Prevention Of AF-related Stroke Research Articles

New-onset as opposed to established atrial fibrillation as a risk factor for incident stroke

BackgroundAtrial fibrillation (AF) is an established risk factor for acute ischemic stroke (AIS). It remains unclear if new-onset AF confers a higher risk of AIS than longer-standing AF. MethodsWe retrospectively analyzed all stroke-free patients who underwent transthoracic echocardiography (TTE) in the Henry Ford Health System between March 6 and September 6, 2016. Incident AIS and new-onset AF were ascertained by the presence of new diagnostic codes in the electronic medical record over a follow-up period of up to 5 years. Cox proportional hazards regression was used to identify risk factors for new-onset AF or AIS. ResultsOf 7310 patients who underwent baseline TTE the mean age was 65 years, 54% were female, 51% were Caucasian, and 46% had left atrial enlargement (LAE). Of at-risk patients, 10.9% developed new-onset AF and 2.9% experienced incident AIS. The risk of new-onset AF among at-risk patients was 3.1 times higher among patients with any degree of LAE compared to those with normal LA size (95% CI 2.6–3.6, P < 0.0001). New-onset AF, more than established AF, in turn had a powerful association with incident AIS. The cumulative 5-year risk of AIS was 3.5% in those without AF, 5.9% in those with established AF prior to TTE, and 20.1% in those with new-onset AF (P < 0.0001). In multivariable analysis new-onset AF had the strongest association with incident AIS (P < 0.0001), followed by increasing age (P = 0.0025), black race (P = 0.0032), and smoking (P = 0.0063). ConclusionsNew-onset AF has a strong relationship with incident AIS. LAE was present in nearly half of stroke-free patients undergoing TTE, and was associated with a significantly higher likelihood of new-onset AF during follow-up. Vigilant cardiac monitoring for AF in individuals with LAE, coupled with the timely initiation of anticoagulation, may be an important strategy for the primary prevention of AF-related stroke.

Simulating atrial fibrillation patterns and screening strategies using virtual patient-level models

Abstract Introduction Atrial fibrillation (AF) is the most common cardiac arrhythmia and is associated with increased morbidity and mortality. However, early detection and treatment of AF are hampered by highly variable occurrence and duration of AF episodes, heterogenous patterns of AF progression, and poor symptom-rhythm correlation present in many patients. Purpose To develop a computational patient-level model for simulating individual AF episodes, AF progression, and associated clinical outcomes, and to compare the effectiveness of systematic or symptom-based 1-minute electrocardiography (ECG) or 14-day Holter screening using this model. Methods We developed a Markov model with 7 different rhythm and/or clinical states (sinus rhythm (SR), asymptomatic and symptomatic AF, each with or without previous stroke, and death) and age/sex-dependent transition probabilities estimated based on clinical data (Figure 1A). Additionally, transitions between SR and AF states were modulated by AF-related remodeling, which itself was controlled by the time in AF and age. Results The virtual patient-level model enabled the simulation of changes in rhythm status and clinical outcomes during an entire lifetime with minute-level resolution (Figure 1B). Age/sex-specific AF prevalence / incidence, the proportion of symptomatic episodes and mortality in 4000 virtual patients were in good agreement with clinical data (Figure 1C). We employed the perfect knowledge about rhythm status at any moment in time provided by the model to evaluate systematic and symptom-based 1-minute ECG and 14-day Holter screening for AF in this population. In total, 2372 virtual patients &amp;gt;65 years developed AF. Systematic yearly 1-minute ECG recordings only identified 58 (2.4%) patients. In contrast, 14-day Holter-monitoring detected 18% of AF patients over 65 with a median of 532 days earlier than their clinical AF diagnosis, and identified 11.8% of AF patients who were either completely asymptomatic or only had symptomatic episodes &amp;lt;3 hours. Short-term (2-week) screening after a first symptom had a very low yield, which increased with increasing screening frequency and duration of follow-up (Figure 2). The majority of the remaining AF patients could be diagnosed when their symptoms lasted ≥3 hours, providing time for a traditional clinical diagnosis. Conclusion Our novel patient-level AF model can simulate individual AF patterns and clinical outcomes such as stroke and death in large cohorts of virtual patients. The model highlights the variability of AF episodes that makes effective early detection of asymptomatic AF with short-term monitoring challenging, and provides a tool for future studies into AF progression, screening and prevention of AF-related stroke and mortality.Figure 1Figure 2

Is There a Role for Vitamin K Antagonist in the Management of Atrial Fibrillation in 2023?

