Patient's values and preferences for stroke prevention in atrial fibrillation: balancing stroke and bleeding risk with oral anticoagulation

Assessment and Mitigation of Bleeding Risk in Atrial Fibrillation and Venous Thromboembolism: Executive Summary of a European and Asia-Pacific Expert Consensus Paper

While there is a clear clinical benefit of oral anticoagulation in patients with atrial fibrillation (AF) and venous thromboembolism (VTE) in reducing the risks of thromboembolism, major bleeding events (especially intracranial bleeds) may still occur and be devastating. The decision for initiating and continuing anticoagulation is often based on a careful assessment of both thromboembolism and bleeding risk. The more common and validated bleeding risk factors have been used to formulate bleeding risk stratification scores, but thromboembolism and bleeding risk factors often overlap. Also, many factors that increase bleeding risk are transient and modifiable, such as variable international normalized ratio values, surgical procedures, vascular procedures, or drug-drug and food-drug interactions. Bleeding risk is also not a static "one-off" assessment based on baseline factors but is dynamic, being influenced by aging, incident comorbidities, and drug therapies. In this executive summary of a European and Asia-Pacific Expert Consensus Paper, we comprehensively review the published evidence and propose a consensus on bleeding risk assessments in patients with AF and VTE, with a view to summarizing "best practice" when approaching antithrombotic therapy in these patients. We address the epidemiology and size of the problem of bleeding risk in AF and VTE, and review established bleeding risk factors and summarize definitions of bleeding. Patient values and preferences, balancing the risk of bleeding against thromboembolism, are reviewed, and the prognostic implications of bleeding are discussed. We propose consensus statements that may help to define evidence gaps and assist in everyday clinical practice.

Screening for untreated atrial fibrillation in the elderly population: A community-based study

Background

Strokes are common in people with atrial fibrillation (AF), and can have devastating consequences, especially in the elderly and if AF is untreated. However, community-based studies on screening for untreated AF have not been conducted in Japan, and there has been no evaluation of the effectiveness of early screening for AF in the elderly (≥65 years).

Methods

The Kyoto Prefectural University of Medicine (KPUM) Education Initiative has conducted an AF awareness campaign consisted of screening tests using a blood pressure (BP) monitor with electrocardiogram (ECG) (the Complete, Omron Healthcare Co., Ltd., Kyoto, Japan) and educational lectures for the elderly (≥65 years) from 2019 to 2020. A modeled effectiveness analysis was performed comparing the life-years and QALYs (quality-adjusted life-years) between direct-acting oral anticoagulation (DOAC)-treated AF and untreated AF in a Japanese setting. The basic description of the Markov model was used for the analysis.

Results

A total of 1648 participants were screened, and after excluding those with missing information or data (n = 41), 1607 were finally enrolled. The mean (± standard deviation) age of participants was 72.4±5.8 years, 827 (51.5%) were female, 628 (39.1%) had hypertension, and 1368 (85.1%) had CHA2DS2-VASc score ≥2. After cardiologists’ evaluation of all ECG recordings of the Complete, 15 (0.93%) AF were newly detected. For each AF treated with DOAC, 0.859 QALYs gained over the lifetime for 65 years-old men, and 0.856 QALYs for 65 years-old women compared to non-treatment.

Conclusion

A moderate number of untreated AF were identified in the community-based study. Identification of an increased number of patients with AF, if properly treated with DOAC, ultimately leads to a reduction in the number of strokes occurred over subjects’ lifetime.

Assessment and mitigation of bleeding risk in atrial fibrillation and venous thromboembolism: A Position Paper from the ESC Working Group on Thrombosis, in collaboration with the European Heart Rhythm Association, the Association for Acute CardioVascular Care and the Asia-Pacific Heart Rhythm Society

Whilst there is a clear clinical benefit of oral anticoagulation (OAC) in patients with atrial fibrillation (AF) and venous thromboembolism (VTE) in reducing the risks of thromboembolism, major bleeding events (especially intracranial bleeds) may still occur and be devastating. The decision to initiate and continue anticoagulation is often based on a careful assessment of both the thromboembolism and bleeding risk. The more common and validated bleeding risk factors have been used to formulate bleeding risk stratification scores, but thromboembolism and bleeding risk factors often overlap. Also, many factors that increase bleeding risk are transient and modifiable, such as variable international normalized ratio values, surgical procedures, vascular procedures, or drug-drug and food-drug interactions. Bleeding risk is also not a static 'one off' assessment based on baseline factors but is dynamic, being influenced by ageing, incident comorbidities, and drug therapies. In this Consensus Document, we comprehensively review the published evidence and propose a consensus on bleeding risk assessments in patients with AF and VTE, with the view to summarizing 'best practice' when approaching antithrombotic therapy in these patients. We address the epidemiology and size of the problem of bleeding risk in AF and VTE, review established bleeding risk factors, and summarize definitions of bleeding. Patient values and preferences, balancing the risk of bleeding against thromboembolism are reviewed, and the prognostic implications of bleeding are discussed. We propose consensus statements that may help to define evidence gaps and assist in everyday clinical practice.

