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)

Rivaroxabana para prevenção de eventos tromboembólicos em pacientes com fibrilação atrial não-valvular / Rivaroxaban for event prevention thromboembolic events in patients with atrial fibrillation non-valvular

INTRODUÇÃO: A fibrilação atrial não-valvular (FANV) é um tipo comum de arritmia cardíaca que afeta cerca de 1 em cada 20 pessoas com idade maior que 65 anos e 1 em cada dez indivíduos com mais de 75 anos (1). A FANV é um importante fator de risco para ocorrência de acidente vascular cerebral (AVC) isquêmico e está implicada em cerca de 15% de todos os casos. Diferentes diretrizes recomendam o uso de antocoagulante oral (ACO) em pacientes com FANV com o objetivo de reduzir o risco da ocorrência do AVC(3). Durante décadas, o antocoagulante oral mais amplamente empregado foi a varfarina. Evidências mostram que a anticoagulação com a varfarina, um antagonista da vitamina K, reduz o risco de AVC em até 64% quando comparada ao placebo. A redução absoluta de risco atribuivel à varfarina ressalta a efetividade da terapia de anticoagulação nestes pacientes, embora o risco ainda permaneneça elevado. No entanto, existem barreiras para a utilização da varfarina na prática clínica. Iniciar e manter o tratamento dos pa

Association of Type of Oral Anticoagulant Dispensed With Adverse Clinical Outcomes in Patients Extending Anticoagulation Therapy Beyond 90 Days After Hospitalization for Venous Thromboembolism.

Importance: Guidelines for managing venous thromboembolism (VTE) recommend at least 90 days of therapy with oral anticoagulants. Limited evidence exists about the optimal drug for continuing therapy beyond 90 days. Objective: To compare having prescriptions dispensed for apixaban, rivaroxaban, or warfarin after an initial 90 days of anticoagulation therapy for the outcomes of hospitalization for recurrent VTE, major bleeding, and death. Design, Setting, and Participants: This exploratory retrospective cohort study used data from fee-for-service Medicare (2009-2017) and from 2 commercial health insurance (2004-2018) databases and included 64 642 adults who initiated oral anticoagulation following hospitalization discharge for VTE and continued treatment beyond 90 days. Exposures: Apixaban, rivaroxaban, or warfarin prescribed after an initial 90-day treatment for VTE. Main Outcomes and Measures: Primary outcomes included hospitalization for recurrent VTE and hospitalization for major bleeding. Analyses were adjusted using propensity score weighting. Patients were followed up from the end of the initial 90-day treatment episode until treatment cessation, outcome, death, disenrollment, or end of available data. Weighted Cox proportional hazards models were used to estimate hazard ratios (HRs) and 95% CIs. Results: The study included 9167 patients prescribed apixaban (mean [SD] age, 71 [14] years; 5491 [59.9%] women), 12 468 patients prescribed rivaroxaban (mean [SD] age, 69 [14] years; 7067 [56.7%] women), and 43 007 patients prescribed warfarin (mean [SD] age, 70 [15] years; 25 404 [59.1%] women). The median (IQR) follow-up was 109 (59-228) days for recurrent VTE and 108 (58-226) days for major bleeding outcome. After propensity score weighting, the incidence rate of hospitalization for recurrent VTE was significantly lower for apixaban compared with warfarin (9.8 vs 13.5 per 1000 person-years; HR, 0.69 [95% CI, 0.49-0.99]), but the incidence rates were not significantly different between apixaban and rivaroxaban (9.8 vs 11.6 per 1000 person-years; HR, 0.80 [95% CI, 0.53-1.19]) or rivaroxaban and warfarin (HR, 0.87 [95% CI, 0.65-1.16]). Rates of hospitalization for major bleeding were 44.4 per 1000 person-years for apixaban, 50.0 per 1000 person-years for rivaroxaban, and 47.1 per 1000 person-years for warfarin, yielding HRs of 0.92 (95% CI, 0.78-1.09) for apixaban vs warfarin, 0.86 (95% CI, 0.71-1.04) for apixaban vs rivaroxaban, and 1.07 (95% CI, 0.93-1.24) for rivaroxaban vs warfarin. Conclusions and Relevance: In this exploratory analysis of patients prescribed extended-duration oral anticoagulation therapy after hospitalization for VTE, prescription dispenses for apixaban beyond 90 days, compared with warfarin beyond 90 days, were significantly associated with a modestly lower rate of hospitalization for recurrent VTE, but no significant difference in rate of hospitalization for major bleeding. There were no significant differences for comparisons of apixaban vs rivaroxaban or rivaroxaban vs warfarin.

