Incidence of Thromboembolic Complications Within 30 Days of Electrical Cardioversion Performed Within 48 Hours of Atrial Fibrillation Onset

Risk of stroke with reduced dose direct oral anticoagulants vs standard dose anticoagulation after cardioversion of atrial fibrillation: A systematic review and meta-analysis

Background

There is consensus on the safety of standard dose direct oral anticoagulants (DOACs) for stroke prevention in patients undergoing cardioversion of atrial fibrillation (AF), but outcomes of reduced dose DOACs in this setting remain unclear.

Objective

This systematic review and meta-analysis aimed to compare the rate of cardioversion-associated thromboembolic events between patients taking reduced dose DOACs and those receiving standard dose anticoagulation.

Methods

A systematic search was conducted for studies published between January 1, 2009, and February 16, 2024 in PubMed, Embase, and Cochrane Central Register of Controlled Trials. The included studies compared the rate of thromboembolic events in patients with AF undergoing cardioversion on reduced dose DOACs with the rate in those on standard dose anticoagulation. Odds ratios were pooled with a random effects model.

Results

We identified 2 randomized controlled trials and 8 cohort studies, which included 5212 patients with AF who underwent cardioversion on anticoagulation (1010 patients on reduced dose DOACs and 4202 patients on standard dose anticoagulation). Follow-up ranged from 3 hours to 90 days after cardioversion. There was a numerically higher rate of thromboembolic events in patients undergoing cardioversion on reduced dose DOACs than in those on standard dose anticoagulation (0.69% vs 0.29%; odds ratio 1.98; 95% confidence interval 0.72-5.45; P = .19; I2 = 0%); however, the difference was not statistically significant.

Conclusion

Our systematic review and meta-analysis suggests that there is a numerically higher risk of thromboembolic events in patients with AF undergoing cardioversion on reduced dose DOACs than in those on standard dose anticoagulation. However, the difference was not statistically significant. These findings raise concern about the safety of reduced dose DOACs in patients undergoing cardioversion.

Computed Tomography to Exclude Cardiac Thrombus in Atrial Fibrillation-An 11-Year Experience from an Academic Emergency Department

BACKGROUND

Computed tomography (CT) could be a suitable method for acute exclusion of left atrial appendage thrombus (LAAT) prior to cardioversion of atrial fibrillation (AF) and atrial flutter (AFL) at the emergency department. Our aim was to present our experiences with this modality in recent years.

METHODS

This registry-based observational study was performed at the Department of Emergency Medicine at the Medical University of Vienna, Austria. We studied all consecutive patients with AF and AFL who underwent CT between January 2012 and January 2023 to rule out LAAT before cardioversion to sinus rhythm was attempted. Follow-ups were conducted by telephone and electronic medical records. The main variables of interest were the rate of LAAT and ischemic stroke at follow-up.

RESULTS

A total of 234 patients (143 [61%] men; median age 68 years [IQR 57-76], median CHA2DS2-VASc 2 [IQR 1-4]) were analyzed. Follow-up was completed in 216 (92%) patients after a median of 506 (IQR 159-1391) days. LAAT was detected in eight patients (3%). A total of 163 patients (72%) in whom LAAT was excluded by CT were eventually successfully cardioverted to sinus rhythm. No adverse events occurred during their ED stay. All patients received anticoagulation according to the CHA2DS2-VASc risk stratification, and no patient had suffered an ischemic stroke at follow-up, resulting in an incidence risk of ischemic strokes of 0% (95% CI 0.0-1.2%).

CONCLUSION

LAAT was rare in patients admitted to the ED with AF and AFL who underwent cardiac CT prior to attempted cardioversion. At follow-up, no patient had suffered an ischemic stroke. Prospective studies need to show whether this strategy is suitable for the acute treatment of symptomatic AF in the emergency setting.

2023 ACC/AHA/ACCP/HRS Guideline for the Diagnosis and Management of Atrial Fibrillation: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines

AIM

The "2023 ACC/AHA/ACCP/HRS Guideline for the Diagnosis and Management of Atrial Fibrillation" provides recommendations to guide clinicians in the treatment of patients with atrial fibrillation.

METHODS

A comprehensive literature search was conducted from May 12, 2022, to November 3, 2022, encompassing studies, reviews, and other evidence conducted on human subjects that were published in English from PubMed, EMBASE, the Cochrane Library, the Agency for Healthcare Research and Quality, and other selected databases relevant to this guideline. Additional relevant studies, published through November 2022, during the guideline writing process, were also considered by the writing committee and added to the evidence tables, where appropriate.

