Clinical events after transitioning from apixaban versus warfarin to warfarin at the end of the Apixaban for Reduction in Stroke and Other Thromboembolic Events in Atrial Fibrillation (ARISTOTLE) trial

Development and validation of a clinical decision support system to prevent anticoagulant duplications

BACKGROUND AND OBJECTIVE

Unintended duplicate prescriptions of anticoagulants increase the risk of serious adverse events. Clinical Decision Support Systems (CDSSs) can help prevent such medication errors; however, sophisticated algorithms are needed to avoid alert fatigue. This article describes the steps taken in our hospital to develop a CDSS to prevent anticoagulant duplication (AD).

METHODS

The project was composed of three phases. In phase I, the status quo was established. In phase II, a clinical pharmacist developed an algorithm to detect ADs using daily data exports. In phase III, the algorithm was integrated into the hospital's electronic health record system. Alerts were reviewed by clinical pharmacists before being sent to the prescribing physician. We conducted a retrospective analysis of all three phases to assess the impact of the interventions on the occurrence and duration of ADs. Phase III was analyzed in more detail regarding the acceptance rate, sensitivity, and specificity of the alerts.

RESULTS

We identified 91 ADs in 1581 patients receiving two or more anticoagulants during phase I, 70 ADs in 1692 patients in phase II, and 57 ADs in 1575 patients in phase III. Mean durations of ADs were 1.8, 1.4, and 1.1 calendar days during phases I, II, and III, respectively. In comparison to the baseline in phase I, the relative risk reduction of AD in patients treated with at least two different anticoagulants during phase III was 42% (RR: 0.58, CI: 0.42-0.81). A total of 429 alerts were generated during phase III, many of which were self-limiting, and 186 alerts were sent to the respective prescribing physician. The acceptance rate was high at 97%. We calculated a sensitivity of 87.4% and a specificity of 87.9%.

CONCLUSION

The stepwise development of a CDSS for the detection of AD markedly reduced the frequency and duration of medication errors in our hospital, thereby improving patient safety.

Efficacy and Safety of Novel Oral Anticoagulants in Atrial Fibrillation: A Systematic Review

In recent times, novel oral anticoagulants (NOACs)/direct oral anticoagulants (DOACs) have emerged as an alternative to the traditionally used Vitamin K oral antagonists (VKA) like warfarin for the treatment of atrial fibrillation (AF). This systematic review and meta-analysis aims to evaluate the efficacy and safety of NOACs in patients with AF and, thus, the related thromboembolic risks and sequelae. Of the 131 published articles we examined, 11 were included in an in-depth systematic review. The articles we reviewed were from the past ten years, from 2013 onward. The analysis derived the efficacy and safety of NOACs in patients with AF and also included different patients' baseline characteristics and subgroups. This systematic review reiterates previous research findings of superior efficacy and safety of the use of NOACs in the AF population and also illuminates certain head-to-head comparisons of individual NOACs with warfarin. It digressed into subgroups of patients with different baseline characteristics to provide evidence and support the existing guidelines for the use of NOACs in the treatment of AF. Overall, there is marked efficacy and safety of NOACs in patients with AF, be they elderly or Asian, with decreased renal function, or with other comorbidities. Adherence to NOACs was also satisfactory. Despite such a review, there needs to be more research on vast subgroups and also on reversal antidotes like andexanet alfa and idarucizumab, as well as more head-to-head analysis between NOACs over a long duration of study, which would provide more answers and pinpoint reasons as to the differences that exist between demographics and subgroups in the usage of NOACs.

The Role of Biomarkers, Metabolomics, and COVID-19 in Venous Thromboembolism-A Review of Literature

In recent years, the field of venous thromboembolism has undergone numerous innovations, starting from the recent discoveries on the role of biomarkers, passing through the role of metabolomics in expanding our knowledge on pathogenic mechanisms, which have opened up new therapeutic targets. A variety of studies have contributed to characterizing the metabolic phenotype that occurs in venous thromboembolism, identifying numerous pathways that are altered in this setting. Among these pathways are the metabolism of carnitine, tryptophan, purine, and fatty acids. Furthermore, new evidence has emerged with the recent COVID-19 pandemic. Hypercoagulability phenomena induced by this viral infection appear to be related to altered von Willebrand factor activity, alteration of the renin-angiotensin-aldosterone system, and dysregulation of both innate and adaptive immunity. This is the first literature review that brings together the most recent evidence regarding biomarkers, metabolomics, and COVID-19 in the field of venous thromboembolism, while also mentioning current therapeutic protocols.

Management of Gastrointestinal Bleeding and Resumption of Oral Anticoagulant Therapy in Patients with Atrial Fibrillation: A Multidisciplinary Discussion

Direct oral anticoagulants (DOACs) are recommended for the prevention of thromboembolism in patients with atrial fibrillation (AF), and are now preferred over vitamin K antagonists due to their beneficial efficacy and safety profile. However, all oral anticoagulants carry a risk of gastrointestinal (GI) bleeding. Although the risk is well documented and acute bleeding well codified, there is limited high-quality evidence and no guidelines to guide physicians on the optimal management of anticoagulation after a GI bleeding event. The aim of this review is to provide a multidisciplinary critical discussion of the optimal management of GI bleeding in patients with AF receiving oral anticoagulants to help physicians provide individualized treatment for each patient and optimize outcomes. It is important to perform endoscopy when a patient presents with bleeding manifestations or hemodynamic instability to determine the bleed location and severity of bleeding and then perform initial resuscitation. Administration of all anticoagulants and antiplatelets should be stopped and bleeding allowed to resolve with time; however, anticoagulant reversal should be considered for patients who have life-threatening bleeding or when the bleeding is not controlled by the initial resuscitation. Anticoagulation needs to be timely resumed considering that bleeding risk outweighs thrombotic risk when anticoagulation is resumed early after the bleeding event. To prevent further bleeding, physicians should prescribe anticoagulant therapy with the lowest risk of GI bleeding, avoid medications with GI toxicity, and consider the effect of concomitant medications on potentiating the bleeding risk.

Oral anticoagulant switching in patients with atrial fibrillation: a scoping review

INTRODUCTION

Oral anticoagulants (OACs) prevent stroke in patients with atrial fibrillation (AF). Several factors may cause OAC switching.

OBJECTIVES

To examine the phenomenon of OAC switching in patients with AF, including all available evidence; frequency and patterns of switch, clinical outcomes, adherence, patient-reported outcomes, reasons for switch, factors associated with switch and evidence gaps.

DESIGN

Scoping review.

DATA SOURCES

MEDLINE, Embase and Web of Science, up to January 2022.

RESULTS

Of the 116 included studies, 2/3 examined vitamin K antagonist (VKA) to direct-acting OAC (DOAC) switching. Overall, OAC switching was common and the definition of an OAC switch varied across. Switching from VKA to dabigatran was the most prevalent switch type, but VKA to apixaban has increased in recent years. Patients on DOAC switched more to warfarin than to other DOACs. OAC doses involved in the switches were hardly reported and patients were often censored after the first switch. Switching back to a previously taken OAC (frequently warfarin) occurred in 5%-21% of switchers.The risk of ischaemic stroke and gastrointestinal bleeding in VKA to DOAC switchers compared with non-switchers was conflicting, while there was no difference in the risk of other types of bleeding. The risk of ischaemic stroke in switchers from DOAC versus non-switchers was conflicting. Studies evaluating adherence found no significant changes in adherence after switching from VKA to DOAC, however, an increase in satisfaction with therapy were reported. Reasons for OAC switch, and factors associated with OAC switch were mostly risk factors for stroke and bleeding. Clinical outcomes, adherence and patient-reported outcomes were sparse for switches from DOACs.

CONCLUSIONS

OAC switching is common in patients with AF and patients often switch back to an OAC they have previously been on. There are aspects of OAC switching that have received little study, especially in switches from DOACs.