Optimizing adherence and persistence to non-vitamin K antagonist oral anticoagulant therapy in atrial fibrillation

Atrial fibrillation (AF) is associated with an increased risk of stroke, which can be prevented by the use of oral anticoagulation. Although non-vitamin K antagonist oral anticoagulants (NOACs) have become the first choice for stroke prevention in the majority of patients with non-valvular AF, adherence and persistence to these medications remain suboptimal, which may translate into poor health outcomes and increased healthcare costs. Factors influencing adherence and persistence have been suggested to be patient-related, physician-related, and healthcare system-related. In this review, we discuss factors influencing patient adherence and persistence to NOACs and possible problem solving strategies, especially involving an integrated care management, aiming for the improvement in patient outcomes and treatment satisfaction.

Starting dose and dose adjustment of non-vitamin K antagonist oral anticoagulation agents in a nationwide cohort of patients with atrial fibrillation

This study aims to provide real-world data about starting-dose of NOACs and dose-adjustment in patients with atrial fibrillation (AF). In fact, even if new oral anticoagulation agents (NOACs) have a predictable effect without need for regular monitoring, dose-adjustments should be performed according to the summary of product information and international guidelines. We employed the Italian Medicines Agency monitoring registries comprising data on a nationwide cohort of patients with AF treated with NOACs from 2013 to 2018. Logistic regression analysis was used to evaluate the determinants of dosage choice. During the reference period, treatment was commenced for 866,539 patients. Forty-five percent of the first prescriptions were dispensed at a reduced dose (dabigatran 60.3%, edoxaban 45.2%, apixaban 40.9%, rivaroxaban 37.4%). The prescription of reduced dose was associated with older age, renal disease, bleeding risk and the concomitant use of drugs predisposing to bleeding, but not with CHA₂DS₂-VASc and HAS-BLED. A relative reduction of the proportion of patients treated with low dosages was evident overtime for dabigatran and rivaroxaban; whereas prescription of low dose apixaban and edoxaban increased progressively among elderly patients. Evidence based on real-world data shows a high frequency of low dose prescriptions of NOACs in AF patients. Except for older age, renal disease, bleeding risk and the concomitant use of drugs predisposing to bleeding, other factors that may determine the choice of reduced dose could not be ascertained. There may be potential under-treatment of AF patients, but further evaluation is warranted.

Symptom management strategies: Rhythm vs rate control in patients with atrial fibrillation in the Balkan region: Data from the BALKAN-AF survey

BACKGROUND

Symptom-focused management is one of the cornerstones of optimal atrial fibrillation (AF) therapy.

OBJECTIVES

To evaluate the use of rhythm control and rate control strategy. Second, to identify predictors of the use of amiodarone in patients with rhythm control and of the use of rhythm control strategy in patients with paroxysmal AF in the Balkans.

METHODS

Prospective enrolment of consecutive patients from seven Balkan countries to the BALKAN-AF survey was performed.

RESULTS

Of 2712 enrolled patients, 2522 (93.0%) with complete data were included: 1622 (64.3%) patients were assigned to rate control strategy and 900 (35.7%) to rhythm control. Patients with rhythm control were younger, more often hospitalised for AF and with less comorbidities (all P < .05) than those with rate control. Symptom score [European Heart Rhythm Association (EHRA)] was not an independent predictor of a rhythm control strategy [odds ratio (OR) 0.99, 95% confidence interval (CI) 0.90-1.10, P = .945]. The most commonly chosen antiarrhythmic agents were amiodarone (49.7%), followed by propafenone (24.3%).

CONCLUSION

More than one-third of patients in the BALKAN-AF survey received a rhythm control strategy, and these patients tended to be younger with less comorbidities than those managed with rate control. EHRA symptom score is not significantly associated with rhythm control strategy. The most commonly used antiarrhythmic agents were amiodarone, followed by propafenone.

Idarucizumab for Emergency Reversal of Anticoagulant Effects of Dabigatran: Interim Results of a Japanese Post-Marketing Surveillance Study

INTRODUCTION

Idarucizumab, a monoclonal antibody fragment, was developed to reverse the anticoagulant effect of dabigatran, and it was approved in Japan in September 2016. An all-case post-marketing surveillance is ongoing to collect data in Japanese patients treated with idarucizumab who had serious bleeding (Group A) or required an urgent procedure (Group B).

METHODS

The primary endpoint was the incidence of adverse drug reactions (ADRs). The secondary endpoint was the maximum extent of reversal of the anticoagulant effect of dabigatran based on activated partial thromboplastin time (aPTT) within 4 h after idarucizumab administration.