STRUCTURE

Atrial fibrillation is the most sustained common arrhythmia, and its incidence and prevalence are increasing in the United States and globally. Recommendations from the "2014 AHA/ACC/HRS Guideline for the Management of Patients With Atrial Fibrillation" and the "2019 AHA/ACC/HRS Focused Update of the 2014 AHA/ACC/HRS Guideline for the Management of Patients With Atrial Fibrillation" have been updated with new evidence to guide clinicians. In addition, new recommendations addressing atrial fibrillation and thromboembolic risk assessment, anticoagulation, left atrial appendage occlusion, atrial fibrillation catheter or surgical ablation, and risk factor modification and atrial fibrillation prevention have been developed.

The Optimal Management of Patients with Atrial Fibrillation and Acute Heart Failure in the Emergency Department

Atrial fibrillation (AF) and acute heart failure (AHF) are two closely interrelated conditions that frequently coexist in a manifold manner, with AF serving either as the causative factor or as the consequence or even as an innocent bystander. The interplay between these two clinical conditions is complex, given that they share common pathophysiological pathways and they can reciprocally exacerbate each other, thus triggering a vicious cycle that worsens the prognosis and increases the thromboembolic risk. The optimal management of AF in the context of AHF in the emergency department remains a challenge depending on the time onset, as well as the nature and the severity of the associated symptoms. Acute rate control, along with early rhythm control, when indicated, and anticoagulation represent the main pillars of the therapeutic intervention. The purpose of this review is to elucidate the pathophysiological link between AF and AHF and accordingly present a stepwise algorithmic approach for the management of AF in AHF patients in the emergency setting.

Diagnosis and Treatment of New-Onset Perioperative Atrial Fibrillation

This article reviews medical and surgical risk factors for developing atrial fibrillation (AF), the most common sustained dysrhythmia in the United States. Evidence for assessment and management of patients with AF, including AF newly identified in the preoperative clinic, immediately preoperatively, intraoperatively, and unstable AF, is presented. A stepwise approach to guide anesthetic decision-making in the assessment of newly identified preoperative AF is proposed. Anesthetic considerations, including the potential impacts of anesthetic and vasopressor selection, and current evidence related to rate control and rhythm control via pharmacologic or electrical cardioversion as well as anticoagulation strategies are discussed.

Emergency medicine updates: Atrial fibrillation with rapid ventricular response

INTRODUCTION

Atrial fibrillation (AF) may lead to stroke, heart failure, and death. When AF occurs in the context of a rapid ventricular rate/response (RVR), this can lead to complications, including hypoperfusion and cardiac ischemia. Emergency physicians play a key role in the diagnosis and management of this dysrhythmia.

OBJECTIVE

This paper evaluates key evidence-based updates concerning AF with RVR for the emergency clinician.

DISCUSSION

Differentiating primary and secondary AF with RVR and evaluating hemodynamic stability are vital components of ED assessment and management. Troponin can assist in determining the risk of adverse outcomes, but universal troponin testing is not required in patients at low risk of acute coronary syndrome or coronary artery disease - especially patients with recurrent episodes of paroxysmal AF that are similar to their prior events. Emergent cardioversion is indicated in hemodynamically unstable patients. Rate or rhythm control should be pursued in hemodynamically stable patients. Elective cardioversion is a safe option for select patients and may reduce AF symptoms and risk of AF recurrence. Rate control using beta blockers or calcium channel blockers should be pursued in those with AF with RVR who do not undergo cardioversion. Anticoagulation is an important component of management, and several tools (e.g., CHA2DS2-VASc) are available to assist with this decision. Direct oral anticoagulants are the first-line medication class for anticoagulation. Disposition can be challenging, and several risk assessment tools (e.g., RED-AF, AFFORD, and the AFTER (complex, modified, and pragmatic) scores) are available to assist with disposition decisions.

CONCLUSION

An understanding of the recent updates in the literature concerning AF with RVR can assist emergency clinicians in the care of these patients.

Cardiovascular foreign body retrieval and its management algorithm

Application of central venous catheters become more common however a rare complication, embolization, can occur which lead to high mortality rate. Therefore, cardiovascular foreign bodies should be immediately remove with a safe and effective method and algorithm. So, we investigate the results of cardiovascular foreign body retrieval in our center based on a designed algorithm. In this case series study, patients who had cardiovascular foreign body embolization were managed by our algorithm. Our approach was based on the time duration of foreign body embolization in cardiovascular system and also its location. If the embolization time was less than 48 h, based on the location of foreign body, insertion site would be right femoral or jugular vein. If the time of foreign body embolization was more than 48 h, echocardiography should be done to assess thrombosis around foreign body. Retrieval was done with snare technique in all patients. Over 12 patients, 9 patient had port catheter foreign body in SVC and atrium, 1 patient had port catheter in atrium, 1 patient had port catheter in pulmonary artery and 1 patient had hemodialysis catheter in inferior vena cava (IVC) and atrium. Foreign body retrieval was successful in all 11 patient. The IVC and atrium were the common site of port catheter fragments. According to our experience, we organize a useful algorithm for retrieval of cardiovascular foreign body based on time of embolization and its location.

