Stroke prevention with rivaroxaban in higher-risk populations with atrial fibrillation

BACKGROUND

Atrial fibrillation (AF), the most common cardiac arrhythmia, is a major risk factor for stroke. Rivaroxaban, an oral factor Xa inhibitor, is approved for the prevention of stroke in patients with non-valvular AF. In the pivotal phase III trial ROCKET AF, rivaroxaban demonstrated non-inferiority compared with warfarin for reducing the risk of stroke or systemic embolism (SE) in patients with AF (intention-to-treat analysis), without an increased risk of major bleeding. Superior efficacy vs. warfarin was achieved while patients were on study medication. Other direct oral factor Xa inhibitors have completed phase III clinical trials in this indication. Compared with warfarin, apixaban (in the ARISTOTLE trial) and edoxaban (in the ENGAGE-AF trial) were shown to be superior or non-inferior, respectively, for reduction in stroke or SE risk in patients with AF. Baseline stroke risk, as indicated by CHADS2 scores, was lower in patients in the ARISTOTLE and ENGAGE-AF trials than in ROCKET AF.

OBJECTIVES

This review discusses the main findings from ROCKET AF, specifically examining recent subgroup analyses investigating rivaroxaban use across various patient types at high risk for adverse outcomes, including those with prior stroke or transient ischaemic attack, reduced renal function, prior myocardial infarction, peripheral artery disease, heart failure or patients aged ≥ 75 years and those resident in East Asia.

CONCLUSIONS

These subgroup analyses demonstrate that the treatment effect for rivaroxaban vs. warfarin is broadly consistent across a wide range of patient groups, with respect to both efficacy and safety.

Non-vitamin K antagonist oral anticoagulants and atrial fibrillation guidelines in practice: barriers to and strategies for optimal implementation

Stroke is a leading cause of morbidity and mortality worldwide. Atrial fibrillation (AF) is an independent risk factor for stroke, increasing the risk five-fold. Strokes in patients with AF are more likely than other embolic strokes to be fatal or cause severe disability and are associated with higher healthcare costs, but they are also preventable. Current guidelines recommend that all patients with AF who are at risk of stroke should receive anticoagulation. However, despite this guidance, registry data indicate that anticoagulation is still widely underused. With a focus on the 2012 update of the European Society of Cardiology (ESC) guidelines for the management of AF, the Action for Stroke Prevention alliance writing group have identified key reasons for the suboptimal implementation of the guidelines at a global, regional, and local level, with an emphasis on access restrictions to guideline-recommended therapies. Following identification of these barriers, the group has developed an expert consensus on strategies to augment the implementation of current guidelines, including practical, educational, and access-related measures. The potential impact of healthcare quality measures for stroke prevention on guideline implementation is also explored. By providing practical guidance on how to improve implementation of the ESC guidelines, or region-specific modifications of these guidelines, the aim is to reduce the potentially devastating impact that stroke can have on patients, their families and their carers.

Anticoagulation in Heart Failure: a Review

Heart failure (HF) with reduced left ventricular function inflicts a large and growing burden of morbidity and mortality in the US and across the globe. One source of this burden is stroke. While it appears that HF itself may impose some risk of stroke, it is in the presence of other risk factors, like atrial fibrillation, that the greatest risks are observed. Therapeutic anticoagulation is the mainstay of risk reduction strategies in this population. While warfarin was the only available therapy for anticoagulation for many decades, there are now four direct oral anticoagulants available. In three of these four, outcomes in the specific subgroup of patients with heart failure have been examined. In this review, we provide some pathophysiologic basis for the risk of stroke in heart failure. In addition, the available therapeutic options for stroke risk prevention in heart failure are described in detail including how these options are incorporated into relevant professional society guidelines.

Population pharmacokinetics of edoxaban and its main metabolite in a dedicated renal impairment study

A model characterizing the population pharmacokinetics (PK) of edoxaban and its major metabolite, M4, following a single oral dose of 15 mg administered to subjects with varying kidney function was developed. Thirty-two subjects contributed with edoxaban plasma, edoxaban urine, and M4 plasma concentrations. Edoxaban urine concentrations allowed estimation of renal clearance, and high contribution of renal to total clearance enabled estimation of absolute oral bioavailability. A 2-compartment model with delayed absorption and elimination parameterized as renal clearance linearly related to creatinine clearance (CLcr ) and nonrenal clearance forming M4 described edoxaban PK. The PK of M4 was described with a 1-compartment model. For a typical subject (70 kg; CLcr , 100 mL/min) bioavailability, clearance, and central and peripheral volume of distribution for edoxaban was estimated to 72.3%, 21.0 L/h, 95.4 L, and 54.3 L, respectively. For both edoxaban and M4, the model predicted systemic exposure to increase 57.0%, 35.0%, and 11.6% in a subject having CLcr of 30, 50, and 80 mL/min, respectively, compared with a subject having a CLcr of 100 mL/min. Concentration ratios (M4 over edoxaban) were predicted to vary with time after dose, but with minor influence of kidney function and body weight. Results were in agreement with previous analyses.

Cortical superficial siderosis: detection and clinical significance in cerebral amyloid angiopathy and related conditions

Cortical superficial siderosis describes a distinct pattern of blood-breakdown product deposition limited to cortical sulci over the convexities of the cerebral hemispheres, sparing the brainstem, cerebellum and spinal cord. Although cortical superficial siderosis has many possible causes, it is emerging as a key feature of cerebral amyloid angiopathy, a common and important age-related cerebral small vessel disorder leading to intracerebral haemorrhage and dementia. In cerebral amyloid angiopathy cohorts, cortical superficial siderosis is associated with characteristic clinical symptoms, including transient focal neurological episodes; preliminary data also suggest an association with a high risk of future intracerebral haemorrhage, with potential implications for antithrombotic treatment decisions. Thus, cortical superficial siderosis is of relevance to neurologists working in neurovascular, memory and epilepsy clinics, and neurovascular emergency services, emphasizing the need for appropriate blood-sensitive magnetic resonance sequences to be routinely acquired in these clinical settings. In this review we focus on recent developments in neuroimaging and detection, aetiology, prevalence, pathophysiology and clinical significance of cortical superficial siderosis, with a particular emphasis on cerebral amyloid angiopathy. We also highlight important areas for future investigation and propose standards for evaluating cortical superficial siderosis in research studies.

Dosing of Target-Specific Oral Anticoagulants in Special Populations

OBJECTIVE

To review current literature for target-specific oral anticoagulants (TSOACs) and provide critical analysis for dosing recommendations in special population groups.

DATA SOURCES

A literature search was conducted in Medline (1996 to April week 2 2015) and Embase (1980 to 2015 week 16) using key terms dabigatran, rivaroxaban, apixaban, edoxaban, kidney diseases, liver diseases, elderly, obesity, and special populations.

STUDY SELECTION AND DATA EXTRACTION

Randomized controlled trials in English assessing efficacy and safety of TSOACs in healthy adults and special populations were selected for analysis.

DATA SYNTHESIS

Phase 3 trials for TSOACs predominately excluded patients with severe renal impairment or active liver disease. There were no exclusion criteria based on age, body weight or body mass index. Additional conclusions were made in special populations, including those with renal or liver impairment and obese and elderly patients, based on secondary analyses, pharmacokinetic, and pharmacodynamic studies.