The Atrial Fibrillation Better Care (ABC) Pathway and Clinical Outcomes in Patients with Atrial Fibrillation: the Prospective Murcia AF Project Phase II Cohort

BACKGROUND

The Atrial fibrillation Better Care (ABC) pathway was proposed for a more holistic or integrated care approach to atrial fibrillation (AF) management. We investigated whether adherence with the ABC pathway reduced the risk of adverse clinical outcomes in real-world AF patients starting vitamin K antagonist (VKAs) therapy.

METHODS

Prospective cohort study including AF outpatients starting VKA therapy from July 2016 to June 2018. Patients were considered as adherent if all ABC pathway criteria (A: Avoid stroke; B: Better symptom control; and C: Cardiovascular risk factors/comorbidities management) were fulfilled. The primary endpoints were all-cause mortality, net clinical outcomes (NCOs), major adverse cardiovascular events (MACE), and composite thrombotic/thromboembolic events at 2 years.

RESULTS

We enrolled 1045 patients (51.6% female; median age 77 [70-83] years). Of these, 63.0% (658) were adherent to the ABC pathway and 37% (387) were considered non-adherent. Compared to non-adherent patients, those who were ABC adherent had lower event rates for all-cause mortality (13.76 vs. 6.56; p<0.001), NCOs (19.65 vs. 11.94; p<0.001), and MACE (11.88 vs. 7.75; p=0.006) during the follow-up. Adjusted Cox regression analyses demonstrated that the ABC pathway adherent care reduced the risks of all-cause mortality (aHR 0.57, 95% CI 0.42-0.78), NCOs (aHR 0.72, 95% CI 0.56-0.92), and cardiovascular mortality (aHR 0.54, 95% CI 0.32-0.90). Event-free survivals for all-cause mortality, NCOs (both log-rank p-values <0.001), and MACE (log-rank p-value = 0.004) were also higher in ABC pathway adherent patients.

CONCLUSIONS

In this real-world prospective cohort of AF patients starting VKA therapy, adherence to the ABC pathway management at baseline significantly reduced the risk of NCOs, all-cause mortality, and cardiovascular death at 2 years.

Platelets and Their Role in Hemostasis and Thrombosis-From Physiology to Pathophysiology and Therapeutic Implications

Hemostasis is a physiological process critical for survival. Meanwhile, thrombosis is amongst the leading causes of death worldwide, making antithrombotic therapy one of the most crucial aspects of modern medicine. Although antithrombotic therapy has progressed tremendously over the years, it remains far from ideal, and this is mainly due to the incomplete understanding of the exceptionally complex structural and functional properties of platelets. However, advances in biochemistry, molecular biology, and the advent of 'omics' continue to provide crucial information for our understanding of the complex structure and function of platelets, their interactions with the coagulation system, and their role in hemostasis and thrombosis. In this review, we provide a comprehensive view of the complex role that platelets play in hemostasis and thrombosis, and we discuss the major clinical implications of these fundamental blood components, with a focus on hemostatic platelet-related disorders and existing and emerging antithrombotic therapies. We also emphasize a number of questions that remain to be answered, and we identify hotspots for future research.

Increased Risk of Stroke Due to Non-adherence and Non-persistence with Direct Oral Anticoagulants (DOACs): Real-World Analyses Using a Nested Case-Control Study from The Netherlands, Italy and Germany

BACKGROUND

A high degree of adherence to direct oral anticoagulants is essential for reducing the risk of ischaemic stroke and systemic embolism in patients with atrial fibrillation, owing to the rapid decline in anticoagulation activity when doses are omitted (i.e. rebound effect).

OBJECTIVE

We aimed to assess the relationship between non-adherence and non-persistence with direct oral anticoagulants and the incidence of ischaemic stroke in patients with atrial fibrillation.

METHODS

A nested case-control study was conducted in the Netherlands, Italy and Germany among patients with atrial fibrillation starting direct oral anticoagulants between the drug approval date and the end of database availability. Patients with an ischaemic stroke during the follow-up were selected as cases and compared with matched controls (matched on age ± 5 years, sex, year of cohort entry date and CHA₂DS₂-VASc-score at cohort entry date). The cohort entry date was the first dispensing date. Study patients were those aged ≥ 45 years, with ≥ 1 year database history, ≥ 1 year follow-up and at least two direct oral anticoagulant dispensings after the cohort entry date. Adherence and persistence to direct oral anticoagulant treatment were defined as the proportion of days covered ≥ 80% or direct oral anticoagulant continuous use between the cohort entry date and the index date (i.e. date of ischaemic stroke), respectively.

RESULTS

In The Netherlands, Italy and Germany, 105 cases and 395 controls, 1580 cases and 6248 controls, and 900 cases and 3570 controls were included, respectively. Odds ratios (ORs) for stroke among current users who were non-adherent compared to adherent users were 0.43 (95% confidence interval [CI] 0.09-1.96) in The Netherlands, 1.11 (95% CI 0.98-1.26) in Italy and 1.21 (95% CI 1.01-1.45) in Germany. The risk of stroke was significantly higher among non-persistent users compared with persistent users in all three databases [OR 1.56 (95% CI 1.00-2.44), OR 1.48 (1.32-1.65) and OR 1.91 (95% CI 1.64-2.22), respectively]. In The Netherlands and Germany, the risk of stroke was higher the longer a patient had stopped using direct oral anticoagulants.

CONCLUSIONS

Both non-adherence (in Germany) and non-persistence increased the risk of stroke, either using a once-daily or twice-daily regime.

Impact of prior oral anticoagulant use and outcomes on patients from secondary analysis in the AUGUSTUS trial

Objective

Managing antithrombotic therapy in patients with atrial fibrillation (AF) and an acute coronary syndrome (ACS) and/or percutaneous coronary intervention (PCI) is challenging and can be affected by prior oral anticoagulant (OAC) treatment. We examined the relationship between prior OAC use and outcomes in the AUGUSTUS trial.

Methods

This prespecified secondary analysis is from AUGUSTUS, an open-label, 2-by-2 factorial, RCT to evaluate the safety of apixaban versus vitamin K antagonist (VKA) and aspirin versus placebo in patients with AF and ACS and/or PCI. The primary endpoint, major or clinically relevant non-major bleeding and clinical outcomes were compared in patients receiving (n=2262) or not receiving (n=2352) an OAC prior to enrolment.

Results

Patients with prior OAC use had more comorbidities, higher CHA₂DS₂-VASC and HAS-BLED scores, and were more likely enrolled following elective PCI. There was no difference in major or clinically relevant non-major bleeding with or without prior OAC (30 days: 5.1% vs 5.9% (adjusted HR (aHR) 0.82, 95% CI 0.63 to 1.06); 180 days: 13.5% vs 13.5% (aHR 0.98, 95% CI 0.83 to 1.16)). Patients with prior OAC use had a lower risk of death or ischaemic events (30 days: 1.7% vs 2.8% (aHR 0.61, 95% CI 0.41 to 0.92); 180 days: 5.4% vs 7.6% (aHR 0.70, 95% CI 0.55 to 0.88)). No interactions between randomised treatment (apixaban vs VKA, aspirin vs placebo) and prior OAC status were observed for outcomes, apart from apixaban (vs VKA) being associated with a lower risk of myocardial infarction with prior OAC use (180 days: 2.0% vs 3.7% (aHR 0.56, 95% CI 0.33 to 0.91().

Conclusions

In AUGUSTUS, prior OAC use was associated with fewer ischaemic events but not more bleeding. In patients with AF and ACS and/or undergoing PCI, clinicians can be assured that the trial results can be applied to patients regardless of their prior OAC status.

Trial registration number

NCT02415400.