Pathophysiology and treatment of adults with arrhythmias in the emergency department, part 1: Atrial arrhythmias

PURPOSE

This article, the first in a 2-part review, aims to reinforce current literature on the pathophysiology of cardiac arrhythmias and various evidence-based treatment approaches and clinical considerations in the acute care setting. Part 1 of this series focuses on atrial arrhythmias.

SUMMARY

Arrhythmias are prevalent throughout the world and a common presenting condition in the emergency department (ED) setting. Atrial fibrillation (AF) is the most common arrhythmia worldwide and expected to increase in prevalence. Treatment approaches have evolved over time with advances in catheter-directed ablation. Based on historic trials, heart rate control has been the long-standing accepted outpatient treatment modality for AF, but the use of antiarrhythmics is often still indicated for AF in the acute setting, and ED pharmacists should be prepared and poised to help in AF management. Other atrial arrhythmias include atrial flutter (AFL), atrioventricular nodal reentry tachycardia (AVNRT), and atrioventricular reentrant tachycardia (AVRT), which warrant distinction due to their unique pathophysiology and because each requires a different approach to utilization of antiarrhythmics. Atrial arrhythmias are typically associated with greater hemodynamic stability than ventricular arrhythmias but still require nuanced management according to patient subset and risk factors. Since antiarrhythmics can also be proarrhythmic, they may destabilize the patient due to adverse effects, many of which are the focus of black-box label warnings that can be overreaching and limit treatment options. Electrical cardioversion for atrial arrhythmias is generally successful and, depending on the setting and/or hemodynamics, often indicated.

CONCLUSION

Atrial arrhythmias arise from a variety of mechanisms, and appropriate treatment depends on various factors. A firm understanding of physiological and pharmacological concepts serves as a foundation for exploring evidence supporting agents, indications, and adverse effects in order to provide appropriate care for patients.

The gray areas of oral anticoagulation for prevention of thromboembolic events in atrial fibrillation patients

Thromboembolic events (TEE) associated with atrial fibrillation (AF) are highly recurrent and usually severe, causing permanent disability or, even, death. Previous data consistently showed significantly lower TEE in anticoagulated patients. While warfarin, a vitamin K antagonist, is still used worldwide, direct-acting oral anticoagulants (DOACs) have shown noninferiority to warfarin in the prevention of TEE, and represent, to date, the preferred treatment. DOACs present favorable pharmacokinetic, safety and efficacy profiles, especially among vulnerable patients including the elderly, those with renal dysfunction or previous TEE. Yet, regarding specific settings of AF patients it is unclear whether oral anticoagulation therapy is beneficial, or otherwise it is the maintenance of sinus rhythm, mostly achieved through a catheter ablation-based rhythm control strategy, that prevents the causal complications linked to AF. While it is known that low-risk patients [CHA2DS2-VASc 0 (males), or score of 1 (females)] present low ischemic stroke or mortality rates (<1%/year), it remains unclear whether they need any prophylaxis. Furthermore, the appropriate anticoagulation regimen for those individuals requiring cardioversion, either pharmacologic or electric, as well as peri-procedural anticoagulation in patients undergoing trans-catheter ablation that nowadays encompasses different energies, are still a matter of debate. In addition, AF concomitant with other clinical conditions is discussed and, lastly, the choice of prescribing anticoagulation to asymptomatic patients diagnosed with subclinical AF at either wearable or implanted devices. The aim of this review will be to provide an update on current strategies in the above-mentioned settings, and to suggest possible therapeutic options, finally focusing on AF-related cognitive decline.

Atrial fibrillation: Primary prevention, secondary prevention, and prevention of thromboembolic complications: Part 2

Atrial fibrillation (AF), the most common sustained cardiac arrhythmia, once thought to be benign as long as the ventricular rate was controlled, is associated with significant cardiac morbidity and mortality. Increasing life expectancy driven by improved health care and decreased fertility rates has, in most of the world, resulted in the population aged ≥65 years growing more rapidly than the overall population. As the population ages, projections suggest that the burden of AF may increase more than 60% by 2050. Although considerable progress has been made in the treatment and management of AF, primary prevention, secondary prevention, and prevention of thromboembolic complications remain a work in progress. This narrative review was facilitated by a search of MEDLINE to identify peer-reviewed clinical trials, randomized controlled trials, meta-analyses, and other clinically relevant studies. The search was limited to English-language reports published between 1950 and 2021. Atrial fibrillation was searched using the terms primary prevention, hyperthyroidism, Wolff-Parkinson-White syndrome, catheter ablation, surgical ablation, hybrid ablation, stroke prevention, anticoagulation, left atrial occlusion and atrial excision. Google and Google scholar as well as bibliographies of identified articles were reviewed for additional references. In these two manuscripts, we discuss the current strategies available to prevent AF, then compare non-invasive and invasive treatment strategies to diminish AF recurrence. In addition, we examine the pharmacological, percutaneous device and surgical approaches to prevent stroke as well as other types of thromboembolic events.

