Periprocedural Anticoagulation for Cardioversion of Acute Onset Atrial Fibrillation and Flutter: Evidence Base for Current Guidelines

Chinese guidelines for the diagnosis and management of atrial fibrillation

Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia, significantly impacting patients' quality of life and increasing the risk of death, stroke, heart failure, and dementia. Over the past two decades, there have been significant breakthroughs in AF risk prediction and screening, stroke prevention, rhythm control, catheter ablation, and integrated management. During this period, the scale, quality, and experience of AF management in China have greatly improved, providing a solid foundation for the development of the guidelines for the diagnosis and management of AF. To further promote standardized AF management, and apply new technologies and concepts to clinical practice timely and fully, the Chinese Society of Cardiology of Chinese Medical Association and the Heart Rhythm Committee of Chinese Society of Biomedical Engineering jointly developed the Chinese Guidelines for the Diagnosis and Management of Atrial Fibrillation. The guidelines comprehensively elaborated on various aspects of AF management and proposed the CHA2DS2‑VASc‑60 stroke risk score based on the characteristics of the Asian AF population. The guidelines also reevaluated the clinical application of AF screening, emphasized the significance of early rhythm control, and highlighted the central role of catheter ablation in rhythm control.

Chinese Guidelines for the Diagnosis and Management of Atrial Fibrillation

Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia, significantly impacting patients' quality of life and increasing the risk of death, stroke, heart failure, and dementia. Over the past two decades, there have been significant breakthroughs in AF risk prediction and screening, stroke prevention, rhythm control, catheter ablation, and integrated management. During this period, the scale, quality, and experience of AF management in China have greatly improved, providing a solid foundation for the development of guidelines for the diagnosis and management of AF. To further promote standardized AF management, and apply new technologies and concepts to clinical practice in a timely and comprehensive manner, the Chinese Society of Cardiology of the Chinese Medical Association and the Heart Rhythm Committee of the Chinese Society of Biomedical Engineering have jointly developed the Chinese Guidelines for the Diagnosis and Management of Atrial Fibrillation. The guidelines have comprehensively elaborated on various aspects of AF management and proposed the CHA2DS2-VASc-60 stroke risk score based on the characteristics of AF in the Asian population. The guidelines have also reevaluated the clinical application of AF screening, emphasized the significance of early rhythm control, and highlighted the central role of catheter ablation in rhythm control.

RAFF-5 Study to Improve the Quality and Safety of Care for Patients Seen in the Emergency Department With Acute Atrial Fibrillation and Flutter

BACKGROUND

We sought to improve the immediate and subsequent care of emergency department (ED) patients with acute atrial fibrillation (AF) and flutter (AFL) by implementing the principles of the Canadian Association of Emergency Physicians AF/AFL Best Practices Checklist.

METHODS

This cohort study included 3 periods: before (7 months), intervention introduction (1 month), and after (7 months), and was conducted at a major academic centre. We included patients who presented with an episode of acute AF or AFL and used multiple strategies to support ED adoption of the Canadian Association of Emergency Physicians checklist. We developed new cardiology rapid-access follow-up processes. The main outcomes were unsafe and suboptimal treatments in the ED.

RESULTS

We included 1108 patient visits, with 559 in the before and 549 in the after period. In a comparison of the periods, there was an increase in use of chemical cardioversion (20.6% vs 25.0%; absolute difference [AD], 4.4%) and in electrical cardioversion (39.2% vs 51.2%; AD, 12.0%). More patients were discharged with sinus rhythm restored (66.9% vs 75.0%; AD, 8.1%). The proportion seen in a follow-up cardiology clinic increased from 24.2% to 39.9% (AD, 15.7%) and the mean time until seen decreased substantially (103.3 vs 49.0 days; AD, -54.3 days). There were very few unsafe cases (0.4% vs 0.7%) and, although there was an increase in suboptimal care (19.5% vs 23.1%), overall patient outcomes were excellent.