CONCLUSIONS

Pharmacokinetic and pharmacodynamic changes associated special populations may alter clinical decision with regard to drug selection and dosing. It is valuable to understand the rationale for labeled dosing recommendations in nonvalvular atrial fibrillation and venous thromboembolism treatment and prevention, particularly in patients that fall into special population groups. Furthermore, the use of TSOACs is likely to increase as clinicians gain experience with these agents and additional TSOACs and indications are approved.

Edoxaban: an update on the new oral direct factor Xa inhibitor

Edoxaban is a once-daily oral anticoagulant that rapidly and selectively inhibits factor Xa in a concentration-dependent manner. This review describes the extensive clinical development program of edoxaban, including phase III studies in patients with non-valvular atrial fibrillation (NVAF) and symptomatic venous thromboembolism (VTE). The ENGAGE AF-TIMI 48 study (N = 21,105; mean CHADS₂ score 2.8) compared edoxaban 60 mg once daily (high-dose regimen) and edoxaban 30 mg once daily (low-dose regimen) with dose-adjusted warfarin [international normalized ratio (INR) 2.0–3.0] and found that both regimens were non-inferior to warfarin in the prevention of stroke and systemic embolism in patients with NVAF. Both edoxaban regimens also provided significant reductions in the risk of hemorrhagic stroke, cardiovascular mortality, major bleeding and intracranial bleeding. The Hokusai-VTE study (N = 8,292) in patients with symptomatic VTE had a flexible treatment duration of 3–12 months and found that following initial heparin, edoxaban 60 mg once daily was non-inferior to dose-adjusted warfarin (INR 2.0–3.0) for the prevention of recurrent VTE, and also had a significantly lower risk of bleeding events. Both studies randomized patients at moderate-to-high risk of thromboembolic events and were further designed to simulate routine clinical practice as much as possible, with edoxaban dose reduction (halving dose) at randomisation or during the study if required, a frequently monitored and well-controlled warfarin group, a well-monitored transition period at study end and a flexible treatment duration in Hokusai-VTE. Given the phase III results obtained, once-daily edoxaban may soon be a key addition to the range of antithrombotic treatment options.

Innovative designs of point-of-care comparative effectiveness trials

One of the provisions of the health care reform legislation in 2010 was for funding pragmatic clinical trials or large observational studies for comparing the effectiveness of different approved medical treatments, involving broadly representative patient populations. After reviewing pragmatic clinical trials and the issues and challenges that have made them just a small fraction of comparative effectiveness research (CER), we focus on a recent development that uses point-of-care (POC) clinical trials to address the issue of "knowledge-action gap" in pragmatic CER trials. We give illustrative examples of POC-CER trials and describe a trial that we are currently planning to compare the effectiveness of newly approved oral anticoagulants. We also develop novel stage-wise designs of information-rich POC-CER trials under competitive budget constraints, by using recent advances in adaptive designs and other statistical methodologies.

Non-Traumatic Spontaneous Spinal Subdural Hematoma in a Patient with Non-Valvular Atrial Fibrillation During Treatment with Rivaroxaban

Patient: Male, 69

Final Diagnosis: Spontaneous spinal subdural hematoma

Symptoms: Paraplegia

Medication: Rivaroxaban

Clinical Procedure: —

Specialty: General Internal Medicine • Hospital Medicine • Cardiology • Hematology • Neurology

External validity of the ARISTOTLE trial in real-life atrial fibrillation patients

OBJECTIVE

Our primary objective was to determine the proportion of patients with atrial fibrillation (AF) eligible for enrollment in a randomized controlled trial for a novel oral anticoagulant, the ARISTOTLE trial. A secondary objective was to describe the reasons for trial ineligibility.

METHODS

We performed a cross-sectional study of an unselected population including 2274 patients in Skellefteå, Sweden with at least one verified episode of AF on or before December 31, 2010. Patients were classified as suitable or unsuitable for anticoagulant treatment according to current guidelines. The enrollment criteria from the ARISTOTLE trial were extracted from the original publication and applied to the population.

RESULTS

Among all patients with AF, 1579 were classified as suitable for anticoagulant treatment. Of these, only 658 patients (42%) were eligible for participation in the ARISTOTLE trial. Among the 921 patients ineligible for participation, 498 did not meet the ECG criteria, 272 had psychosocial problems, and in addition, 78 patients were excluded due to both of these criteria.

CONCLUSION

Our study shows that a majority of the patients in an unselected population with AF suitable for anticoagulant treatment were ineligible for participation in the ARISTOTLE trial. The applicability of the ARISTOTLE trial is therefore unknown for a considerable proportion of patients with AF in real life.

New-onset atrial fibrillation after recent coronary stenting: Warfarin or non-vitamin K-antagonist oral anticoagulants to be added to aspirin and clopidogrel? A viewpoint

The antithrombotic management of patients on oral anticoagulation (OAC), with either warfarin or non-vitamin K-antagonist oral anticoagulants (NOACs), undergoing percutaneous coronary intervention with stent (PCI-S) has been recently addressed in a joint European consensus document. In accordance, triple therapy (TT) of OAC, aspirin and clopidogrel should generally be given as the initial therapy. More uncertainty exists over whether warfarin or a NOAC should be added in patients already on dual antiplatelet therapy of aspirin and clopidogrel (DAPT) after recent PCI-S. Upon review of available data, it appears that the risk of major bleeding of TT as compared to DAPT is similar with either warfarin or a NOAC. In particular, TT consistently appears associated to an approximately 2.5 fold increase in the risk of major bleeding. Because of the higher convenience, NOACs might be considered the preferred OAC to be added to DAPT. Given the reported different safety profiles of the various NOACs on the incidence of major, and gastrointestinal, bleeding, the NOACs, and the dose, showing the greatest safety in this regard should be selected. In accordance, dabigatran 110 mg and apixaban 2.5mg twice daily appear as the most valuable options in patients who are not and who are respectively, at increased risk of bleeding. As an alternative, apixaban 5mg twice daily might be considered in patients at risk of bleeding not increased, whereas rivaroxaban 15 mg once daily may be considered in the presence of increased risk of bleeding (essentially when related to moderate renal impairment).

Edoxaban versus placebo, aspirin, or aspirin plus clopidogrel for stroke prevention in atrial fibrillation. An indirect comparison analysis

As non-valvular atrial fibrillation (AF) brings a risk of stroke, oral anticoagulants (OAC) are recommended. In 'real world' clinical practice, many patients (who may be, or perceived to be, intolerant of OACs) are either untreated or are treated with anti-platelet agents. We hypothesised that edoxaban has a better net clinical benefit (NCB, balancing the reduction in stroke risk vs increased risk of haemorrhage) than no treatment or anti-platelet agents. We performed a network meta-analysis of published data from 24 studies of 203,394 AF patients to indirectly compare edoxaban with aspirin alone, aspirin plus clopidogrel, and placebo. Edoxaban 30 mg once daily significantly reduced the risk of all stroke, ischaemic stroke and mortality compared to placebo and aspirin. Compared to aspirin plus clopidogrel, there was a lower risk of intra-cranial haemorrhage (ICH). Edoxaban 60 mg once-daily had a reduced risk of any stroke and systemic embolism compared to placebo, aspirin, and aspirin plus clopidogrel. Mortality rates for both edoxaban doses were estimated to be lower compared to any anti-platelet, and significantly lower compared to placebo. With overall reduced risk of ischemic stroke and ICH, both edoxaban doses bring a NCB of mean (SD) 1.68 (0.15) saved events per 100 patients per year compared to anti-platelet drugs in a clinical trial population. The NCB was demonstrated to be lower, at 0.77 (0.12) events saved (p< 0.01) when modeled to data from a 'real world' cohort of AF patients. In conclusion, edoxaban is likely to provide even better protection from stroke and ICH than placebo, aspirin alone, or aspirin plus clopidogrel in both clinical trial populations and unselected community populations. Both edoxaban doses would also bring a positive NCB compared to anti-platelet drugs or placebo/non-treatment based on 'real world' data.