Incidence and Determinants of Spontaneous Cardioversion of Early Onset Symptomatic Atrial Fibrillation

Atrial fibrillation (AF) is the most frequent chronic arrhythmia worldwide, and it is associated with significant morbidity and mortality, making it a considerable burden both to patients and the healthcare system. Nowadays, an early attempt to restore sinus rhythm in acute symptomatic AF through electrical or pharmacological cardioversion is the most common approach in the Emergency Department (ED). However, considering the high percentage of spontaneous cardioversion of paroxysmal AF reported by many studies, this approach may not be the ideal choice for all patients. In this manuscript we performed a review of the most relevant studies found in literature with the aim of identifying the main determinants of spontaneous cardioversion, focusing on those easy to detect in the ED. We have found that the most relevant predictors of spontaneous cardioversion are the absence of Heart Failure (HF), a small atrial size, recent-onset AF, rapid Atrial Fibrillatory Rate and the relationship between a previous AF episode and Heart Rate/Blood Pressure. A number of those are utilized, along with other easily determined parameters, in the recently developed "ReSinus" score which predicts the likelihood of AF spontaneous cardioversion. Such identification may help the physician decide whether immediate cardioversion is necessary, or whether to adopt a "watch-and-wait" strategy in the presence of spontaneous cardioversion determinants.

Cardioversion of recent-onset atrial fibrillation using intravenous antiarrhythmics: A European perspective

Pharmacological cardioversion using intravenous antiarrhythmic agents is commonly indicated in symptomatic patients with recent-onset atrial fibrillation (AF). Except in hemodynamically unstable patients who require emergency direct current electrical cardioversion, for the majority of hemodynamically stable patients, pharmacological cardioversion represents a valid option and requires the clinician to be familiar with the properties and use of antiarrhythmic agents. The main characteristics of selected intravenous antiarrhythmic agents for conversion of recent-onset AF, the reported success rates, and possible adverse events are discussed. Among intravenous antiarrhythmics, flecainide, propafenone, amiodarone, sotalol, dofetilide, ibutilide, and vernakalant are commonly used. Antazoline, an old antihistaminic agent with antiarrhythmic properties was also reported to give encouraging results in Poland. Intravenous flecainide and propafenone are the only Class I agents still recommended by recent guidelines. Intravenous new Class III agents as dofetilide and ibutilide have high and rapid efficacy in converting AF to sinus rhythm but require strict surveillance with electrocardiogram (ECG) monitoring during and after intravenous administration because of the potential risk of QT prolongation and Torsades de Pointes, which can be prevented and properly managed. Vernakalant, a partial atrial selective was shown to have a high success rate and to be safe in real-life use.

Clinical prediction scores and early anticoagulation therapy for new-onset atrial fibrillation in critical illness: a post-hoc analysis

Purpose

This study sought to describe the epidemiology of anticoagulation therapy for critically ill patients with new-onset atrial fibrillation (NOAF) according to CHA2DS2-VASc and HAS-BLED scores and to assess the efficacy of early anticoagulation therapy.

Method

Adult patients who developed NOAF during intensive care unit stay were included. We compared the patients who were treated with and without anticoagulation therapy within 48 h from AF onset. The primary outcome was a composite outcome that included mortality and ischemic stroke during the period until hospital discharge.

Results

In total, 308 patients were included in this analysis. Anticoagulants were administered to 95 and 33 patients within 48 h and after 48 h from NOAF onset, respectively. After grouping the patients into four according to their CHA2DS2-VASc and HAS-BLED bleeding scores, we found that the proportion of anticoagulation therapy administered was similar among all groups. After adjustment using a multivariable Cox regression model, we noted that early anticoagulation therapy did not decrease the composite outcome (adjusted hazard ratio [HR] 0.77; 95% confidence interval [CI] 0.47‒1.23). However, in patients without rhythm control drugs, early anticoagulation was significantly associated with better outcomes (adjusted HR 0.46; 95% CI; 0.22‒0.87, P = 0.041).

Conclusions

We found that clinical prediction scores were supposedly not used in the decision to implement anticoagulation therapy and that early anticoagulation therapy did not improve clinical outcomes in critically ill patients with NOAF.

Trial registration UMIN-CTR UMIN000026401. Registered 5 March 2017.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12872-021-02235-8.