CONCLUSIONS

We successfully improved the care for ED patients with acute AF/AFL and achieved more frequent and more rapid cardiology follow-up. Although cases of unsafe management were uncommon and patient outcomes were excellent, there are opportunities for physicians to improve their care of acute AF/AFL patients.

CLINICALTRIALS

GOV IDENTIFIER

NCT05468281.

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.

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.

Clinical decision support to Optimize Care of patients with Atrial Fibrillation or flutter in the Emergency department: protocol of a stepped-wedge cluster randomized pragmatic trial (O'CAFÉ trial)

BACKGROUND

Management of adults with atrial fibrillation (AF) or atrial flutter in the emergency department (ED) includes rate reduction, cardioversion, and stroke prevention. Different approaches to these components of care may lead to variation in frequency of hospitalization and stroke prevention actions, with significant implications for patient experience, cost of care, and risk of complications. Standardization using evidence-based recommendations could reduce variation in management, preventable hospitalizations, and stroke risk.

METHODS

We describe the rationale for our ED-based AF treatment recommendations. We also describe the development of an electronic clinical decision support system (CDSS) to deliver these recommendations to emergency physicians at the point of care. We implemented the CDSS at three pilot sites to assess feasibility and solicit user feedback. We will evaluate the impact of the CDSS on hospitalization and stroke prevention actions using a stepped-wedge cluster randomized pragmatic clinical trial across 13 community EDs in Northern California.

DISCUSSION

We hypothesize that the CDSS intervention will reduce hospitalization of adults with isolated AF or atrial flutter presenting to the ED and increase anticoagulation prescription in eligible patients at the time of ED discharge and within 30 days. If our hypotheses are confirmed, the treatment protocol and CDSS could be recommended to other EDs to improve management of adults with AF or atrial flutter.

TRIAL REGISTRATION

ClinicalTrials.gov NCT05009225 .  Registered on 17 August 2021.

Healthcare utilization and quality of life for atrial fibrillation burden: the CIRCA-DOSE study

AIMS

Atrial tachyarrhythmia recurrence ≥30 s remains the primary endpoint of clinical trials; however, this definition has not been correlated with clinical outcomes or pathophysiological processes. This study sought to determine the atrial tachyarrhythmia duration and burden associated with meaningful clinical outcomes.

METHODS AND RESULTS

The time and duration of every atrial tachyarrhythmia episode recorded on implantable cardiac monitor were evaluated. Healthcare utilization and quality of life in the year following ablation were prospectively collected. Three hundred and forty-six patients provided 126 110 monitoring days. One-year freedom from recurrence increased with arrhythmia duration thresholds, from 52.6 (182/346) to 93.3% (323/346; P < 0.0001). Patients with atrial fibrillation (AF) recurrence limited to durations ≤1 h had rates of healthcare utilization comparable with patients free of recurrence, while patients with AF recurrences lasting >1 h had a relative risk for emergency department consultation of 3.2 [95% confidence interval (CI) 2.0-5.3], hospitalization of 5.3 (95% CI 2.9-9.6), and repeat ablation of 27.1 (95% CI 10.5-71.0). Patients with AF burden of ≤0.1% had rates of healthcare utilization comparable with patients free of recurrence, while patients with AF burden of >0.1% had a relative risk for emergency department consultation of 2.4 (95% CI 1.9-3.9), hospitalization of 6.8 (95% CI 3.6-13.0), cardioversion of 9.1 (95% CI 3.3-25.6), and repeat ablation of 21.8 (95% CI 9.2-52.2). Compared with patients free of recurrence, the disease-specific quality of life was significantly impaired with AF episode durations >24 h, or AF burdens >0.1%.

CONCLUSION

AF recurrence, as defined by 30 s of arrhythmia, lacks clinical relevance. AF episode durations >1 h or burdens >0.1% were associated with increased rates of healthcare utilization.