RESULTS

This interim analysis included 262 patients who received idarucizumab. Eighteen patients (6.9%) experienced ADRs within 4 weeks. The reversal effect of idarucizumab based on aPTT within 4 h after idarucizumab administration was assessed in 30 patients and the median maximum percentage reversal was 100%. In Group A, the median time to bleeding cessation in patients without intracranial bleeding was 3.3 h. In Group B, normal intraoperative hemostasis was reported in 63 patients (72.4%).

CONCLUSIONS

The results of this interim analysis suggest that idarucizumab is safe and effective for the reversal of dabigatran in Japanese patients in a real-world setting, and support the continued use of idarucizumab.

TRIAL REGISTRATION

ClinicalTrials.gov identifier, NCT02946931.

Direct Oral Anticoagulants in Octogenarians With Atrial Fibrillation: It Is Never Too Late

Atrial fibrillation is the most common arrhythmia in clinical practice, and age is one of the strongest predictors/risk factors for ischemic stroke in patients with atrial fibrillation. Elderly patients, in particular patients aged 80 years and older, are at higher risk of both ischemic and bleeding events compared with younger patients. Vitamin K antagonists (VKAs) reduce the risk of ischemic stroke, especially in the elderly, but increase the bleeding risk. In addition, frequent international normalized ratio monitoring is needed to ensure the optimal level of anticoagulation. Furthermore, VKAs have multiple drug and food interactions. Direct oral anticoagulants (DOACs) have recently emerged as alternatives to VKAs and are gradually increasing their popularity mainly because of their fewer drug and food interactions and ease of use. Their effectiveness and safety have been well-established in the general population, but the benefit in the very elderly (≥80 years old) is still unclear. Data about the safety and the effectiveness of DOACs in patients older than 75 years are available in literature, but the evidences of the use of DOACs in patients aged 80 years and older are lacking. This review aims to give light to the differences, in terms of benefits and safety, of the DOACs in this subset of patients.

A prospective survey of the persistence of warfarin or NOAC in nonvalvular atrial fibrillation: a COmparison study of Drugs for symptom control and complication prEvention of Atrial Fibrillation (CODE-AF)

BACKGROUND/AIMS

Efforts to reduce stroke in patients with atrial fibrillation (AF) have focused on increasing physician adherence to oral anticoagulant (OAC) guidelines; however, the high early discontinuation rate of vitamin K antagonists (VKAs) is a limitation. Although non-VKA OACs (NOACs) are more convenient to administer than warfarin, their lack of monitoring may predispose patients to nonpersistence. We compared the persistence of NOAC and VKA treatment for AF in real-world practice.

METHODS

In a prospective observational registry (COmparison study of Drugs for symptom control and complication prEvention of Atrial Fibrillation [CODE-AF] registry), 7,013 patients with nonvalvular AF (mean age 67.2 ± 10.9 years, women 36.4%) were consecutively enrolled between June 2016 and June 2017 from 10 tertiary hospitals in Korea. This study included 3,381 patients who started OAC 30 days before enrollment (maintenance group) and 572 patients who newly started OAC (new-starter group). The persistence rate of OAC was evaluated.

RESULTS

In the maintenance group, persistence to OAC declined during 6 months, to 88.3% for VKA and 95.5% for NOAC (p < 0.0001). However, the persistence rate was not different among NOACs. In the new-starter group, persistence to OAC declined during 6 months, to 78.9% for VKA and 92.1% for NOAC (p < 0.0001). The persistence rate was lower for rivaroxaban (83.7%) than apixaban (94.6%) and edoxaban (94.1%, p < 0.001). In the new-starter group, diabetes, valve disease, and cancer were related to nonpersistence of OAC.

CONCLUSION

Nonpersistence was significantly lower with NOAC than VKA in both the maintenance and new-starter groups. In only the new-starter group, apixaban or edoxaban showed higher persistence rates than rivaroxaban.

Management of patients with newly-diagnosed atrial fibrillation: Insights from the BALKAN-AF survey

•

23.6% of patients in the survey had newly-diagnosed atrial fibrillation (AF).

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Those patients had different risk profiles than those with a history of AF.

•

The specificity of the management of first-diagnosed AF patients was presented.

Background

BALKAN-AF evaluated patterns of atrial fibrillation (AF) management in real-world clinical practice in the Balkans. The objectives were: to assess the proportion of patients with first-diagnosed AF in the BALKAN-AF cohort and to compare the management of patients with newly-diagnosed AF and those with previously known AF in clinical practice.

Methods

Consecutive patients from 7 Balkan countries were enrolled prospectively to the snapshot BALKAN-AF survey.