Epidemiology, diagnosis, and management of atrial fibrillation in women

Atrial fibrillation (AF) is the most common arrhythmia and has become a serious public health problem. Moreover, epidemiological data demonstrate that incidence and prevalence of AF are increasing. Several differences in epidemiological patterns, clinical manifestations, and incidence of stroke have been reported between AF in women and in men, particularly in elderly women. Elderly women have higher blood pressure than men and a higher prevalence of heart failure with preserved ejection fraction, both independent risk factors for stroke. On the basis of the evidence on the higher stroke risk among AF in women, recently, female sex has been accepted as a risk factor for stroke and adopted to stratify patients, especially if they are not at high risk for stroke. This review focuses on available evidence on sex differences in AF patients, and examines factors contributing to different stroke risk, diagnosis, and prognosis of arrhythmia in women, with the aim to provide an analysis of the available evidence.

Direct oral anticoagulants: key considerations for use to prevent stroke in patients with nonvalvular atrial fibrillation

Atrial fibrillation (AF) is the most common cardiac arrhythmia worldwide. Strokes that occur as a complication of AF are usually more severe and associated with a higher disability or morbidity and mortality rate compared with non-AF-related strokes. The risk of stroke in AF is dependent on several risk factors; AF itself acts as an independent risk factor for stroke. The combination of effective anticoagulation therapy, risk stratification (based on stroke risk scores, such as CHADS₂ and CHA₂DS₂-VASc), and recommendations provided by guidelines is essential for decreasing the risk of stroke in patients with AF. Although effective in preventing the occurrence of stroke, vitamin K antagonists (VKAs; eg, warfarin) are associated with several limitations. Therefore, direct oral anticoagulants, such as apixaban, dabigatran etexilate, edoxaban, and rivaroxaban, have emerged as an alternative to the VKAs for stroke prevention in patients with nonvalvular AF. Compared with the VKAs, these agents have more favorable pharmacological characteristics and, unlike the VKAs, they are given at fixed doses without the need for routine coagulation monitoring. It remains important that physicians use these direct oral anticoagulants responsibly to ensure optimal safety and effectiveness. This article provides an overview of the existing data on the direct oral anticoagulants, focusing on management protocols for aiding physicians to optimize anticoagulant therapy in patients with nonvalvular AF, particularly in special patient populations (eg, those with renal impairment) and other specific clinical situations.

Association between edoxaban dose, concentration, anti-Factor Xa activity, and outcomes: an analysis of data from the randomised, double-blind ENGAGE AF-TIMI 48 trial

BACKGROUND

New oral anticoagulants for stroke prevention in atrial fibrillation were developed to be given in fixed doses without the need for the routine monitoring that has hindered usage and acceptance of vitamin K antagonists. A concern has emerged, however, that measurement of drug concentration or anticoagulant activity might be needed to prevent excess drug concentrations, which significantly increase bleeding risk. In the ENGAGE AF-TIMI 48 trial, higher-dose and lower-dose edoxaban were compared with warfarin in patients with atrial fibrillation. Each regimen incorporated a 50% dose reduction in patients with clinical features known to increase edoxaban drug exposure. We aim to assess whether adjustment of edoxaban dose in this trial prevented excess drug concentration and the risk of bleeding events.

METHODS

We analysed data from the randomised, double-blind ENGAGE AF-TIMI 48 trial. We correlated edoxaban dose, plasma concentration, and anti-Factor Xa (FXa) activity and compared efficacy and safety outcomes with warfarin stratified by dose reduction status. Patients with atrial fibrillation and at moderate to high risk of stroke were randomly assigned in a 1:1:1 ratio to receive warfarin, dose adjusted to an international normalised ratio of 2·0-3·0, higher-dose edoxaban (60 mg once daily), or lower-dose edoxaban (30 mg once daily). Randomisation was done with use of a central, 24 h, interactive, computerised response system. International normalised ratio was measured using an encrypted point-of-care device. To maintain masking, sham international normalised ratio values were generated for patients assigned to edoxaban. Edoxaban (or placebo-edoxaban in warfarin group) doses were halved at randomisation or during the trial if patients had creatinine clearance 30-50 mL/min, bodyweight 60 kg or less, or concomitant medication with potent P-glycoprotein interaction. Efficacy outcomes included the primary endpoint of all-cause stroke or systemic embolism, ischaemic stroke, and all-cause mortality. Safety outcomes included the primary safety endpoint of major bleeding, fatal bleeding, intracranial haemorrhage, and gastrointestinal bleeding. This trial is registered with ClinicalTrials.gov, number NCT00781391.

FINDINGS

Between Nov 19, 2008 and Nov 22, 2010, 21 105 patients were recruited. Patients who met clinical criteria for dose reduction at randomisation (n=5356) had higher rates of stroke, bleeding, and death compared with those who did not have a dose reduction (n=15 749). Edoxaban dose ranged from 15 mg to 60 mg, resulting in a two-fold to three fold gradient of mean trough drug exposure (16·0-48·5 ng/mL in 6780 patients with data available) and mean trough anti-FXa activity (0·35-0·85 IU/mL in 2865 patients). Dose reduction decreased mean exposure by 29% (from 48·5 ng/mL [SD 45·8] to 34·6 ng/mL [30·9]) and 35% (from 24·5 ng/mL [22·7] to 16·0 ng/mL [14·5]) and mean anti-FXa activity by 25% (from 0·85 IU/mL [0·76] to 0·64 IU/mL [0·54]) and 20% (from 0·44 IU/mL [0·37] to 0·35 IU/mL [0·28]) in the higher-dose and lower-dose regimens, respectively. Despite the lower anti-FXa activity, dose reduction preserved the efficacy of edoxaban compared with warfarin (stroke or systemic embolic event: higher dose pinteraction=0·85, lower dose pinteraction=0·99) and provided even greater safety (major bleeding: higher dose pinteraction 0·02, lower dose pinteraction=0·002).

INTERPRETATION

These findings validate the strategy that tailoring of the dose of edoxaban on the basis of clinical factors alone achieves the dual goal of preventing excess drug concentrations and helps to optimise an individual patient's risk of ischaemic and bleeding events and show that the therapeutic window for edoxaban is narrower for major bleeding than thromboembolism.

FUNDING

Daiichi-Sankyo Pharma Development.