Adherence to Direct Oral Anticoagulants in Patients With Non-Valvular Atrial Fibrillation: A Cross-National Comparison in Six European Countries (2008-2015)

Aims: To describe and compare the adherence to different direct oral anticoagulants (DOACs) in eight European databases representing six countries. Methods: Longitudinal drug utilization study of new users (≥18 years) of DOACs (dabigatran, rivaroxaban, apixaban) with a diagnosis of non-valvular atrial fibrillation (2008-2015). Adherence was examined by estimating persistence, switching, and discontinuation rates at 12 months. Primary non-adherence was estimated in BIFAP and SIDIAP databases. Results: The highest persistence rate was seen for apixaban in the CPRD database (81%) and the lowest for dabigatran in the Mondriaan database (22%). The switching rate for all DOACs ranged from 2.4 to 13.1% (Mondriaan and EGB databases, respectively). Dabigatran had the highest switching rate from 5.0 to 20.0% (Mondriaan and EGB databases, respectively). The discontinuation rate for all DOACs ranged from 16.0 to 63.9% (CPRD and Bavarian CD databases, respectively). Dabigatran had the highest rate of discontinuers, except in the Bavarian CD and AOK NORDWEST databases, ranging from 23.2 to 64.6% (CPRD and Mondriaan databases, respectively). Combined primary non-adherence for examined DOACs was 11.1% in BIFAP and 14.0% in SIDIAP. There were differences in population coverage and in the type of drug data source among the databases. Conclusion: Despite the differences in the characteristics of the databases and in demographic and baseline characteristics of the included population that could explain some of the observed discrepancies, we can observe a similar pattern throughout the databases. Apixaban was the DOAC with the highest persistence. Dabigatran had the highest proportion of discontinuers and switchers at 12 months in most databases (EMA/2015/27/PH).

Left Atrial Thrombus Mimicking Myxoma Secondary to Rebound Hypercoagulable State

Novel oral anticoagulants (NOACs) have made the use of anticoagulation in patients with atrial fibrillation (AFib) much more convenient and predictable. It is a very common practice to hold anticoagulation either in anticipation of surgical procedures (to prevent excessive bleeding) or in case of acute bleeding episodes. This abrupt withdrawal of anticoagulation tilts the balance in favor of pro-thrombotic state in the body. We present a case of a 60-year-old man with past medical history of AFib who abruptly discontinued his apixaban (Eliquis). This patient presented to emergency room with the complaint of weakness and numbness of left arm and left half of the face. Stroke code was activated, and patient received tissue plasminogen activator (t-PA). This resulted in significant improvement of symptoms within hours of receiving treatment. Later during the same day, patient developed numbness and tingling of fingers of left hand. On physical exam, left hand was cold to touch and radial pulse was absent. Arterial duplex revealed occluded ulnar and radial arteries. Vascular surgery performed embolectomy to establish blood flow in the radial and ulnar arteries. Transthoracic echocardiogram revealed large left atrial mass attached to the atrial septum. Most likely t-PA infusion in the setting of atrial mass led to distal showering of emboli resulting in stenosis of radial and ulnar arteries. The left atrial mass was most likely thrombus as patient had cardiac imaging including transthoracic echocardiogram and computed tomography of heart prior to these events which did not reveal any mass in left atrium. In short, as clinicians we should be aware of the hypercoagulability associated with withdrawal of anticoagulation. In addition, we should be wary of the challenges associated with differentiating cardiac masses of different etiology.

Risk of stroke and other thromboembolic complications after interruption of DOAC therapy compared with warfarin therapy in patients with atrial fibrillation: a retrospective cohort analysis

Direct oral anticoagulants (DOACs) have become the treatment of choice in thromboembolism prophylaxis for non-valvular atrial fibrillation, surpassing warfarin. While interruption of DOAC therapy for various reasons is a common eventuality, the body of data from real-world clinical practice on the implications of such interruptions in different clinical settings is still limited. We assessed complication rates from DOAC (apixaban, rivaroxaban, dabigatran) interruption compared with warfarin in hospitalized patients. We performed a retrospective cohort analysis of electronic records of patients hospitalized in Rabin Medical Center between 2010 and 2017. Incidents of anticoagulation interruptions for various reasons (including unintended interruptions) were collected. DOAC-treated patients were excluded if they reported non-compliance, and warfarin-treated patients were excluded if their international normalized ratio measurement on admission was subtherapeutic. Outcomes included ischemic stroke, systemic thromboembolism, myocardial infarction, and all-cause mortality within 90 days of anticoagulation interruption. The median CHA2DS2-VASc score was 5.0 (IQR 4.0-6.0) in both treatment groups. The associated risk of stroke, thromboembolic complications, myocardial infarction, and all-cause mortality after interruption of anticoagulation was not significantly different between the 2 treatment groups. Selective comparison of patients who were well balanced on warfarin before treatment interruption to DOAC-treated patients did not significantly influence the outcomes. This study did not find a significant difference in the complication rate after interruption of DOAC therapy compared with interruption of warfarin therapy in hospitalized patients with a high risk of thromboembolism.

Using the Case-Crossover Design to Assess Short-Term Risks of Bleeding and Arterial Thromboembolism After Switching Between Oral Anticoagulants in a Population-Based Cohort of Patients With Atrial Fibrillation

Using nationwide Danish registries, we conducted a population-based case-crossover study evaluating the association between switching from a vitamin K antagonist (VKA) to a direct oral anticoagulant (DOAC), and vice versa, and 30-day risks of bleeding and arterial thromboembolism in patients with atrial fibrillation (AF). The case-crossover population was identified among oral anticoagulant users during 2011-2018 (n = 123,217) as patients with AF with 1) a case-defining outcome and 2) an anticoagulant switch during the 180 days preceding the outcome. Odds ratios were estimated using conditional logistic regression by comparing the occurrence of switching during the 30-day window immediately preceding the outcome to that in reference windows in the same individual 60-180 days before the outcome. The case-crossover populations for switching from VKA to DOAC and DOAC to VKA comprised 1,382 and 287 case patients, respectively. Switching from VKA to DOAC, but not from DOAC to VKA, was associated with an increased short-term risk of bleeding (odds ratio = 1.42; 95% confidence intervals: 1.13, 1.79, and 1.06; and 0.64, 1.75, respectively) and ischemic stroke (odds ratio = 1.74; 95% confidence intervals: 1.21, 2.51, and 0.92; and 0.46, 1.83, respectively). Our findings suggest that switching from VKA to DOAC is an intermittent risk factor of bleeding and ischemic stroke in patients with AF.

The importance of adherence and persistence in the elderly atrial fibrillation patient

Older adults with atrial fibrillation are at the highest risk of ischaemic stroke yet are the least likely to be prescribed anticoagulant therapy, adhere to this therapy, and maintain long-term persistence with this therapy. The reasons for this under treatment are multifactorial and include patient-driven factors, physician-driven factors, medical system complexities, and current unknowns regarding the biology and natural history of AF. Understanding these challenges to stroke prevention and addressing identified barriers to medication adherence and persistence in this vulnerable age group will improve outcomes related to AF.

Long-Term Treatment with Apixaban in Patients with Atrial Fibrillation: Outcomes during the Open-Label Extension following AVERROES

BACKGROUND

 AVERROES, a randomized controlled trial in high-risk patients with atrial fibrillation, unsuitable for vitamin K antagonist therapy, demonstrated efficacy and safety of apixaban compared with aspirin. At the conclusion of the double-blind phase, an open-label extension was initiated to allow study participants to receive apixaban until it became locally available. This study reports outcomes of patients on apixaban during the open-label extension.

METHODS

 Rates of stroke or systemic embolism, hemorrhagic stroke, major bleeding, and other outcomes during the open-label extension are reported.