Results

Of 2712 enrolled patients, 2677 (98.7%) with complete data were included. 631 (23.6%) patients had newly-diagnosed AF and 2046 (76.4%) patients had known AF. Patients with newly-diagnosed AF were more likely to be hospitalized for AF and to receive single antiplatelet therapy (SAPT) alone and less likely to receive OACs than those with known AF (all p < 0.001). The use of OAC was not significantly associated with the CHA₂DS₂-VASc (p = 0.624) or HAS-BLED score (p = 0.225) on univariate analysis. Treatment in capital city, hypertension, dilated cardiomyopathy, mitral valve disease, country of residence or rate control strategy were independent predictors of OAC use, whilst non-emergency centre, treatment by cardiologist, paroxysmal AF, palpitations, symptoms attributable to AF (as judged by physician), mean heart rate and AF as the main reason for hospitalization were independent predictors of rhythm control strategy use.

Conclusions

In BALKAN-AF survey, patients with newly-diagnosed AF were more often hospitalized, less often received OAC and were more likely to receive SAPT alone. The use of OAC for stroke prevention has not been driven by the individual patient stroke risk.

Physicians' Perceptions of Their Patients' Attitude and Knowledge of Long-Term Oral Anticoagulant Therapy in Bulgaria

Background and Objectives: Oral anticoagulation (OAC) is widely used in daily clinical practice worldwide for various indications. We aimed to explore the perception of Bulgarian clinicians about their patients' attitude and knowledge of long-term OAC, prescribed for atrial fibrillation (AF) and/or known deep venous thrombosis (DVT)/pulmonary embolism (PE). Materials and Methods: We performed a cross-sectional study that involved 226 specialists: 187 (82.7%) cardiologists, 23 (10.2%) neurologists, and 16 (7.1%) vascular surgeons. They filled in a questionnaire, specially designed for our study, answering various questions regarding OAC treatment in their daily clinical practice. Results: The mean prescription rate of OACs in AF patients was 80.3% and in DVT/PE-88.6%. One hundred and eighty-seven (82.7%) of the participants stated they see their patients on OAC at least once per month. According to more than one-third of the inquired clinicians, the patients did not understand well enough the provided information concerning net clinical benefit of OAC treatment. About 68% of the clinicians declared that their patients would prefer a "mutual" approach, discussing with the physician the OAC options and taking together the final decision, whereas according to 43 (19.0%), the patients preferred the physician to take a decision for them. Patients' OAC treatment had been interrupted at least once within the last year due to a physician's decision by 178 (78.8%) of the participants and the most common reason was elective surgery. The most influential factors for a patient's choice of OAC were the need of a specific diet to be kept, intake frequency, and possible adverse reactions. Conclusions: Our results suggest that a clinician's continuous medical education, shared decision-making, and appropriate local strategies for improved awareness of AF/DVT/PE patients are key factors for improvement of OAC management.

2018 Korean Guideline of Atrial Fibrillation Management

Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia in the general population. The Korean Heart Rhythm Society organized a Korean AF Management Guideline Committee and analyzed all available studies regarding the management of AF, including studies on Korean patients. This guideline is based on recent data of the Korean population and the recent guidelines of the European Society of Cardiology, European Association for Cardio-Thoracic Surgery, American Heart Association, and Asia Pacific Heart Rhythm Society. Expert consensus or guidelines for the optimal management of Korean patients with AF were achieved after a systematic review with intensive discussion. This article provides general principles for appropriate risk stratification and selection of anticoagulation therapy in Korean patients with AF. This guideline deals with optimal stroke prevention, screening, rate and rhythm control, risk factor management, and integrated management of AF.

Patients' Perceptions of Atrial Fibrillation, Stroke Risk, and Oral Anticoagulation Treatment: An International Survey

Background  Global differences exist in the management of atrial fibrillation (AF), and cultural differences may influence patients' expectations and perceptions of healthcare. This survey investigated whether country-specific differences in patients' perceptions of AF and oral anticoagulation (OAC) exist and if recent stroke influences these perceptions. Methods  Cross-sectional survey of 937 adults with nonvalvular AF receiving OAC for stroke prevention was conducted across United States, Canada, Germany, France, and Japan. Thirty-minute online interviews conducted between April and November 2015 included AF patients with recent stroke, and newly diagnosed AF and established AF, both without recent stroke. Results  U.S. patients and those with recent stroke perceived AF as more serious (54.0 and 55.2%, respectively) and were more concerned about stroke (50.0 and 68.0%, respectively). Japanese patients were more likely to perceive AF as not serious (41.0%), but 50.4% were frequently concerned about stroke. Patients in the United States, Canada, and Germany and those without recent stroke preferred to be involved in OAC treatment decisions (either shared decision making or patient's choice), while French and Japanese patients and those with recent stroke preferred their doctor to choose. For all country groups, stroke prevention was the most important factor when choosing OAC. Conclusion  In this international cohort of AF patients, country-specific differences exist in patients' perceptions of AF, concerns about stroke, and preference for involvement in OAC treatment decisions; recent experience of stroke significantly influenced patients' values and preferences regarding AF and treatment. Stroke prevention was rated as the most important factor when choosing OAC treatment.