Safety and Efficacy Evaluation of Antithrombotic Therapy with Rivaroxaban and Clopidogrel After PCI in Chinese Patients.

OBJECTIVE: To investigate the efficacy and safety of the antithrombotic therapy using the oral anticoagulant rivaroxaban and clopidogrel in Chinese patients with acute coronary syndrome complicated with atrial fibrillation after percutaneous coronary intervention. METHODS: A total of 100 patients were selected. Patients were randomly divided into two groups: the treatment group (rivaroxaban group) received a therapy of rivaroxaban and clopidogrel. The control group (warfarin group) receivied a combined treatment of warfarin, clopidogrel, and aspirin. The primary outcome endpoint was evaluated based on the adverse cardiac and cerebrovascular events within 12 months. RESULTS: A total of 8 (8.00%) main adverse cardiac and cerebrovascular events occurred during the 12 months of follow-up, including 5 (9.80%) in the warfarin group and 3 (6.10%) in the rivaroxaban group. The risk of having main adverse cardiac and cerebrovascular events in the two groups was comparable (P = 0.479). A total of 9 patients (9.00%) were found to have bleeding events, among which 8 patients (15.7%) were in the warfarin group, whereas only 1 patient (2.00%) was in the rivaroxaban group. Therefore, the risk of bleeding in the warfarin group was significantly higher than that in the rivaroxaban group (P = 0.047). CONCLUSIONS: In Chinese patients with acute coronary syndrome complicated with atrial fibrillation, the efficacy of the dual therapy of oral anticoagulant rivaroxaban plus clopidogrel after percutaneous coronary intervention was similar to that of the traditional triple therapy combined with warfarin, aspirin and clopidogrel, but it has a better safety property, which has potential to widely apply to antithrombotic therapy after PCI.

Evaluation of direct oral anticoagulant use on thromboelastography in an emergency department population.

BACKGROUND: Direct oral anticoagulant (DOAC) use presents a challenge to all providers involved in emergency care of patients since widely accepted laboratory tests to assess the level of anticoagulation for such medications are lacking. Viscoelastic tests such as thromboelastography (TEG) tests are increasingly used throughout major trauma centers to help guide resuscitation efforts in patients presenting with trauma and/or hemorrhagic shock. OBJECTIVE: The primary outcome compared TEG parameters between emergency department trauma patients reporting DOAC therapy and known normal TEG parameter values. The secondary outcome evaluated patients who reported time of last known DOAC dose within a preferred time frame of <12 h for once daily dosing DOAC therapy or < 6 h for twice daily dosing DOAC therapy. METHODS: This single-center, retrospective cohort study assessed TEG values in patients receiving DOAC therapy and compared these to institution TEG ranges considered normal. TEG values of reaction time (R time), kinetics (K), alpha angle (AA), maximum amplitude (MA), and percent lysis in 30 min (LY30) were collected for patients reporting DOAC therapy. RESULTS: 40 patients were included in this study. 19 patients reported apixaban therapy and 21 reported rivaroxaban therapy. 5 (12.5%) patients had an elevated R time and 1 (2.5%) patient had a reduced MA. All other TEG values did not suggest hypocoagulability. For the secondary outcome assessing patients reporting last known dose within the preferred time frame, only the R time was elevated in 2 (14.3%) patients. Lastly, in a subgroup analysis of patients with elevated low-molecular-weight heparin (LMWH) orAnti- Xa levels, the R time was the only parameter affected in 25% of patients. CONCLUSION: TEG values were typically not affected by rivaroxaban or apixaban use in an emergency department trauma population suggesting that TEG is not sensitive for Xa inhibitor detection and should not be relied upon for assessing anticoagulation in such settings.

