Adherence to Oral Anticoagulants in Atrial Fibrillation: An Australian Survey

Background:

The aim of this study was to investigate the proportion of patients who have suboptimal adherence to oral anticoagulant (OAC), identify the predictors of adherence, and determine whether patient-related factors vary across adherence levels in Australia.

Methods:

Respondents were recruited for an online survey using Facebook. Survey instruments included the Morisky Medication Adherence Scale, the Anticoagulation Knowledge Tool, the Perception of Anticoagulant Treatment Questionnaires, and a modified Cancer Information Overload scale. Predictors of medication adherence were identified using ordinal regression analysis.

Results:

Of the 386 responses eligible for analysis, only 54.9% reported a high level of adherence. Participants aged 65 years or younger were less likely to have high adherence compared to older participants (odds ratio [OR], 0.54; 95% confidence interval [CI], 0.33-0.88; P = .013), while females were more likely to be highly adherent compared to males (OR, 1.69; 95% CI, 1.08-2.64; P = .023). The analyses showed that age, gender, treatment satisfaction, information overload, concerns about making mistake when taking OACs, and cost of medication were significant predictors of adherence.

Conclusion:

Self-reported suboptimal adherence to OAC is common among patients with atrial fibrillation. A focus on supporting people who are at higher risk of suboptimal adherence is needed to maximize the benefit of OAC therapy in this population.

Two-year follow-up of patients treated with dabigatran for stroke prevention in atrial fibrillation: Global Registry on Long-Term Antithrombotic Treatment in Patients with Atrial Fibrillation (GLORIA-AF) registry

BACKGROUND AND PURPOSE

GLORIA-AF is a large, global, prospective registry program of newly diagnosed atrial fibrillation (AF) patients with ≥1 stroke risk factors. We describe the effectiveness and safety of dabigatran etexilate over 2 years from routine clinical practice in nearly 3000 patients from GLORIA-AF who are newly diagnosed with non-valvular AF and at risk of stroke.

METHODS

Consecutive enrollment into phase II of GLORIA-AF was initiated following approval of dabigatran for stroke prevention in non-valvular AF. Within this Phase II, 2937 dabigatran patients completed 2-year follow-up by May 2016 and were eligible for analysis. Patients who took at least 1 dose of dabigatran (n=2932) were used to estimate incidence rates.

RESULTS

Overall incidence rates per 100 person-years of 0.63 (95% confidence interval [CI], 0.42-0.92) for stroke, 1.12 (0.83-1.49) for major bleeding, 0.47 (0.29-0.72) for myocardial infarction, and 2.69 (2.22-3.23) for all-cause death were observed. For patients taking 150 mg dabigatran twice daily (BID), corresponding rates (95% CI) were 0.56 (0.30-0.94), 1.00 (0.64-1.47), 0.48 (0.25-0.83), and 2.07 (1.55-2.72), respectively. For patients taking 110 mg dabigatran BID, event rates (95% CI) were 0.67 (0.33-1.20), 1.16 (0.70-1.80), 0.43 (0.17-0.88), and 3.16 (2.36-4.15).

CONCLUSIONS

These global data confirm the sustained safety and effectiveness of dabigatran over 2 years of follow-up, consistent with the results from clinical trials as well as contemporary real-world studies.

WHAT IS KNOWN

• Non-vitamin K antagonist (VKA) anticoagulants (NOACs) are the preferred therapy for prevention of ischemic stroke based on phase 3 trials, but there is insufficient information on their efficacy and safety in daily practice, based on prospectively collected data.

WHAT IS NEW

• This study shows that in non-valvular AF patient population, with up to 2 years of follow-up, the use of dabigatran led to a low incidence of ischemic stroke, major bleeding, and myocardial infarction in routine clinical care, confirming the sustained safety and effectiveness of dabigatran in clinical practice over 2 years of follow-up.

Demographics, treatment and outcomes of atrial fibrillation in a developing country: the population-based TuRkish Atrial Fibrillation (TRAF) cohort

Aims

Although atrial fibrillation (AF) is increasingly common in developed countries, there is limited information regarding its demographics, co-morbidities, treatments and outcomes in the developing countries. We present the profile of the TuRkish Atrial Fibrillation (TRAF) cohort which provides real-life data about prevalence, incidence, co-morbidities, treatment, healthcare utilization and outcomes associated with AF.

Methods and results

The TRAF cohort was extracted from MEDULA, a health insurance database linking hospitals, general practitioners, pharmacies and outpatient clinics for almost 100% of the inhabitants of the country. The cohort includes 507 136 individuals with AF between 2008 and 2012 aged >18 years who survived the first 30 days following diagnosis. Of 507 136 subjects, there were 423 109 (83.4%) with non-valvular AF and 84 027 (16.6%) with valvular AF. The prevalence was 0.80% in non-valvular AF and 0.28% in valvular AF; in 2012 the incidence of non-valvular AF (0.17%) was higher than valvular AF (0.04%). All-cause mortality was 19.19% (97 368) and 11.47% (58 161) at 1-year after diagnosis of AF. There were 35 707 (7.04%) ischaemic stroke/TIA/thromboembolism at baseline and 34 871 (6.87%) during follow-up; 11 472 (2.26%) major haemorrhages at baseline and 10 183 (2.01%) during follow-up, and 44 116 (8.69%) hospitalizations during the follow-up.