Choosing a particular oral anticoagulant and dose for stroke prevention in individual patients with non-valvular atrial fibrillation: part 1

Patients with atrial fibrillation (AF) have a high risk of stroke and mortality, which can be considerably reduced by oral anticoagulants (OAC). Recently, four non-vitamin-K oral anticoagulants (NOACs) were compared with warfarin in large randomized trials for the prevention of stroke and systemic embolism. Today's clinician is faced with the difficult task of selecting a suitable OAC for a patient with a particular clinical profile or a particular pattern of risk factors and concomitant diseases. We reviewed analyses of subgroups of patients from trials of vitamin K antagonists vs. NOACs for stroke prevention in AF with the aim to identify patient groups who might benefit from a particular OAC more than from another. In the first of a two-part review, we discuss the choice of NOAC for stroke prevention in the following subgroups of patients with AF: (i) stable coronary artery disease or peripheral artery disease, including percutaneous coronary intervention with stenting and triple therapy; (ii) cardioversion, ablation and anti-arrhythmic drug therapy; (iii) mechanical valves and rheumatic valve disease, (iv) patients with time in therapeutic range of >70% on warfarin; (v) patients with a single stroke risk factor (CHA2DS2VASc score of 1 in males, 2 in females); and (vi) patients with a single first episode of paroxysmal AF. Although there are no major differences in terms of efficacy and safety between the NOACs for some clinical scenarios, in others we are able to suggest that particular drugs and/or doses be prioritized for anticoagulation.

Editor's Choice - Frailty and the management of patients with acute cardiovascular disease: A position paper from the Acute Cardiovascular Care Association

Frailty is increasingly seen among patients with acute cardiovascular disease. A combination of an ageing population, improved disease survival, treatable long-term conditions as well as a greater recognition of the syndrome has accelerated the prevalence of frailty in the modern world. Yet, this has not been matched by an expansion of research. National and international bodies have identified acute cardiovascular disease in the frail as a priority area for care and an entity that requires careful clinical decisions, but there remains a paucity of guidance on treatment efficacy and safety, and how to manage this complex group. This position paper from the Acute Cardiovascular Care Association presents the latest evidence about frailty and the management of frail patients with acute cardiovascular disease, and suggests avenues for future research.

Dabigatran in nonvalvular atrial fibrillation: from clinical trials to real-life experience

: Atrial fibrillation is the most common arrhythmia in over-midlife patients. In addition to systolic heart failure, cerebral thromboembolism represents the most dramatic complication of this rhythm disorder, contributing to morbidity and mortality. Traditionally, anticoagulation has been considered the main strategy in preventing stroke and systemic embolism in atrial fibrillation patients and vitamin K-dependent antagonists have been widely used in clinical practice. Recently, the development of direct oral anticoagulants has certainly improved the management of this disease, providing, for the first time, the opportunity to go beyond vitamin K-dependent antagonists limits. In the RE-LY trial, dabigatran 150 mg twice daily was superior to warfarin in the prevention of stroke or systemic embolism and dabigatran 110 mg twice daily was noninferior. Both doses greatly reduced hemorrhagic stroke, and dabigatran 110 mg twice daily significantly reduced major bleeding compared with warfarin. Based on these results, dabigatran, a direct thrombin inhibitor, was the first direct oral anticoagulant to receive the regulatory approval for nonvalvular atrial fibrillation patients. To date, a specific reversal agent has just been approved as an antidote for this molecule. This review provides a summary of randomized trials, postmarket registries and specific clinical-settings summary on dabigatran in nonvalvular atrial fibrillation.

Non-valvular atrial fibrillation patients with none or one additional risk factor of the CHA2DS2-VASc score

Oral anticoagulation (OAC) to prevent stroke has to be balanced against the potential harm of serious bleeding, especially intracranial haemorrhage (ICH). We determined the net clinical benefit (NCB) balancing effectiveness and safety of no antithrombotic therapy, aspirin and warfarin in AF patients with none or one stroke risk factor. Using Danish registries, we determined NCB using various definitions intrinsic to our cohort (Danish weights at 1 and 5 year follow-up), with risk weights which were derived from the hazard ratio (HR) of death following an event, relative to HR of death after ischaemic stroke. When aspirin was compared to no treatment, NCB was neutral or negative for both risk strata. For warfarin vs no treatment, NCB using Danish weights was neutral where no risk factors were present and using five years follow-up. For one stroke risk factor, NCB was positive for warfarin vs no treatment, for one year and five year follow-up. For warfarin vs aspirin use in patients with no risk factors, NCB was positive with one year follow-up, but neutral with five year follow-up. With one risk factor, NCB was generally positive for warfarin vs aspirin. In conclusion, we show a positive overall advantage (i.e. positive NCB) of effective stroke prevention with OAC, compared to no therapy or aspirin with one additional stroke risk factor, using Danish weights. ‘Low risk’ AF patients with no additional stroke risk factors (i.e. CHA2DS2-VASc 0 in males, 1 in females) do not derive any advantage (neutral or negative NCB) with aspirin, nor with warfarin therapy in the long run.