To address the following question: Are vitamin K antagonists (VKA) obsolete as stroke prevention therapy for patients with atrial fibrillation (AF) and thromboembolic risk factors? A patient-level meta-analysis of the pivotal phase III randomized trials confirmed the favorable treatment effect of direct oral anticoagulants (DOAC) over VKA in multiple key patient subgroups. Among patients with AF and rheumatic heart disease (85% of whom had mitral stenosis), a randomized trial showed that rivaroxaban was not superior to VKA for stroke prevention. Caution should be exercised when prescribing DOAC for AF-related stroke prevention for patients with elevated body mass indices or history of bariatric surgery, patients with bioprosthetic heart valves, and those who require treatment with drugs that interact with cytochrome P450 and P-glycoprotein. Drug costs associated with DOAC remain considerably higher than VKA, by up to 30-fold. Direct oral anticoagulants are preferable over VKA in the large majority of eligible patients with AF and thromboembolic risk factors. The use of DOAC should be avoided for patients with mechanical heart valves or moderate/severe rheumatic mitral stenosis. Vitamin K antagonist is a reasonable option for patients who are under-represented in randomized trials, when there are significant drug-drug interactions or when patients cannot afford DOAC agents due to their higher costs.

Mechanistic modelling of Virchows triad to assess thrombogenicity and stroke risk in atrial fibrillation patients

Abstract Background Atrial fibrillation (AF) is responsible for almost one third of all strokes, with the left atrial appendage (LAA) being the primary thromboembolic source due to localised stimulation of prothrombotic mechanisms; blood stasis, hypercoagulability and endothelial damage, known as Virchow's triad. Aim We propose an in-silico modelling pipeline that leverages clinical imaging data to mechanistically assess patient thrombogenicity for all aspects of Virchow's triad to improve the prediction and prevention of AF-related stroke. Methods Two AF patients undergoing Cine magnetic resonance imaging (sinus rhythm (SR) N=1 or AF N=1 during imaging) were selected for 3D left atrial (LA) modelling with patient-specific myocardial deformation prescribed from image-derived wall motion. Blood stasis was quantified by computational fluid dynamics (CFD) simulations of 5 cardiac cycles [1]. Generation of three key coagulation proteins; thrombin, fibrinogen and fibrin, were modelled to represent thrombus growth and hypercoagulability [2]. Regions prone to thrombogenesis by endothelial damage were identified by the oscillatory shear index (OSI), time averaged wall shear stress (TAWSS) and endothelial cell activation potential (ECAP) metrics in the LAA [3]. Results Patient-specific LA simulations enabled the assessment of differences between SR and AF conditions, quantified as numerical characteristics of each aspect of Virchow's triad. In SR, blood flow velocities were in the range 0–2.6 m/s with mean of 0.85 m/s in the LA cavity, while AF had a range between 0–1.6 m/s with mean of 0.55 m/s. The peak and mean LAA velocities in SR were 0.85 m/s and 0.14 m/s, while AF had a peak LAA velocity of 0.32 m/s and mean of 0.09 m/s, showing a 38% decrease during AF. The thrombin concentration reached its steady state at 1.26 mmol/m3 in the AF case after 4.7 seconds, while thrombin was washed away from the initial injury site in SR. After 5 cardiac cycles of thrombus growth dynamics, the peak fibrin concentration in the LAA was 1.3 mmol/m3 in SR and 3.8 mmol/m3 in AF, with the thrombus area in AF being 40% larger. Fibrinogen concentration decreased at a rate equal to fibrin generation in both SR and AF solely in the area of thrombus formation. ECAP in the LAA had peak values of 2.9 in SR and 3.7 in AF, with the location at highest risk of thrombogenesis above the LAA entrance. LAA OSI had an average value of 0.45 in AF versus 0.36 in SR, showing a 26% increase. Similarly, the TAWSS was 3.5x10–3 Pa on average over the LAA in AF compared to 1.4x10–3 Pa in SR. Conclusions Patient-specific LA models combining these three quantitative characteristics can be used to predict the higher thrombogenic risk in AF. After further validation, this novel approach for quantitative assessment of AF patient thrombogenicity based on modelling all factors in Virchow's triad can personalise and improve management of AF patients with a risk of stroke. Funding Acknowledgement Type of funding sources: Public grant(s) – National budget only. Main funding source(s): UK Engineering and Physical Sciences Research Council