Conclusion

The TRAF cohort is the first population-based, whole-country cohort of AF epidemiology, quality of care and outcomes. It provides a unique opportunity to study the patterns, causes and impact of treatments on the incidence and outcomes of AF in a developing country.

'Real-world' atrial fibrillation management in Europe: observations from the 2-year follow-up of the EURObservational Research Programme-Atrial Fibrillation General Registry Pilot Phase

Aims

Atrial fibrillation (AF) is commonly associated with a high risk of stroke, thromboembolism, and mortality. The 1-year follow-up of the EURObservational Research Programme-Atrial Fibrillation (EORP-AF) Pilot Registry demonstrated a high mortality but good outcomes with European Society of Cardiology guideline-adherent therapy. Whether these 'real-world' observations on patients managed by European cardiologists extend to 2 years remains uncertain.

Methods and results

In this report from the EORP-AF General Registry Pilot Phase, we provide data on the 2-year follow-up outcomes. Consistent with the 1-year follow-up report, only a small proportion of patients were symptomatic (24.9%), with minor differences between the different AF subtypes. Persistence of oral anticoagulant (OAC) therapy remains high at 2-years, with ∼80% of patients treated with OAC. The prescribing rates of non-vitamin K antagonist oral anticoagulants are progressively increasing (13.7% at 2 years). Rate and rhythm control approaches remained consistent across the entire follow-up observation. Overall mortality rates remained high, with 5.0% of patients dead during the 2-year follow-up, mostly due to cardiovascular causes (61.8%). Atrial fibrillation readmissions were frequent, particularly related to arrhythmias and heart failure. On multivariate analyses, any cardiovascular reason for admission rather than AF was significantly associated with increased mortality during the 2-year follow-up.

Conclusion

In this 2-year follow-up report from EORP-AF, mortality rates with AF remain high from cardiovascular causes, despite the high prevalent use of OAC. Improved management strategies to reduce major adverse outcomes in AF patients are needed.

Emerging pharmacotherapies for the treatment of atrial fibrillation

INTRODUCTION

The main aim of current research on the field of atrial fibrillation (AF) treatment is to find new antiarrhythmic drugs with less side effects. Areas covered: Dronedarone and vernakalant showed promising result in term of efficacy and safety in selected patients. Ranolazine and colchicine are obtaining a role as a potential antiarrhythmic drug. Ivabradine is used in experimental studies for the rate control of AF. Moreover, new compounds (vanoxerine, moxonidine, budiodarone) are still under investigation. Monoclonal antibodies or selective antagonist of potassium channel are under investigation for long term maintenance of sinus rhythm. Clinical evidence and new pharmacological investigation on new drugs will be accurately reviewed in this article. Expert opinion: Dronedarone use is not recommended in patients with symptomatic heart failure (HF), NYHA class III-IV, depressed ventricular function and permanent AF, especially in patients assuming a concomitant therapy with digoxin. Vernakalant had superior efficacy than amiodarone, flecainide and propafenone in single studies and similar efficacy to direct current cardioversion. Several of the developing drugs examined in this paper show an interesting potential, in particular the research on selective ionic channel inhibition and on compounds which reduce the inflammation state, especially after ablation or surgery.

Integrating new approaches to atrial fibrillation management: the 6th AFNET/EHRA Consensus Conference

There are major challenges ahead for clinicians treating patients with atrial fibrillation (AF). The population with AF is expected to expand considerably and yet, apart from anticoagulation, therapies used in AF have not been shown to consistently impact on mortality or reduce adverse cardiovascular events. New approaches to AF management, including the use of novel technologies and structured, integrated care, have the potential to enhance clinical phenotyping or result in better treatment selection and stratified therapy. Here, we report the outcomes of the 6th Consensus Conference of the Atrial Fibrillation Network (AFNET) and the European Heart Rhythm Association (EHRA), held at the European Society of Cardiology Heart House in Sophia Antipolis, France, 17-19 January 2017. Sixty-two global specialists in AF and 13 industry partners met to develop innovative solutions based on new approaches to screening and diagnosis, enhancing integration of AF care, developing clinical pathways for treating complex patients, improving stroke prevention strategies, and better patient selection for heart rate and rhythm control. Ultimately, these approaches can lead to better outcomes for patients with AF.

A stakeholder co-design approach for developing a community pharmacy service to enhance screening and management of atrial fibrillation

Background

Community pharmacies provide a suitable setting to promote self-screening programs aimed at enhancing the early detection of atrial fibrillation (AF). Developing and implementing novel community pharmacy services (CPSs) is a complex and acknowledged challenge, which requires comprehensive planning and the participation of relevant stakeholders. Co-design processes are participatory research approaches that can enhance the development, evaluation and implementation of health services. The aim of this study was to co-design a pharmacist-led CPS aimed at enhancing self-monitoring/screening of AF.

Methods

A 3-step co-design process was conducted using qualitative methods: (1) interviews and focus group with potential service users (n = 8) to identify key needs and concerns; (2) focus group with a mixed group of stakeholders (n = 8) to generate a preliminary model of the service; and (3) focus group with community pharmacy owners and managers (n = 4) to explore the feasibility and appropriateness of the model. Data were analysed qualitatively to identify themes and intersections between themes. The JeMa2 model to conceptualize pharmacy-based health programs was used to build a theoretical model of the service.

