Rationale and design of the eXplore the efficacy and safety of once-daily oral riVaroxaban for the prEvention of caRdiovascular events in patients with nonvalvular aTrial fibrillation scheduled for cardioversion trial: A comparison of oral rivaroxaban once daily with dose-adjusted vitamin K antagonists in patients with nonvalvular atrial fibrillation undergoing elective cardioversion

Cardioversion of atrial fibrillation and atrial flutter revisited: current evidence and practical guidance for a common procedure

Cardioversion is widely used in patients with atrial fibrillation (AF) and atrial flutter when a rhythm control strategy is pursued. We sought to summarize the current evidence on this important area of clinical management of patients with AF including electrical and pharmacological cardioversion, peri-procedural anticoagulation and thromboembolic complications, success rate, and risk factors for recurrence to give practical guidance.

Non-Vitamin K Antagonist Oral Anticoagulants Provide Less Adverse Renal Outcomes Than Warfarin In Non-Valvular Atrial Fibrillation: A Systematic Review and MetaAnalysis

Background

Non‐vitamin K antagonist oral anticoagulants (NOACs) have better pharmacologic properties than warfarin and are recommended in preference to warfarin in most patients with non‐valvular atrial fibrillation. Besides lower bleeding complications, other advantages of NOACs over warfarin particularly renal outcomes remain inconclusive.

Methods and Results

Electronic searches were conducted through Medline, Scopus, Cochrane Library databases, and ClinicalTrial.gov. Randomized controlled trials and observational cohort studies reporting incidence rates and hazard ratio (HR) of renal outcomes (including acute kidney injury, worsening renal function, doubling serum creatinine, and end‐stage renal disease) were selected. The random‐effects model was used to calculate pooled incidence and HR with 95% CI. Eighteen studies were included. A total of 285 201 patients were enrolled, 118 863 patients with warfarin and 166 338 patients with NOACs. The NOACs group yielded lower incidence rates of all renal outcomes when compared with the warfarin group. Patients treated with NOACs showed significantly lower HR of risk of acute kidney injury (HR, 0.70, 95% CI, 0.64–0.76; P<0.001), worsening renal function (HR, 0.83; 95% CI, 0.73–0.95; P=0.006), doubling serum creatinine (HR, 0.58; 95% CI, 0.41–0.82; P=0.002), and end‐stage renal disease (HR, 0.82; 95% CI, 0.78–0.86; P<0.001).

Conclusions

In non‐valvular atrial fibrillation, patients treated with NOACs have a lower risk of both acute kidney injury and end‐stage renal disease when compared with warfarin.

[Efficacy and safety of new oral anticoagulants as part of triple antithrombotic therapy in patients with atrial fibrillation and acute coronary syndrome. Data from an observational study]

Aim To study efficacy and safety of a triple antithrombotic therapy with direct oral anticoagulants (DOAC) versus warfarin in patients with atrial fibrillation after acute coronary syndrome, for 12 months following discharge from the hospital.Materials and methods This single-site cohort, prospective, observational study performed at the Regional Vascular Center 2 of the N.A. Semashko Nizhniy Novgorod Regional Clinical Hospital included 402 patients. It was possible to maintain contacts with 206 patients for 12 months. These patients were divided into two groups, the DOAC treatment (n=105) and the warfarin treatment (n=101) as a part of triple antithrombotic therapy upon discharge. Clinical observation was performed at 1, 3, 6, and 12 months after the discharge by structured telephone interview. Predetermined efficacy endpoints included cardiovascular death, myocardial infarction, stent thrombosis, and ischemic stroke. Safety endpoints included bleeding defined as small, medium (clinically significant), and major in accordance with the TIMI classification.Results At 12 months of follow-up, 80 patients (76.19%) continued taking DOAC and 39 patients (38.61%, p&lt;0.001) continued taking warfarin; in this process, only 25 patients (24.75%) monitored their INR on a regular basis. With a regular INR monitoring and TTR &gt;70%, death rate did not differ in the warfarin and the DOAC treatment groups. However, there was a difference in reaching the composite efficacy endpoint (p=0.048): ischemic events occurred statistically significantly more frequently in the warfarin treatment group than in the DOAC treatment group.Conclusions In 12 months after discharge from the hospital, compliance with the DOAC treatment as a part of the antithrombotic therapy was significantly higher than compliance with the warfarin treatment. The triple antithrombotic therapy with DOAC was safer than the warfarin treatment by the number of hemorrhagic complications and more effective in prevention of ischemic events, primarily due to no need for monitoring of lab test values.