Note: The review process for this manuscript was fully handled by Christian Weber, Editor in Chief.

Therapy persistence in newly diagnosed non-valvular atrial fibrillation treated with warfarin or NOAC

Efforts to reduce stroke in atrial fibrillation (AF) have focused on increasing physician adherence to oral anticoagulant (OAC) guidelines, but high early vitamin K antagonist (VKA) discontinuation is a limitation. We compared persistence of non-VKA OAC (NOAC) with VKA treatment in the first year after OAC inception for incident AF in real-world practice. We studied 27,514 anticoagulant-naïve patients with incident non-valvular AF between January 2011 and May 2014 in the UK primary care Clinical Practice Research Datalink, with full medication use linkage: mean age 74.2 ± 12.4, 45.7 % female, mean follow-up 1.9 ± 1.1 years. After treatment initiation and follow-up until 1/2015, the proportion remaining on OAC at one year (persistence) was estimated using competing risk survival analyses. OAC was commenced ≤90 days after incident AF in 13,221 patients (48.1 %): 12,307 VKA and 914 NOAC (apixaban, dabigatran, rivaroxaban). Amongst those treated with OAC, the proportion commencing NOAC increased from zero in 1/2011 to 27.0 % in 5/2014, and OAC prescriptions for CHA2DS2VASc score ≥2 (guideline adherence) increased from 41.2 % to 65.5 %. Persistence with OAC declined over 12 months to 63.6 % for VKA and 79.2 % for NOAC (p< 0.0001). Persistence for those with CHA2DS2VASc ≥2 was significantly greater for NOAC (83.0 %) than VKA (65.3 %, p< 0.0001) at one year and all earlier time points. Comparison of VKA and NOAC cohorts matched on individual CHA2DS2VASc components showed consistent results. In conclusion, persistence was significantly higher with NOAC than VKA, and could alone lead to fewer cardioembolic strokes. Increased guideline adherence following NOAC introduction could further decrease AF stroke burden.

Supplementary Material to this article is available online at www.thrombosis-online.com.

Effectiveness and safety of dabigatran therapy in daily-care patients with atrial fibrillation

The effectiveness and safety of dabigatran for stroke prevention in atrial fibrillation (SPAF) demonstrated in RE-LY needs to be confirmed in daily care. To evaluate treatment persistence, effectiveness and safety of dabigatran therapy in SPAF patients in daily care, we used data from an ongoing, prospective, non-interventional registry of more than 2,500 patients on novel oral anticoagulants in daily care. Between October 1, 2011 and February 28, 2013, a total of 341 SPAF patients receiving dabigatran were enrolled. The combined endpoint of stroke/transient ischaemic attack/systemic embolism occurred at a rate of 2.93/100 patient-years in the intention-to-treat analysis (95%-CI 1.6–4.9) and at 1.9/100 patient-years in the on treatment analysis (events within three days after last intake). On-treatment rates were higher in patients selected for 110 mg dabigatran (n=183) BID compared to the 158 patients selected for 150 mg BID (2.88 [95% CI 1.16–5.93] vs 0.86/100 patient-years [95% CI 0.10, 3.12]). On treatment, major bleeding occurred at a rate of 2.3/100 patient-years and numerically more often in patients receiving the 110 mg BID dose compared to the 150 mg BID dose (2.9 vs 1.7/100 patient-years). Dabigatran treatment discontinuation occurred in a total of 124 patients during follow-up (25.8 per 100 patient-years in Kaplan Meier analysis). Main reasons for treatment discontinuation were nonbleeding side effects. Our data contribute to the confirmation of effectiveness and relative safety of dabigatran in unselected patients in daily care. However, discontinuation rates are not lower than those reported for patients treated with vitamin K antagonists.