Results

Stakeholders delineated: a clear target population (i.e., individuals ≥65 years old, with hypertension, with or without previous AF or stroke); the components of the service (i.e., patient education; self-monitoring at home; results evaluation, referral and follow-up); and a set of circumstances that may influence the implementation of the service (e.g., quality of the service, competency of the pharmacist, inter-professional relationships, etc.). A number of strategies were recommended to enable implementation (e.g.,. endorsement by leading cardiovascular organizations, appropriate communication methods and channels between the pharmacy and the general medical practice settings, etc.).

Conclusion

A novel and preliminary model of a CPS aimed at enhancing the management of AF was generated from this participatory process. This model can be used to inform decision making processes aimed at adopting and piloting of the service. It is expected the co-designed service has been adapted to suit existing needs of patients and current care practices, which, in turn, may increase the feasibility and acceptance of the service when it is implemented into a real setting.

Electronic supplementary material

The online version of this article (10.1186/s12913-018-2947-7) contains supplementary material, which is available to authorized users.

Cardiolaminopathies from bench to bedside: challenges in clinical decision-making with focus on arrhythmia-related outcomes

Lamin A/C gene mutations can be associated with cardiac diseases, usually referred to as 'cardiolaminopathies' characterized by arrhythmic disorders and/or left ventricular or biventricular dysfunction up to an overt picture of heart failure. The phenotypic cardiac manifestations of laminopathies are frequently mixed in complex clinical patterns and specifically may include bradyarrhythmias (sinus node disease or atrioventricular blocks), atrial arrhythmias (atrial fibrillation, atrial flutter, atrial standstill), ventricular tachyarrhythmias and heart failure of variable degrees of severity. Family history, physical examination, laboratory findings (specifically serum creatine phosphokinase values) and ECG findings are often important 'red flags' in diagnosing a 'cardiolaminopathy'. Sudden arrhythmic death, thromboembolic events or stroke and severe heart failure requiring heart transplantation are the most dramatic complications of the evolution of cardiolaminopathies and appropriate risk stratification is clinically needed combined with clinical follow-up. Treatment with cardiac electrical implantable devices is indicated in case of bradyarrhythmias (implant of a device with pacemaker functions), risk of life-threatening ventricular tachyarrhythmias (implant of an ICD) or in case of heart failure with wide QRS interval (implant of a device for cardiac resynchronization). New technologies introduced in the last 5 years can help physicians to reduce device-related complications, thanks to the extension of device longevity and availability of leadless pacemakers or defibrillators, to be implanted in appropriately selected patients. An improved knowledge of the complex pathophysiological pathways involved in cardiolaminopathies and in the determinants of their progression to more severe forms will help to improve clinical management and to better target pharmacological and non-pharmacological treatments.

A new clinical decision support tool for improving the adequacy of anticoagulant therapy and reducing the incidence of stroke in nonvalvular atrial fibrillation: A randomized clinical trial in primary care

INTRODUCTION

Atrial fibrillation (AF) is the most common cardiac arrhythmia and increases the risk of ischemic stroke 4 to 5-fold. The first choice of anticoagulant therapy (AT) is the vitamin K antagonist (VKA). Contraindication to VKA or poor control of the International Normalized Ratio leads to the administration of direct-acting oral anticoagulants. There is a trend toward inadequate AT in nonvalvular AF (NVAF) patients.

AIM

To evaluate the impact of the implementation of a decision support tool linked to the digital clinical history on the adequacy of AT, the incidence of complications, and the mortality in patients with NVAF in primary care centers (PCCs) of the Catalan Institute of Health (ICS).

METHODS AND ANALYSIS

Randomized clinical trial in 287 PCCs, formed by 2 groups (intervention and control).

POPULATION

patients controlled in PCCs, diagnosed with NVAF 1 year before the implementation of the decision support tool and with VKA treatment over a minimum of 1 year. A simple randomization method will be performed at a sector level. The decision support tool will be available for 1 year. The time in therapeutic range (TTR) will be available in the digital clinical history only to professionals of the intervention group. The information system for primary care research development database will be used for the data extraction. Statistical analysis will be done at 3 time points: before the implementation of the tool, at 1 year, and at 2 years after the beginning of the intervention. Multilevel (patient and professional levels) logistic regression models will be used to estimate the effect of the intervention.

ETHICS AND DISSEMINATION

This study protocol was approved by the Ethical Committee of Clinical Investigation of the Institut Universitari d'Investigació en Atenció Primària Jordi Gol (code P17/091). Articles will be published in scientific journals.

TRIAL REGISTRATION

Clinical-Trials.gov: NCT03367325.

Structured care of patients with atrial fibrillation improves guideline adherence

Aims

There are many reports of lack of guideline adherence in the treatment of patients with atrial fibrillation (AF), and AF affects health-related quality of life (HRQoL) negatively. The aim of this study was to investigate whether structured care compared to standard care of a general AF population could improve guideline adherence and HRQoL, and reduce symptoms,anxiety and depression.

Methods

In total, 176 patients were recruited to the intervention and 146 patients to the control group.The intervention consisted of a structured follow-up program, while patients serving as controls received standard care. The primary outcome was guideline adherence evaluated through: appropriate use of oral anticoagulants (OAC) and antiarrhythmics, whether echocardiogram and thyroid lab tests were performed, and patient-reported outcome measures (PROMs), assessed with the questionnaires SF-36, EQ-5D, HADS and ASTA at baseline and after one year.

