed from first prescription until the end of exposure or available data. Primary outcomes were analyzed by Cox proportional hazard regression models and included ischemic stroke and systemic embolism for effectiveness, and intracranial hemorrhage (ICH) for safety. Subgroups of interest were patients with diabetes and patients with renal impairment. RESULTS: The total study population was 64,920; 36.3% of patients initiated phenprocoumon, 34.4% initiated rivaroxaban, 25.0% apixaban, and 4.4% edoxaban. Treatment with phenprocoumon is associated with a similar risk of ischemic stroke/systemic embolism as treatment with rivaroxaban or apixaban; while rivaroxaban (adjusted hazard ratio [HR] 0.57, 95% confidence interval [CI] 0.43-0.75) and apixaban (adjusted HR 0.43, 95% CI 0.31-0.6) were associated with a lower risk of ICH compared to phenprocoumon in NVAF patients. The use of rivaroxaban and apixaban was associated with a lower risk of developing kidney failure in patients with diabetes or renal impairment in comparison to those treated with phenprocoumon. CONCLUSION: The factor Xa NOACs rivaroxaban and apixaban demonstrated similar effectiveness and lower rates of ICH compared with phenprocoumon in this study.

Primary results of the brazilian registry of atherothrombotic disease (NEAT).

There is limited contemporary prospective real-world evidence of patients with chronic arterial disease in Latin America. The Network to control atherothrombosis (NEAT) registry is a national prospective observational study of patients with known coronary (CAD) and/or peripheral arterial disease (PAD) in Brazil. A total of 2,005 patients were enrolled among 25 sites from September 2020 to March 2022. Patient characteristics, medications and laboratorial data were collected. Primary objective was to assess the proportion of patients who, at the initial visit, were in accordance with good medical practices (domains) for reducing cardiovascular risk in atherothrombotic disease. From the total of patients enrolled, 2 were excluded since they did not meet eligibility criteria. Among the 2,003 subjects included in the analysis, 55.6% had isolated CAD, 28.7% exclusive PAD and 15.7% had both diagnoses. Overall mean age was 66.3 (± 10.5) years and 65.7% were male patients. Regarding evidence-based therapies (EBTs), 4% were not using any antithrombotic drug and only 1.5% were using vascular dose of rivaroxaban (2.5 mg bid). Only 0.3% of the patients satisfied all the domains of secondary prevention, including prescription of EBTs and targets of body-mass index, blood pressure, LDL-cholesterol, and adherence of lifestyle recommendations. The main barrier for prescription of EBTs was medical judgement. Our findings highlight that the contemporary practice does not reflect a comprehensive approach for secondary prevention and had very low incorporation of new therapies in Brazil. Large-scale populational interventions addressing these gaps are warranted to improve the use of evidence-based therapies and reduce the burden of atherothrombotic disease.ClinicalTrials.gov NCT04677725.

Andexanet Alfa: What We Have Learned from Clinical Trials and Real-World Data.

Andexanet alfa is a specific reversal agent for factor Xa inhibitors with immediate reversal of their anticoagulant effect. Andexanet alfa is currently approved for use in patients treated with rivaroxaban and apixaban who have life-threatening or uncontrolled bleeding. New data from both controlled clinical trials and real-world experience are continuously being published, providing greater insight into the clinical characteristics of the drug, such as efficacy and safety. It is worth considering that andexanet alfa could be of benefit in a variety of different clinical scenarios where patients receiving treatment with apixaban and rivaroxaban (and endoxaban) have life-threatening conditions. These different clinical scenarios, which range from pre-treatment of urgent surgery, especially neurosurgical interventions, and concomitant use of andexanet alfa and prothrombin complex concentrate to onset of bleeding more than 6 h prior to admission, should be clarified as well as the issue of "low/high" dose of andexanet alfa and the need for baseline anti-Xa inhibitor levels measured by point-of-care testing. Finally, management of patients at high risk of thrombosis or recent arterial/venous thrombotic events needs to be further explored. In this current opinion, we address these urgent questions in the light of recent literature and clinical trial data.

Optimizing warfarin dosing for patients with atrial fibrillation using machine learning.

While novel oral anticoagulants are increasingly used to reduce risk of stroke in patients with atrial fibrillation, vitamin K antagonists such as warfarin continue to be used extensively for stroke prevention across the world. While effective in reducing the risk of strokes, the complex pharmacodynamics of warfarin make it difficult to use clinically, with many patients experiencing under- and/or over- anticoagulation. In this study we employed a novel implementation of deep reinforcement learning to provide clinical decision support to optimize time in therapeutic International Normalized Ratio (INR) range. We used a novel semi-Markov decision process formulation of the Batch-Constrained deep Q-learning algorithm to develop a reinforcement learning model to dynamically recommend optimal warfarin dosing to achieve INR of 2.0-3.0 for patients with atrial fibrillation. The model was developed using data from 22,502 patients in the warfarin treated groups of the pivotal randomized clinical trials of edoxaban (ENGAGE AF-TIMI 48), apixaban (ARISTOTLE) and rivaroxaban (ROCKET AF). The model was externally validated on data from 5730 warfarin-treated patients in a fourth trial of dabigatran (RE-LY) using multilevel regression models to estimate the relationship between center-level algorithm consistent dosing, time in therapeutic INR range (TTR), and a composite clinical outcome of stroke, systemic embolism or major hemorrhage. External validation showed a positive association between center-level algorithm-consistent dosing and TTR (R2 = 0.56). Each 10% increase in algorithm-consistent dosing at the center level independently predicted a 6.78% improvement in TTR (95% CI 6.29, 7.28; p < 0.001) and a 11% decrease in the composite clinical outcome (HR 0.89; 95% CI 0.81, 1.00; p = 0.015). These results were comparable to those of a rules-based clinical algorithm used for benchmarking, for which each 10% increase in algorithm-consistent dosing independently predicted a 6.10% increase in TTR (95% CI 5.67, 6.54, p < 0.001) and a 10% decrease in the composite outcome (HR 0.90; 95% CI 0.83, 0.98, p = 0.018). Our findings suggest that a deep reinforcement learning algorithm can optimize time in therapeutic range for patients taking warfarin. A digital clinical decision support system to promote algorithm-consistent warfarin dosing could optimize time in therapeutic range and improve clinical outcomes in atrial fibrillation globally.