RESULTS

 Of the 5,599 participants enrolled in AVERROES, 3,275 (58.5%) received apixaban during the open-label extension. Median (interquartile range) follow-up in the open-label extension was 3.0 (2.5-3.5) years. The rate of stroke or systemic embolism during the open-label extension was 1.0% per year, and the annual rates of hemorrhagic stroke and major bleeding were 0.3 and 1.2%, respectively. After adjustment for imbalances in patient variables, event rates in patients on apixaban during the open-label extension were similar to those of patients receiving apixaban during AVERROES. Additional analyses in all patients who received apixaban, at any time from the start of AVERROES to the end of the open-label extension, were performed. This cohort (n = 4,414) showed annual event rates of 1.1% for stroke or systemic embolism, 0.3% for hemorrhagic stroke, and 1.2% for major bleeding.

CONCLUSION

 During the open-label extension, annual rates of stroke or systemic embolism, hemorrhagic stroke, and major bleeding remained as low as those observed during apixaban treatment in AVERROES. These data support the long-term efficacy and safety of apixaban in patients with atrial fibrillation.

Premature permanent discontinuation of apixaban or warfarin in patients with atrial fibrillation

AIMS

The ARISTOTLE (Apixaban for Reduction in Stroke and Other Thromboembolic Events in Atrial Fibrillation) trial randomised patients with atrial fibrillation at risk of stroke to apixaban or warfarin. We sought to describe patients from ARISTOTLE who prematurely permanently discontinued study drug.

METHODS/RESULTS

We performed a posthoc analysis of patients from ARISTOTLE who prematurely permanently discontinued study drug during the study or follow-up period. Discontinuation rates and reasons for discontinuation were described. Death, thromboembolism (stroke, transient ischaemic attack, systemic embolism), myocardial infarction and major bleeding rates were stratified by ≤30 days or >30 days after discontinuation. A total of 4063/18 140 (22.4%) patients discontinued study drug at a median of 7.3 (2.2, 15.2) months after randomisation. Patients with discontinuation were more likely to be female and had a higher prevalence of cardiovascular disease, diabetes, renal impairment and anaemia. Premature permanent discontinuation was more common in those randomised to warfarin than apixaban (23.4% vs 21.4%; p=0.002). The most common reasons for discontinuation were patient request (46.1%) and adverse event (34.9%), with no significant difference between treatment groups. The cumulative incidence of clinical events ≤30 days after premature permanent discontinuation for all-cause death, thromboembolism, myocardial infarction, and major bleeding was 5.8%, 2.6%, 0.9%, and 3.0%, respectively. No significant difference was seen between treatment groups with respect to clinical outcomes after discontinuation.

CONCLUSION

Premature permanent discontinuation of study drug in ARISTOTLE was common, less frequent in patients receiving apixaban than warfarin and was followed by high 30-day rates of death, thromboembolism and major bleeding. Initiatives are needed to reduce discontinuation of oral anticoagulation.

Effectiveness and safety of direct oral anticoagulants in atrial fibrillation patients switched from vitamin K antagonists: A systematic review and meta-analysis

A substantial proportion of atrial fibrillation patients initiating direct oral anticoagulants (DOAC) are vitamin K antagonists (VKA)-experienced, for example switchers from VKA to DOAC. With this study, we aimed to summarize available evidence on the effectiveness and safety of DOAC vs VKA in real-life VKA-experienced atrial fibrillation patients. We searched EMBASE, MEDLINE and Cochrane Library systematically for English-language studies indexed any time before October 2018. We included studies of VKA-experienced atrial fibrillation patients initiating DOAC therapy, with continued VKA therapy as comparator. Outcomes included arterial thromboembolism and bleeding. When appropriate, meta-analysis was performed by calculating pooled, weighted and adjusted hazard ratios (aHR) with 95% confidence intervals (CI). Eight cohort studies comparing VKA-experienced DOAC (dabigatran or rivaroxaban) users with continued VKA users were included. When comparing DOAC to VKA, an increased risk of ischaemic stroke and myocardial infarction was found for dabigatran (pooled aHR of 1.61 [95% CI 1.19-2.19, I2  = 65%] and 1.29 [95% CI 1.10-1.52, I2  = 0%], respectively), but not for rivaroxaban. The use of dabigatran in VKA-experienced users was associated with an increased risk of gastrointestinal bleeding (pooled aHR 1.63 [95% CI 1.36-1.94, I2  = 30%]), but a decreased risk of intracranial bleeding (pooled aHR 0.45 [95% CI 0.32-0.64, I2  = 0%]). In conclusion, the use of dabigatran in prior VKA users in clinical practice was associated with a slightly increased risk of arterial thromboembolism and gastrointestinal bleeding, but a decreased risk of intracranial bleeding. Importantly, observational studies of real-life VKA-experienced oral anticoagulant users may be confounded by the reason for switching.

The 2018 European Heart Rhythm Association Practical Guide on the use of non-vitamin K antagonist oral anticoagulants in patients with atrial fibrillation

The current manuscript is the second update of the original Practical Guide, published in 2013 [Heidbuchel et al. European Heart Rhythm Association Practical Guide on the use of new oral anticoagulants in patients with non-valvular atrial fibrillation. Europace 2013;15:625-651; Heidbuchel et al. Updated European Heart Rhythm Association Practical Guide on the use of non-vitamin K antagonist anticoagulants in patients with non-valvular atrial fibrillation. Europace 2015;17:1467-1507]. Non-vitamin K antagonist oral anticoagulants (NOACs) are an alternative for vitamin K antagonists (VKAs) to prevent stroke in patients with atrial fibrillation (AF) and have emerged as the preferred choice, particularly in patients newly started on anticoagulation. Both physicians and patients are becoming more accustomed to the use of these drugs in clinical practice. However, many unresolved questions on how to optimally use these agents in specific clinical situations remain. The European Heart Rhythm Association (EHRA) set out to coordinate a unified way of informing physicians on the use of the different NOACs. A writing group identified 20 topics of concrete clinical scenarios for which practical answers were formulated, based on available evidence. The 20 topics are as follows i.e., (1) Eligibility for NOACs; (2) Practical start-up and follow-up scheme for patients on NOACs; (3) Ensuring adherence to prescribed oral anticoagulant intake; (4) Switching between anticoagulant regimens; (5) Pharmacokinetics and drug-drug interactions of NOACs; (6) NOACs in patients with chronic kidney or advanced liver disease; (7) How to measure the anticoagulant effect of NOACs; (8) NOAC plasma level measurement: rare indications, precautions, and potential pitfalls; (9) How to deal with dosing errors; (10) What to do if there is a (suspected) overdose without bleeding, or a clotting test is indicating a potential risk of bleeding; (11) Management of bleeding under NOAC therapy; (12) Patients undergoing a planned invasive procedure, surgery or ablation; (13) Patients requiring an urgent surgical intervention; (14) Patients with AF and coronary artery disease; (15) Avoiding confusion with NOAC dosing across indications; (16) Cardioversion in a NOAC-treated patient; (17) AF patients presenting with acute stroke while on NOACs; (18) NOACs in special situations; (19) Anticoagulation in AF patients with a malignancy; and (20) Optimizing dose adjustments of VKA. Additional information and downloads of the text and anticoagulation cards in different languages can be found on an EHRA website (www.NOACforAF.eu).

Outcome reporting from clinical trials of non-valvular atrial fibrillation treated with traditional Chinese medicine or Western medicine: a systematic review

OBJECTIVES

To examine variation in outcomes, outcome measurement instruments (OMIs) and measurement times in clinical trials of non-valvular atrial fibrillation (NVAF) and to identify outcomes for prioritisation in developing a core outcome set (COS) in this field.

DESIGN

This study was a systematic review.

DATA SOURCES

Clinical trials published between January 2015 and March 2019 were obtained from PubMed, the Cochrane Library, Web of Science, Wanfang Database, the China National Knowledge Infrastructure and SinoMed.

ELIGIBILITY CRITERIA

Randomised controlled trials (RCTs) and observational studies were considered. Interventions included traditional Chinese medicine and Western medicine. The required treatment duration or follow-up time was ≥4 weeks. The required sample size was ≥30 and≥50 in each group in RCTs and observational studies, respectively. We excluded trials that aimed to investigate the outcome of complications of NVAF, to assess the mechanisms or pharmacokinetics, or for which full text could not be acquired.