Results

Guideline adherence was significantly better in the intervention group, 91% vs. 63% (p < 0.01), mainly due to appropriate OAC treatment 94% vs. 74% (p < 0.01). Symptoms assessed with ASTA were less frequent and the negative impact of AF was reduced in the intervention group after one year/ at follow-up. Five scales in SF-36, and the visual analogue scale for current health status in EQ-5D (EQ-VAS), improved significantly in both groups.

Conclusion

Structured care of patients with AF significantly improved guideline adherence and patients reported fewer symptoms and a reduced negative impact on disease-specific HRQoL compared to standard care at one year follow-up.

Stroke prevention in atrial fibrillation: Past, present and future

Concepts and our approaches to stroke prevention in atrial fibrillation (AF) have changed markedly over the last decade. There has been an evolution over the approach to stroke and bleeding risk assessment, as well as new treatment options. An increasing awareness of AF has led to calls to improve the detection of and population screening for AF. Stroke and bleeding risk assessment continues to evolve, and the ongoing debate on balance between simplicity and practicality, against precision medicine will continue. In this review article, we provide an overview of past, present and the (likely) future concepts and approaches to stroke prevention in AF. We propose three simple steps (the Birmingham ‘3-step’) that offers a practical management pathway to help streamline and simplify decision-making for stroke prevention in patients with AF.

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

The future of atrial fibrillation management: integrated care and stratified therapy

Atrial fibrillation is one of the major cardiovascular health problems: it is a common, chronic condition, affecting 2-3% of the population in Europe and the USA and requiring 1-3% of health-care expenditure as a result of stroke, sudden death, heart failure, unplanned hospital admissions, and other complications. Early diagnosis of atrial fibrillation, ideally before the first complication occurs, remains a challenge, as shown by patients who are only diagnosed with the condition when admitted to hospital for acute cardiac decompensation or stroke. Once diagnosed, atrial fibrillation requires chronic, multidimensional management in five domains (acute management, treatment of underlying and concomitant cardiovascular conditions, stroke prevention therapy, rate control, and rhythm control). The consistent provision of these treatment options to all patients with atrial fibrillation is difficult, despite recent improvements in organisation of care, knowledge about atrial fibrillation, and treatment options. Integrated care models that provide patient-centred care in, or close to, the patient's community while maintaining access to all specialist treatment options, emerge as the best approach to achieve consistent delivery of these chronic treatments to all patients with atrial fibrillation. Ongoing research efforts will establish when to initiate oral anticoagulation in patients with device-detected atrial high-rate episodes, quantify the prognostic effect of early and comprehensive rhythm control therapy, including atrial fibrillation ablation, and delineate optimum methods to reduce bleeding complications in patients treated with anticoagulation. Additionally, research efforts are needed to define different types of atrial fibrillation on the basis of the main causes of atrial fibrillation to pave the way for the clinical development of stratified atrial fibrillation therapy.

The relationship between knowledge, health literacy, and adherence among patients taking oral anticoagulants for stroke thromboprophylaxis in atrial fibrillation

BACKGROUND

Patients' knowledge regarding their oral anticoagulant (OAC) treatment for stroke prevention in atrial fibrillation (AF), their level of medication adherence, and health literacy are known to affect treatment outcomes. However, contemporary data regarding the relationships between these variables are lacking.

OBJECTIVE

To investigate the relationships between anticoagulant knowledge, health literacy, and self-reported adherence in patients taking warfarin and the directly acting oral anticoagulants.

METHODS

A cross-sectional survey was conducted in 48 patients with AF identified from general practices. The Anticoagulation Knowledge Tool (AKT) was used to assess anticoagulation knowledge; the Short Test of Functional Health Literacy in Adults (s-TOFHLA) for health literacy; and the 8-item Morisky Medication Adherence Scale (MMAS) for medication adherence.

RESULTS

Participants had mean scores of 61.6 ± 15.8, 7.2 ± 1.1, and 24.7 ± 9.5 for the AKT, MMAS-8 and s-TOFHLA, respectively. Significant correlations were observed between anticoagulation knowledge and health literacy with medication adherence (0.37, P < .01 and .30, P < .05, respectively). Participants with inadequate health literacy had a significantly lower mean knowledge score than those with adequate health literacy (55.8 ± 15.9 vs 66.1 ± 14.4, P < .05). Participants who self-reported adherence to their OAC had significantly higher knowledge scores than those who did not (67.5 ± 13.3 vs 56.1 ± 16.2, P < .05).

CONCLUSION

Significant correlations between health literacy, OAC knowledge, and adherence were observed, and these relationships should to be considered by health professionals responsible for monitoring patients who are prescribed anticoagulants. We also observed serious gaps in OAC knowledge. Interventions designed to optimize the outcomes of anticoagulant treatment need to address these factors.

A review of rate control in atrial fibrillation, and the rationale and protocol for the RATE-AF trial

BACKGROUND AND OBJECTIVE

Atrial fibrillation (AF) is common and causes impaired quality of life, an increased risk of stroke and death as well as frequent hospital admissions. The majority of patients with AF require control of heart rate. In this article , we summarise the limited evidence from clinical trials that guides prescription, and present the rationale and protocol for a new randomised trial. As rate control has not yet been shown to reduce mortality, there is a clear need to compare the impact of therapy on quality of life, cardiac function and exercise capacity. Such a trial should concentrate on the long-term effects of treatment in the largest proportion of patients with AF, those with symptomatic permanent AF, with the aim of improving patient well-being.