Mechanistic modelling of Virchows triad to assess thrombogenicity and stroke risk in atrial fibrillation patients

Abstract Background Atrial fibrillation (AF) is responsible for almost one third of all strokes, with the left atrial appendage (LAA) being the primary thromboembolic source due to localised stimulation of prothrombotic mechanisms; blood stasis, hypercoagulability and endothelial damage, known as Virchow's triad. Aim We propose an in-silico modelling pipeline that leverages clinical imaging data to mechanistically assess patient thrombogenicity for all aspects of Virchow's triad to improve the prediction and prevention of AF-related stroke. Methods Two AF patients undergoing Cine magnetic resonance imaging (sinus rhythm (SR) N=1 or AF N=1 during imaging) were selected for 3D left atrial (LA) modelling with patient-specific myocardial deformation prescribed from image-derived wall motion. Blood stasis was quantified by computational fluid dynamics (CFD) simulations of 5 cardiac cycles [1]. Generation of three key coagulation proteins; thrombin, fibrinogen and fibrin, were modelled to represent thrombus growth and hypercoagulability [2]. Regions prone to thrombogenesis by endothelial damage were identified by the oscillatory shear index (OSI), time averaged wall shear stress (TAWSS) and endothelial cell activation potential (ECAP) metrics in the LAA [3]. Results Patient-specific LA simulations enabled the assessment of differences between SR and AF conditions, quantified as numerical characteristics of each aspect of Virchow's triad. In SR, blood flow velocities were in the range 0–2.6 m/s with mean of 0.85 m/s in the LA cavity, while AF had a range between 0–1.6 m/s with mean of 0.55 m/s. The peak and mean LAA velocities in SR were 0.85 m/s and 0.14 m/s, while AF had a peak LAA velocity of 0.32 m/s and mean of 0.09 m/s, showing a 38% decrease during AF. The thrombin concentration reached its steady state at 1.26 mmol/m3 in the AF case after 4.7 seconds, while thrombin was washed away from the initial injury site in SR. After 5 cardiac cycles of thrombus growth dynamics, the peak fibrin concentration in the LAA was 1.3 mmol/m3 in SR and 3.8 mmol/m3 in AF, with the thrombus area in AF being 40% larger. Fibrinogen concentration decreased at a rate equal to fibrin generation in both SR and AF solely in the area of thrombus formation. ECAP in the LAA had peak values of 2.9 in SR and 3.7 in AF, with the location at highest risk of thrombogenesis above the LAA entrance. LAA OSI had an average value of 0.45 in AF versus 0.36 in SR, showing a 26% increase. Similarly, the TAWSS was 3.5x10–3 Pa on average over the LAA in AF compared to 1.4x10–3 Pa in SR. Conclusions Patient-specific LA models combining these three quantitative characteristics can be used to predict the higher thrombogenic risk in AF. After further validation, this novel approach for quantitative assessment of AF patient thrombogenicity based on modelling all factors in Virchow's triad can personalise and improve management of AF patients with a risk of stroke. Funding Acknowledgement Type of funding sources: Public grant(s) – National budget only. Main funding source(s): UK Engineering and Physical Sciences Research Council