Thromboembolic events following cardioversion of acute atrial fibrillation and flutter: a systematic review and meta-analysis

BACKGROUND

Recent studies have presented concerning data on the safety of cardioversion for acute atrial fibrillation and flutter. We conducted this meta-analysis to evaluate the effect of oral anticoagulation use on thromboembolic events post-cardioversion of low-risk acute atrial fibrillation and flutter patients of < 48 h in duration.

METHODS

We searched MEDLINE, Embase, and Cochrane from inception through February 6, 2020 for studies reporting thromboembolic events post-cardioversion of acute atrial fibrillation and flutter. Main outcome was thromboembolic events within 30 days post-cardioversion. Primary analysis compared thromboembolic events based on oral anticoagulation use versus no oral anticoagulation use. Secondary analysis was based on baseline thromboembolic risk. We performed meta-analyses where 2 or more studies were available, by applying the DerSimonian-Laird random-effects model. Risk of bias was assessed with the Quality in Prognostic Studies tool.

RESULTS

Of 717 titles screened, 20 studies met inclusion criteria. Primary analysis of seven studies with low risk of bias demonstrated insufficient evidence regarding the risk of thromboembolic events associated with oral anticoagulation use (RR = 0.82 where RR < 1 suggests decreased risk with oral anticoagulation use; 95% CI 0.27 to 2.47; I² = 0%). Secondary analysis of 13 studies revealed increased risk of thromboembolic events with high baseline thromboembolic risk (RR = 2.25 where RR > 1 indicates increased risk with higher CHADS₂ or CHA₂DS₂-VASc scores; 95% CI 1.25 to 4.04; I² = 0%).

CONCLUSION

Primary analysis revealed insufficient evidence regarding the effect of oral anticoagulation use on thromboembolic events post-cardioversion of low-risk acute atrial fibrillation and flutter, though the event rate is low in contemporary practice. Our findings can better inform patient-centered decision-making when considering 4-week oral anticoagulation use for acute atrial fibrillation and flutter patients.

Antithrombotic treatment management in low stroke risk patients undergoing cardioversion of atrial fibrillation <48 h duration: results of an EHRA survey

Data supporting the safety of cardioversion (CV) of atrial fibrillation (AF) without anticoagulation in patients with AF duration <48 h are scarce. Observational studies suggest that the risk of stroke in these patients is very low when the definite duration of the AF episode is of <48 h and the clinical risk profile as estimated through the CHA2DS2VASc score is low (a score of 0 for men and 1 for women). As the recent 2020 European Society of Cardiology (ESC) guidelines indication for this clinical scenario is based mainly on consensus, we sent out a survey to assess the current clinical practice on anticoagulation prior to and post-CV in patients with AF <24-48 h duration and low stroke risk across centres in Europe. Of the 136 respondents, half were affiliated to university hospitals (68/136; 50%). Non-university hospitals (50/136; 36%) and private hospitals (2/136; 1.4%) accounted over a third of respondents. The main findings of our survey were (i) heterogeneity in the anticoagulation management both before and post-CV in low stroke-risk patients with AF <48 h, (ii) higher utilization of periprocedural low-molecular-weight heparin than of non-vitamin K antagonist oral anticoagulant, (iii) higher utilization of pre-CV transoesophageal echocardiography for electrical CV than for pharmacological CV regardless of the duration of AF, (iv) high adherence to a 4-week post-CV oral anticoagulant (OAC) therapy, mainly for electrical CV, and finally, (v) perceived higher acceptance of lack of post-CV OAC therapy in patients with <24 h than 24-48 h episode duration. The results obtained in this survey highlight the need for more research providing definitive clarification on the safety of CV without anticoagulation in patients with short duration AF.

Atrial Fibrillation and Ischemic Stroke: A Clinical Review

Atrial fibrillation (AF) is an important risk factor for ischemic stroke resulting in a fivefold increased stroke risk and a twofold increased mortality. Our understanding of stroke mechanisms in AF has evolved since the concept of atrial cardiopathy was introduced as an underlying pathological change, with both AF and thromboembolism being common manifestations and outcomes. Despite the strong association with stroke, there is no evidence that screening for AF in asymptomatic patients improves clinical outcomes; however, there is strong evidence that patients with embolic stroke of undetermined source may require long-term monitoring to detect silent or paroxysmal AF. Stroke prevention in patients at risk, assessed by the CHA₂DS₂-VASc score, was traditionally achieved with warfarin; however, direct oral anticoagulants have solidified their role as safe and effective alternatives. Additionally, left atrial appendage exclusion has emerged as a viable option in patients intolerant of anticoagulation. When patients with AF have an acute stroke, the timing of initiation or resumption of anticoagulation for secondary stroke prevention has to be balanced against the risk of hemorrhagic conversion. Multiple randomized clinical trials are currently underway to determine the best timing for administration of anticoagulants following acute ischemic stroke.