Genetics and the clinical response to warfarin and edoxaban: findings from the randomised, double-blind ENGAGE AF-TIMI 48 trial

BACKGROUND

Warfarin is the most widely used oral anticoagulant worldwide, but serious bleeding complications are common. We tested whether genetic variants can identify patients who are at increased risk of bleeding with warfarin and, consequently, those who would derive a greater safety benefit with a direct oral anticoagulant rather than warfarin.

METHODS

ENGAGE AF-TIMI 48 was a randomised, double-blind trial in which patients with atrial fibrillation were assigned to warfarin to achieve a target international normalised ratio of 2·0-3·0, or to higher-dose (60 mg) or lower-dose (30 mg) edoxaban once daily. A subgroup of patients was included in a prespecified genetic analysis and genotyped for variants in CYP2C9 and VKORC1. The results were used to create three genotype functional bins (normal, sensitive, and highly sensitive responders to warfarin). This trial is registered with ClinicalTrials.gov, number NCT00781391.

FINDINGS

14,348 patients were included in the genetic analysis. Of 4833 taking warfarin, 2982 (61·7%) were classified as normal responders, 1711 (35·4%) as sensitive responders, and 140 (2·9%) as highly sensitive responders. Compared with normal responders, sensitive and highly sensitive responders spent greater proportions of time over-anticoagulated in the first 90 days of treatment (median 2·2%, IQR 0-20·2; 8·4%, 0-25·8; and 18·3%, 0-32·6; ptrend<0·0001) and had increased risks of bleeding with warfarin (sensitive responders hazard ratio 1·31, 95% CI 1·05-1·64, p=0·0179; highly sensitive responders 2·66, 1·69-4·19, p<0·0001). Genotype added independent information beyond clinical risk scoring. During the first 90 days, when compared with warfarin, treatment with edoxaban reduced bleeding more so in sensitive and highly sensitive responders than in normal responders (higher-dose edoxaban pinteraction=0·0066; lower-dose edoxaban pinteraction=0·0036). After 90 days, the reduction in bleeding risk with edoxaban versus warfarin was similarly beneficial across genotypes.

INTERPRETATION

CYP2C9 and VKORC1 genotypes identify patients who are more likely to experience early bleeding with warfarin and who derive a greater early safety benefit from edoxaban compared with warfarin.

FUNDING

Daiichi Sankyo.

Predictors of gastrointestinal bleeding among patients with atrial fibrillation after initiating dabigatran therapy

STUDY OBJECTIVES

To identify demographic and clinical risk factors associated with gastrointestinal (GI) bleeding among a large cohort of patients with atrial fibrillation (AF) who initiated dabigatran therapy for stroke prevention, and to describe patterns of subsequent anticoagulant use after occurrence of the GI bleeding event.

DESIGN

Retrospective cohort study.

DATA SOURCES

Large, nationwide United States commercial insurance database.

PATIENTS

A total of 21,033 patients with nonvalvular AF who initiated dabigatran between October 19, 2010, and December 31, 2012.

MEASUREMENTS AND MAIN RESULTS

We used multivariate Cox regression analysis to estimate the effect of baseline demographic and clinical characteristics on the probability of a GI bleeding event. Patterns of anticoagulation use after GI bleeding were also examined descriptively. Of the 21,033 patients receiving dabigatran, 446 (2.1%) experienced a GI bleed during follow-up. GI bleeding rates differed across many baseline characteristics. Male sex was associated with a lower risk (adjusted hazard ratio [aHR] 0.78, 95% confidence interval [CI] 0.64-0.95) of GI bleeding. Compared with patients younger than 55 years, those aged 55-64, 65-74, and 75 years or older yielded aHRs of 1.54 (95% CI 0.89-2.68), 2.72 (95% CI 1.59-4.65), and 4.52 (95% CI 2.68-7.64), respectively. Renal impairment (aHR 1.67, 95% CI 1.24-2.25), heart failure (aHR 1.25, 95% CI 1.01-1.56), alcohol abuse (aHR 2.57, 95%CI 1.52-4.35), previous Helicobacter pylori infection (aHR 4.75, 95% CI 1.93-11.68), antiplatelet therapy (aHR 1.49, 95% CI 1.19-1.88), and digoxin use (aHR 1.49, 95% CI 1.19-1.88) were also associated with an increased GI bleeding risk. Of the 446 patients who experienced a GI bleed, 193 (43.3%) restarted an anticoagulant, with most (65.8%) filling prescriptions for dabigatran; the mean time was 50.4 days until restarting any subsequent anticoagulant.

CONCLUSION

The risk of GI bleeding in patients receiving dabigatran is highly associated with increased age and cardiovascular, renal, and other comorbidities, even after adjusting for other factors. Fewer than 50% of patients restarted an anticoagulant after experiencing a GI bleed. Clinicians should continue to monitor for these risk factors or consider whether alternative therapies may be appropriate.

Triple therapy for percutaneous coronary intervention in atrial fibrillation: standard of care, or a nightmare soon to end?

The need to combine anticoagulant and antiplatelet therapy ('triple therapy') in patients with atrial fibrillation and coronary artery disease increases the risk of bleeding. As percutaneous intervention is now the dominant therapy for coronary disease, clinicians question how to manage the risk of stroke in patients with atrial fibrillation and a coronary stent that require dual antiplatelet therapy. In this review, the risk of stroke and coronary thrombosis in this difficult group of patients will be summarized using current recommendations and guidelines. The scarce randomized data on triple therapy are reviewed, and there will be a focus on currently running trials on this topic.

Comparison of differences in medical costs when new oral anticoagulants are used for the treatment of patients with non-valvular atrial fibrillation and venous thromboembolism vs warfarin or placebo in the US

OBJECTIVE

Medical costs that may be avoided when any of the four new oral anticoagulants (NOACs), dabigatran, rivaroxaban, apixaban, and edoxaban, are used instead of warfarin for the treatment of non-valvular atrial fibrillation (NVAF) were estimated and compared. Additionally, the overall differences in medical costs were estimated for NVAF and venous thromboembolism (VTE) patient populations combined.

METHODS

Medical cost differences associated with NOAC use vs warfarin or placebo among NVAF and VTE patients were estimated based on clinical event rates obtained from the published trial data. The clinical event rates were calculated as the percentage of patients with each of the clinical events during the trial periods. Univariate and multivariate sensitivity analyses were conducted for the medical-cost differences determined for NVAF patients. A hypothetical health plan population of 1 million members was used to estimate and compare the combined medical-cost differences of the NVAF and VTE populations and were projected in the years 2015-2018.

RESULTS

In a year, the medical-cost differences associated with NOAC use instead of warfarin were estimated at -$204, -$140, -$495, and -$340 per patient for dabigatran, rivaroxaban, apixaban, and edoxaban, respectively. In 2014, among the hypothetical population, the medical-cost differences were -$3.7, -$4.2, -$11.5, and -$6.6 million for NVAF and acute VTE patients treated with dabigatran, rivaroxaban, apixaban, and edoxaban, respectively. In 2014, for the combined NVAF, acute VTE, and extended VTE patient populations, medical-cost differences were -$10.0, -$10.9, -$21.0, and -$21.0 million for dabigatran, rivaroxaban, 2.5 mg apixaban, and 5 mg apixaban, respectively. Medical-cost differences associated with use of NOACs were projected to steadily increase from 2014 to 2018.

CONCLUSIONS

Medical costs are reduced when NOACs are used instead of warfarin/placebo for the treatment of NVAF or VTE, with apixaban being associated with the greatest reduction in medical costs.