Patients’ perspective on a pill-in-the-pocket oral anticoagulation as an alternative stroke prevention strategy in atrial fibrillation

Abstract Funding Acknowledgements Type of funding sources: None. Introduction Oral anticoagulation (OAC) decisions are binary: if atrial fibrillation (AF) is detected and additional risk factors are presented, lifelong continuous OAC is recommended regardless of AF burden or temporal patterns. AF-related stroke risk appears to be lower in patients with paroxysmal AF and, therefore, indefinite OAC may have limited benefit whilst exposing patients to a significant bleeding risk. ‘Pill-in-the-pocket’ OAC during and shortly after AF challenges this dichotomous approach to OAC and is being explored in several pilot studies as an alternative AF-related stroke prevention strategy. Purpose This patient questionnaire sought to examine patients’ perspective of ‘pill-in-the pocket’ OAC strategy. Methods An 8-question interactive survey was developed in collaboration with AF Association (UK based charity) and included a short description of implantable cardiac monitors main features, implant procedure and associated risks. The survey was available online on the AF Association website from 30/09/2020 to 2/11/2020. Results Overall, 321 participants with an underlying diagnosis of AF replied to the online survey over the course of four and half weeks. The majority (82%) were taking direct oral anticoagulants. Just over two thirds of patients had concerns regarding bleeding side-effects from taking OAC and, approximately, a quarter had experienced a bleeding event (1.5% major bleeding and 24.2% minor bleeding). When asked if it was shown to be safe to monitor their heart rhythm continuously and take anticoagulants only during an episode of AF and for a small number of days afterwards (i.e. ‘pill-in-the-pocket’), 53.7% of participants would use guided by an implantable cardiac monitored. Slightly lower number of patients (48%) would take pill-in-the-pocket oral anticoagulation guided by a wearable device. In the comments the main reasons not to pursue ‘pill-in-the-pocket’ were permanent AF, previous thromboembolic events and concerns regarding reliability of monitoring technologies. In contrast, those who were receptive to this alternative approach had previous bleeding episodes, had very infrequent AF episodes and wanted to reduce their medication burden. Conclusion Approximately half of patients with choose a ‘pill-in-the-pocket’ OAC guided by daily rhythm monitoring with an ICM if proven to be safe and effective at reducing thromboembolism.

Italian Society of Interventional Cardiology (SICI-GISE) Position paper: Transcatheter left atrial appendage occlusion in patients with non-valvular atrial fibrillation

Atrial fibrillation (AF) is the most common arrhythmia worldwide. Thromboembolism from the left atrial appendage (LAA) is the most feared complication in patients with AF. The cornerstone for the management of AF is oral anticoagulation to reduce the incidence of cardioembolic stroke. There is, however, a significant proportion of patients who cannot undergo long-term oral anticoagulation. Transcatheter LAA occlusion is an evolving technology with proven benefits in terms of AF-related stroke prevention, representing a valid alternative to anticoagulation for high-risk patients with contraindications for long-term oral anticoagulation. This has resulted in the development of a plethora of transcatheter devices to achieve endocardial occlusion or epicardial exclusion of the LAA.A panel of expert Italian cardiologists gathered under the aegis of the Italian Society of Interventional Cardiology (SICI-GISE) with the aim of reviewing the most relevant aspects of LAA occlusion, underlying anatomy and pathophysiology, summarizing current clinical knowledge, and discussing the practicalities of available devices and imaging techniques. Finally, the position paper highlights the importance of an adequate environment and of an appropriate organization in order to optimize all steps of the procedure.

Addition of direct oral anticoagulants to the World Health Organization model list of essential medicines for the treatment of atrial fibrillation: An African perspective.