DATA EXTRACTION AND SYNTHESIS

The general information and outcomes, OMIs and measurement times were extracted. The methodological and outcome reporting quality were assessed. The results were analysed by descriptive analysis.

RESULTS

A total of 218 articles were included from 25 255 articles. For clinical trials of antiarrhythmic therapy, 69 outcomes from 16 outcome domains were reported, and 28 (31.82%, 28/88) outcomes were reported only once; the most frequently reported outcome was ultrasonic cardiogram. Thirty-one outcomes (44.93%, 31/69) were provided definitions or OMIs; the outcome measurement times ranged from 1 to 20 with a median of 3. For clinical trials of anticoagulation therapy, 82 outcomes from 18 outcome domains were reported; 38 (29.23%, 38/130) outcomes were reported only once. The most frequently reported outcome was ischaemic stroke. Forty (48.78%, 40/82) outcomes were provided OMIs or definitions; and the outcome measurement times ranged from 1 to 27 with a median of 8.

CONCLUSION

Outcome reporting in NVAF is inconsistent. Thus, developing a COS that can be used in clinical trials is necessary.

Direct Oral Anticoagulant (DOAC) to Warfarin Transitions in a Pharmacist-led Anticoagulation Clinic

Purpose Patients with non-valvular atrial fibrillation or venous thromboembolism have historically been treated with vitamin-k antagonist therapy; however, due to well-documented limitations, direct oral anticoagulant (DOAC) use has been increasing.(1)(2) The convenience and clinical utility of DOACs is not applicable to all patients, and some must be transitioned to warfarin therapy. Despite practice recommendations, suggestions from package inserts, and clinical trial evidence, there remains a lack of literature describing real-word examples of patient transition from DOACs to warfarin.(3–11) Summary All patients who were transitioned from a DOAC to warfarin from January to December 2016 and were managed by the clinic were included. Patients were excluded if the transition to warfarin did not include ≥ 2 days of DOAC overlap or if DOAC therapy was used as a bridge to surgery or procedure. St. Joseph's/Candler Health System IRB granted expedited approval and waived informed consent. Four elderly, Caucasian patients met the inclusion criteria. Four patients were successfully transitioned from a DOAC to warfarin for their atrial fibrillation, 3 were transitioned from apixaban and 1 was transitioned from rivaroxaban. Conclusion Overall the purpose of this retrospective, observational study was to highlight real-world management of the transition of DOACs to warfarin in an outpatient, pharmacist-led clinic.

Vascular protease-activated receptor 4 upregulation, increased platelet aggregation, and coronary lipid deposits induced by long-term dabigatran administration - results from a diabetes animal model

Essentials The impact of long-term thrombin inhibition outside the coagulation cascade is far from clear. We aimed to assess the impact of dabigatran etexilate (DE) in diabetic and control rats. In diabetic rats, DE increased platelet aggregation and lead to coronary lipid deposits. Long-term thrombin inhibition may increase atherosclerotic and atherothrombotic risk. SUMMARY: Background Besides its role in the coagulation cascade, thrombin contributes to platelet aggregation and to a plethora of non-hemostatic functions. Objectives To assess the impact of long-term thrombin inhibition with dabigatran etexilate (DE) on platelet aggregation and on extrahemostatic thrombin-related functions in diabetic and control rats. Methods Markers of inflammation, endothelial dysfunction, oxidative stress, angiogenesis and cell adhesion molecules were quantified in control rats (Control; n = 6), DE-treated control rats (Control-Dabi; n = 8), diabetic rats (Diabetes; n = 5), and DE-treated diabetic rats (Diabetes-Dabi; n = 8). Agonist-induced platelet aggregation, aortic and coronary lipid deposits and aortic protease-activated receptor 4 (PAR4) expression were also assessed. Results Control-Dabi rats showed significantly higher high-sensitivity C-reactive protein, von Willebrand factor (VWF), vascular endothelial growth factor (VEGF) and fibronectin levels, and significantly lower PAR4 agonist-induced aggregation, than Control rats. Control-Dabi rats also showed mild aortic lipid deposits, whereas no such changes were observed in Control rats. Diabetes-Dabi rats showed significantly higher VWF, VEGF and fibronectin levels than Diabetes rats, and similar PAR4 agonist-induced aggregation as Diabetes rats, and significantly higher ADP-induced aggregation than Diabetes rats. Coronary lipid deposits were observed in 75% of Diabetes-Dabi rats and in none of the Diabetes rats. PAR4 expression was 20.4% higher in Control-Dabi rats and 27.4% higher in Diabetes-Dabi rats than in their non-treated peers. Conclusions This study indicates that long-term thrombin inhibition increases vascular PAR4 expression, promotes atherosclerosis-related mechanisms, and, in diabetic rats, increases platelet aggregation and favors the occurrence of coronary lipid deposits. These experimental data suggest that long-term thrombin inhibition may increase atherosclerotic and atherothrombotic risk, particularly in the presence of diabetes.

American Society of Hematology 2018 guidelines for management of venous thromboembolism: optimal management of anticoagulation therapy

BACKGROUND

Clinicians confront numerous practical issues in optimizing the use of anticoagulants to treat venous thromboembolism (VTE).

OBJECTIVE

These evidence-based guidelines of the American Society of Hematology (ASH) are intended to support patients, clinicians and other health care professionals in their decisions about the use of anticoagulants in the management of VTE. These guidelines assume the choice of anticoagulant has already been made.

METHODS

ASH formed a multidisciplinary guideline panel balanced to minimize potential bias from conflicts of interest. The McMaster University GRADE Centre supported the guideline development process, including updating or performing systematic evidence reviews. The panel prioritized clinical questions and outcomes according to their importance for clinicians and patients. The Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach was used to assess evidence and make recommendations, which were subject to public comment.

RESULTS

The panel agreed on 25 recommendations and 2 good practice statements to optimize management of patients receiving anticoagulants.

CONCLUSIONS

Strong recommendations included using patient self-management of international normalized ratio (INR) with home point-of-care INR monitoring for vitamin K antagonist therapy and against using periprocedural low-molecular-weight heparin (LMWH) bridging therapy. Conditional recommendations included basing treatment dosing of LMWH on actual body weight, not using anti-factor Xa monitoring to guide LMWH dosing, using specialized anticoagulation management services, and resuming anticoagulation after episodes of life-threatening bleeding.

COMPARISON OF SCHEMES OF PERIOPERATIONAL ANTICOAGULATION IN ATRIAL FIBRILLATION PATIENTS DEMANDING FOR SURGERY

A literature review provided, on the usage of various schemes of perioperational anticoagulation therapy (ACT) in atrial fibrillation patients undergoing scheduled surgery. It is noted that clinicians quite often pass through a situation when patients taking ACT require invasive investigations and surgery. Perioperational management of such category of patients is complicated as, on the one hand, the surgery under ACT is associated with intraoperational hemorrhagic complications, and, on the other hand, ACT cessation might increase the risk of thrombotic complications. The variants assessed, of different periprocedural ACT in patients taking vitamin K antagonists. It was found that as an alternative to continuous ACT recently, bridge therapy with low molecular weight heparins applied, aiming the decrease of the risk of bleeding in adequate thromboprophylaxis. The results of clinical trials provided on the assessment of bridge therapy in surgery. Risk stratification approaches presents for thromboembolic and hemorrhagic complications in surgery.

Clinical events after interruption of anticoagulation in patients with atrial fibrillation: An analysis from the ENGAGE AF-TIMI 48 trial

BACKGROUND

Patients with atrial fibrillation (AF) who interrupt anticoagulation are at high risk of thromboembolism and death.