Revascularisation for Symptomatic Peripheral Artery Disease: External Applicability of the VOYAGER PAD Trial.

OBJECTIVE: In the VOYAGER PAD trial, rivaroxaban 2.5 mg plus aspirin significantly reduced the primary composite efficacy outcome of acute limb ischaemia, major amputation, myocardial infarction, ischaemic stroke, or cardiovascular death compared with aspirin alone. However, patients enrolled in the trial may not reflect patients encountered in daily clinical practice. This study described the proportion of patients eligible for VOYAGER PAD within the nationwide Danish Vascular Registry (DVR), reasons for ineligibility, and outcomes according to eligibility. METHODS: In total, 32 911 patients who underwent lower extremity revascularisation for symptomatic peripheral arterial disease (PAD) in the DVR (2000-2016) were identified. Trial inclusion and exclusion criteria were applied, and the three year cumulative incidence of primary and secondary trial outcomes was estimated. RESULTS: Altogether, 27.1% of patients with PAD in the DVR were "VOYAGER eligible". Of those not included, 30.7% had at least one exclusion criterion ("VOYAGER excluded"), and an additional 42.3% did not fulfil the inclusion criteria ("VOYAGER not included"). The main reasons for exclusion were atrial fibrillation (32.3%), poorly regulated hypertension (20.6%), requirement for long term dual antiplatelet therapy (10.9%), cytochrome P450 inhibitors or inducers (9.7%), and renal failure (9.3%). The three year rate of the primary efficacy outcome was 10.08 per 100 person years among the "VOYAGER eligible", 16.32 among "VOYAGER excluded", and 6.98 among the "VOYAGER not included". For the primary safety outcome of thrombolysis in myocardial infarction (TIMI) major bleeding, rates were 2.24, 3.76, and 1.17, respectively. Rates of secondary endpoints were also consistently lower for patients who did not meet the inclusion criteria (predominantly due to central aorto-iliac procedures) and highest for "VOYAGER excluded" patients. "VOYAGER eligible" patients experienced a higher cumulative incidence of most endpoints than patients enrolled in the control arm of the VOYAGER PAD trial. CONCLUSION: Among patients in routine clinical practice, 27.1% were eligible for the VOYAGER PAD trial. These patients were older, had more severe vascular symptoms, higher bleeding risk, and worse prognosis than trial participants.

Rationale and Design of the H-REPLACE Study: Safety and Efficacy of LMWH Versus Rivaroxaban in ChinEse Patients HospitaLized with Acute Coronary SyndromE.

BACKGROUND: Acute coronary syndrome (ACS) is a serious and life-threatening condition. Anticoagulation during the acute phase of ACS is effective in reducing ischemic events. The most widely used parenteral anticoagulation agent in ACS patients is enoxaparin. Rivaroxaban is a novel oral anticoagulant with potent anti-Xa activity, which might be an attractive alternative drug to enoxaparin. In fact, rivaroxaban was consistently shown to be non-inferior to enoxaparin therapy in terms of reduction of recurrent venous thromboembolism events. OBJECTIVE: This prospective, randomized, open-label, active-controlled, multicenter study is designed to compare the safety and efficacy of rivaroxaban versus enoxaparin in patients with ACS, who missed the primary reperfusion therapy window and before selective revascularization. METHODS AND RESULTS: Up to 2055 participants receiving background treatment of aspirin plus clopidogrel or ticagrelor will be randomly assigned to either oral rivaroxaban 2.5 mg twice daily or rivaroxaban 5 mg twice daily or subcutaneous enoxaparin 1 mg/kg twice daily until hospital discharge for a maximum of 8 days or 12 h before revascularization therapy. The primary safety endpoint is the International Society on Thrombosis and Hemostasis definition of bleeding events [minor, clinically relevant non-major and major bleeding]. The primary efficacy endpoint is a composite of major adverse cardiac events (MACE), including cardiac death, myocardial infarction, re-revascularization or stroke, and major bleeding events. Secondary endpoints include cardiac-related rehospitalization and all-cause death. Patients will be followed for 12 months after randomization. CONCLUSIONS: The H-REPLACE trial offers an opportunity to assess clinical outcomes of rivaroxaban versus enoxaparin during the acute phase of ACS and may provide an alternative anticoagulation strategy for ACS patients, who missed the primary reperfusion therapy window and before selective revascularization. TRIAL REGISTRATION: ClinicalTrials.gov; NCT03363035.