Atrial fibrillation (AF) is a major cause of adverse cardiovascular outcomes, and its prevalence is fast rising in Africa. The advent of direct oral anticoagulants (DOACs) has been a major revolution for the prevention of AF-related stroke and systemic embolism given the significant advantage over vitamin K antagonists in terms of both efficacy, safety, and adherence. However, due to their high cost, equitable access to DOACs has been a challenge, especially in low- and middle-income countries. Therefore, the recent addition of DOACs to the 21st WHO list of essential medicines comes as good news. African governments should take this opportunity to scale up the accessibility to DOACs for African patients with AF. This could be achieved through advocacy, appropriate training of health professionals, task shifting, patient education, strategic partnership to increase availability and quality of low-cost generic drugs, and appropriate medico-economic studies.

Many Good Reasons to Switch from Vitamin K Antagonists to Non-Vitamin K Antagonists in Patients with Non-Valvular Atrial Fibrillation.

Non-vitamin K oral anticoagulants (NOACs) are the first choice for prophylaxis of cardioembolism in patients with non-valvular atrial fibrillation (AF) who are anticoagulant-naïve, as well as the preferable anticoagulation strategy in those who are on vitamin K antagonists (VKAs), but with a low time in therapeutic range (TTR). Nonetheless, there are many good reasons to consider switching from VKAs to NOACs also when TTR is >70%. From the pharmacological standpoint, anticoagulation with VKAs may remain erratic even in those patients who have high TTR values, owing to the mode of action of this drug class. Furthermore, experimental data suggest that, unlike VKAs, NOACs favorably modulate the effects of factor Xa and thrombin in the cardiovascular system through the protease-activated receptor family. Clinically, the most striking advantage provided by NOACs over VKAs, irrespective of the TTR, is the substantially lower risk of intracranial hemorrhage. NOACs have also been associated with less deterioration of renal function as compared with VKAs and may confer protection against cardiovascular events not strictly related to AF, especially the acute complications of peripheral artery disease. In this narrative review, we discuss the evidence according to which it is warranted to systematically substitute NOACs for VKAs for the prevention of AF-related stroke and systemic embolism.

All DOACs recommended for prevention of AF-related stroke, new NICE guideline states

Four direct oral anticoagulants (DOACs) are all recommended as options for people with atrial fibrillation (AF) and a CHA2DS2‑VASc score of 2 or above for the prevention of stroke, new guidance from the National Institute for Health and Care Excellence (NICE) has said. The final guideline, which was published on 27 April 2021, has been […]

Stroke prevention in atrial fibrillation

Stroke is the second leading cause of death worldwide. Atrial fibrillation (AF), the most common sustained cardiac arrhythmia, is an independent risk factor for stroke.AF-caused stroke has a high risk of recurrence and disability, mainly involving large cerebral artery.Thus, stroke prevention in AF becomes a major health priority. Anticoagulant therapy can significantly reduce the risk of ischemic stroke in patients with AF.This review summarized the epidemiological status of AF-related stroke, and reported updated information on AF detection, risk assessment, anticoagulation as well as other preventive measures in stroke prevention in AF, in order to provide theoretical references for clinical practice. At present, the prevention of AF-related stroke still needs to be promoted. Better risk assessment model, as well as cost-effective and safe ischemic stroke prevention methods, are still need to be further studied. Key words: Stroke; Atrial fibrillation; Prevention; Risk assessment

Uptake of a Primary Care Atrial Fibrillation Screening Program (AF-SMART): A Realist Evaluation of Implementation in Metropolitan and Rural General Practice