Simultaneous determination of Rivaroxaban and TAK-438 in rat plasma by LC-MS/MS: application to pharmacokinetic interaction study

Aim: A sensitive and reliable LC-MS/MS method has been established and validated to the quantitation of rivaroxaban (RIV) and TAK-438 in rat plasma using carbamazepine as internal standard. Results: The procedure of method validation was conducted according to the guidelines of EMA and US FDA. At the same time, the method was applied to pharmacokinetic interactions study between RIV and TAK-438 for the first time. When RIV and TAK-438 co-administration to rats, main pharmacokinetic parameters of TAK-438 like AUC_(0-t), AUC_(0-∞) and C_max had statistically significant increase. The main pharmacokinetic parameters of RIV have no statistically significant difference (p > 0.05) when co-administered except for t_1/2 (p < 0.01). Conclusion: The results indicated that drug-drug interactions occurred between RIV and TAK-438 when co-administered to rats.

Effects of Rivaroxaban on Biomarkers of Coagulation and Inflammation: A Post Hoc Analysis of the X-VeRT Trial

Introduction  This X-VeRT (eXplore the efficacy and safety of once-daily oral riVaroxaban for the prevention of caRdiovascular events in patients with nonvalvular aTrial fibrillation scheduled for cardioversion) substudy evaluated the effects of treatment with rivaroxaban or a vitamin-K antagonist (VKA) on levels of biomarkers of coagulation (D-dimer, thrombin–antithrombin III complex [TAT] and prothrombin fragment [F1.2]) and inflammation (high sensitivity C-reactive protein [hs-CRP] and high-sensitivity interleukin-6 [hs-IL-6]) in patients with atrial fibrillation (AF) who were scheduled for cardioversion and had not received adequate anticoagulation at baseline (defined as, in the 21 days before randomization: no oral anticoagulant; international normalized ratio <2.0 with VKA treatment; or <80% compliance with non-VKA oral anticoagulant treatment).

Methods  Samples for biomarker analysis were taken at baseline ( n  = 958) and treatment completion (42 days after cardioversion; n  = 918). The influence of clinical characteristics on baseline biomarker levels and the effect of treatment on changes in biomarker levels were evaluated using linear and logistic models.

Results  Baseline levels of some biomarkers were significantly associated with type of AF (D-dimer and hs-IL-6) and with history of congestive heart failure (hs-CRP, D-dimer, and hs-IL-6). Rivaroxaban and VKA treatments were associated with reductions from baseline in levels of D-dimer (−32.3 and −37.6%, respectively), TAT (−28.0 and −23.1%, respectively), hs-CRP (−12.5 and −17.9%, respectively), and hs-IL-6 (−9.2 and −9.8%, respectively). F1.2 levels were reduced from baseline in patients receiving a VKA (−53.0%) but not in those receiving rivaroxaban (2.7%).

Conclusion  Anticoagulation with rivaroxaban reduced levels of key inflammation and coagulation biomarkers to a similar extent as VKAs, with the exception of F1.2. Further investigation to confirm the value of these biomarkers in patients with AF is merited.

LC-MS/MS method for simultaneous determination of rivaroxaban and metformin in rat plasma: application to pharmacokinetic interaction study

Aim: A reliable, sensitive and simple LC-MS/MS method has been established and validated for the quantitation of rivaroxaban (RIV) and metformin (MET) in rat plasma. Results: The procedure of method validation was conducted according to the guiding principles of EMA and US FDA. At the same time, the method was applied to pharmacokinetic interactions study between RIV and MET for the first time. When RIV and MET coadministered to rats, pharmacokinetic parameters of MET like AUC_(0-t), AUC_(0-∞) and C_max had statistically significant increased. t_max of RIV was prolonged without affecting t_1/2 obviously and C_max was inhibited significantly (p < 0.05) by comparison to the single group. Conclusion: The results indicated that drug-drug interactions occurred when the coadministration of RIV and MET.