Atrial fibrillation: villain or bystander in vascular brain injury

Atrial fibrillation (AF) and stroke are inextricably connected, with classical Virchow pathophysiology explaining thromboembolism through blood stasis in the fibrillating left atrium. This conceptualization has been reinforced by the remarkable efficacy of oral anticoagulant (OAC) for stroke prevention in AF. A number of observations showing that the presence of AF is neither necessary nor sufficient for stroke, cast doubt on the causal role of AF as a villain in vascular brain injury (VBI). The requirement for additional risk factors before AF increases stroke risk; temporal disconnect of AF from a stroke in patients with no AF for months before stroke during continuous ECG monitoring but manifesting AF only after stroke; and increasing recognition of the role of atrial cardiomyopathy and atrial substrate in AF-related stroke, and also stroke without AF, have led to rethinking the pathogenetic model of cardioembolic stroke. This is quite separate from recognition that in AF, shared cardiovascular risk factors can lead both to non-embolic stroke, or emboli from the aorta and carotid arteries. Meanwhile, VBI is now expanded to include dementia and cognitive decline: research is required to see if reduced by OAC. A changed conceptual model with less focus on the arrhythmia, and more on atrial substrate/cardiomyopathy causing VBI both in the presence or absence of AF, is required to allow us to better prevent AF-related VBI. It could direct focus towards prevention of the atrial cardiomyopathy though much work is required to better define this entity before the balance between AF as villain or bystander can be determined.

Short-term anticoagulation after acute cardioversion of early-onset atrial fibrillation

BACKGROUND

Controversy exists regarding anticoagulation management following acute cardioversion in patients with early-onset (<48 hours) atrial fibrillation without class I guideline indication for long-term oral anticoagulation (CHA2DS2-VASc 0-1).

METHODS AND RESULTS

A random-effect meta-analysis of observational studies reporting 30-day incidence of thromboembolic complications after cardioversion without post-procedural oral anticoagulation therapy in patients at low-moderate thromboembolic risk (CHA2DS2-VASc 0-1) was performed. Four studies were included, encompassing 3276 cardioversions. The analysis revealed that the pooled risk of 30-day incidence of thromboembolic complications in this subset of patients is low (0.10%, 95% confidence interval: 0.00%-0.30%).

CONCLUSIONS

Given these data, considering the bleeding risk unavoidably conferred by OAT, which is known to be higher in the first month from treatment onset, short-term anticoagulation limited to 4 weeks post-cardioversion of early-onset (<48 hours) atrial fibrillation in patients with low-moderate risk of stroke (CHA2DS2-VASc 0-1) may be omitted, at least in patients with high-bleeding risk.

The 2020 Canadian Cardiovascular Society/Canadian Heart Rhythm Society Comprehensive Guidelines for the Management of Atrial Fibrillation

The Canadian Cardiovascular Society (CCS) atrial fibrillation (AF) guidelines program was developed to aid clinicians in the management of these complex patients, as well as to provide direction to policy makers and health care systems regarding related issues. The most recent comprehensive CCS AF guidelines update was published in 2010. Since then, periodic updates were published dealing with rapidly changing areas. However, since 2010 a large number of developments had accumulated in a wide range of areas, motivating the committee to complete a thorough guideline review. The 2020 iteration of the CCS AF guidelines represents a comprehensive renewal that integrates, updates, and replaces the past decade of guidelines, recommendations, and practical tips. It is intended to be used by practicing clinicians across all disciplines who care for patients with AF. The Grading of Recommendations, Assessment, Development and Evaluations (GRADE) system was used to evaluate recommendation strength and the quality of evidence. Areas of focus include: AF classification and definitions, epidemiology, pathophysiology, clinical evaluation, screening and opportunistic AF detection, detection and management of modifiable risk factors, integrated approach to AF management, stroke prevention, arrhythmia management, sex differences, and AF in special populations. Extensive use is made of tables and figures to synthesize important material and present key concepts. This document should be an important aid for knowledge translation and a tool to help improve clinical management of this important and challenging arrhythmia.

Cardioversion Safety - Are We Doing Enough?

There is a considerable periprocedural risk of thromboembolic events in atrial fibrillation patients undergoing cardioversion, and treatment with anticoagulants is therefore a hallmark of cardioversion safety. Based on retrospective subgroup analyses and prospective studies, non-vitamin K anticoagulants are at least as efficient as vitamin K-antagonists in preventing thromboembolic complications after cardioversion. The risk of thromboembolic complications after cardioversion very much depends on the comorbidities in a given patient, and especially heart failure, diabetes, and age >75 years carry a markedly increased risk. Cardioversion has been considered safe within a 48-h time window after onset of atrial fibrillation without prior treatment with anticoagulants, but recent studies have set this practice into question based on e.g. erratic debut assessment of atrial fibrillation. Therefore, a simple and more practical approach is here suggested, where early cardioversion is performed only in hemodynamically unstable patients.