Screening for atrial fibrillation (AF) in people aged ≥65 years is recommended by international guidelines. The Atrial Fibrillation Screen, Management And guideline-Recommended Therapy (AF-SMART) studies of opportunistic AF screening in 16 metropolitan and rural general practices were conducted from November 2016–June 2019. These studies trialled custom-designed eHealth tools to support all stages of AF screening in general practice. A realist evaluation of the AF-SMART studies, which aimed to explain the circumstances in which the program worked (or not) to increase the proportion of people screened for AF. The initial program theory was based on our previous research, policy documents and screening studies. To test this, we conducted 45 semi-structured interviews with general practitioners (GPs), nurses and practice managers across all participating practices, and collected observational and quantitative screening data. These data were analysed and interpreted to refine the program theory. GPs/nurses liked the eHealth tools, although technical problems sometimes disrupted screening. Time was the main barrier to screening for GPs/nurses, so systems need to be very efficient. Practices with leadership from a senior GP ‘screening champion’ had broader uptake, especially from the nursing team. Providing regular feedback on screening data was beneficial for quality improvement and motivation. Clear protocols for follow-up of abnormal results were required for successful nurse-led screening in a hierarchical system. Participation in the program had broader benefits of improving AF knowledge and raising the profile of cardiovascular health in the practice. Screening for a shorter, more intense period (eg during influenza vaccination) worked well for practices where sufficient staff time was allocated. Introducing an AF screening program is likely to be successful in contexts where there is a senior GP ‘screening champion’, a clear protocol exists for abnormal results, and there is regular data reporting to staff. These contexts link to mechanisms around motivation, leadership, empowerment of nurses, and efficient screening systems. The contexts and mechanisms contribute to the longer-term outcomes of increasing the proportion of people screened and treated for AF, which is recommended by guidelines as a key strategy for the prevention of AF-related stroke. AF SMART (metropolitan): ACTRN12616000850471 (Australia New Zealand Clinical Trials Registry). AF SMART II (rural): ACTRN12618000004268 (Australia New Zealand Clinical Trials Registry).

ANTITHROMBOTIC THERAPIES FOR PATIENTS WITH AN INDICATION FOR ANTICOAGULATION AND STABLE CORONARY ARTERY DISEASE: A NETWORK META-ANALYSIS

The optimal antithrombotic strategy for patients with atrial fibrillation and stable coronary artery disease (CAD) remains unclear. Oral anticoagulation (OAC) is indicated for the prevention of AF-related stroke and systemic embolism, whereas single antiplatelet therapy (SAPT) is indicated for the primary and secondary prevention of coronary events. We sought to determine if OAC alone a reasonable alternative to SAPT for the management of ischemic coronary outcomes in the non-ACS population, and whether there was incremental benefit to the addition of antiplatelet therapy to OAC therapy (dual pathway therapy - DT). We conducted a systematic review of studies in patients with coronary artery disease that reported a comparison of ASA, OAC, or DT, and presented absolute rates for safety outcomes (major bleeding) and efficacy outcomes (ischemic stroke, myocardial infarction, and all-cause mortality). A network meta-analysis was conducted to directly and indirectly compare the efficacy and safety with a Bayesian random-effects model. Results were presented as relative risks (RRs) and 95% confidence intervals (CIs). Fourteen randomized and six observational studies with 128,908 patients were included. Compared to SAPT, OAC alone reduced the risk of stroke (RR 0.66; 95%CI 0.49-0.87), and recurrent MI (RR 0.77; 95%CI 0.60-0.98), with a trend to reduced all-cause mortality (RR 0.85, 95%CI 0.68-1.06). Conversely DT was only superior to SAPT for stroke reduction (RR 0.77; 95%CI 0.61-0.99), with negligible influence on all-cause mortality and only a trend to reduction in recurrent MI. Both OAC and DT significantly increased the risk of bleeding over SAPT alone (RR 1.47, 95%CI 1.21-1.78 for OAC alone, and RR 2.02, 95%CI 1.70-2.39 for DT), however OAC alone was associated with significantly less major bleeding compared to DT (RR 0.73; 95%CI 0.64-0.83). Restricting the analysis to the 14 randomised studies (52,095 patients) reduced the power without substantially changing the point estimates. In patients with stable CAD at risk of AF-associated stroke/systemic embolism, OAC alone provides optimal protection against both stroke and ischemic coronary events. The addition of antiplatelet therapy to OAC offers no additional beneficial effect on ischemic or thrombotic coronary outcomes, while conferring a significantly increased risk of bleeding.