Oral anticoagulant use in cardiovascular disorders: a perspective on present and potential indications for rivaroxaban

BACKGROUND

Four non-vitamin-K-antagonist oral anticoagulants (NOACs) have been approved for use in various cardiovascular indications. The direct thrombin inhibitor dabigatran and the direct factor Xa inhibitors apixaban, edoxaban and rivaroxaban are now increasingly used in clinical practice. For some of these agents, available data from real-world studies support the efficacy and safety data in phase III clinical trials.

OBJECTIVES

This review aims to summarize the current status of trials and observational studies of oral anticoagulant use over the spectrum of cardiovascular disorders (excluding venous thrombosis), provide a reference source beyond stroke prevention for atrial fibrillation (AF) and examine the potential for novel applications in the cardiovascular field.

METHODS

We searched the recent literature for data on completed and upcoming trials of oral anticoagulants with a particular focus on rivaroxaban.

RESULTS

Recent data in specific patient subgroups, such as patients with AF undergoing catheter ablation or cardioversion, have led to an extended approval for rivaroxaban, whereas the other NOACs have ongoing or recently completed trials in this setting. However, there are unmet medical needs for several arterial thromboembolic-related conditions, including patients with: AF and acute coronary syndrome, AF and coronary artery disease undergoing elective percutaneous coronary intervention, coronary artery disease and peripheral artery disease, implanted cardiac devices, and embolic stroke of unknown source.

CONCLUSION

NOACs may provide alternative treatment options in areas of unmet need, and numerous studies are underway to assess their benefit-risk profiles in these settings.

Exploring unmet needs in venous and arterial thromboembolism with rivaroxaban

The vast clinical research programme for the direct, oral factor Xa inhibitor rivaroxaban has generated a wealth of data since the first rivaroxaban approval in 2008 for the prevention of venous thrombo embolism (VTE) in patients undergoing elective hip or knee replacement surgery. While rivaroxaban is widely used across a spectrum of seven indications, there is continuous commitment to investigating its wider benefits in new indications and attempts to refine current evidence. Key data from recently completed randomised controlled trials (RCTs) have shown that rivaroxaban is a feasible anticoagulation option for patients with non-valvular atrial fibrillation (NVAF) undergoing cardioversion or catheter ablation. Now, a number of Phase II and III RCTs are underway that seek to uncover further roles for rivaroxaban in patients at risk of thrombosis and aim to improve quality of life. This article will introduce and provide context for these RCTs in the contemporary management of arterial and venous thromboembolism in the following underserved areas: Patients with both NVAF and acute coronary syndrome (ACS) requiring percutaneous coronary intervention (PCI); patients with embolic stroke of undetermined source (ESUS); patients who require transcatheter aortic valve replacement (TAVR); patients with acute or chronic coronary artery disease (CAD; including those with heart failure [HF]); those at risk of or suffering from cancer-associated thrombosis (CAT) and those requiring long-term anticoagulation. It is hoped that this collection of studies provides clarity around the use of rivaroxaban as a fundamental component of antithrombotic therapy in an array of clinical situations.

Evolving cardiovascular uses of direct-acting oral anticoagulants: a paradigm shift on the horizon?

Direct-acting oral anticoagulants (DOACs), by virtue of pharmacological properties perceived as innovative, are changing the therapeutic scenario of patients requiring short- and long-term anticoagulation. The evidence gathered so far (from pre-approval pivotal trials to real-world post-marketing observational data) consistently confirms that DOACs are overall comparable to vitamin-K antagonists (VKAs) in terms of safety, efficacy, effectiveness and unequivocally documents a clinically relevant reduced risk of intracranial bleeding in the settings of non-valvular atrial fibrillation (AF) and venous thromboembolism. The following issues are attracting considerable clinical interest: (a) identifying specific subpopulations of patients with AF most likely to benefit from one of these agents (the so-called tailored therapy), and (b) expanding therapeutic indications in emerging diseases characterized by arterial and venous thromboembolic risk. In these scenarios, the risk-benefit profile of DOACs, as compared to VKAs or heparins, is still incompletely characterized. In cardiology, the challenging task of selecting a suitable or even the most appropriate DOAC for patients with AF and a particular phenotype prompted experts to provide suggestions based on careful review of subgroups of patients from pivotal RCTs. However, in the past few months, variegated multicenter trials have been published (RE-CIRCUIT, PIONEER-AF-PCI, GEMINI-ACS-1), with potential influence on clinical practice. Therefore, this review aims to update the latest evidence on the evolving therapeutic uses of DOACs in the cardiovascular area, addressing potential impact for clinicians.