Feasibility and cost-effectiveness of stroke prevention through community screening for atrial fibrillation using iPhone ECG in pharmacies

Atrial fibrillation (AF) causes a third of all strokes, but often goes undetected before stroke. Identification of unknown AF in the community and subsequent anti-thrombotic treatment could reduce stroke burden. We investigated community screening for unknown AF using an iPhone electrocardiogram (iECG) in pharmacies, and determined the cost-effectiveness of this strategy. Pharmacists performed pulse palpation and iECG recordings, with cardiologist iECG over-reading. General practitioner review/12-lead ECG was facilitated for suspected new AF. An automated AF algorithm was retrospectively applied to collected iECGs. Cost-effectiveness analysis incorporated costs of iECG screening, and treatment/outcome data from a United Kingdom cohort of 5,555 patients with incidentally detected asymptomatic AF. A total of 1,000 pharmacy customers aged ≥65 years (mean 76 ± 7 years; 44% male) were screened. Newly identified AF was found in 1.5% (95% CI, 0.8–2.5%); mean age 79 ± 6 years; all had CHA2DS2-VASc score ≥2. AF prevalence was 6.7% (67/1,000). The automated iECG algorithm showed 98.5% (CI, 92–100%) sensitivity for AF detection and 91.4% (CI, 89–93%) specificity. The incremental cost-effectiveness ratio of extending iECG screening into the community, based on 55% warfarin prescription adherence, would be $AUD5,988 (€3,142; $USD4,066) per Quality Adjusted Life Year gained and $AUD30,481 (€15,993; $USD20,695) for preventing one stroke. Sensitivity analysis indicated cost-effectiveness improved with increased treatment adherence. Screening with iECG in pharmacies with an automated algorithm is both feasible and cost-effective. The high and largely preventable stroke/thromboembolism risk of those with newly identified AF highlights the likely benefits of community AF screening. Guideline recommendation of community iECG AF screening should be considered.

Previous Presentation: This study was presented in part as an oral presentation at the Cardiac Society of Australia and New Zealand Conference; 9 August 2013; Sydney, Australia, abstract published in Heart Lung Circulation 2013;22:S223.

Trial registration: Australian New Zealand clinical trials registry: ACTRN12612000406808.

Effectiveness and safety of reduced dose non-vitamin K antagonist oral anticoagulants and warfarin in patients with atrial fibrillation: propensity weighted nationwide cohort study

Objective To examine clinical effectiveness and safety of apixaban 2.5 mg, dabigatran 110 mg, and rivaroxaban 15 mg compared with warfarin among patients with atrial fibrillation who had not previously taken an oral anticoagulant.Design Propensity weighted (inverse probability of treatment weighted) nationwide cohort study.Setting Individual linked data from three nationwide registries in Denmark.Participants Patients with non-valvular atrial fibrillation filling a first prescription for an oral anticoagulant from August 2011 to February 2016. Patients who filled a prescription for a standard dose non-vitamin K antagonist oral anticoagulant (novel oral anticoagulants, NOACs) were excluded. To control for baseline differences in the population, a propensity score for receipt of either of the four treatment alternatives was calculated to apply an inverse probability treatment weight.Intervention Initiated anticoagulant treatment (dabigatran 110 mg, rivaroxaban 15 mg, apixaban 2.5 mg, and warfarin).Main outcome measures Patients were followed in the registries from onset of treatment for the primary effectiveness outcome of ischaemic stroke/systemic embolism and for the principal safety outcome of any bleeding events.Results Among 55 644 patients with atrial fibrillation who met inclusion criteria, the cohort was distributed according to treatment: apixaban n=4400; dabigatran n=8875; rivaroxaban n=3476; warfarin n=38 893. The overall mean age was 73.9 (SD 12.7), ranging from a mean of 71.0 (warfarin) to 83.9 (apixaban). During one year of follow-up, apixaban was associated with higher (weighted) event rate of ischaemic stroke/systemic embolism (4.8%), while dabigatran, rivaroxaban, and warfarin had event rates of 3.3%, 3.5%, and 3.7%, respectively. In the comparison between a non-vitamin K antagonist oral anticoagulant and warfarin in the inverse probability of treatment weighted analyses and investigation of the effectiveness outcome, the hazard ratios were 1.19 (95% confidence interval 0.95 to 1.49) for apixaban, 0.89 (0.77 to 1.03) for dabigatran, and 0.89 (0.69 to 1.16) for rivaroxaban. For the principal safety outcome versus warfarin, the hazard ratios were 0.96 (0.73 to 1.27) for apixaban, 0.80 (0.70 to 0.92) for dabigatran, and 1.06 (0.87 to 1.29) for rivaroxaban.Conclusion In this propensity weighted nationwide study of reduced dose non-vitamin K antagonist oral anticoagulant regimens, apixaban 2.5 mg twice a day was associated with a trend towards higher rates of ischaemic stroke/systemic embolism compared with warfarin, while rivaroxaban 15 mg once a day and dabigatran 110 mg twice a day showed a trend towards lower thromboembolic rates. The results were not significantly different. Rates of bleeding (the principal safety outcome) were significantly lower for dabigatran, but not significantly different for apixaban and rivaroxaban compared with warfarin.

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.