Direct oral anticoagulants in trauma patients.

PURPOSE OF REVIEW: Direct oral anticoagulants (DOACs) are increasingly prescribed for prevention of thromboembolic events. Thus, trauma care providers are facing a steadily raising number of injured patients on DOACs. RECENT FINDINGS: Despite a predictable pharmacokinetic profile, the resulting plasma levels of trauma patients upon admission and bleeding risks remain uncertain. Therefore, recent guidelines recommend the measurement of DOAC plasma concentrations in injured patients. Alternatively, DOAC specific visco-elastic tests assays can be applied to identify DOAC patients at bleeding risk.Bleeding complications in trauma patients on DOACs are generally higher compared to nonanticoagulated subjects, but comparable to vitamin K antagonists (VKAs). In particular, a traumatic brain injury does not carry an increased risk of intracranial bleeding due to a DOAK intake compared to VKAs. Current studies demonstrated that up to 14% of patients with a hip fracture are on DOACs prior to surgery. However, the majority can be operated safely within a 24h time window without an increased bleeding rate.Specific antagonists facilitate rapid reversal of patients on DOACs. Idarucizumab for dabigatran, and andexanet alfa for apixaban and rivaroxaban have been approved for life threatening bleeding. Alternatively, prothrombin complex concentrate can be used. Dialysis is a potential treatment option for dabigatran and haemoabsorption with special filters can be applied in patients on FXa-inhibitors. SUMMARY: Current guidelines recommend the measurement of DOAC plasma levels in trauma patients. Compared to VKAs, DOACs do not carry a higher bleeding risk. DOAC specific antagonists facilitate the individual bleeding management.

The impact of factor Xa inhibitors on bleeding risk in patients with respiratory diseases.

It is unclear which factor Xa (FXa) inhibitors are associated with higher bleeding risk in patients with respiratory diseases, and there are no studies on the association between prothrombin time-international normalized ratio (PT-INR) and bleeding risk. We conducted a retrospective cohort study comparing 1-year-outcomes and PT-INR between patients with respiratory diseases treated with rivaroxaban (R group, n = 82) or edoxaban (E group, n = 138) for atrial fibrillation or venous thromboembolism from 2013 to 2021. The most frequent event of all bleeding discontinuations was respiratory bleeding in both groups (7.3 and 4.3%, respectively). The cumulative incidence of bleeding discontinuation was significantly higher in the R group (25.6%) than in the E group (14.4%) (hazard ratio [HR], 2.29; 95% confidence interval [CI] 1.13-4.64; P = 0.023). PT-INR after initiation of therapy significantly increased and was higher in the R group than in the E group (median value, 1.4 and 1.2, respectively; P < 0.001). Multivariate analysis using Cox proportional hazards and Fine-Gray models revealed that PT-INR after initiation of therapy was an independent risk factor of bleeding discontinuation events (HR = 4.37, 95% CI 2.57-7.41: P < 0.001). Respiratory bleeding occasionally occurs in patients receiving FXa inhibitors, and monitoring the PT-INR may need to ensure safety.

Patterns of atrial fibrillation anticoagulation with rivaroxaban - 7-year follow-up from the Dresden NOAC registry.

INTRODUCTION: Data on long-term effectiveness and safety of rivaroxaban for stroke prevention in atrial fibrillation (SPAF) are scarce and not available from randomized clinical trials. METHODS: We used data from the prospective, non-interventional DRESDEN NOAC REGISTRY to evaluate rates of stroke/transient ischaemic attack (TIA)/systemic embolism (SE) and ISTH major bleeding, in general and changes of event patterns over time. RESULTS: Between 1st October 2011 and 31st December 2022, 1204 SPAF patients receiving rivaroxaban were followed for 6.7 ± 3.4 years with a mean rivaroxaban exposure of 4.9 ± 3.5 years. During follow up, intention-to treat rates of stroke/TIA/SE were 3.5/100 pt. years (95 % CI 2.5-4.7) in the first year and fell to 1.6/100 pt. years (95 % CI 1.2-2.0) in years 2-5 and 2.1/100 pt. years (95 % CI 1.6-2.7) after 5 years. Similarly, on-treatment event rates fell from 2.4/100 pt. years (95 % CI 1.5-3.5) to 1.1 (95 % CI 0.7-1.5) and 1.6 (95 % CI 1.0-2.3), respectively. Major bleeding rates on treatment were 3.5/100 pt. years in the first treatment year (95 % CI 2.5-4.8) and 2.7 (95 % CI 2.2-3.4) and 3.5 (95 % CI 2.7-4.6) in the periods 2-5 and > 5 years, respectively. Of note, rates of fatal bleeding were low throughout follow-up (0.2 vs. 0.2 vs. 0.1/100 pt. years). CONCLUSIONS: Our results demonstrate the long-term effectiveness and safety of rivaroxaban therapy in unselected SPAF patients in daily care. Our data indicate that patterns of cardiovascular events remain constant over many years. In contrast, bleeding patterns change over time, possibly due to effects of co-morbidities in an ageing population.