Effect of Rivaroxaban and Clopidogrel Combination Therapy on In-Stent Responses After Everolimus-Eluting Stent Implantation in a Porcine Coronary Model.

AIM: According to recent clinical trials, a combination of direct oral anticoagulants with antiplatelet drugs is often recommended for atrial fibrillation patients who receive drug-eluting stents (DESs). Although the optimal combination comprises direct factor Xa inhibitors and a P2Y12 receptor antagonist (or aspirin), their influence on vascular responses to DESs remains unclear. METHODS: Pigs were given either aspirin and clopidogrel (dual antiplatelet therapy [DAPT] group), aspirin and rivaroxaban (AR group), or clopidogrel and rivaroxaban (CR group), followed by everolimus-eluting stent (Promus Element) implantation into the coronary artery. Stented coronary arteries were evaluated via intravascular optical coherence tomography (OCT) and histological analysis at 1 and 3 months. RESULTS: OCT revealed lower neointimal thickness in the DAPT group and comparable thickness among all groups at 1 and 3 months, respectively. Histological analyses revealed comparable neointimal area among all groups and the smallest neointimal area in the CR group at 1 and 3 months, respectively. In the DAPT and AR groups, the neointima continued to grow from 1 to 3 months. A shortened time course for neointima growth was observed in the CR group, with rapid growth within a month (maintained for 3 months). A higher incidence of in-stent thrombi was observed in the AR group at 1 month; no thrombi were found in either group at 3 months. More smooth muscle cells with contractile features were found in the CR group at both 1 and 3 months. CONCLUSIONS: Our results proved the noninferiority of the combination of rivaroxaban with an antiplatelet drug, particularly the dual therapy using rivaroxaban and clopidogrel, compared to DAPT after DES implantation.

Indirect antiplatelet effects of rivaroxaban in a patient with intracranial hemorrhage: An underappreciated coagulopathy of factor Xa inhibitors?

Rivaroxaban is a direct oral anticoagulant (DOAC) used for prophylaxis and treatment of many prothrombotic states. The anticoagulation effects of rivaroxaban are produced by selectively binding and inhibiting factor Xa, causing delayed thrombin generation. Additionally, the delay in thrombin generation produces an indirect, dose dependent antiplatelet effect via reduction in tissue factor platelet aggregation. As with any anticoagulant, rivaroxaban use increases a patient's risk for major and minor hemorrhagic events. With mortality rates reported as high as 25% for those who experience an intracranial hemorrhage (ICH), immediate mitigation of hematoma and hemorrhage volume expansion is imperative. Management strategies include utilizing prothrombin complex concentrates (PCC) and factor Xa inhibitor specific antidotes, such as coagulation factor Xa recombinant, inactivated-zhzo. Routine monitoring or management of DOAC induced antiplatelet effects is ill-defined and not a part of routine standard of care. We report the first case, to our knowledge, of rivaroxaban's indirect antiplatelet effects identified by platelet function assays and managed with four-factor PCC and desmopressin in a patient experiencing an ICH. Further exploration is needed to determine the true clinical impact attributed to rivaroxaban's antiplatelet effects.

Low-dose rivaroxaban and aspirin among patients with peripheral artery disease: a meta-analysis of the COMPASS and VOYAGER trials.