Apixaban compared with parenteral heparin and/or vitamin K antagonist in patients with nonvalvular atrial fibrillation undergoing cardioversion: Rationale and design of the EMANATE trial

BACKGROUND

Stroke prevention in anticoagulation-naïve patients with atrial fibrillation undergoing cardioversion has not been systematically studied.

OBJECTIVE

To determine outcomes in anticoagulation-naïve patients (defined as those receiving an anticoagulant for <48 hours during the index episode of atrial fibrillation) scheduled for cardioversion.

METHODS

This is a randomized, prospective, open-label, real-world study comparing apixaban to heparin plus warfarin. Early image-guided cardioversion is encouraged. For apixaban, the usual dose is 5 mg BID with a dose reduction to 2.5 mg BID if 2 of the following are present: age >80 years, weight <60 kg, or serum creatinine >1.5 mg/dL. If cardioversion is immediate, a single starting dose of 10 mg (or 5 mg if the dose is down-titrated) of apixaban is administered. Cardioversion may be attempted up to 90 days after randomization. Patients are followed up for 30 days after cardioversion or 90 days postrandomization if cardioversion is not performed within that timeframe. Outcomes are stroke, systemic embolization, major bleeds, clinically relevant nonmajor bleeding, and death, all adjudication-blinded.

STATISTICS

The warfarin-naive cohort from the ARISTOTLE study was considered the closest data set to the patients being recruited into this study. The predicted incidence of stroke, systemic embolism, and major bleeding within 30 days after randomization was approximately 0.75%. To adequately power for a noninferiority trial, approximately 48,000 participants would be needed, a number in excess of feasibility. The figure of 1,500 patients was considered clinically meaningful and achievable.

CLINICAL CONTEXT

This first prospective cardioversion study of a novel anticoagulant in anticoagulation-naïve patients should influence clinical practice.

Patient-reported treatment satisfaction and budget impact with rivaroxaban vs. standard therapy in elective cardioversion of atrial fibrillation: a post hoc analysis of the X-VeRT trial

Aims

We compared patient-reported treatment satisfaction and the economic impact of anticoagulation therapy with rivaroxaban vs. vitamin K antagonists (VKAs) in patients with non-valvular atrial fibrillation undergoing elective cardioversion procedures.

Methods and results

The current study is a post hoc analysis of the prospective, multicentre X-VeRT (EXplore the efficacy and safety of once-daily oral riVaroxaban for the prevention of caRdiovascular events in subjects with non-valvular aTrial fibrillation scheduled for cardioversion) trial. Patient-reported treatment satisfaction with anticoagulation therapy was assessed using the Treatment Satisfaction Questionnaire for Medication version II in seven countries (US, UK, Canada, Germany, France, Italy, and the Netherlands). An economic model was also developed to estimate the impact of postponed cardioversions for two countries (UK and Italy). This model estimated the total costs of cardioversion, taking into consideration the costs for drug therapy (including extended treatment duration due to cardioversion postponement), international normalized ratio monitoring of VKAs, the cardioversion procedure, and rescheduling the procedure. These costs were linked to the respective X-VeRT study data to estimate the total costs. Patients receiving rivaroxaban in the delayed cardioversion group had significantly higher scores for Convenience, Effectiveness, and Global satisfaction (81.74 vs. 65.78; 39.41 vs. 32.95; and 82.07 vs. 66.74, respectively; P < 0.0001). Based on the total patient population included in the treatment satisfaction substudy (n = 632) in the delayed cardioversion group in X-VeRT, the use of rivaroxaban was estimated to result in a saving of £421 and €360 per patient in UK and Italian settings, respectively.