METHODS AND RESULTS

Patients enrolled in the ENGAGE AF-TIMI 48 trial (randomized comparison of edoxaban vs. warfarin) who interrupted study anticoagulant for >3 days were identified. Clinical events (ischemic stroke/systemic embolism, major cardiac and cerebrovascular events [MACCE]) were analyzed from day 4 after interruption until day 34 or study drug resumption. During 2.8 years median follow-up, 13,311 (63%) patients interrupted study drug for >3 days. After excluding those who received open-label anticoagulation during the at-risk window, the population for analysis included 9148 patients. The rates of ischemic stroke/systemic embolism and MACCE post interruption were substantially greater than in patients who never interrupted (15.42 vs. 0.26 and 60.82 vs. 0.36 per 100 patient-years, respectively, p_adj < .001). Patients who interrupted study drug for an adverse event (44.1% of the cohort), compared to those who interrupted for other reasons, had an increased risk of MACCE (HR_adj 2.75; 95% CI 2.02-3.74, p < .0001), but similar rates of ischemic stroke/systemic embolism. Rates of clinical events after interruption of warfarin and edoxaban were similar.

CONCLUSION

Interruption of study drug was frequent in patients with AF and was associated with a substantial risk of major cardiac and cerebrovascular events over the ensuing 30 days. This risk was particularly high in patients who interrupted as a result of an adverse event; these patients deserve close monitoring and resumption of anticoagulation as soon as it is safe to do so.

Comparison of Anticoagulant Therapy for Atrial Fibrillation - Novel Oral Anticoagulants Versus Vitamin K Antagonists

In patients with non-valvular atrial fibrillation (NVAF), oral anticoagulation is important for prevention of stroke and systemic embolism (SE). While Vitamin K antagonists (VKAs) have historically been the standard of care, these medications are limited by numerous food and drug interactions with onerous requirements for frequent monitoring and dose adjustments. Over the past decade, several novel oral anticoagulants (NOACs) have been developed to directly inhibit factor IIa/thrombin (dabigatran) or activated factor X (apixaban, rivaroxaban, edoxaban). These medications have been shown to be at least as effective as warfarin for stroke prevention in NVAF with more favorable safety profiles. However, their advantages are underscored by a lack of specific antidotes and assays quantifying their anticoagulant effects. This paper addresses the use of NOACs compared to VKAs in patients with NVAF, with a special focus on high-risk populations, including the elderly, those with renal disease, diabetes mellitus, coronary artery disease, and previous stroke. The current literature surrounding special clinical scenarios including the treatment of bleeding, perioperative management, and the use of NOACs in cardioversion and catheter ablation will be also discussed.

New Standards of Care in Ischemic Stroke

BACKGROUND

Ischemic arterial strokes of the ophthalmic artery and its branches and posterior cerebral artery are common causes of visual disability. Etiologies of stroke affecting the retina, optic nerve, optic radiation, and visual cortex overlap with other types of ischemic strokes. Stenosis of the internal carotid is the most common cause of central retinal artery occlusion (CRAO). One-fourth of patients with CRAO have cerebral strokes. We report recent developments in the acute treatment and secondary prevention of ischemic stroke of relevance to clinicians who encounter patients with acute vision loss.

EVIDENCE ACQUISITION

A search of Pubmed and practice guidelines over the past 5 years was performed, with a focus on significant changes in treatment and prevention of ischemic stroke.

RESULTS

Recent randomized controlled trials provide Level I evidence for the use of endovascular therapy with current stent retriever devices for patients with large vessel anterior circulation occlusions within 6 hours of presentation. Number needed to treat to achieve one additional patient with an independent functional outcome was in the range of 3-7, and benefit was additive to that of intravenous tissue plasminogen activator alone. Paroxysmal atrial fibrillation (AF) is a major cause of cryptogenic stroke with incidence expected to rise with the aging population. Since 2014, prolonged 30-day cardiac monitoring has been recommended as a part of transient ischemic attack and stroke workup in patients with cryptogenic stroke. Even longer term monitoring of 6 months to 1 year with external and implantable loop recorders improves rates of diagnosing AF. First available in 2010, the novel anticoagulants-dabigatran, apixaban, rivaroxaban, and edoxaban-have been compared with warfarin in the prevention of stroke in patients with nonvalvular AF. Apixaban demonstrated superiority in safety and efficacy, with the novel anticoagulants as a group having favorable risk-benefit profile at higher dosages compared with standard warfarin therapy.

CONCLUSIONS

Endovascular therapy is now standard of care for eligible patients with anterior large vessel occlusions. Prolonged cardiac monitoring is recommended for patients with cryptogenic stroke. The novel anticoagulants are an alternative to warfarin in patients with AF.

Updated European Heart Rhythm Association practical guide on the use of non-vitamin-K antagonist anticoagulants in patients with non-valvular atrial fibrillation: Executive summary

In 2013, the European Heart Rhythm Association (EHRA) published a Practical Guide on the use of non-VKA oral anticoagulants (NOACs) in patients with atrial fibrillation (AF) (Heidbuchel H, Verhamme P, Alings M, Antz M, Hacke W, Oldgren J, Sinnaeve P, Camm AJ, Kirchhof P, European Heart Rhythm A. European Heart Rhythm Association Practical Guide on the use of new oral anticoagulants in patients with non-valvular atrial fibrillation. Europace 2013;15:625-651; Heidbuchel H, Verhamme P, Alings M, Antz M, Hacke W, Oldgren J, Sinnaeve P, Camm AJ, Kirchhof P. EHRA practical guide on the use of new oral anticoagulants in patients with non-valvular atrial fibrillation: executive summary. Eur Heart J 2013;34:2094-2106). The document received widespread interest, not only from cardiologists but also from neurologists, geriatricians, and general practitioners, as became evident from the distribution of >350 000 copies of its pocket version (the EHRA Key Message Booklet) world-wide. Since 2013, numerous new studies have appeared on different aspects of NOAC therapy in AF patients. Therefore, EHRA updated the Practical Guide, including new information but also providing balanced guiding in the many areas where prospective data are still lacking. The outline of the original guide that addressed 15 clinical scenarios has been preserved, but all chapters have been rewritten. Main changes in the Update comprise a discussion on the definition of 'non-valvular AF' and eligibility for NOAC therapy, inclusion of finalized information on the recently approved edoxaban, tailored dosing information dependent on concomitant drugs, and/or clinical characteristics, an expanded chapter on neurologic scenarios (ischaemic stroke or intracranial haemorrhage under NOAC), an updated anticoagulation card and more specifics on start-up and follow-up issues. There are also many new flow charts, like on appropriate switching between anticoagulants (VKA to NOAC or vice versa), default scenarios for acute management of coronary interventions, step-down schemes for long-term combined antiplatelet-anticoagulant management in coronary heart disease, management of bleeding, and cardioversion under NOAC therapy. The Updated Guide is available in full in EP Europace (Heidbuchel H, Verhamme P, Alings M, Antz M, Diener HC, Hacke W, Oldgren J, Sinnaeve P, Camm AJ, Kirchhof P, Advisors. Updated European Heart Rhythm Association Practical Guide on the use of non-vitamin K antagonist anticoagulants in patients with non-valvular atrial fibrillation. Europace 2015;17:1467-1507), while additional resources can be found at the related ESC/EHRA website (www.NOACforAF.eu).

Atrial fibrillation as a complication of ibrutinib therapy: clinical features and challenges of management

Ibrutinib is a Bruton's tyrosine kinase (BTK) inhibitor finding increasingly widespread use in non-Hodgkin lymphoma. Evidence of an increased risk of atrial fibrillation (AF) emerged in Phase III studies with a median incidence of approximately 6%. The mechanism remains unknown, but inhibition of a cardioprotective pathway has been proposed. Ibrutinib induces a platelet function defect, increasing the bleeding risk of anticoagulation for AF stroke prophylaxis. Multiple potential drug interactions are an added complication. In this review we examine the characteristics and management of the reported cases of AF with ibrutinib and where possible make recommendations. The evidence suggests dose reduction or temporary suspension of drug, are feasible alternative to discontinuation. The optimum choice of thromboprophylaxis has not been determined, but we propose the use of novel anticoagulants (NOACs) and avoidance of anti-platelet agents where possible. Further research and consensus guidelines are required.