How to Manage Atrial Fibrillation in the Emergency Department: a Critical Appraisal

Atrial fibrillation is the most common cardiac arrhythmia in emergency departments. There is growing evidence that certain patients with acute atrial fibrillation can be safely managed in the emergency room without the need for hospitalization, minimizing costs and reducing unnecessary exposures. This review addresses the emergency management of atrial fibrillation based on the latest updates on the subject with a focus on the assessment and prevention of thromboembolic phenomena, control of frequency x control of rhythm and strategies for cardioversion and restoration of sinus rhythm or for heart rate control.

Anesthesiologists Guide to the 2019 AHA/ACC/HRS Focused Update for the Management of Patients With Atrial Fibrillation

Perioperative physicians should be well versed in atrial fibrillation (AF) management because it is the most common sustained arrythmia in the United States. In this narrative review of the 2019 American Heart Association/American College of Cardiologists/Heart Rhythm Society Focused Update on Atrial Fibrillation, the authors detail the emergence of new evidence from completed studies that may affect the management of patients with AF presenting for surgery. Updates regarding non-vitamin K oral anticoagulants (NOACs) comprise the bulk of the update with newer evidence emerging regarding their equivalence and/or superiority compared to Coumadin. Apixaban is now the preferred drug of choice for first line stroke prevention in nonvalvular AF over Coumadin. Renal dysfunction and the management of patients with AF on hemodialysis is examined; in patients on hemodialysis with AF, the focused update recommends administration of either warfarin or dose-reduced apixaban. Evidence from new trials addressing the appropriate bridging of NOACs before surgery is discussed. Patients with nonvalvular AF may not exhibit an added benefit from bridging of anticoagulation, and perioperative physicians should balance the risks of stroke and major bleeding before surgery. Advances in nonpharmacologic treatment and management of AF are outlined, including left atrial appendage occlusion devices, catheter ablations, and electrical cardioversion. Anesthesiologists' understanding of these 2019 updated guidelines will allow for more adept optimization of patients with AF presenting for surgery.

Vernakalant in Atrial Fibrillation: A Relatively New Weapon in the Armamentarium Against an Old Enemy

Atrial fibrillation is the most common sustained cardiac arrhythmia, and its prevalence is increasing with age; also it is associated with significant morbidity and mortality. Rhythm control is advised in recent-onset atrial fibrillation, and in highly symptomatic patients, also in young and active individuals. Moreover, rhythm control is associated with lower incidence of progression to permanent atrial fibrillation. Vernakalant is a relatively new anti-arrhythmic drug that showed efficacy and safety in recent-onset atrial fibrillation. Vernakalant is indicated in atrial fibrillation (⩽7 days) in patients with no heart disease (class I, level A) or in patients with mild or moderate structural heart disease (class IIb, level B). Moreover, Vernakalant may be considered for recent-onset atrial fibrillation (⩽3 days) post cardiac surgery (class IIb, level B). Although it is mainly indicated in patients with recent-onset atrial fibrillation and with no structural heart disease, it can be given in moderate stable cardiac disease as alternative to Amiodarone. Similarly to electrical cardioversion, pharmacological cardioversion requires a minimal evaluation and cardioversion should be included in a comprehensive management strategy for better outcome.

Safe Cardioversion for Patients With Acute-Onset Atrial Fibrillation and Flutter: Practical Concerns and Considerations

In this Viewpoint concerns raised by Canadian emergency physicians regarding recommendations 2 and 6 from the recent Canadian Cardiovascular Society 2018 update for atrial fibrillation are discussed. These recommendations narrow the window for safe cardioversion and suggest 4 weeks of anticoagulation for all patients who undergo urgent cardioversion regardless of their CHADS-65 status. We discuss the implications of Grading of Recommendations, Assessment, Development, and Evaluation weak recommendations on the basis of low-quality evidence.

Anticoagulation in the cardiac patient: A concise review

Anticoagulation has multiple roles in the treatment of cardiovascular disease, including in management of acute myocardial infarction, during percutaneous coronary intervention, as stroke prophylaxis in patients with atrial arrhythmias, and in patients with mechanical heart valves. Clinical anticoagulation choices in the aforementioned diseases vary widely, due to conflicting data to support established agents and the rapid evolution of evidence-based practice that parallels more widespread use of novel oral anticoagulants. This review concisely summarizes evidence-based guidelines for anticoagulant use in cardiovascular disease, and highlights new data specific to direct oral anticoagulants.

