Atrial fibrillation (AF) is a common and morbid arrhythmia. Stroke is a major hazard of AF and may be preventable with oral anticoagulation. Yet since AF is often asymptomatic, many individuals with ...AF may be unaware and do not receive treatment that could prevent a stroke. Screening for AF has gained substantial attention in recent years as several studies have demonstrated that screening is feasible. Advances in technology have enabled a variety of approaches to facilitate screening for AF using both medical-prescribed devices as well as consumer electronic devices capable of detecting AF. Yet controversy about the utility of AF screening remains owing to concerns about potential harms resulting from screening in the absence of randomized data demonstrating effectiveness of screening on outcomes such as stroke and bleeding. In this review, we summarize current literature, present technology, population-based screening considerations, and consensus guidelines addressing the role of AF screening in practice.
Background Device-detected subclinical atrial fibrillation (AF) refers to infrequent, short-lasting, asymptomatic AF that is detected only with long-term continuous monitoring. Subclinical AF is ...common and associated with an increased risk of stroke; however, the risk of stroke with subclinical AF is lower than for clinical AF, and very few patients with subclinical AF alone have been included in large AF anticoagulation trials. The net benefit of anticoagulation in patients with subclinical AF is unknown. Design ARTESiA is a prospective, multicenter, double-blind, randomized controlled trial, recruiting patients with subclinical AF detected by an implanted pacemaker, defibrillator, or cardiac monitor, and who have additional risk factors for stroke. Patients with clinical AF documented by surface electrocardiogram will be excluded from the study. Participants will be randomized to receive either apixaban (according to standard AF dosing) or aspirin 81 mg daily. The primary outcome is the composite of stroke, transient ischemic attack with diffusion-weighted magnetic resonance imaging evidence of cerebral infarction, and systemic embolism. Approximately 4,000 patients will be enrolled from around 230 clinical sites, with an anticipated mean follow-up of 36 months until 248 adjudicated primary outcome events have occurred. Summary ARTESiA will determine whether oral anticoagulation therapy with apixaban compared with aspirin reduces the risk of stroke or systemic embolism in patients with subclinical AF and additional risk factors.
Oral anticoagulation (OAC) therapy is effective in atrial fibrillation but requires vigilance to maintain the international normalized ratio in the therapeutic range. This report examines how ...differences in time in therapeutic range (TTR) between centers and between countries affect the outcomes of OAC therapy.
In a posthoc analysis, the TTRs of patients on OAC in a randomized trial of OAC versus clopidogrel plus aspirin (Atrial Fibrillation Clopidogrel Trial With Irbesartan for Prevention of Vascular Events ACTIVE W) were used to calculate the mean TTR for each of 526 centers and 15 countries. Proportional-hazards analysis, with and without adjustment for baseline variables, was performed, with patients stratified by TTR quartile and country. A wide variation in TTRs was found between centers, with mean TTRs for centers in the 4 quartiles of 44%, 60%, 69%, and 78%. For patients at centers below the median TTR (65%), no treatment benefit was demonstrated as measured by relative risk for vascular events of clopidogrel plus aspirin versus OAC (relative risk, 0.93; 95% confidence interval, 0.70 to 1.24; P=0.61). However, for patients at centers with a TTR above the study median, OAC had a marked benefit, reducing vascular events by >2-fold (relative risk, 2.14; 95% confidence interval, 1.61 to 2.85; P<0.0001). Mean TTR also varied between countries from 46% to 78%; relative risk (clopidogrel plus aspirin versus OAC) varied from 0.6 to 3.6 (a 5-fold difference). A population-average model predicted that a TTR of 58% would be needed to be confident that patients would benefit from being on OAC.
A wide variation exists in international normalized ratio control, as measured by TTR, between clinical centers and between countries, which has a major impact on the treatment benefit of OAC therapy. For centers and countries, a target threshold TTR exists (estimated between 58% and 65%) below which there appears to be little benefit of OAC over antiplatelet therapy.
Atrial fibrillation (AF) is the most common rhythm disorder seen in clinical practice. Antiarrhythmic drugs are effective for reduction of recurrence in patients with symptomatic paroxysmal AF. ...Radiofrequency ablation is an accepted therapy in patients for whom antiarrhythmic drugs have failed; however, its role as a first-line therapy needs further investigation.
To compare radiofrequency ablation with antiarrhythmic drugs (standard therapy) in treating patients with paroxysmal AF as a first-line therapy.
A randomized clinical trial involving 127 treatment-naive patients with paroxysmal AF were randomized at 16 centers in Europe and North America to received either antiarrhythmic therapy or ablation. The first patient was enrolled July 27, 2006; the last patient, January 29, 2010. The last follow-up was February 16, 2012.
Sixty-one patients in the antiarrhythmic drug group and 66 in the radiofrequency ablation group were followed up for 24 months.