Validating emergency department cardioversion procedures in provincial administrative data in Ontario, Canada

BACKGROUND

Cardioversion of acute-onset atrial fibrillation (AF) via electrical or pharmacological means is a common procedure performed in many emergency departments. While these procedures appear to be very safe, the rarity of subsequent adverse outcomes such as stroke would require huge sample sizes to confirm that conclusion. Big data can supply such sample sizes.

OBJECTIVE

We aimed to validate several potential codes for successful emergency department cardioversion of AF patients.

METHODS

This study combined 3 observational datasets of emergency department AF visits seen at one of 26 hospitals in Ontario, Canada, between 2008 and 2012. We linked patients who were eligible for emergency department cardioversion to several province-wide health administrative datasets to search for the associated cardioversion billing and procedural codes. Using the observational data as the gold standard for successful cardioversion, we calculated the test characteristics of a billing code (Z437) and of procedural codes 1.HZ.09JAFS and 1.HZ.09JAJS. Both include pharmacological and electrical cardioversions, as well as unsuccessful attempts; the latter is <10% using electricity (in Canada, standard practice is to proceed to electrical cardioversion if pharmacological cardioversion is unsuccessful).

RESULTS

Of 4557 unique patients in the three datasets, 2055 (45.1%) were eligible for cardioversion. Nine hundred thirty-three (45.4%) of these were successfully cardioverted to normal sinus rhythm. The billing code had slightly better test characteristics overall than the procedural codes. Positive predictive value (PPV) of a billing was 89.8% (95% CI, 87.0-92.2), negative predictive value (NPV) 70.5% (95% CI, 68.1-72.8), sensitivity 52.1% (95% CI, 48.8-55.3), and specificity 95.1% (95% CI, 93.7-96.3).

CONCLUSIONS

AF patients who have been successfully cardioverted in an emergency department can be identified with high PPV and specificity using a billing code. Studies that require high sensitivity for cardioversion should consider other methods to identify cardioverted patients.

Effectiveness and Safety of Cryoablation in Patients With Atrial Fibrillation Episodes of <24 h Duration: A Propensity-Matched Analysis

Background: Paroxysmal atrial fibrillation (AF) is closely related to pathophysiologic processes and clinical outcomes. However, it is uncertain whether cryoablation of pulmonary veins isolation is effective and safe for patients with symptomatic and drug refractory AF episodes of <24-h duration.

Methods: The patients were designed into Group A (253 patients with paroxysmal AF episodes of <24-h duration) and Group B (253 patients with paroxysmal AF lasting for 24 h or longer) on a 1:1 basis by identical propensity scores. Mortality, stroke/transient ischemic attack (TIA), and complications relevant to the cryoablation procedure were compared, and recurrence of atrial tachyarrhythmia was analyzed for clinical independent predictors.

Results: The rate of atrial tachyarrhythmia recurrence was 21.74% in Group A and 30.04% in Group B, respectively (P = 0.042). At 12-month follow-up from the procedure, lower incidences of stroke/TIA endpoint of the patients were observed in Group A compared with Group B by Kaplan–Meier analysis [HR 0.34 (0.13–0.87), P = 0.025]. No significant differences in mortality and complications relevant to the cryoablation procedure were observed between Group A and Group B. Moreover, adjusted multivariable Cox regression analysis showed that <24-h paroxysmal AF type (HR 0.644, 95% CI: 0.455–0.913, P = 0.014) and left atrium diameter (LAD) (>40 mm) (HR 1.696, 95% CI: 1.046–2.750, P = 0.032) were independently associated with the incidence of recurrence of atrial tachyarrhythmia in the study.

Conclusion: Our findings indicated that <24-h paroxysmal AF type was obviously associated with an increased success rate of cryoablation and reduced incidence of stroke/TIA during the follow-up period. Therefore, there is superior effectiveness and similar safety in patients with AF episodes of <24-h duration compared with patients with longer paroxysmal AF duration.

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.

Adverse Events Associated With Electrical Cardioversion in Patients With Acute Atrial Fibrillation and Atrial Flutter

BACKGROUND

We sought to evaluate safety of electrical cardioversion (ECV) for patients with acute atrial fibrillation (AF) or atrial flutter (AFL) in the emergency department (ED).