DESIGN AND INTERVENTION

The RAte control Therapy Evaluation in permanent Atrial Fibrillation (RATE-AF) trial will enrol 160 participants with a prospective, randomised, open-label, blinded end point design comparing initial rate control with digoxin or bisoprolol. This will be the first head-to-head randomised trial of digoxin and beta-blockers in AF.

PARTICIPANTS

Recruited patients will be aged ≥60 years with permanent AF and symptoms of breathlessness (equivalent to New York Heart Association class II or above), with few exclusion criteria to maximise generalisability to routine clinical practice.

OUTCOME MEASURES

The primary outcome is patient-reported quality of life, with secondary outcomes including echocardiographic ventricular function, exercise capacity and biomarkers of cellular and clinical response. Follow-up will occur at 6 and 12 months, with feasibility components to inform the design of a future trial powered to detect a difference in hospital admission. The RATE-AF trial will underpin an integrated approach to management including biomarkers, functions and symptoms that will guide future research into optimal, personalised rate control in patients with AF.

ETHICS AND DISSEMINATION

East Midlands-Derby Research Ethics Committee (16/EM/0178); peer-reviewed publications.

TRIAL REGISTRATION

Clinicaltrials.gov: NCT02391337; ISRCTN: 95259705. Pre-results.

Heart Failure With Preserved Ejection Fraction and Atrial Fibrillation: Vicious Twins

Heart failure with preserved ejection fraction (HFpEF) and atrial fibrillation (AF) are age-related conditions that are increasing in prevalence, commonly coexist, and share clinical features. This review provides a practical update on the epidemiology, pathophysiology, diagnosis, and management of patients with concomitant HFpEF and AF. Epidemiological studies highlight the close and complex links between HFpEF and AF, the shared risk factors, the high AF occurrence in the natural history of HFpEF, and the independent contribution of each condition to poor outcomes. Diagnosis of HFpEF in the setting of AF is challenging because the symptoms overlap. AF is associated with changes in echocardiographic parameters and circulating natriuretic peptides that confound HFpEF diagnosis. Symptomatic improvement with diuretic therapy supports the presence of HFpEF in patients with concomitant AF. Important knowledge gaps need to be addressed by a multidisciplinary and translational research approach to develop novel therapies that can improve prognosis.

Epidemiology and Management of Atrial Fibrillation and Stroke: Review of Data from Four European Countries

In Europe, 1-3% of the population suffers from atrial fibrillation (AF) and has increased stroke risk. By 2060 a doubling in number of cases and great burden in managing this medical condition are expected. This paper offers an overview of data on epidemiology and management of AF and stroke in four European countries as well as the interconnection between these dimensions. A search index was developed to access multiple scientific and "grey" literatures. Information was prioritised based on strength of evidence and date. Information on country reports was double-checked with national experts. The overall prevalence of AF is consistent across countries. France has the lowest stroke incidence and mortality, followed by Netherland and UK, while Romania has higher rates. GPs or medical specialists are responsible for AF treatment; exception are the special thrombosis services in the Netherlands. Prevention measurements are only present in UK through screening programs. Although international and national guidelines are available, undertreatment is present in all countries. Despite differences in healthcare systems and management of AF, epidemiology is comparable between three of the countries. Romania is an outlier, by being limited in data accessibility. This knowledge can contribute to improved AF care in Europe.

The burden of proof: The current state of atrial fibrillation prevention and treatment trials

Atrial fibrillation (AF) is an age-related arrhythmia of enormous socioeconomic significance. In recent years, our understanding of the basic mechanisms that initiate and perpetuate AF has evolved rapidly, catheter ablation of AF has progressed from concept to reality, and recent studies suggest lifestyle modification may help prevent AF recurrence. Emerging developments in genetics, imaging, and informatics also present new opportunities for personalized care. However, considerable challenges remain. These include a paucity of studies examining AF prevention, modest efficacy of existing antiarrhythmic therapies, diverse ablation technologies and practice, and limited evidence to guide management of high-risk patients with multiple comorbidities. Studies examining the long-term effects of AF catheter ablation on morbidity and mortality outcomes are not yet completed. In many ways, further progress in the field is heavily contingent on the feasibility, capacity, and efficiency of clinical trials to incorporate the rapidly evolving knowledge base and to provide substantive evidence for novel AF therapeutic strategies. This review outlines the current state of AF prevention and treatment trials, including the foreseeable challenges, as discussed by a unique forum of clinical trialists, scientists, and regulatory representatives in a session endorsed by the Heart Rhythm Society at the 12th Global CardioVascular Clinical Trialists Forum in Washington, DC, December 3-5, 2015.

Cost Effectiveness of Apixaban versus Warfarin or Aspirin for Stroke Prevention in Patients with Atrial Fibrillation: A Greek Perspective

BACKGROUND

Strokes attributed to atrial fibrillation (AF) represent a major cause of adult disability and a great burden to society and healthcare systems.

OBJECTIVES

Our objective was to assess the cost effectiveness of apixaban, a direct acting oral anticoagulant (DOAC), versus warfarin or aspirin for patients with AF in the Greek healthcare setting.