The time to the first documented atrial tachyarrhythmia of more than 30 seconds (symptomatic or asymptomatic AF, atrial flutter, or atrial tachycardia), detected by either scheduled or unscheduled electrocardiogram, Holter, transtelephonic monitor, or rhythm strip, was the primary outcome. Secondary outcomes included symptomatic recurrences of atrial tachyarrhythmias and quality of life measures assessed by the EQ-5D tool.
Forty-four patients (72.1%) in the antiarrhythmic group and in 36 patients (54.5%) in the ablation group experienced the primary efficacy outcome (hazard ratio HR, 0.56 95% CI, 0.35-0.90; P = .02). For the secondary outcomes, 59% in the drug group and 47% in the ablation group experienced the first recurrence of symptomatic AF, atrial flutter, atrial tachycardia (HR, 0.56 95% CI, 0.33-0.95; P = .03). No deaths or strokes were reported in either group; 4 cases of cardiac tamponade were reported in the ablation group. In the standard treatment group, 26 patients (43%) underwent ablation after 1-year. Quality of life was moderately impaired at baseline in both groups and improved at the 1 year follow-up. However, improvement was not significantly different among groups.
Among patients with paroxysmal AF without previous antiarrhythmic drug treatment, radiofrequency ablation compared with antiarrhythmic drugs resulted in a lower rate of recurrent atrial tachyarrhythmias at 2 years. However, recurrence was frequent in both groups.
clinicaltrials.gov Identifier: NCT00392054.
Approximately 10% of ischemic strokes are associated with atrial fibrillation (AF) first diagnosed at the time of stroke. Detecting asymptomatic AF would provide an opportunity to prevent these ...strokes by instituting appropriate anticoagulation. The AF-SCREEN international collaboration was formed in September 2015 to promote discussion and research about AF screening as a strategy to reduce stroke and death and to provide advocacy for implementation of country-specific AF screening programs. During 2016, 60 expert members of AF-SCREEN, including physicians, nurses, allied health professionals, health economists, and patient advocates, were invited to prepare sections of a draft document. In August 2016, 51 members met in Rome to discuss the draft document and consider the key points arising from it using a Delphi process. These key points emphasize that screen-detected AF found at a single timepoint or by intermittent ECG recordings over 2 weeks is not a benign condition and, with additional stroke factors, carries sufficient risk of stroke to justify consideration of anticoagulation. With regard to the methods of mass screening, handheld ECG devices have the advantage of providing a verifiable ECG trace that guidelines require for AF diagnosis and would therefore be preferred as screening tools. Certain patient groups, such as those with recent embolic stroke of uncertain source (ESUS), require more intensive monitoring for AF. Settings for screening include various venues in both the community and the clinic, but they must be linked to a pathway for appropriate diagnosis and management for screening to be effective. It is recognized that health resources vary widely between countries and health systems, so the setting for AF screening should be both country- and health system-specific. Based on current knowledge, this white paper provides a strong case for AF screening now while recognizing that large randomized outcomes studies would be helpful to strengthen the evidence base.
Device-detected atrial fibrillation (also known as subclinical atrial fibrillation or atrial high-rate episodes) is a common finding in patients with an implanted cardiac rhythm device and is ...associated with an increased risk of ischemic stroke. Whether oral anticoagulation is effective and safe in this patient population is unclear.
We performed a systematic review of MEDLINE and Embase for randomized trials comparing oral anticoagulation with antiplatelet or no antithrombotic therapy in adults with device-detected atrial fibrillation recorded by a pacemaker, implantable cardioverter defibrillator, cardiac resynchronization therapy device, or implanted cardiac monitor. We used random-effects models for meta-analysis and rated the quality of evidence using the Grading of Recommendations Assessment, Development and Evaluation framework (GRADE). The review was preregistered (PROSPERO CRD42023463212).
From 785 citations, we identified 2 randomized trials with relevant clinical outcome data: NOAH-AFNET 6 (Non-Vitamin K Antagonist Oral Anticoagulants in Patients With Atrial High Rate Episodes; 2536 participants) evaluated edoxaban, and ARTESiA (Apixaban for the Reduction of Thrombo-Embolism in Patients With Device-Detected Sub-Clinical Atrial Fibrillation; 4012 participants) evaluated apixaban. Meta-analysis demonstrated that oral anticoagulation with these agents reduced ischemic stroke (relative risk RR, 0.68 95% CI, 0.50-0.92; high-quality evidence). The results from the 2 trials were consistent (I
statistic for heterogeneity=0%). Oral anticoagulation also reduced a composite of cardiovascular death, all-cause stroke, peripheral arterial embolism, myocardial infarction, or pulmonary embolism (RR, 0.85 95% CI, 0.73-0.99; I
=0%; moderate-quality evidence). There was no reduction in cardiovascular death (RR, 0.95 95% CI, 0.76-1.17; I
=0%; moderate-quality evidence) or all-cause mortality (RR, 1.08 95% CI, 0.96-1.21; I
=0%; moderate-quality evidence). Oral anticoagulation increased major bleeding (RR, 1.62 95% CI, 1.05-2.50; I²=61%; high-quality evidence).