New strategies for effective treatment of vitamin K antagonist-associated bleeding

Vitamin K antagonists have been used as oral anticoagulants in the treatment and prevention of thromboembolic events for over half a century. Although vitamin K antagonists are effective in the management of thromboembolic events, the need for routine monitoring and the associated risk of bleeding has resulted in the development and licensing of direct oral anticoagulants for specific clinical indications. Despite these developments, vitamin K antagonists remain the oral anticoagulants of choice in many clinical conditions. Severe bleeding associated with oral anticoagulation requires urgent reversal. Several options for the reversal of vitamin K antagonist exist, including vitamin K, prothrombin complex concentrates and plasma. In this manuscript, we review current evidence and provide physicians with treatment strategies for more effective management of vitamin K antagonist-associated bleeding.

Novel oral anticoagulants and reversal agents: Considerations for clinical development

This white paper provides a summary of presentations and discussions that were held at an Anticoagulant-Induced Bleeding and Reversal Agents Think Tank co-sponsored by the Cardiac Safety Research Consortium and the US Food and Drug Administration (FDA) at the FDA's White Oak Headquarters on April 22, 2014. Attention focused on a development pathway for reversal agents for the novel oral anticoagulants (NOACs). This is important because anticoagulation is still widely underused for stroke prevention in patients with atrial fibrillation. Undertreatment persists, although NOACs, in general, overcome some of the difficulties associated with anticoagulation provided by vitamin K antagonists. One reason for the lack of a wider uptake is the absence of NOAC reversal agents. As there are neither widely accepted academic and industry standards nor a definitive regulatory policy on the development of such reversal agents, this meeting provided a forum for leaders in the fields of cardiovascular clinical trials and cardiovascular safety to discuss the issues and develop recommendations. Attendees included representatives from pharmaceutical companies; regulatory agencies; end point adjudication specialist groups; contract research organizations; and active, academically based physicians. There was wide and solid consensus that NOACs overall offer improvements in convenience, efficacy, and safety compared with warfarin, even without reversal agents. Still, it was broadly accepted that it would be helpful to have reversal agents available for clinicians to use. Because it is not feasible to do definitive outcomes studies demonstrating a reversal agent's clinical benefits, it was felt that these agents could be approved for use in life-threatening bleeding situations if the molecules were well characterized preclinically, their pharmacodynamic and pharmacokinetic profiles were well understood, and showed no harmful adverse events in early human testing. There was also consensus that after such approval, efforts should be made to augment the available clinical information until such time as there is a body of evidence to demonstrate real-world clinical outcomes with the reversal agents. No recommendations were made for more generalized use of these agents in the setting of non-life-threatening situations. This article reflects the views of the authors and should not be construed to represent FDA's views or policies.

Prescription patterns of oral anticoagulants for patients with non-valvular atrial fibrillation: experience at a Japanese single institution

New oral anticoagulants (NOACs) are now clinically available. However, few studies have demonstrated which patients with non-valvular atrial fibrillation (NVAF) actually receive NOACs in a clinical setting. We analyzed 182 NVAF patients who received oral anticoagulants. Clinical backgrounds and the risk of stroke, systemic embolism, and bleeding associated with oral anticoagulants were investigated. Seventy-three (40 %) patients were treated with NOACs and 109 (60 %) patients were treated with warfarin. A significantly lower mean number of bleeding risk factors was observed among the patients treated with NOACs than among those treated with warfarin (P = 0.010). Of the bleeding risk factors, NOACs were significantly less frequently prescribed in patients with a bleeding history and elderly subjects (>65 years) than in those who received warfarin (P < 0.001 and P = 0.029). A multivariate logistic regression analysis revealed that CHF and bleeding history were independently and significantly associated with the administration of NOACs (P = 0.047 and P = 0.003). The rate of a history of intracranial hemorrhage was comparable between the patients treated with NOACs and those treated with warfarin (P = 1.000). Significantly lower rates of a history of gastrointestinal and other minor bleeding were observed in the patients who received NOACs versus those who received warfarin (P = 0.001 and P = 0.026). NOACs were less frequently prescribed in patients with a history of bleeding, especially those with a history of gastrointestinal bleeding in a clinical setting.

Antithrombotic Management of Patients with Nonvalvular Atrial Fibrillation and Ischemic Stroke or Transient Ischemic Attack: Executive Summary of the Korean Clinical Practice Guidelines for Stroke

Cardioembolic stroke related to nonvalvular atrial fibrillation is associated with a high recurrence rate and high mortality and morbidity. In this population, therefore, optimal anticoagulant therapy is required to prevent the occurrence of second stroke. Oral anticoagulant, warfarin has been traditionally used, but it is greatly limited by its narrow efficacy window, complex pharmacokinetics, and multiple drug interactions, thus requiring frequent blood monitoring. Recently, oral anticoagulants targeted for a specific coagulation component have been newly developed and tested in large clinical trials. Dabigatran, direct thrombin inhibitor, and rivaroxaban, apixaban, and edoxaban, inhibitors of factor Xa harbor great merits of rapid action time, short half-life, stable plasma concentration, and little drug interaction. Recently, large randomized clinical trials and meta-analyses have been published to show the efficacy and safety of the new oral anticoagulants compared with warfarin. Based on the results from recent clinical trials, we revised recommendations to apply optimal anticoagulant therapy in patients with nonvalvular atrial fibrillation and ischemic stroke or transient ischemic attack.

Lack of Association of Clinical Factors (SAMe-TT2R2) with CYP2C9/VKORC1 Genotype and Anticoagulation Control Quality

Background and Purpose

Advantages of new oral anticoagulations may be greater in atrial fibrillation (AF) patients of poor anticoagulation control with warfarin. The SAMe-TT₂R₂ scoring system, based on clinical variables, was recently developed to aid in identifying these patients. In this study, we investigated the association of this clinical composite score with genetic factors related warfarin dosing and the quality of anticoagulation control.

Methods

Clinical and genetic data were collected from 380 consecutive Korean patients with AF (CHA₂DS₂-VASc score, 3.5±1.8) who were followed for an average of 4 years. We evaluated factors associated with time in therapeutic range (TTR, INR 2-3), including the CYP2C9 and VKORC1 genotypes and the SAMe-TT₂R₂ score (Sex female, Age <60 years, Medical history [>two co-morbidities], Treatment [interacting drugs, e.g., amiodarone], Tobacco use within 2 years [doubled], and Race non-white [doubled]).

Results

The average SAMe-TT₂R₂ score was 3.4±0.9, range 2-7; and 153 patients (40.2%) had SAMe-TT₂R₂ scores ≥4. Time in specific INR ranges varied depending on the VKORC1 genotype but not with the CYP2C9 genotype or the SAMe-TT₂R₂ score. TTR was higher in patients with the VKORC1 1173C>T than in VKORC1 TT (61.7±16% vs. 56.7±17.4%, P=0.031). Multivariate testing showed that VKORC1 genotype but not the SAMe-TT₂R₂ score was significantly associated with labile INRs. There was no correlation between the SAMe-TT₂R₂ scores and pharmacogenetic data.

Conclusions

A genetic factor, but none of the common clinical and demographic factors, as combined in the SAMe-TT₂R₂ score, was associated with the quality of anticoagulation control in Korean patients with AF.