METHODS

We used a previously published Markov model to simulate clinical events for patients with AF treated with apixaban, the vitamin K antagonist (VKA) warfarin, or aspirin. Clinical events (ischemic and hemorrhagic stroke, intracranial hemorrhage, other major bleed, clinically relevant non-major bleed, myocardial infarction, and cardiovascular [CV] hospitalizations) were modeled using efficacy data from the ARISTOTLE and AVERROES clinical trials. The cohort's baseline characteristics also sourced from these trials. Among VKA-suitable patients, 64.7% were men with a mean age of 70 years and average CHADS₂ (cardiac failure, hypertension, age, diabetes, stroke₂) score of 2.1, whereas 58.5% of VKA-unsuitable patients were men with a mean age of 70 years and a CHADS₂ score of 2.0. A panel of experts (cardiologists and internists) provided information on the resource use associated with the management of AF. Cost calculations reflect the local clinical setting and a third-party payer perspective (€, discounted at 3%).

RESULTS

Based on a simulation of 1000 VKA-suitable patients over a lifetime horizon, the use of apixaban versus warfarin resulted in 26 fewer strokes and systemic embolisms in total, 65 fewer bleeds, 41 fewer myocardial infarctions, and 29 fewer CV-related deaths, with an incremental cost-effectiveness ratio (ICER) of €14,478/quality-adjusted life-year (QALY). For VKA-unsuitable patients, apixaban versus aspirin resulted in 72 fewer strokes and systemic embolisms and 57 fewer CV-related deaths, with an ICER of €7104/QALY. Sensitivity analyses indicated that results were robust.

CONCLUSIONS

Based on the present analysis, apixaban represents a cost-effective treatment option versus warfarin and aspirin for the prevention of stroke in patients with AF from a Greek healthcare payer perspective over a lifetime horizon.

The role of the Arrhythmia Team, an integrated, multidisciplinary approach to treatment of patients with cardiac arrhythmias: results of the European Heart Rhythm Association survey

Management of patients with cardiac arrhythmias is increasingly complex because of continuous technological advance and multifaceted clinical conditions associated with ageing of the population, the presence of co-morbidities and the need for polypharmacy. The aim of this European Heart Rhythm Association Scientific Initiatives Committee survey was to provide an insight into the role of the Arrhythmia Team, an integrated, multidisciplinary approach to management of patients with cardiac arrhythmias. Forty-eight centres from 18 European countries replied to the Web-based questionnaire. The presence of an Arrhythmia Team was reported by 44% of the respondents, whereas 17% were not familiar with this term. Apart from the electrophysiologist, health professionals who should belong to such teams, according to the majority of the respondents, include a clinical cardiologist, a nurse, a cardiac surgeon, a heart failure specialist, a geneticist, and a geriatrician. Its main activity should be dedicated to the management of patients with complex clinical conditions or refractory or inherited forms of arrhythmias. When present, the Arrhythmia Team was considered helpful by 95% of respondents; the majority of centres (79%) agreed that it should be implemented. The Arrhythmia Team seems to be connected to important expectations in the management of cardiac arrhythmias. The efficacy of such an integrated and multidisciplinary approach should be encouraged and tested in clinical practice.

Pneumatic Burst Pressures After Inverted Closure of the Left Atrial Appendage: An Ex Vivo Model

BACKGROUND

The left atrial (LA) appendage (LAA) is the main source of thromboembolism in atrial fibrillation. This study addressed initial pressure resistance of surgical LAA closures.

METHODS

In an experimental model, pneumatic pressure resistances of different surgical closure techniques were examined, and variations in technique and access were studied. In preparations of the LA from freshly slaughtered pigs, pneumatic pressure was applied to the LAA. Burst pressures (mbar) of various closure techniques (n = 12 specimens per group) were measured: (1) epicardial double-layer suture, (2) epicardial stapler closure (staple height 2 mm), (3) epicardial stapler closure (staple height 4, 4.5, and 5 mm), (4) endocardial inverse double-layer suture, (5) endocardial inverse stapler seam (staple height 2 mm), and (6) endocardial inverse stapler seam (staple height 4, 4.5, and 5 mm).

RESULTS

The mean burst pressure in group 1 was 175.5 ± 19.35 mbar. There was no significant difference compared with group 2 (174.5 ± 28.45 mbar) or group 3 (176 ± 27.69 mbar). Group 4 scored significantly higher than all other groups (198.9 ± 18.35 mbar). Burst pressures in group 5 (136.2 ± 16.68 mbar) were significantly lower than in group 4 and in group 6 (165.1 ± 21.94 mbar), but the differences between groups 5 and 6 were also significant.

CONCLUSIONS

In an ex vivo model, double-layer suturing of the inverted LAA from an internal LA access led to higher burst pressures compared with epicardial suturing and with both endocardial and epicardial stapled closures.

Atrial high-rate episodes and stroke prevention

While the benefit of oral anticoagulants (OACs) for stroke prevention in patients with atrial fibrillation (AF) is well established, it is not known whether oral anticoagulation is indicated in patients with atrial high-rate episodes (AHRE) recorded on a cardiac implantable electronic device, sometimes also called subclinical AF, and lasting for at least 6 min in the absence of clinically diagnosed AF. Clinical evidence has shown that short episodes of rapid atrial tachycarrhythmias are often detected in patients presenting with stroke and transient ischaemic attack. Patients with AHRE have a higher likelihood of suffering from subsequent strokes, but their stroke rate seems lower than in patients with diagnosed AF, and not all AHRE episodes correspond to AF. The prognostic and pathological significance of AHRE is not yet fully understood. Clinical trials of OAC therapy are being conducted to determine whether therapeutic intervention would be beneficial to patients experiencing AHRE in terms of reducing the risk of stroke.