Atrial Fibrillation and Coronary Artery Disease: Deciding on The Best Antithrombotic Regimen

Atrial fibrillation (AF) is a chronic progressive disease characterized by exacerbations and remissions. Up to 20-30% of patients with AF also have coronary artery disease (CAD). In patients with concomitant AF and CAD, the management of antithrombotic therapy is challenging. Oral anticoagulation (OAC) is indicated for the prevention of AF-related stroke and systemic embolism, whereas antiplatelet therapy is indicated for the prevention of coronary events. Each of these therapeutic avenues offers a relative efficacy benefit (e.g. dual antiplatelet therapy [DAPT] is more effective than OAC alone in reducing cardiovascular death, myocardial infarction, stent thrombosis, and ischemic coronary events in an ACS population), but with a relative compromise (e.g. DAPT is significantly inferior to OAC for the prevention of stroke/systemic embolism in an AF population at increased risk of AF-related stroke). The purpose of this review is to explore the current evidence and rationale for antithrombotic treatment strategies in patients with both AF and CAD.

Exploring the Quality of Anticoagulant Prescribed for Patients With Atrial Fibrillation at the St John of God Hawkesbury District Health Centre, New South Wales, Australia.

Limited data are available on the clinical management of atrial fibrillation (AF) and its outcomes from an Australian perspective. To describe the appropriateness of antithrombotic prescribing for patients who presented with a diagnosis of AF to the Hawkesbury St John of God Hospital, New South Wales, Australia. This retrospective observational study reviewed patients admitted to St John of God Hawkesbury Hospital with AF between June 2016 and June 2017. We calculated stroke risk using the CHA2DS2-VASc score based on medical records and reviewed the appropriateness of oral anticoagulant (OAC) prescribing compared to the 2016 European Society of Cardiology guidelines. Patients were excluded if they had only 1 episode of AF that reverted either spontaneously or upon cardioversion without any documented recurrences. A total of 200 patients (18 years) were included, with 180 (90%) deemed eligible for anticoagulation. Of these 72.8% (n = 131) were prescribed an OAC. A total of 40.0% of patients at low risk of stroke and 68.4% at intermediate risk were prescribed an OAC, respectively. Apixaban was the direct OAC of choice with 36.6% of patients prescribed an OAC receiving apixaban. Warfarin was prescribed for 25.1% of the patients who were prescribed an OAC. The underutilization of anticoagulant medication in high-risk groups and over utilization in low-risk groups remains an ongoing issue in contemporary AF management, and it highlights the need to improve AF-related stroke prevention in our jurisdiction.

Approaches to Left Atrial Appendage Closure: Device Design, Performance, and Limitations.

Up to 6.1 million people in the United States have atrial fibrillation (AF), which is associated with an increased risk of stroke. Oral anticoagulants are the mainstay of stroke prevention in AF. For decades, warfarin was the only available drug, fraught with compliance limitations, a narrow therapeutic window, and a high risk of hemorrhage. Pharmacologic developments have produced new anticoagulants that have improved the rates of stroke related to AF; however, they still confer a high risk of bleeding, making them unsuitable for some patients. Studies have shown that roughly 90% of strokes in patients with AF occur in the left atrial appendage (LAA). This understanding has prompted the development and testing of novel percutaneous strategies for LAA closure as an alternative to anticoagulation therapy. The following review examines the relative merits and shortcomings of these strategies and explores future prospects in the prevention of AF-related stroke.

Benefits of once-daily dosing with non-vitamin K antagonist oral anticoagulants in patients with atrial fibrillation.