METHODS

This was an analysis of data from 4 multicentre AF/AFL studies conducted from 2008 to 2019 at 23 large EDs. We included adult patients who received attempts at ECV and who had presented acutely after symptom onset. Staff manually reviewed study and clinical records to abstract data.

RESULTS

We evaluated 1736 ECV cases with a mean age of 60.1 years and 67.1% male. The overall success of ECV was 90.2% (95% confidence interval 88.7%-91.6%), with 4.9% of patients admitted. ED physicians performed the ECV in 95.2% and provided sedation in 96.5%; 13.9% (12.3%-15.7%) of cases experienced important adverse events that required treatment, and 0.4% were classified as life threatening. Another 5.6% had adverse events that did not require treatment. Logistic regression found that the RAFF-3 study cohort (odds ratio [OR] 2.0), age ≥ 85 years (OR 2.1), coronary artery disease (OR 1.5), midazolam (OR 1.9), and fentanyl (OR 1.5) were associated with important adverse events.

CONCLUSIONS

This large evaluation of the safety of ECV for acute AF/AFL in the ED found that while serious adverse events were rare, there were a concerning number of events following sedation that required intervention. Physicians should be aware that older age, coronary artery disease, and fentanyl are associated with higher risks of important adverse events. This study provides more information for shared decision making discussions with patients when choosing between drug-shock and shock-only cardioversion strategies.

RAFF-3 Trial: A Stepped-Wedge Cluster Randomized Trial to Improve Care of Acute Atrial Fibrillation and Flutter in the Emergency Department

BACKGROUND

We sought to improve care of patients with acute atrial fibrillation (AF) and flutter (AFL) in the emergency department (ED) by implementing the CAEP AAFF Best Practice Checklist.

METHODS

We conducted a stepped-wedge cluster randomized trial at 11 large community and academic hospital EDs, in five Canadian provinces and enrolled consecutive AF/AFL patients. The study intervention was the introduction of the CAEP Checklist using a knowledge translation-implementation approach that included behavior change techniques and organization/system level strategies. The primary outcome was length of stay in ED and secondary outcomes were discharge home, use of rhythm control, adverse events, and 30-day status. Analysis used mixed effects regression adjusting for covariates.

RESULTS

Patient visits in the control (N=314) and intervention (N=404) periods were similar with mean age 62.9, 54% male, 71% onset <12 hours, and 86% atrial fibrillation, 14% atrial flutter. We observed a reduction in length of stay of 20.9% (95% CI 5.5 to 33.8%, P=0.01), an increase in use of rhythm control (adjusted odds ratio (OR 4.5, 1.8-11.6; P=0.002), and decrease in use of rate control medications (OR 0.5, 0.2 to 0.9; P=0.02). There was no change in adverse events and no strokes or deaths by 30 days.

CONCLUSIONS

The RAFF-3 Trial led to optimized care of AF/AFL patients with decreased ED lengths of stay, increased ED rhythm control by drug or electricity, and no increase in adverse events. Early cardioversion allows AF/AFL patients to quickly resume normal activities. CLINICALTRIALS.

GOV IDENTIFIER

NCT03627143.

Stroke due to Left Atrial Appendage Thrombus after Pulmonary Vein Isolation despite Novel Oral Anticoagulant: A Case Report

In patients with atrial fibrillation, catheter ablation is suggested to reduce the mortality rate and is thus frequently performed. However, peri- and postprocedural thromboembolic complications as well as high recurrence rates of atrial fibrillation limit its advantages and require concomitant anticoagulation. With the advent of novel oral anticoagulants (NOACs), fixed dosing without routine laboratory monitoring became feasible. Nevertheless, several factors are associated with either an overdose or an insufficient drug activity of NOACs. We report on a patient with atrial fibrillation undergoing catheter ablation and cardioversion suffering from ischemic stroke despite being under oral anticoagulation. It turned out that the drug activity of the NOACs used was repeatedly insufficient in spite of regular intake and adequate dosing. In sum, drug activity controls should be taken into consideration in patients with thrombotic events despite oral anticoagulation with NOACs.