The results of the NOAH-AFNET 6 and ARTESiA trials are consistent with each other. Meta-analysis of these 2 large randomized trials provides high-quality evidence that oral anticoagulation with edoxaban or apixaban reduces the risk of stroke in patients with device-detected atrial fibrillation and increases the risk of major bleeding.
Growing evidence suggests a consistent association between atrial fibrillation (AF) and cognitive impairment and dementia that is independent of clinical stroke. This report from the AF-SCREEN ...International Collaboration summarizes the evidence linking AF to cognitive impairment and dementia. It provides guidance on the investigation and management of dementia in patients with AF on the basis of best available evidence. The document also addresses suspected pathophysiologic mechanisms and identifies knowledge gaps for future research. Whereas AF and dementia share numerous risk factors, the association appears to be independent of these variables. Nevertheless, the evidence remains inconclusive regarding a direct causal effect. Several pathophysiologic mechanisms have been proposed, some of which are potentially amenable to early intervention, including cerebral microinfarction, AF-related cerebral hypoperfusion, inflammation, microhemorrhage, brain atrophy, and systemic atherosclerotic vascular disease. The mitigating role of oral anticoagulation in specific subgroups (eg, low stroke risk, short duration or silent AF, after successful AF ablation, or atrial cardiopathy) and the effect of rhythm versus rate control strategies remain unknown. Likewise, screening for AF (in cognitively normal or cognitively impaired patients) and screening for cognitive impairment in patients with AF are debated. The pathophysiology of dementia and therapeutic strategies to reduce cognitive impairment warrant further investigation in individuals with AF. Cognition should be evaluated in future AF studies and integrated with patient-specific outcome priorities and patient preferences. Further large-scale prospective studies and randomized trials are needed to establish whether AF is a risk factor for cognitive impairment, to investigate strategies to prevent dementia, and to determine whether screening for unknown AF followed by targeted therapy might prevent or reduce cognitive impairment and dementia.
Arrhythmic mitral valve prolapse (MVP) has gained great interest recently because of the increasing recognition of its potential role in unexplained cardiac arrest. Although evidence has accumulated ...to show the association of arrhythmic MVP (AMVP) with sudden cardiac death (SCD), risk stratification and management remain unclear. Physicians are faced with the challenges of screening for AMVP among MVP patients and the dilemma of when and how to intervene to prevent SCD in these patients. In addition, there is little guidance to help approach MVP patients who present with an otherwise unexplained cardiac arrest to know whether MVP was the primary cause of cardiac arrest or just an innocent bystander. Herein we review the epidemiology and definition of AMVP, the risk and mechanisms of SCD, and summarize the clinical evidence behind risk markers of SCD and therapeutic interventions that could potentially prevent it. We also propose an algorithm that provides guidance as to how to screen for AMVP and what therapeutic interventions to use. Last, we propose a diagnostic algorithm for approaching patients with otherwise unexplained cardiac arrest who are shown to have MVP.
Le prolapsus valvulaire mitral (PVM) arythmique a suscité beaucoup d’intérêt dernièrement parce qu’on croit de plus en plus qu’il pourrait jouer un rôle dans l’arrêt cardiaque inexpliqué. Bien que les données s’accumulant montrent l’association du PVM arythmique avec une mort subite cardiaque, la stratification et la gestion des risques demeurent floues. Les médecins sont confrontés au défi de dépister le PVM arythmique chez les patients atteints de PVM et doivent déterminer quand et comment intervenir afin de prévenir la mort subite cardiaque chez ces patients. En outre, il n’existe pas de directives sur la prise en charge des patients atteints de PVM qui se présentent avec un arrêt cardiaque qui ne peut être expliqué autrement, pour déterminer si le PVM était la cause principale de l’arrêt cardiaque ou simplement une affection concomitante sans lien. Dans ce rapport, nous étayons l’épidémiologie et la définition du PVM arythmique, les risques et les mécanismes de la mort subite cardiaque, et nous résumons les données cliniques sur les marqueurs de risque de mort subite cardiaque et les interventions thérapeutiques qui pourraient la prévenir. Nous proposons aussi un algorithme qui offre une orientation sur le dépistage du PVM arythmique et sur les interventions thérapeutiques à utiliser. Enfin, nous proposons un algorithme diagnostique pour les patients ayant subi un arrêt cardiaque ne pouvant être expliqué autrement qui présentent un PVM.
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