Atrial fibrillation (AF) is the most prevalent clinically relevant arrhythmia, affecting millions of individuals in Europe and the USA. Atrial fibrillation increases the risk of stroke; the long-term standard of care for prevention of AF-related stroke is anticoagulation. The use of anticoagulants should be based on the absolute risks of stroke and bleeding and the relative benefit-risk profile of the individual patient. Treatment options include vitamin K antagonists (VKAs) such as warfarin, whose use is long-established but associated with drawbacks, including regular coagulation monitoring requirements and many food and drug interactions. The non-VKA oral anticoagulants are gaining widespread use as alternatives to VKAs, and are supported in treatment guidelines for patients with AF at moderate to high risk of stroke. Adherence to medication is important for the long-term efficacy of any therapy; however, relatively low levels of medication adherence are to be expected in 'real-world' AF patients compared with clinical trials. Experience across several therapy areas, including cardiovascular disease, shows that poor adherence to chronic medication is common. However, simple dosing schedules may be advantageous in this respect, and because long-term outcomes in AF are likely to be influenced by adherence, once-daily dosing has the potential to improve rates of stroke prevention in patients with AF.

Stroke prevention following modified endoscopic ablation and appendectomy for atrial fibrillation.

We reported the results of stroke prevention following modified endoscopic procedure for atrial fibrillation. 82 patients underwent modified endoscopic procedure for atrial fibrillation (AF), in whom 47 had paroxysmal, 28 had persistent, and 7 had long-standing atrial fibrillation. CHA2DS2VASC median score was 3 (range from 0 to 8). The procedure was performed on the beating heart, through 3 ports on the left chest wall. Pulmonary vein isolation and ablation of the left atrium were achieved by bipolar radiofrequency ablation. Left atrial appendage (LAA) was excluded by stapler. Brain CT, cardiac CT and 24-h Holter monitoring were performed following the procedure. The procedure was successfully completed for all patients. The mean duration was 122±40.1min. LAA was excluded after appendectomy and checked by intraoperative transesophageal echocardiography. The mean follow-up duration was 24.3±3.5months. No patients showed signs and symptoms of transient ischemic attack or stroke. No new positive findings were demonstrated by recurring brain CT scan performed after the procedure. Cardiac CT confirmed the absence of LAA and thrombosis in the left atrium. 87.8% (72/82) of all patients were in sinus rhythm. Our results demonstrate that the modified endoscopic procedure is a safe, effective, and appropriate treatment for AF, which restores sinus rhythm and may be associated with the prevention of AF-related stroke.

Reply: Health status, geriatric syndromes and prescription of oral anticoagulant therapy in elderly medical in-patients with atrial fibrillation: A prospective observational study

We agree with the content of the letter from Dr Jolobe OMP and, specifically we concur with his conclusion, where he underlines the fragile evidence for aspirin use in the prevention of atrial fibrillation (AF)-related stroke. According to recent European guidelines [ [1] Camm A.J. Lip G.Y. De Caterina R. Savelieva I. Atar D. Hohnloser S.H. et al. 2012 focused update of the ESC Guidelines for the management of atrial fibrillation: an update of the 2010 ESC Guidelines for the management of atrial fibrillation. Developed with the special contribution of the European Heart Rhythm Association. Eur. Heart J. Nov 2012; 33: 2719-2747 Crossref PubMed Scopus (3093) Google Scholar ], our study aimed to assess prevalence of and variables associated with under-prescription of currently recommended anticoagulant therapy for AF patients, including vitamin K antagonists (VKAs) and new direct oral anticoagulants (DOAs), but not those associated with use or under-use of aspirin, which is currently not recommended for prevention of AF-related stroke.

Cost Effectiveness of Treatments for Stroke Prevention in Atrial Fibrillation: Focus on the Novel Oral Anticoagulants

For more than 5 decades, the only available treatment for the prevention of atrial fibrillation (AF)-related stroke were the vitamin K antagonists. Recently, novel oral anticoagulants (NOAC) have been approved for the prevention of AF-related stroke. In the present article, the cost effectiveness of AF-related stroke-prevention strategies is reviewed. The emphasis on NOACs aims to provide an overview of their impact on health economics based on the published cost-effectiveness analyses. The available evidence suggests that the balance from the efficacy and safety point of view makes the treatment with the NOACs a cost-effective alternative to warfarin. Thus, the NOACs offer efficacy, safety and convenience, as well as cost effectiveness, for stroke prevention in AF.