AIMS: Peripheral artery disease (PAD) patients suffer a high risk of major cardiovascular (CV) events, with athero-thrombo-embolism as the underlying pathophysiologic mechanism. Recently, two large randomized clinical trials evaluated the efficacy and safety of low-dose rivaroxaban twice daily plus aspirin in stable PAD outpatients and those immediately after peripheral revascularization. We sought to determine if the effects of low-dose rivaroxaban and aspirin compared to aspirin alone are consistent across this broad spectrum of PAD patients. METHODS AND RESULTS: We conducted a random-effects meta-analysis of the COMPASS and VOYAGER randomized trials among 11 560 PAD patients (4996 from COMPASS and 6564 from VOYAGER) in the primary analysis and 9332 (2768 from COMPASS and 6564 from VOYAGER) with lower extremity (LE)-PAD in the secondary analysis. The hazard ratio (HR) for the composite of CV death, myocardial infarction, ischaemic stroke, acute limb ischaemia, or major vascular amputation was 0.79 (95% confidence interval, CI: 0.65-0.95) comparing low-dose rivaroxaban plus aspirin to aspirin alone. While the risk of major bleeding was increased with low-dose rivaroxaban plus aspirin compared to aspirin alone [HR: 1.51 (95% CI: 1.22-1.87)], there was no significant increase in severe bleeding [HR: 1.18 (95% CI: 0.79-1.76)]. Similar effects were observed in the subset with symptomatic LE-PAD. CONCLUSIONS: Among PAD patients, low-dose rivaroxaban plus aspirin is superior to aspirin alone in reducing CV and limb outcomes including acute limb ischaemia and major vascular amputation. This reduction is offset by a relative increase in major bleeding, but not by an excess of fatal or critical organ bleeding. The consistency of findings of these trials supports the use of combination low-dose rivaroxaban plus aspirin in PAD patients across a broad spectrum of disease.

Standard- vs. low-dose rivaroxaban in patients with atrial fibrillation: a systematic review and meta-analysis.

PURPOSE: Low-dose rivaroxaban is often given to patients with atrial fibrillation (AF) around the world, but the rationale for its use remains unclear. We aimed to compare the efficacy and safety of standard- or low-dose rivaroxaban in patients with AF through systematic review of literature with meta-analysis. METHODS: We searched PubMed, Web of Science, EMBASE, Clinical Trials.gov, the Cochrane Library, and Bayer trial website from inception of each database until June 2020. Randomized controlled trials (RCTs) and cohort studies were included in the meta-analysis. A random-effects model was employed to calculate the pooled effect estimates. RESULTS: Two RCTs and 17 cohort studies were included in the qualitative analysis. Indirect comparison of RCTs showed no significant difference between the two rivaroxaban dosages in risk of efficacy or safety outcomes (p > 0.05). Indirect comparison of cohort studies showed a lower risk of MACE among Caucasians in standard-dose group (HR 0.779; 95% CI 0.687-0.884; p < 0.001). Bleeding outcomes did not differ significantly between the two dosage regimens in Asian or Caucasian populations, except that the standard dose was associated with higher risk of major bleeding among elderly Caucasian patients (HR 1.329; 95% CI 1.141-1.547; p < 0.001). The quality of evidence was rated ranging from very low to low for all the efficacy and safety outcomes. CONCLUSION: In Caucasians with AF, standard-dose rivaroxaban may prevent MACE significantly better than low-dose treatment. Further studies in Asians are needed to verify the advantages of the standard dose.

Using a low-molecular weight heparin-calibrated anti-factor Xa assay to assess the concentration of apixaban and rivaroxaban.