Management of bleeding with oral anticoagulants in patients with atrial fibrillation

Fear of bleeding is a common barrier to the use of anticoagulants. Warfarin has been the only oral anticoagulant for more than 60 years and warfarin-related bleeding is reported to be the most common drug-related cause of emergency hospitalization in elderly Americans. Non-vitamin K oral antagonists were introduced five years ago and compared with warfarin are associated with lower risk of intracranial bleeding, and similar or lower case fatality after major bleeding. Despite their superior safety profile, serious bleeding can occur. Most bleeding can be managed with holding the drug, local measures to control the bleeding and transfusion support as required because the NOACs have a relatively short half life and their anticoagulant effect rapidly dissipates. In patients with ongoing bleeding despite supportive measures and in those with life-threatening bleeding, consideration may be given to the use of general hemostatic agents. Experimental and animal evidence suggests that 3 and 4 factor prothrombin complex concentrates can improve hemostasis in the presence of a NOAC and this is reinforced by anecdotal evidence in humans. Specific antidotes are currently in phase 3 trials and could become available in the near future.

An evidence-based review of edoxaban and its role in stroke prevention in patients with nonvalvular atrial fibrillation

Atrial fibrillation is the most common arrhythmia in the elderly. It is responsible for significant morbidity and mortality from cardioembolic complications like stroke. As a result, atrial fibrillation patients are risk-stratified using the CHADS2 or CHA2DS2-VASc scoring systems. Those at intermediate-to-high risk have traditionally been treated with therapeutic anticoagulation with warfarin for stroke prevention. Although effective, warfarin use is fraught with multiple concerns, such as a narrow therapeutic window, drug-drug and drug-food interactions, and excessive bleeding. Novel oral anticoagulant agents have recently become available as viable alternatives for warfarin therapy. Direct thrombin inhibitor dabigatran and factor Xa inhibitors like rivaroxaban and apixaban have already been approved by the US Food and Drug Administration (FDA) for stroke prevention in patients with nonvalvular atrial fibrillation. Edoxaban is the latest oral direct factor Xa inhibitor studied in the largest novel oral anticoagulant trial so far: ENGAGE AF-TIMI 48. Treatment with a 30 mg or 60 mg daily dose of edoxaban was found to be noninferior to dose-adjusted warfarin in reducing the rate of stroke and systemic embolism in patients with nonvalvular atrial fibrillation, with a lower incidence of bleeding complications and cardiovascular deaths. Edoxaban was recently reviewed by an FDA advisory committee and recommended as a stroke-prophylaxis agent. Once approved, it promises to provide another useful alternative to warfarin therapy.

Prevalence of auricular thrombosis before atrial flutter cardioversion: a 17-year transoesophageal echocardiographic study

AIMS

Prevalence of left appendage thrombosis ranges from 6 to 18% in persistent atrial fibrillation (AF). Few and low sample size studies have assessed left and right atrial thrombosis in persistent atrial flutter (AFL) and a wide variety of frequencies, from 1 to 21%, has been reported. The aim of this study was to evaluate the prevalence of atrial appendage thrombosis in a large population of patients undergoing transoesophageal echocardiography (TEE)-guided cardioversion (CV) for recent AFL onset and compare it with AF.

METHODS AND RESULTS

From 1999 to September 2014, we collected data of 1081 patients to CV: 877 affected by AF (81.1%) and 204 by AFL (18.9%). The presence of auricular thrombosis was evaluated by TEE in AF or AFL persisting for more than 48 h. The presence of appendage thrombosis, Doppler emptying velocities, and severe spontaneous echo contrast (SEC) was studied. The overall prevalence of atrial thrombosis was 9.62% (104/1081). Frequency of atrial thrombosis in AFL patients was 6.4% (13/204) vs. 10.5% among AF (92/877), P = 0.074. Comparing the two appendages, frequency of left atrial appendage thrombosis was in AFL 5.9% (12/204) vs. 9.9% (87/877) in the AF group, P = 0.07. Right atrial appendage thrombosis was present in 0.5% (1/204) in the AFL group vs. 0.8% (7/877) in the AF group, P = 0.64. Moderate to severe SEC (3+/4+) was present in 28% of AFL patients (57/204) vs. 35% of AF patients (307/877), P = 0.05.

CONCLUSION

Auricular thrombosis is not an infrequent finding in AFL before CV. Our study suggests the use of TEE screening in AFL, as well as in AF, when patients arrive to clinical attention after more than 48 h from arrhythmia onset.

Implementation of non-vitamin K antagonist oral anticoagulants in daily practice: the need for comprehensive education for professionals and patients

Non-vitamin K antagonist oral anticoagulants (NOACs) are increasingly used for the prevention and treatment of venous thromboembolism and for stroke prevention in patients with atrial fibrillation. NOACs do not require routine coagulation monitoring, creating a challenge to established systems for patient follow-up based on regular blood tests. Healthcare professionals (HCPs) are required to cope with a mixture of patients receiving either a vitamin K antagonist or a NOAC for the same indications, and both professionals and patients require education about the newer drugs. A European working group convened to consider the challenges facing HCPs and healthcare systems in different countries and the educational gaps that hinder optimal patient management. Group members emphasised the need for regular follow-up and noted national, regional and local variations in set-up and resources for follow-up. Practical incorporation of NOACs into healthcare systems must adapt to these differences, and practical follow-up that works in some systems may not be able to be implemented in others. The initial prescriber of a NOAC should preferably be a true anticoagulation specialist, who can provide initial patient education and coordinate the follow-up. The long-term follow-up care of patients can be managed through specialist coagulation nurses, in a dedicated anticoagulation clinic or by general practitioners trained in NOAC use. The initial prescriber should be involved in educating those who perform the follow-up. Specialist nurses require access to tools, potentially including specific software, to guide systematic patient assessment and workflow. Problem cases should be referred for specialist advice, whereas in cases for which minimal specialist attention is required, the general practitioner could take responsibility for patient follow-up. Hospital departments and anticoagulation clinics should proactively engage with all downstream HCPs (including pharmacists) to ensure their participation in patient management and reinforcement of patient education at every opportunity. Ideally, (transmural) protocols for emergency situations should be developed. Last but not least, patients should be well-informed about their condition, the treatment, possible risk scenarios, including the consequences of non-adherence to prescribed therapy, and the organisation of follow-up care.

A case of Trousseau syndrome caused by pulmonary adenocarcinoma that was controlled for one year and 10 months with thrombosis treatment using an EGFR tyrosine kinase inhibitor and chemotherapy

A 47-year-old female with no history of previous illnesses developed cerebral infarction and was diagnosed with lung cancer, specifically EGFR mutation-positive adenocarcinoma, and Trousseau syndrome.

The patient's response to anticoagulant therapy with non-fractionated heparin was very poor; however we were able to control the thrombosis with chemotherapy. She survived for one year and 10 months following treatment with gefitinib, CBDCA + PEM and erlotinib, without recurrence of thrombosis.