Haemorrhagic Transformation after Ischaemic Stroke in Patients Taking Non-vitamin K Antagonist Oral Anticoagulants

Background and Purpose

To evaluate the frequency and outcome of haemorrhagic transformation (HT) after ischaemic stroke in patients treated with non-vitamin K antagonist oral anticoagulants (NOACs).

Methods

Patients with stroke on treatment with a NOAC were prospectively enrolled in this multicentre observational study between February 2012 and 2015. Brain imaging at admission and follow-up imaging until day 7 were reviewed for HT. Functional outcome was assessed by the modified Rankin scale (mRS) before the index event, at discharge, and at 3-months.

Results

231 patients without recanalisation therapy (no-RT), and 32 patients with RT were eligible for analysis. Any HT was present at admission in 9/231 no-RT patients (3.9%, 95% CI 2.0 to 7.3) and in none of the patients with RT. In patients with follow-up imaging (no-RT, n=129, and RT, n=32), HT was present in 14.0% (no-RT; 95% CI, 8.9 to 21.1), and 40.6% (RT, 95% CI, 25.5 to 57.8), respectively. After adjustment for stroke severity, this difference between the no-RT and RT groups became non-significant. Symptomatic ICH was observed in 1 patient per group. HT was not associated with unfavourable outcome (mRS 3-6) at 3-months in multivariable analysis. Resumption of OAC after stroke was delayed in patients with HT compared to those without (15 d [IQR, 5–26] vs. 1 d [0–4], P<0.001).

Conclusions

The frequency and severity of HT after stroke on NOAC appears similar to previous reports for vitamin K antagonists and no anticoagulation. Whether asymptomatic HT should delay resumption of preventive anticoagulation requires further investigation.

Catheter ablation in patients with persistent atrial fibrillation

Catheter ablation is increasingly offered to patients who suffer from symptoms due to atrial fibrillation (AF), based on a growing body of evidence illustrating its efficacy compared with antiarrhythmic drug therapy. Approximately one-third of AF ablation procedures are currently performed in patients with persistent or long-standing persistent AF. Here, we review the available information to guide catheter ablation in these more chronic forms of AF. We identify the following principles: Our clinical ability to discriminate paroxysmal and persistent AF is limited. Pulmonary vein isolation is a reasonable and effective first approach for catheter ablation of persistent AF. Other ablation strategies are being developed and need to be properly evaluated in controlled, multicentre trials. Treatment of concomitant conditions promoting recurrent AF by life style interventions and medical therapy should be a routine adjunct to catheter ablation of persistent AF. Early rhythm control therapy has a biological rationale and trials evaluating its value are underway. There is a clear need to generate more evidence for the best approach to ablation of persistent AF beyond pulmonary vein isolation in the form of adequately powered controlled multi-centre trials.

[Implantable loop recorder in atrial fibrillation and after catheter ablation]

BACKGROUND

Implantable loop recorders (ILR) are an established diagnostic method for detection of cardiac arrhythmias including atrial fibrillation.

OBJECTIVE

The aim of this work is to provide an overview of available data and indications of ILR in atrial fibrillation, especially after catheter ablation, in order to illustrate practice-oriented recommendations.

MATERIALS AND METHODS

We conducted a selective PubMed literature search.

RESULTS AND DISCUSSION

ILR can record asymptomatic/rare atrial fibrillation episodes and prevent thromboembolic events by allowing timely initiation of oral anticoagulation. They can be used to assess therapeutic success after percutaneous or surgical ablation, if despite increased thromboembolic risk, no oral anticoagulation is desired. ILR equipped with remote monitoring function and special P wave detection algorithms may improve diagnostic confidence.

Overcoming global challenges in stroke prophylaxis in atrial fibrillation: The role of non-vitamin K antagonist oral anticoagulants

Atrial fibrillation is the world's most common sustained cardiac arrhythmia and is associated with a significantly increased risk of stroke. The global burden of atrial fibrillation is rising, commensurate with the ageing population. Well-controlled vitamin K antagonist-based anticoagulation has been shown to reduce the risk of stroke secondary to atrial fibrillation by two-thirds. However, patients with atrial fibrillation have frequently been denied anticoagulation because of a variety of perceived risks related to bleeding, falls, chronological age, and poor compliance. Even when vitamin K antagonists are used, maximum benefit and safety are only delivered when high quality control of therapy (TTR > 70%) is achieved, which has proven remarkably difficult in many health-care systems and amongst many patient groups. The non-vitamin K antagonist oral anticoagulants (NOACs) offer solutions to many of the challenges of achieving widespread, safe, and effective anticoagulation for stroke prophylaxis in atrial fibrillation, yet their uptake into routine clinical practice remains variable. The evidence supporting their more widespread use to overcome the challenges of stroke prophylaxis for atrial fibrillation is reviewed in this article.