INTRODUCTION: Direct oral anticoagulant (DOAC)-inhibiting factor Xa (FXa-DOAC) are being increasingly used as prophylaxis of venous thromboembolism and for prevention of stroke in patients with atrial fibrillation. In contrast to vitamin K antagonists, DOACs do not require monitoring in general. However, it is sometimes of value in the acute setting, for instance when considering a reversal agent in uncontrolled bleeding in patients on DOAC. METHODS: We evaluated if a low-molecular weight heparin (LMWH)-calibrated anti-factor Xa assay could be used to estimate FXa-DOAC concentration in the concentration range <100 ng/mL by spiking known concentrations of FXa-DOAC and from those result calculate the FXa-DOAC concentration from the response of the LMWH assay. This procedure was then evaluated by comparing the result with a drug-calibrated chromogenic assay and liquid chromatography tandem mass spectrometry (LC-MS/MS) on clinical plasma samples from patients treated with apixaban or rivaroxaban. RESULTS: Although the measuring range was narrower for the LMWH-calibrated assay, concentrations recalculated from the LMWH assay was comparable with those measured by the drug-calibrated method when compared with LC-MS/MS. CONCLUSION: We suggest that an LMWH-calibrated anti-factor Xa assay can be used after characterization of the response of FXa-DOACs to give guidance on the concentration of apixaban and rivaroxaban. Shorter turnaround time than LC-MS/MS and the greater availability than drug-calibrated chromogenic assays could make this a valuable option in the acute setting.

Dosing Regimen Prediction and Confirmation With Rivaroxaban for Thromboprophylaxis in Children After the Fontan Procedure: Insights From the Phase III UNIVERSE Study.

Thrombosis remains an important complication for children with single-ventricle physiology following the Fontan procedure, and effective thromboprophylaxis is an important unmet medical need. To obviate conventional dose-finding studies and expedite clinical development, a rivaroxaban dose regimen for this indication was determined using a model-informed drug development approach. A physiologically based pharmacokinetic rivaroxaban model was used to predict a pediatric dosing regimen that would produce drug exposures similar to that of 10 mg once daily in adults. This regimen was used in an open-label, multicenter phase III study, which investigated the use of rivaroxaban for thromboprophylaxis in post-Fontan patients 2 to 8 years of age. The pharmacokinetics (PK) of rivaroxaban was assessed in part A (n = 12) and in part B (n = 64) of the UNIVERSE study. The safety and efficacy in the rivaroxaban group were compared to those in the acetylsalicylic acid group for 12 months. Pharmacodynamic end points were assessed in both parts of the study. Rivaroxaban exposures achieved in parts A and B were similar to the adult reference exposures. Prothrombin time also showed similarity to the adult reference. Exposure-response analysis did not identify a quantitative relationship between rivaroxaban exposures and efficacy/safety outcomes within the observed exposure ranges. A body weight-based dose regimen selected by physiologically based pharmacokinetic modeling was shown in the UNIVERSE study to be appropriate for thromboprophylaxis in the post-Fontan pediatric population. Model-based dose selection can support pediatric drug development and bridge adult dose data to pediatrics, thereby obviating the need for dose-finding studies in pediatric programs.

Influence of direct oral anticoagulants on thrombin generation on Ceveron TGA.

INTRODUCTION: Monitoring of direct oral anticoagulants (DOACs) with calibrated anti-Xa assay is limited by the high intra- and interindividual variations of the test results. Thrombin generation (TG) is a global hemostatic assay that reflects the patient´s individual coagulation status. The aim of this study was to investigate the influence of DOACs on TG measured with a fully automated assay system. METHODS: All consecutive patients under apixaban and rivaroxaban coming to the outpatient coagulation center MVZ Limbach, Magdeburg, Germany between October 2017 and April 2020 were included. DOAC plasma levels were correlated with TG assessed using the fully automated Ceveron TG analyzer. RESULTS: A total of 703 rivaroxaban and 252 apixaban containing plasma samples were included. There was a significant correlation between DOAC plasma levels and all TG parameters except for lag time regarding apixaban. Time to peak and peak thrombin followed an exponential regression curve, while this was linear for the endogenous thrombin potential (ETP). Apixaban showed a lower correlation coefficient for all TG parameters compared with rivaroxaban, and thrombin generation was less influenced by apixaban than rivaroxaban at plasma levels >100 ng/ml. The sensitivity and negative predictive value of normal TG parameters for the prediction of DOAC plasma levels <30 ng/ml was >85%. CONCLUSION: The present data show a moderate predominantly nonlinear correlation between TG parameters and plasma levels of apixaban and rivaroxaban. Rivaroxaban has a stronger effect on TG than apixaban.