Conclusion

The use of rivaroxaban in the setting of cardioversion resulted in greater patient satisfaction and cost savings, compared with that of VKA.

Left Atrial Appendage Thrombosis During Therapy with Rivaroxaban in Elective Cardioversion for Permanent Atrial Fibrillation

Electric external cardioversion (EEC) for permanent atrial fibrillation (AF) carries a risk of thromboembolic events (TE). The use of transesophageal echocardiography (TEE) to guide the management of atrial fibrillation may be considered a clinically effective alternative strategy to conventional therapy for patients in whom elective cardioversion is planned. Therapeutic anticoagulation with novel oral anticoagulants (NOAC) is recommended for 3 to 4 weeks before and an anticoagulation life-long therapy is recommended after EEC to reduce TE, in patients with high CHA₂DS₂-VASc score; however, only few data are currently available about safety of short-term anticoagulation with NOAC in the setting of EEC. Patients with increased risk of thromboembolism have not been adequately studied and the monitoring of anticoagulant effects can also have important benefits in case of drug interactions. We report a case of a 68-year old man with AF from September 2014. Moderate depression of global left ventricular systolic function was detected by echocardiographic exam. On the basis of a high thromboembolic risk, an anticoagulant therapy with rivaroxaban, at the dose of 20 mg/day, was started. TEE showed a thrombus in the left atrial appendage. This case demonstrates the utility of performing TEE prior than EEC in patients with hypokinetic cardiomyopathy other than AF in therapy with NOAC. We underline the presence of significant pharmacodynamic interference of rivaroxaban with other drugs such as oxcarbazepine.

Rivaroxaban in atrial fibrillation cardioversion: insights from the X-VeRT trial

ABSTRACT  Vitamin K antagonists (VKAs) have traditionally been the standard of care for the thromboprophylactic anticoagulation of patients with nonvalvular atrial fibrillation (NVAF) undergoing cardioversion. X-VeRT was the first prospective trial to explore the safety and efficacy of one of the non-VKA oral anticoagulants, rivaroxaban, compared with dose-adjusted VKA as thromboprophylaxis in patients with NVAF scheduled to undergo cardioversion. The protocol allowed either early (1-5 days) or delayed (3-8 weeks) cardioversion to be performed. Rivaroxaban use (20 mg once daily or 15 mg if creatinine clearance was 30-49 ml/min) was associated with a similar incidence of adverse cardiovascular events and bleeding as VKA use; however, rivaroxaban significantly reduced the time to cardioversion in those undergoing delayed cardioversion. Thus, rivaroxaban is a safe alternative to VKAs for thromboprophylaxis in patients with NVAF undergoing elective cardioversion.

Non-vitamin K oral anticoagulants in atrial fibrillation: Where are we now?

Atrial fibrillation (AF) confers increased risk of stroke and other thromboembolic events, and oral anticoagulation therefore is the essential part of AF management to reduce the risk of these complications. Until recently, the vitamin K antagonists (VKAs, e.g., warfarin) were the only oral anticoagulants available, acting by decreased synthesis of vitamin K-dependent coagulation factors (II, VI, IX, and X). The VKAs had many limitations: delayed onset and prolonged offset of action, variability of anticoagulant effect among patients, multiple food and drug interactions affecting pharmacological properties of warfarin, narrow therapeutic window, and obligatory regular laboratory control, which all made warfarin "inconvenient" both for patients and clinicians. The limitations of VKAs led to development of a new class of drugs collectively defined as non-VKA oral anticoagulants (NOACs), which included direct thrombin inhibitors (dabigatran) and factor Xa inhibitors (rivaroxaban, apixaban, and edoxaban). The NOACs avoid many of the VKA drawbacks. In this review, we will focus on the current evidence justifying the use of NOACs in non-valvular AF.

[Novel oral anticoagulants in patients with atrial fibrillation, how to avoid accidents?]

Know the indications of these new drugs, and respect them. Do not confuse easiness of administration and absence of precautions. Renal function: a key parameter before and during treatment. Know when to use a low-dose drug regimen. Cardioversion: lack of safety evidence for some drugs. Drug interactions: beware of P-glycoprotein and cytochrome P450.