A Simple, Non-Invasive Score to Predict Paroxysmal Atrial Fibrillation

Paroxysmal atrial fibrillation (pAF) is a major risk factor for stroke but remains often unobserved. To predict the presence of pAF, we developed model scores based on echocardiographic and other clinical parameters from routine cardiac assessment. The scores can be easily implemented to clinical practice and might improve the early detection of pAF. In total, 47 echocardiographic and other clinical parameters were collected from 1000 patients with sinus rhythm (SR; n = 728), pAF (n = 161) and cAF (n = 111). We developed logistic models for classifying between pAF and SR that were reduced to the most predictive parameters. To facilitate clinical implementation, linear scores were derived. To study the pathophysiological progression to cAF, we analogously developed models for cAF prediction. For classification between pAF and SR, amongst 12 selected model parameters, the most predictive variables were tissue Doppler imaging velocity during atrial contraction (TDI, A’), left atrial diameter, age and aortic root diameter. Models for classifying between pAF and SR or between cAF and SR showed areas under the ROC curves of 0.80 or 0.93, which resembles classifiers with high discriminative power. The novel risk scores were suitable to predict the presence of pAF based on variables readily available from routine cardiac assessment. Modelling helped to quantitatively characterize the pathophysiologic transition from SR via pAF to cAF. Applying the scores may improve the early detection of pAF and might be used as decision aid for initiating preventive interventions to reduce AF-associated complications.

Rate control in atrial fibrillation

Control of the heart rate (rate control) is central to atrial fibrillation management, even for patients who ultimately require control of the rhythm. We review heart rate control in patients with atrial fibrillation, including the rationale for the intervention, patient selection, and the treatments available. The choice of rate control depends on the symptoms and clinical characteristics of the patient, but for all patients with atrial fibrillation, rate control is part of the management. Choice of drugs is patient-dependent. β blockers, alone or in combination with digoxin, or non-dihydropyridine calcium-channel blockers (not in heart failure) effectively lower the heart rate. Digoxin is least effective, but a reasonable choice for physically inactive patients aged 80 years or older, in whom other treatments are ineffective or are contraindicated, and as an additional drug to other rate-controlling drugs, especially in heart failure when instituted cautiously. Atrioventricular node ablation with pacemaker insertion for rate control should be used as an approach of last resort but is also an option early in the management of patients with atrial fibrillation treated with cardiac resynchronisation therapy. However, catheter ablation of atrial fibrillation should be considered before atrioventricular node ablation. Although rate control is a top priority and one of the first management issues for all patients with atrial fibrillation, many issues remain.

Stroke prevention in atrial fibrillation

Atrial fibrillation is found in a third of all ischaemic strokes, even more after post-stroke atrial fibrillation monitoring. Data from stroke registries show that both unknown and untreated or under treated atrial fibrillation is responsible for most of these strokes, which are often fatal or debilitating. Most could be prevented if efforts were directed towards detection of atrial fibrillation before stroke occurs, through screening or case finding, and treatment of all patients with atrial fibrillation at increased risk of stroke with well-controlled vitamin K antagonists or non-vitamin K antagonist anticoagulants. The default strategy should be to offer anticoagulant thromboprophylaxis to all patients with atrial fibrillation unless defined as truly low risk by simple validated risk scores, such as CHA2DS2-VASc. Assessment of bleeding risk using the HAS-BLED score should focus attention on reversible bleeding risk factors. Finally, patients need support from physicians and various other sources to start anticoagulant treatment and to ensure adherence to and persistence with treatment in the long term.

Atrial fibrillation burden and atrial fibrillation type: Clinical significance and impact on the risk of stroke and decision making for long-term anticoagulation

Atrial fibrillation (AF) is a common arrhythmia increasing the risk of morbidity and adverse outcomes (stroke, heart failure, death). AF is found in 1-2% of the general population, with increasing prevalence with aging. Its exact epidemiological profile is incomplete and underestimated, because 10-40% of AF patients (particularly the elderly) can be asymptomatic ("clinically silent or subclinical AF"), with occasional electrocardiographic diagnosis. The research interest on silent AF has increased by the evidence that its outcome is no less severe, in terms of risks of stroke and death, than that for symptomatic patients. Data collected from more than 18,000 patients indicate that cardiac implantable electrical devices (CIEDs) are validated tools for detecting silent AF and measuring the time spent in AF, defined as "AF burden." A maximum daily AF burden of ≥5-6min, but particularly ≥1h, is associated with a significant increase in the risk of stroke, and may be clinically relevant to improve current risk stratification based on risk scores and for "personalizing" prescription of oral anticoagulants. An in-depth study of the temporal relationship between AF and ischemic stroke showed that data from CIEDs reveal a complex scenario, by which AF is certainly a risk factor for cardioembolic stroke, with a cause-effect relationship related to atrial thrombi, but can also be a simple "marker of risk," with a noncausal association with stroke. In such cases, stroke is possibly related to atheroemboli from the aorta, the carotid arteries, or other sources.

Atrial fibrillation

Atrial fibrillation (AF) is the most common sustained cardiac rhythm disorder, and increases in prevalence with increasing age and the number of cardiovascular comorbidities. AF is characterized by a rapid and irregular heartbeat that can be asymptomatic or lead to symptoms such as palpitations, dyspnoea and dizziness. The condition can also be associated with serious complications, including an increased risk of stroke. Important recent developments in the clinical epidemiology and management of AF have informed our approach to this arrhythmia. This Primer provides a comprehensive overview of AF, including its epidemiology, mechanisms and pathophysiology, diagnosis, screening, prevention and management. Management strategies, including stroke prevention, rate control and rhythm control, are considered. We also address quality of life issues and provide an outlook on future developments and ongoing clinical trials in managing this common arrhythmia.