Trousseau syndrome carries a poor prognosis and controlling thrombosis is difficult. In this case, the administration of anticancer therapy allowed use to control the patient's thrombosis. Therefore, this case highlights the importance of treating cancer in patients with Trousseau syndrome. In addition, the FDP and D-dimer levels changed in parallel with changes in the CEA level, which suggests that the activity of cancer is related to an internal thrombotic tendency. Hence, changes in the FDP and D-dimer values are associated with the efficacy of treatment with EGFR tyrosine kinase inhibitors and chemotherapy and may function as markers of recurrence.

The Italian START-Register on Anticoagulation with Focus on Atrial Fibrillation

START-Register – Survey on anTicoagulated pAtients RegisTer – is an independent, inception-cohort, observational, collaborative database aimed at recording prospectively the clinical history of adult patients starting anticoagulant treatment for any reason and using whatever drug. In this article we present the START-Register and give cross section baseline data focusing on non valvular atrial fibrillation (NVAF). Participants are asked to insert prospectively consecutive patients recorded as electronic file on the web-site of the registry. Required data are: demographic and clinical characteristics of patients, associated risk factors for stroke and bleeding, laboratory routine data, clinical indication for treatment, expected therapeutic range (in cases of treatment with vitamin K antagonists -VKAs). The follow-up is carried out to record: quality of treatment (for patients on VKAs), bleeding complications, thrombotic events, and the onset of any type of associated disease. To date 5252 patients have been enrolled; 97.6% were on VKAs because direct oral anticoagulants (DOAC) have been available in Italy only recently. The median age was 74 years [interquartile range (IQR) 64-80]; males 53.7%. This analysis is focused on the 3209 (61.1%) NVAF patients. Mean CHADS₂ score was 2.1±1.1, CHADSVASc score was 3.1±1.3;median age was 76 years (IQR 70-81); 168 patients (5.3%) had severe renal failure [Creatinine clearance (CrCl) <30 ml/min]. Moderate renal failure (CrCl 30-59 ml/min) was found in 1265 patients (39.5%). The analysis of the START-Register data shows that two-third of patients who started chronic anticoagulant treatment had NVAF, one-third of them was > 80 years with high prevalence of renal failure.

Efficacy and Harms of Direct Oral Anticoagulants in the Elderly for Stroke Prevention in Atrial Fibrillation and Secondary Prevention of Venous Thromboembolism: Systematic Review and Meta-Analysis

BACKGROUND

Evidence regarding the use of direct oral anticoagulants (DOACs) in the elderly, particularly bleeding risks, is unclear despite the presence of greater comorbidities, polypharmacy, and altered pharmacokinetics in this age group.

METHODS AND RESULTS

We performed a systematic review and meta-analysis of randomized trials of DOACs (dabigatran, apixaban, rivaroxaban, and edoxaban) for efficacy and bleeding outcomes in comparison with vitamin K antagonists (VKA) in elderly participants (aged ≥75 years) treated for acute venous thromboembolism or stroke prevention in atrial fibrillation. Nineteen studies were eligible for inclusion, but only 11 reported data specifically for elderly participants. The efficacy in managing thrombotic risks for each DOAC was similar or superior to VKA in elderly patients. A nonsignificantly higher risk of major bleeding than with VKA was observed with dabigatran 150 mg (odds ratio, 1.18; 95% confidence interval, 0.97-1.44) but not with the 110-mg dose. Significantly higher gastrointestinal bleeding risks with dabigatran 150 mg (1.78, 1.35-2.35) and dabigatran 110 mg (1.40, 1.04-1.90) and lower intracranial bleeding risks than VKA for dabigatran 150 mg (0.43, 0.26-0.72) and dabigatran 110 mg (0.36, 0.22-0.61) were also observed. A significantly lower major bleeding risk in comparison with VKA was observed for apixaban (0.63, 0.51-0.77), edoxaban 60 mg (0.81, 0.67-0.98), and 30 mg (0.46, 0.38-0.57), whereas rivaroxaban showed similar risks.

CONCLUSIONS

DOACs demonstrated at least equal efficacy to VKA in managing thrombotic risks in the elderly, but bleeding patterns were distinct. In particular, dabigatran was associated with a higher risk of gastrointestinal bleeding than VKA. Insufficient published data for apixaban, edoxaban, and rivaroxaban indicate that further work is needed to clarify the bleeding risks of these DOACs in the elderly.

SYSTEMATIC REVIEW REGISTRATION

http://www.crd.york.ac.uk/PROSPERO. Unique identifier: PROSPERO CRD42014007171/.

Coagulation assessment with the new generation of oral anticoagulants

Long-term oral anticoagulant (OAC) therapy is used for the treatment and prevention of thrombosis and thromboembolism. As OAC use is so widespread, emergency physicians are likely to encounter patients on anticoagulant therapy in the emergency department (ED) on a regular basis, either for the same reasons as the population in general or as a result of the increased bleeding risk that OAC use entails.

The vitamin K antagonist warfarin has been the standard OAC for several decades, but recently, the newer agents dabigatran etexilate, rivaroxaban and apixaban (collectively, novel OACs, non-vitamin K OACs, or simply ‘NOACs’) have become available for long-term use. Protocols for assessing and managing warfarin-treated patients in the ED are well established and include international normalised ratio (INR) testing, which helps guide patient management. However, the INR does not give an accurate evaluation of coagulation status with NOACs, and alternative tests are therefore needed for use in emergency settings. This paper discusses what information the INR provides for a patient taking warfarin and which coagulation tests can guide the physician when treating patients on one of the NOACs, as well as other differences in emergency anticoagulation management.

Persistence of non-vitamin K antagonist oral anticoagulant use in Japanese patients with atrial fibrillation: A single-center observational study

Background

Non-vitamin K antagonist oral anticoagulants (NOACs) show a favorable balance between efficacy and safety compared with warfarin for patients with non-valvular atrial fibrillation (NVAF). In “real-world” practice, however, NOAC adherence and persistence among patients are not clear. The aim of this study is to evaluate NOAC and warfarin persistence in Japanese patients with NVAF who newly started these drugs.

Methods

We retrospectively studied 401 patients with NVAF who had newly started NOACs during the first 18 months after our hospital adopted their use (197 dabigatran, 107 rivaroxaban, 102 apixaban) and 200 patients with NVAF who had newly started warfarin during the same period. The endpoint was drug discontinuation for each drug.

Results

During the follow-up period (up to a maximum of 24 months), 113 (28%) patients who had newly started NOACs and 33 (17%) patients who had newly started warfarin discontinued the drug. The persistence rates of patients prescribed NOACs was lower than that of patients prescribed warfarin at 3, 6, and 12 months (85% versus 93%, 79% versus 88%, and 70% versus 82%, respectively). One-tenth of patients who had newly started NOACs discontinued the drug by their own decision. Drug adverse events, worsening renal dysfunction, and patient desire were the major causes of NOAC discontinuation.

Conclusions

The rate of persistence of prescribed NOACs was significantly lower than that of warfarin in Japanese patients with NVAF.

Edoxaban vs. warfarin in patients with atrial fibrillation on amiodarone: a subgroup analysis of the ENGAGE AF-TIMI 48 trial

BACKGROUND

In the ENGAGE AF-TIMI 48 trial, the higher-dose edoxaban (HDE) regimen had a similar incidence of ischaemic stroke compared with warfarin, whereas a higher incidence was observed with the lower-dose regimen (LDE). Amiodarone increases edoxaban plasma levels via P-glycoprotein inhibition. The current pre-specified exploratory analysis was performed to determine the effect of amiodarone on the relative efficacy and safety profile of edoxaban.