Cancer-associated thrombosis - treatment and prevention with direct oral factor Xa inhibitors.

BACKGROUND: Venous thromboembolism (VTE) is a frequent cause of morbidity and mortality in patients with cancer. Moreover, management of VTE is frequently connected with complications, namely risk of recurrent VTE and bleeding. Low molecular weight heparins (LMWH) therapy administrated for 3-6 months is currently considered a standard for the treatment of cancer-associated VTE (CA-VTE). Direct oral factor Xa inhibitors (FXaI) apixaban, edoxaban and rivaroxaban have emerged as a new possibility for long-term antithrombotic therapy for VTE. These agents expose several advantages in individuals with cancer, and might overcome several disadvantages connected with LMWH therapy. PURPOSE: First clinical studies with oral FXaI for the treatment of CA-VTE with very promising results were recently published. The article summarizes current data regarding the use of oral FXaI in the treatment of CA-VTE.

Impact of different renal function equations on direct oral anticoagulant concentrations.

The purpose of this study is to investigate the correlation between glomerular filtration rate (GFR) estimated by different renal function equations and non-vitamin K antagonist oral anticoagulant concentration. Atrial fibrillation patients who aged ≥ 20 years and used dabigatran, rivaroxaban, or apixaban for thromboembolism prevention were enrolled to collect blood samples and measure drug concentrations using ultra-high-performance liquid chromatography with tandem mass spectrometry. The GFR was estimated using the Cockroft-Gault formula (abbreviated as creatinine clearance, CrCL), Chronic Kidney Disease Epidemiology Collaboration formula (CKD-EPI) featuring both creatinine and cystatin C, and the Modification of Diet in Renal Disease Study equation (MDRD). Multivariate regression was used to investigate the associations of different renal function estimates with drug concentrations. A total of 511 participants were enrolled, including 146 dabigatran users, 164 rivaroxaban users and 201 apixaban users. Compared to clinical trials, 35.4% of dabigatran, 4.9% of rivaroxaban, and 5.5% of apixaban concentrations were higher than the expected range (p < 0.001). CKD-EPI and MDRD estimates classified fewer patients as having GFR < 50 mL/min than CrCL in all 3 groups. Both CrCL and CKD-EPI were associated with higher-than-expected ranges of dabigatran or rivaroxaban concentrations. Nevertheless, none of the renal function equations was associated with higher-than-expected apixaban concentrations. For participants aged ≥ 75 years, CKD-EPI may be associated with higher-than-expected trough concentration of dabigatran. In conclusion, CrCL and CKD-EPI both can be used to identify patients with high trough concentrations of dabigatran or rivaroxaban. Among elderly patients who used dabigatran, CKD-EPI may be associated with increased drug concentration.

Exploratory Evaluation of Rhythm Control by Dronedarone in Combination With Low-Dose Rivaroxaban, Warfarin, Antiplatelet, or None of the Antithrombotic Therapy in High-Risk Patients With Non-Permanent Atrial Fibrillation: A Retrospective Cohort Study.

The emerging data supports rhythm control to prevent major adverse cardiac events (MACE) in high-risk patients with atrial fibrillation (AF). Limited data demonstrated rivaroxaban 10 mg combining dronedarone seemed feasible. This study aimed at investigating clinical events in a dronedarone-treated cohort. This exploratory, retrospective chart review was conducted in nonpermanent AF patients receiving dronedarone for ≥ 3 months between 2009/1 and 2016/2. In Taiwan, dronedarone's labeled indication was strict to age ≥ 70 or 65 to 70 years with either hypertension, diabetes, prior stroke, or left atrium >50 mm. We divided all into 4 groups using antithrombotic strategies to evaluate the safety, effectiveness, and MACE endpoints. A total of 689 patients (mean CHA2DS2-VASc score 3.8 ± 1.4) were analyzed: rivaroxaban 10 mg (n = 93, 13.5%), warfarin (n = 89, 12.9%), antiplatelet (n = 331, 48.0%), and none (n = 176, 25.5%). During the follow-up period (mean 946 ± 493.8 days), the rivaroxaban group did not report any stroke or thromboembolism (ishcmeic stroke rate: antiplatelet [0.6%], none [1.1%]; hemorrahgic stroke rate: warfarin [2.2%]; thromboembolism rate: warfarin [2.2%]). There was no significant difference in safety, effectiveness, and MACE endpoints between groups. Also, >104 weeks of dronedarone use was the independent predictor for MACE after adjusting the strategy and other covariates (hazard ratio 0.14 [95% confidence interval 0.04-0.44], P = .001). Our findings warrant concomitant rivaroxaban 10 mg and dronedarone for further investigation. Regardless of antithrombotic strategies, a more extended persistence of dronedarone was associated with fewer MACE.