Stroke Prevention in Atrial Fibrillation: Focus on Latin America

Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia, with an estimated prevalence of 1-2% in North America and Europe. The increased prevalence of AF in Latin America is associated with an ageing general population, along with poor control of key risk factors, including hypertension. As a result, stroke prevalence and associated mortality have increased dramatically in the region. Therefore, the need for effective anticoagulation strategies in Latin America is clear. The aim of this review is to provide a contemporary overview of anticoagulants for stroke prevention. The use of vitamin K antagonists (VKAs, eg, warfarin) and aspirin in the prevention of stroke in patients with AF in Latin America remains common, although around one fifth of all AF patients receive no anticoagulation. Warfarin use is complicated by a lack of access to effective monitoring services coupled with an unpredictable pharmacokinetic profile. The overuse of aspirin is associated with significant bleeding risks and reduced efficacy for stroke prevention in this patient group. The non-VKA oral anticoagulants (NOACbs) represent a potential means of overcoming many limitations associated with VKA and aspirin use, including a reduction in the need for monitoring and a reduced risk of hemorrhagic events. The ultimate decision of which anticoagulant drug to utilize in AF patients depends on a multitude of factors. More research is needed to appreciate the impact of these factors in the Latin American population and thereby reduce the burden of AF-associated stroke in this region.

Oral anticoagulant therapy in atrial fibrillation patients at high stroke and bleeding risk

Atrial fibrillation (AF) is associated with a 5-fold greater risk of ischemic stroke or systemic embolism compared with normal sinus rhythm. Cardioembolic AF-related strokes are often more severe, fatal or associated with greater permanent disability and higher recurrence rates than strokes of other aetiologies. These strokes may be effectively prevented with oral anticoagulant (OAC) therapy, using either vitamin K antagonists (VKAs) or non-vitamin K antagonist OACs (NOACs) such as the direct thrombin inhibitor dabigatran or direct factor Xa inhibitors rivaroxaban, apixaban or edoxaban. Most AF patients have a positive net clinical benefit from OAC, excluding those with AF and no conventional stroke risk factors. Balancing the risks of stroke and bleeding is necessary for optimal use of OAC in clinical practice, and modifiable bleeding risk factors must be addressed. Concerns remain over 'non-changeable' bleeding risk factors such as older age, significant renal or hepatic impairment, prior stroke(s) or prior bleeding event(s) and active malignancies. Such AF patients are often termed 'special' AF populations, due to their 'special' risk profile that includes increased risks of both thromboembolic and bleeding events, and due to fear of bleeding complications these AF patients are often denied OAC. Evidence shows, however, that the absolute benefits of OAC are the greatest in patients at the highest risk, and NOACs may offer even a greater net clinical benefit compared to warfarin particularly in these high risk patients. In this review article, we summarize available data on stroke prevention in AF patients at increased risk of both stroke and bleeding and discuss the use of NOACs for thromboprophylaxis in these 'special' AF populations.

Selection of Warfarin or One of the New Oral Antithrombotic Agents for Long-Term Prevention of Stroke among Persons with Atrial Fibrillation

OPINION STATEMENT

Atrial fibrillation (AF) is the most common sustained cardiac rhythm disorder, which can potentially increases the risk of stroke by five-fold, thus, resulting in high public healthcare burden. Stroke prevention is vital in the management of AF patients. Vitamin K antagonists (VKA, eg, warfarin) have been the mainstay treatment to prevent ischemic stroke and systemic thromboembolism in AF patients for several decades. Despite the efficacy of warfarin, its limitations have recently driven the advent of some new antithrombotic agents, the non-VKA oral anticoagulant (NOACs, including dabigatran, rivaroxaban, apixaban, and edoxaban). The NOACs have changed the landscape for thromboembolic prophylaxis among patients with nonvalvular AF. Although three NOACs thus far (dabigatran, rivaroxaban, and apixaban) have been approved in Europe and the United States, for stroke prevention in patients with nonvalvular AF on the basis of several Phase III clinical trials, warfarin still remain important in preventing stroke for patients. This is especially true for those with optimal control of international normalized ratio with high (>70 %) time in therapeutic range, valvular AF or associated prosthetic valve. These NOACs are attractive alternatives for stroke prevention in patients with nonvalvular AF who are unable or unwilling to receive warfarin. However, several issues should be taken into consideration on safe and effective use of these NOACs in day-to-day clinical practice, for example, pharmacological properties, drug interactions, monitoring and compliance, and treatment of frail elderly patients or patients with renal impairment, etc. The decision about whether to initiate oral anticoagulation either with warfarin or NOACs should be patient-centered and after consideration of both stroke and bleeding risks. It is important for clinical practitioner to offer patients with AF an individualized decision about drug choice, making decision after adequate patient education plus discussion about the risks and benefits of these agents, thus fitting the drug to the patient profile.