METHODS AND RESULTS

At randomization, 2492 patients (11.8%) were receiving amiodarone. The primary efficacy endpoint of stroke or systemic embolic event was significantly lower with LDE compared with warfarin in amiodarone treated patients vs. patients not on amiodarone (hazard ratio [HR] 0.60, 95% confidence intervals [CIs] 0.36-0.99 and HR 1.20, 95% CI 1.03-1.40, respectively; P interaction <0.01). In patients randomized to HDE, no such interaction for efficacy was observed (HR 0.73, 95% CI 0.46-1.17 vs. HR 0.89, 95% CI 0.75-1.05, P interaction = 0.446). Major bleeding was similar in patients on LDE (HR 0.35, 95% CI 0.21-0.59 vs. HR 0.53, 95% CI 0.46-0.61, P interaction = 0.131) and HDE (HR 0.94, 95% CI 0.65-1.38 vs. HR 0.79, 95% CI 0.69-0.90, P interaction = 0.392) when compared with warfarin, independent of amiodarone use.

CONCLUSIONS

Patients randomized to the LDE treated with amiodarone at the time of randomization demonstrated a significant reduction in ischaemic events vs. warfarin when compared with those not on amiodarone, while preserving a favourable bleeding profile. In contrast, amiodarone had no effect on the relative efficacy and safety of HDE.

Renal function and non-vitamin K oral anticoagulants in comparison with warfarin on safety and efficacy outcomes in atrial fibrillation patients: a systemic review and meta-regression analysis

OBJECTIVE

To investigate the relative effect of warfarin versus non-vitamin K oral anticoagulants (NOACs) in thrombotic and bleeding outcomes in subgroups of atrial fibrillation (AF) patients with varying degrees of renal dysfunction.

METHODS

Systemic review and meta-regression analyses on NOACs versus warfarin, supplemented with indirect comparisons were conducted. The eligibility criteria for inclusion were randomised controlled trials comparing NOACs against warfarin for stroke prevention in AF patients. Outcomes of interest were stroke or systemic embolism (SE) and major bleeding.

RESULTS

Five studies comprising 72,845 AF patients randomised to either a NOAC or warfarin were included in the meta-regression analysis. A shift in strata from no renal impairment to renal impairment resulted in a non-significant impact on bleeding and stroke/SE, indicating similar safety and efficacy, despite renal function status. Apixaban was associated with less major bleeding compared to dabigatran and rivaroxaban but not edoxaban in patients with moderate renal impairment. For efficacy outcomes, only dabigatran 150 mg was statistically significantly favoured compared to edoxaban 30 mg. For efficacy outcomes in mild renal impairment, both dabigatran 150 mg and rivaroxaban 10 mg (J-ROCKET) were statistically significantly favoured against edoxaban 30 mg.

CONCLUSION

Non-vitamin K oral anticoagulants had similar efficacy and safety compared to warfarin across different levels of renal function. Indirect comparisons suggest that apixaban and edoxaban were associated with a better safety profile in patients with moderate renal impairment. However, caution is warranted when interpreting indirect comparisons of drugs investigated in different trials. Prescribers should fit the most appropriate NOAC to the AF patient characteristics (and vice versa) to individualise effective stroke prevention.

Impact of new oral anticoagulants on gastrointestinal bleeding in atrial fibrillation: A meta-analysis of interventional trials

BACKGROUND

New oral anticoagulants represent an alternative to standard therapy with vitamin K antagonists but data regarding gastrointestinal bleeding are still unclear.

AIMS

To investigate if new oral anticoagulants are associated with an enhanced risk of gastrointestinal bleeding vs warfarin in patients with atrial fibrillation.

METHODS

Meta-analysis of phase three randomized controlled trials to compare the incidence of gastrointestinal bleeding in atrial fibrillation patients treated with new oral anticoagulants (apixaban, dabigatran, edoxaban and rivaroxaban) vs warfarin.

RESULTS

Four studies including 71,302 patients were selected. Compared with warfarin, new oral anticoagulants significantly increased gastrointestinal bleeding (RR: 1.23; 95% CI 1.03-1.46; p=0.01). Rivaroxaban (RR: 1.46; 95% CI 1.2-1.8; p<0.001) and high dosages of edoxaban (RR: 1.22; 95% CI 1.01-1.47; p=0.038) and dabigatran (RR: 1.50; 95% CI 1.20-1.88; p<0.001) significantly increased gastrointestinal bleeding while a null effect was detected with apixaban.

CONCLUSIONS

This meta-analysis suggests that rivaroxaban and high dosages of dabigatran and edoxaban should be avoided in patients at high risk of gastrointestinal bleeding.

A prospective evaluation of edoxaban compared to warfarin in subjects undergoing cardioversion of atrial fibrillation: The EdoxabaN vs. warfarin in subjectS UndeRgoing cardiovErsion of Atrial Fibrillation (ENSURE-AF) study

We designed a prospective, randomized, open-label, blinded end point evaluation parallel group Phase 3b clinical trial comparing edoxaban (a new oral factor Xa inhibitor) with enoxaparin/warfarin followed by warfarin alone in subjects undergoing planned electrical cardioversion of non-valvular atrial fibrillation. The primary efficacy end point is the composite end points of stroke, systemic embolic event, myocardial infarction, and cardiovascular (CV) mortality, from randomization until the end of follow-up (day 56 post cardioversion). The primary safety end point is the composite of major and clinically-relevant non-major bleeding, from the first administration of study drug to end of treatment (Day 28 post cardioversion) +3 days. The primary efficacy analysis will be conducted on the intention-to-treat population whereas the primary safety analysis, on the safety population. The study includes stratification on the following levels: (i) approach to cardioversion (transoesophagel echocardiography or non-transoesophagel echocardiography) as determined by the Investigator; (ii) subject's experience in taking anticoagulants at the time of randomization (anticoagulant-experienced or anticoagulant-naïve); and (iii) assigned edoxaban dose (full 60 mg QD or reduced 30 mg dose QD). A subject with one or more factors (CrCl ≥15 mL/min and ≤50 mL/min, low body weight [≤60 kg], and concomitant use of p-pg inhibitors (excluding amiodarone) will receive a reduced dose (30 mg) of edoxaban if the subject is randomized to the edoxaban group. ENSURE-AF will be the largest prospective randomised trial of anticoagulation for cardioversion, also involving a Non-VKA Oral Anticoagulant-edoxaban.

[Management of new oral anticoagulants in gastrointestinal bleeding and endoscopy]

New oral direct anticoagulants agents are alternatives to warfarin for long-term anticoagulation in a growing number of patients that require long-term anticoagulation for atrial fibrillation, deep venous thrombosis and pulmonary embolism. These new agents with predictable pharmacokinetic and pharmacodynamics profiles offer a favorable global safety profile, but increased gastrointestinal bleeding compared to the vitamin K antagonists. Many gastroenterologists are unfamiliar and may be wary of these newer drugs, since Clinical experience is limited and no specific antidote is available to reverse their anticoagulant effect. In this article the risk of these new agents and, how to manage these agents in both the presence of acute gastrointestinal bleeding and in patients undergoing endoscopic procedures is reviewed.