Direct Acting Oral Anticoagulants Following Gastrointestinal Tract Surgery.

ABSTRACT: Direct-acting oral anticoagulants (DOACs) vary in bioavailability and sites of absorption in the gastrointestinal tract (GIT). Data on DOAC use after major GIT surgery are limited. The aim of this case series was to report the impact of surgical resection or bypass of the GIT on rivaroxaban and apixaban peak plasma concentrations. This was a case series of patients who received rivaroxaban or apixaban after GIT surgery, during the period of July 1, 2019, to December 31, 2020. Peak plasma concentrations of rivaroxaban and apixaban were assessed for the expected concentrations. Of the 27 assessed patients, 18 (66.7%) received rivaroxaban, and 9 (33.3%) received apixaban. After rivaroxaban therapy, 4 of 5 patients (80%) who underwent gastrectomy, and 3 of 3 patients (100%) who underwent duodenum and proximal jejunum exclusion had peak plasma concentrations of rivaroxaban lower than the effective range, whereas 11 of 11 patients (100%) who underwent distal bowel or ileostomy had peak rivaroxaban plasma within the effective range. After apixaban therapy, 5 of 6 patients (83.3%) who underwent total or partial gastrectomy achieved effective peak concentrations. All the patients who underwent proximal and distal bowel resection or bypass had peak concentrations of apixaban within the effective range. In conclusion, surgical resection or bypass of the upper GIT could affect DOAC absorption and subsequently peak plasma concentrations. This effect was more observed among rivaroxaban recipients. An injectable anticoagulant or vitamin K antagonist may be preferred if DOAC concentrations cannot be measured after GIT surgery.

Efficacy of Rivaroxaban Use in Solid Tumour Malignancy: Experience from a Tertiary Care Cancer Centre.

OBJECTIVE: Cancer-associated venous thromboembolism (CAT) is a common disease or complication which is associated with reduced survival and incurring a substantial health-care cost. Low molecular weight heparin (LMWH) remained the gold standard treatment option available. Direct oral anticoagulants (DOACs) have recently become more popular in the guidelines, they are still few and inconsistent across the current literature. The aim of this study was to evaluate rivaroxaban in treatment of CAT. METHODS: In this prospective real-world study, we recruited and followed up patients diagnosed with CAT treated with rivaroxaban or standard of care as a control for 12 months or until death. Baseline characteristics were collected at the study entry. The primary outcomes were recurrent DVT or PE and death within 12 months after treatment initiation. Safety outcomes were composite outcomes of major and minor bleeding.    Results: A total of 80 patients confirm CAT with radiological imaging were recruited; 39 patients were evaluated in the control arm and 41 patients in the rivaroxaban arm. The 12 months cumulative CAT recurrence rate was 46.2% in control and 39% in rivaroxaban (p=0.519). The 12-month death was not a statistically significant difference between both arms (20.5% vs. 31.7%, p=0.255). The cumulative rate of composite safety outcomes was similar in both groups (17.9% vs. 12.2%, p=0.471). CONCLUSION: The result of this small but important real-world evidence proofs that rivaroxaban is an effective and safe alternative to the standard of care for CAT in Malaysia's cancer population.