Ischemic Stroke in Nonvalvular Atrial Fibrillation at Warfarin Initiation

Background and Purpose—

Stroke risk may increase shortly after warfarin initiation in nonvalvular atrial fibrillation patients. Because of the brief period and limited number of events, large samples are needed to study this effect. We compared 30-day rates of ischemic stroke between nonvalvular atrial fibrillation patients initiating warfarin to nonwarfarin comparators using an insurance claims database.

Methods—

We identified nonvalvular atrial fibrillation patients via 1 inpatient/2 outpatient diagnosis claims from the MarketScan database, January 1, 2009, to December 31, 2010. We studied patients initiating warfarin using prescription claims and 1:1 matched 22 669 initiators to comparators based on age, sex, diagnosis date, and warfarin propensity score. Follow-up began on initiation date; patients were censored at discontinuation/switch of therapy, disenrollment, or end of the study. The median follow-up was 415 days. Cox regression was used to study differences in ischemic stroke risks between warfarin initiators and comparators while controlling for important prognostic factors.

Results—

Warfarin initiators were generally similar to comparators in clinical features but had higher CHADS 2 scores (1.26 versus 1.19). The first 30-day ischemic stroke rate was higher among warfarin initiators than comparators (1.47%/y (27/1836) versus 0.98%/y (18/1837); P =0.18) but lower subsequently (0.81%/y [134/16 543] versus 1.09%/y [406/37 248]; P =0.002). Multivariable regression confirmed a significant interaction between follow-up and warfarin use with the adjusted hazard ratios (95% confidence intervals) for warfarin/comparator as 1.46 (0.80–2.65) in the first 30 days and 0.70 (0.57–0.85) afterward.

Conclusions—

Warfarin effect was qualitatively different in the first 30 days after initiation than subsequently. This is consistent with a modest increase in stroke risk occurring briefly after starting warfarin.

Apixaban to prevent stroke in patients with atrial fibrillation: a review

Atrial fibrillation is a common, costly and morbid cardiovascular arrhythmia. Stroke prevention remains the mainstay of treatment for atrial fibrillation, and the recent advent of novel oral anticoagulants with direct factor IIa or factor Xa inhibition has significantly revolutionized this aspect of treatment for atrial fibrillation patients. This review focuses on the tolerability and efficacy of apixaban and tackles the generalizability of the findings with apixaban to broader patient populations than those primarily enrolled in the clinical trials, drawing from the AVERROES and ARISTOTLE trials and their subsequent secondary analyses. Taken together, findings from these trials show that apixaban is superior to warfarin in preventing stroke with a lower risk of major bleeding in the general population of patients with atrial fibrillation as well as in several key high-risk patient subgroups.

Management of Patients on Non-Vitamin K Antagonist Oral Anticoagulants in the Acute Care and Periprocedural Setting: A Scientific Statement From the American Heart Association

Non-vitamin K oral anticoagulants (NOACs) are now widely used as alternatives to warfarin for stroke prevention in atrial fibrillation and management of venous thromboembolism. In clinical practice, there is still widespread uncertainty on how to manage patients on NOACs who bleed or who are at risk for bleeding. Clinical trial data related to NOAC reversal for bleeding and perioperative management are sparse, and recommendations are largely derived from expert opinion. Knowledge of time of last ingestion of the NOAC and renal function is critical to managing these patients given that laboratory measurement is challenging because of the lack of commercially available assays in the United States. Idarucizumab is available as an antidote to rapidly reverse the effects of dabigatran. At present, there is no specific antidote available in the United States for the oral factor Xa inhibitors. Prothrombin concentrate may be considered in life-threatening bleeding. Healthcare institutions should adopt a NOAC reversal and perioperative management protocol developed with multidisciplinary input.

Recent advances in the understanding and management of atrial fibrillation: a focus on stroke prevention

Atrial fibrillation (AF) is associated with an increased risk of stroke compared with the general population. It is anticipated that by 2030 an estimated 14-17 million patients will be diagnosed with this most prevalent arrhythmia within the European Union. AF-related stroke confers a higher mortality and morbidity risk, and thus early detection and assessment for the initiation of effective stroke prevention with oral anticoagulation (OAC) is crucial. Recent guidelines point to the use of non-vitamin K antagonist OACs (NOACs) where appropriate in stroke prevention of patients with non-valvular AF. At present, there are four NOACS available, with no direct head-to-head comparisons to suggest the superiority of one drug over another. Simple and practical risk assessment tools have evolved over the years to facilitate stroke and bleeding risk assessment in busy clinics and wards to aid decision-making. At present, the CHA ₂DS ₂VASc (congestive heart failure, hypertension, age 65-74/>75, diabetes mellitus, stroke/transient ischemic attack/thromboembolism, vascular disease, female sex) score is recommended by many international guidelines as a simple and practical method of assessing stroke risk in such patients. Alongside this, use of the HAS BLED (hypertension systolic blood pressure >160 mmHg, abnormal liver/renal function [with creatinine ≥200 μmol/L], stroke, bleeding history or predisposition, labile international normalized ratio [range <60% of the time], elderly [>65], concomitant drugs/alcohol) score aims to identify patients at high risk of bleeding for more regular review and follow-up and draws attention to potentially reversible bleeding risk factors. The aim of this review article is to provide an overview of recent advances in the understanding and management of AF with a focus on stroke prevention.

Edoxaban in patients with atrial fibrillation

Edoxaban, a direct factor Xa inhibitor, was extensively studied in the prevention and treatment of venous thromboembolism and in patients with nonvalvular atrial fibrillation (AF). The aim of this review is to focus specifically on the efficacy and safety profile of edoxaban in patients with AF from preclinical development through the phase III trial that led to regulatory approval.

Risk of Thromboembolic Events in Patients with Non-Valvular Atrial Fibrillation After Dabigatran or Rivaroxaban Discontinuation - Data from the Ljubljana Registry

Background and Aim

Interruption of anticoagulant treatment with warfarin or non-vitamin K antagonist oral anticoagulants (NOAC) represents a vulnerable period with an increased risk of thromboembolic events. What is the incidence of thromboembolic events in real-life patients with non-valvular atrial fibrillation treated with NOAC who had a discontinuation or cessation of treatment in comparison to patients on continuous treatment?

Patients and Methods

Registry data from 866 patients with non-valvular atrial fibrillation, aged 74.3 (SD 9.8) years, with an average CHADS₂ score of 2.1 (SD 1.2), who were started on dabigatran or rivaroxaban, were analysed for thromboembolic events and survival. Patients who had temporary or permanent discontinuation of NOAC were compared to patients on continuous NOAC treatment.

Results

Among 866 patients started on NOAC, 705 were treated without interruption, 84 patients had temporary interruption (69 because of planned invasive procedures, 10 due to bleeding, 5 for other causes) and 77 had permanent cessation of NOAC treatment. In patients without interruptions, the incidence of thromboembolic events was 1.0 (95% CI 0.4–2.1) per 100 patient-years, while in patients with interruption/cessation the rate of thromboembolic events was 21.6 (95% CI 10.3–45.2) per 100 patient-years, p < 0.001. There was a distinct clustering of thromboembolic events in the first weeks of NOAC discontinuation with the median occurring on day 14 (range 1–37 days) after discontinuation.

Conclusion

Dabigatran and rivaroxaban offered good protection against thromboembolic events during treatment, but interruption of NOAC treatment increased the short-term thromboembolic risk more than 20-fold.