Real-World Comparative Effectiveness, Safety, and Health Care Costs of Oral Anticoagulants in Nonvalvular Atrial Fibrillation Patients in the U.S. Department of Defense Population

BACKGROUND

The ARISTOTLE trial demonstrated that apixaban had significantly lower rates of stroke/systemic embolism (SE) and major bleeding than warfarin; however, no direct clinical trials between apixaban and other direct oral anticoagulants (DOACs) are available. Few real-world studies comparing the effectiveness and safety between DOACs have been conducted.

OBJECTIVE

To compare effectiveness, safety, and health care costs among oral anticoagulants (OACs) for nonvalvular atrial fibrillation (NVAF) patients in the U.S. Department of Defense (DoD) population.

METHODS

Adult NVAF patients initiating warfarin or DOACs (apixaban, rivaroxaban, and dabigatran) were selected from U.S. DoD data from January 1, 2013, to September 30, 2015. The first OAC claim date was designated as the index date. Patients initiating another OAC were matched 1:1 to apixaban patients using propensity score matching to balance demographics and clinical characteristics. Cox proportional hazards models were used to estimate the risk of stroke/SE and major bleeding for each OAC versus apixaban. Generalized linear and two-part models with bootstrapping were used to compare all-cause health care costs and stroke/SE-related and major bleeding-related medical costs.

RESULTS

Of the 41,001 eligible patients, 7,607 warfarin-apixaban, 4,129 dabigatran-apixaban, and 11,284 rivaroxaban-apixaban pairs were matched. Warfarin (HR = 1.84; 95% CI = 1.30-2.59; P < 0.001) and rivar-oxaban (HR = 1.46; 95% CI = 1.08-1.98; P = 0.015) were associated with a significantly higher risk of stroke/SE compared with apixaban. Dabigatran (HR = 1.17; 95% CI = 0.68-2.03; P = 0.573) was associated with a numerically higher risk of stroke/SE compared with apixaban. Warfarin (HR = 1.53; 95% CI = 1.24-1.89; P < 0.001), dabigatran (HR = 1.76; 95% CI = 1.27-2.43; P < 0.001), and rivaroxaban (HR = 1.59; 95% CI = 1.34-1.89; P < 0.001) were associated with higher risks of major bleeding compared with apixaban. Compared with apixaban, patients prescribed warfarin incurred numerically higher all-cause total health care costs per patient per month (PPPM) ($2,498 vs. $2,277; P = 0.148) and significantly higher stroke/SE-related ($118 vs. $46; P = 0.012) and major bleeding-related ($166 vs. $76; P = 0.003) medical costs. Dabigatran patients incurred numerically higher all-cause total health care PPPM costs ($2,372 vs. $2,143; P = 0.150) and stroke/SE-related medical costs ($61 vs. $32; P = 0.240) but significantly higher major bleeding-related costs ($114 vs. $58; P = 0.025). Rivaroxaban patients incurred significantly higher all-cause total health care costs ($2,546 vs. $2,200; P < 0.001) and major bleeding-related medical costs PPPM ($137 vs. $69; P < 0.001) but numerically higher stroke/SE-related medical costs PPPM ($58 vs. $38; P = 0.057).

CONCLUSIONS

Among NVAF patients in the U.S. DoD population, warfarin and rivaroxaban were associated with a significantly higher risk of stroke/SE and major bleeding compared with apixaban. Dabigatran use was associated with a numerically higher risk of stroke/SE and a significantly higher risk of major bleeding compared with apixaban. Warfarin and dabigatran incurred numerically higher all-cause total health care costs compared with apixaban. Rivaroxaban was associated with significantly higher all-cause total health care costs compared with apixaban. DISCLOSURES This study was funded by Bristol-Myers Squibb and Pfizer, which were involved in the study design, as well as in the writing and revision of the manuscript. Keshishian and Zhang are paid employees of STATinMED Research, which was paid by Bristol-Myers Squibb and Pfizer to conduct this study and develop the manuscript. Gupta, Rosenblatt, Hede, and Nadkarni are paid employees of Bristol-Myers Squibb. Trocio, Dina, Mardekian, Liu, and Shank are paid employees of Pfizer.

Cardioverting acute atrial fibrillation and the risk of thromboembolism: not all patients are created equal

Current guidelines support the well-established clinical practice that patients who present with atrial fibrillation (AF) of less than 48 hours duration should be considered for cardioversion, even in the absence of pre-existing anticoagulation. However, with increasing evidence that short runs of AF confer significant risk of stroke, on what evidence is this 48-hour rule based and is it time to adopt a new approach? We review existing evidence and suggest a novel approach to risk stratification in this setting. Overall, the risk of thromboembolism associated with acute cardioversion of patients with AF that is estimated to be of <48 hours duration is low. However, this risk varies widely depending on patient characteristics. From existing evidence, we show that using the CHA2DS2-VASc score may allow better selection of appropriate patients in order to prevent exposing specific patient groups to an unacceptably high risk of a potentially devastating complication.