Newer Oral Anticoagulants: Stroke Prevention and Pitfalls

Warfarin is very effective in preventing stroke in patients with atrial fibrillation. However, its use is limited due to fear of hemorrhagic complications, unpredictable anticoagulant effects related to multiple drug interactions and dietary restrictions, a narrow therapeutic window, frequent difficulty maintaining the anticoagulant effect within a narrow therapeutic window, and the need for inconvenient monitoring. Several newer oral anticoagulants have been approved for primary and secondary prevention of stroke in patients with non-valvular atrial fibrillation. These agents have several advantages relative to warfarin therapy. As a group, these direct oral anticoagulants (DOAC), which include the direct thrombin inhibitor, dabigatran, and the factor Xa inhibitors (rivaroxaban, apixaban, and edoxaban), are more effective than dose adjusted warfarin for prevention of all-cause stroke (including both ischemic and hemorrhagic stroke), and have an overall more favorable safety profile. Nevertheless, an increased risk of gastrointestinal bleeding (with the exception of apixaban), increased risk for thrombotic complication with sudden discontinuation, and inability to accurately assess and reverse anticoagulant effect require consideration prior to therapy initiation, and pose a challenge for decision making in acute stroke therapy.

Once-daily rivaroxaban for long-term stroke prevention in patients with atrial fibrillation

Oral anticoagulation is the long-term standard of care for preventing stroke in patients with atrial fibrillation (AF). However, anticoagulation is associated with an increased risk of bleeding, such that its use should be based on the absolute risks of stroke and bleeding, and the relative benefit-risk profile of the individual patient. Non-vitamin K antagonist oral anticoagulants, including rivaroxaban, are alternatives to vitamin K antagonists such as warfarin in this setting, and are supported in treatment guidelines as the optimal choice for patients with AF at moderate to high risk of stroke. Rivaroxaban can be given in fixed doses without routine coagulation monitoring, and phase III studies have demonstrated its safety profile and efficacy in patients with non-valvular AF, including the elderly and those with co-morbidities. Moreover, rivaroxaban is administered once daily, which has advantages for optimal patient adherence to medication over the long term. The established efficacy and safety profile of rivaroxaban, together with its convenient once-daily dosing schedule, may contribute to improved patient outcomes and lead to sustained benefits for patients with non-valvular AF at risk of stroke.

Direct Oral Anticoagulants in Dental Patients Including the Frail Elderly Population

Direct oral anticoagulants (DOACs) have led to a paradigm shift in the field of anticoagulation, providing safe and convenient anticoagulation without the need for regular blood testing. Currently, there are three major DOACs available-Factor Xa inhibitors (apixaban and rivaroxaban) and direct thrombin inhibitors (dabigatran)-that are available for use in atrial fibrillation and venous thromboembolism. While these agents have been shown to be as effective as warfarin, with a similar or better bleeding profile, there remains some concern of the use of these drugs in vulnerable populations, such as the frail elderly patients; particularly since reversal agents and drug monitoring are not routinely available. We aim to provide a review of the use of DOACs and the impact of DOACs on dental treatment in the elderly population.

Bridging Anticoagulation: Primum Non Nocere

Chronic oral anticoagulation frequently requires interruption for various reasons and durations. Whether or not to bridge with heparin or other anticoagulants is a common clinical dilemma. The evidence to inform decision making is limited, making current guidelines equivocal and imprecise. Moreover, indications for anticoagulation interruption may be unclear. New observational studies and a recent large randomized trial have noted significant perioperative or periprocedural bleeding rates without reduction in thromboembolism when bridging is employed. Such bleeding may also increase morbidity and mortality. In light of these findings, physician preferences for routine bridging anticoagulation during chronic anticoagulation interruptions may be too aggressive. More randomized trials, such as PERIOP2 (A Double Blind Randomized Control Trial of Post-Operative Low Molecular Weight Heparin Bridging Therapy Versus Placebo Bridging Therapy for Patients Who Are at High Risk for Arterial Thromboembolism), will help guide periprocedural management of anticoagulation for indications such as venous thromboembolism and mechanical heart valves. In the meantime, physicians should carefully consider both the need for oral anticoagulation interruption and the practice of routine bridging when anticoagulation interruption is indicated.

Updated European Heart Rhythm Association Practical Guide on the use of non-vitamin K antagonist anticoagulants in patients with non-valvular atrial fibrillation

The current manuscript is an update of the original Practical Guide, published in June 2013[Heidbuchel H, Verhamme P, Alings M, Antz M, Hacke W, Oldgren J, et al. European Heart Rhythm Association Practical Guide on the use of new oral anticoagulants in patients with non-valvular atrial fibrillation. Europace 2013;15:625-51; Heidbuchel H, Verhamme P, Alings M, Antz M, Hacke W, Oldgren J, et al. EHRA practical guide on the use of new oral anticoagulants in patients with non-valvular atrial fibrillation: executive summary. Eur Heart J 2013;34:2094-106]. Non-vitamin K antagonist oral anticoagulants (NOACs) are an alternative for vitamin K antagonists (VKAs) to prevent stroke in patients with non-valvular atrial fibrillation (AF). Both physicians and patients have to learn how to use these drugs effectively and safely in clinical practice. Many unresolved questions on how to optimally use these drugs in specific clinical situations remain. The European Heart Rhythm Association set out to coordinate a unified way of informing physicians on the use of the different NOACs. A writing group defined what needs to be considered as 'non-valvular AF' and listed 15 topics of concrete clinical scenarios for which practical answers were formulated, based on available evidence. The 15 topics are (i) practical start-up and follow-up scheme for patients on NOACs; (ii) how to measure the anticoagulant effect of NOACs; (iii) drug-drug interactions and pharmacokinetics of NOACs; (iv) switching between anticoagulant regimens; (v) ensuring adherence of NOAC intake; (vi) how to deal with dosing errors; (vii) patients with chronic kidney disease; (viii) what to do if there is a (suspected) overdose without bleeding, or a clotting test is indicating a risk of bleeding?; (xi) management of bleeding complications; (x) patients undergoing a planned surgical intervention or ablation; (xi) patients undergoing an urgent surgical intervention; (xii) patients with AF and coronary artery disease; (xiii) cardioversion in a NOAC-treated patient; (xiv) patients presenting with acute stroke while on NOACs; and (xv) NOACs vs. VKAs in AF patients with a malignancy. Additional information and downloads of the text and anticoagulation cards in >16 languages can be found on an European Heart Rhythm Association web site (www.NOACforAF.eu).

Oral anticoagulants for stroke prevention in atrial fibrillation: current status, special situations, and unmet needs

In patients with non-valvular atrial fibrillation, oral anticoagulation with vitamin K antagonists reduces the risk of stroke by more than 60%. But vitamin K antagonists have limitations, including causing serious bleeding such as intracranial haemorrhage and the need for anticoagulation monitoring. In part related to these limitations, they are used in only about half of patients who should be treated according to guideline recommendations. In the past decade, oral agents have been developed that directly block the activity of thrombin (factor IIa), as well as drugs that directly inhibit activated factor X (Xa), which is the first protein in the final common pathway to the activation of thrombin. These novel non-vitamin K antagonist oral anticoagulants (NOACs) have been shown to be at least as good as warfarin for stroke prevention in atrial fibrillation and they have proved to have better safety profiles. Their net advantage is underscored by significantly lower all-cause mortality compared with warfarin in large clinical trials. Because of these features and their ease of use, they are recommended for stroke prevention in atrial fibrillation. They have also a fast onset and offset of action, but they currently lack specific antidotes. This paper addresses the role of anticoagulation for stroke prevention in atrial fibrillation in the era of NOACs, with a focus on special situations including management in the event of bleeding and around the time of procedures including cardioversion, catheter ablation, and device implantation. Also their use in patients with concomitant coronary artery disease, with advanced age, with chronic kidney disease, or with valvular heart disease will be discussed as well as the interaction of NOACs with other cardiac medication, and switching between anticoagulants.