Effect of Outcome Measures on the Apparent Efficacy of Ablation for Atrial Fibrillation: Why "Success" is an Inappropriate Term

INTRODUCTION

Different endpoint criteria, different durations of follow-up and the completeness of follow-up can dramatically affect the perceived benefits of atrial fibrillation (AF) ablation.

METHODS

We defined three endpoints for recurrence of AF post ablation in a cohort of 200 patients with symptomatic AF, refractory to antiarrhythmic drugs (AADs). A 'Strict Endpoint' where patients were considered to have a recurrence with any symptomatic or documented recurrence for ≥30 seconds with no blanking period, and off their AADs, a 'Liberal Endpoint' where only documented recurrences after the blanking period, either on or off AADs were counted, and a 'Patient-defined Outcome endpoint' which was the same as the Liberal endpoint but allowed for up to two recurrences and one repeat ablation or DCCV during follow-up. We also surveyed 50 patients on the waiting list for an AF ablation and asked them key questions regarding what they would consider to be a successful result for them.

RESULTS

Freedom from recurrence of atrial tachyarrhythmias (AT) at 5 years was 62% for the Strict Endpoint, 73% for the Liberal Endpoint, and 80% for the Patient-defined Outcome endpoint (p<0.001). Of the 50 patients surveyed awaiting AF ablation, 70% said they would still consider the procedure a success if it required one repeat ablation or one DCCV (p=0.004), and 76% would be accepting of one or two recurrences during follow-up (p<0.001).

CONCLUSION

In this study, the majority of patients still considered AF ablation a successful treatment if they had up to two recurrences of AF, one repeat procedure or one DCCV. Furthermore, a 'Patient-defined' definition of success lead to significantly different results in this AF ablation cohort when compared to conventionally used/guideline directed measures of success.

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.

Association of Atrial Fibrillation Episode Duration With Arrhythmia Recurrence Following Ablation: A Secondary Analysis of a Randomized Clinical Trial

IMPORTANCE

Contemporary guidelines recommend that atrial fibrillation (AF) be classified based on episode duration, with these categories forming the basis of therapeutic recommendations. While pragmatic, these classifications are not based on pathophysiologic processes and may not reflect clinical outcomes.

OBJECTIVE

To evaluate the association of baseline AF episode duration with post-AF ablation arrhythmia outcomes.

DESIGN, SETTING, AND PARTICIPANTS

The current study is a secondary analysis of a prospective, parallel-group, multicenter, single-masked randomized clinical trial (the Cryoballoon vs Irrigated Radiofrequency Catheter Ablation: Double Short vs Standard Exposure Duration [CIRCA-DOSE] study), which took place at 8 Canadian centers. Between September 2014 and July 2017, 346 patients older than 18 years with symptomatic AF referred for first catheter ablation were enrolled. All patients received an implantable cardiac monitor at least 30 days before ablation. Data analysis was performed in September 2019.

EXPOSURE

Before ablation, patients were classified based on their longest AF episode. Ablation consisted of circumferential pulmonary vein isolation using standard techniques.

MAIN OUTCOMES AND MEASURES

Time to first recurrence of symptomatic or asymptomatic atrial tachyarrhythmia (AF, atrial flutter, or atrial tachycardia) following ablation and AF burden (percentage of time in AF) on preablation and postablation continuous rhythm monitoring.

RESULTS

The study included 346 patients (mean [SD] age, 59 [10] years; 231 [67.7%] men). Overall, 263 patients (76.0%) had AF episode duration of less than 24 hours; 25 (7.2%), 24 to 48 hours; 40 (11.7%), 2 to 7 days; and 18 (5.2%), more than 7 days. Documented recurrence of any atrial tachyarrhythmia following ablation was significantly lower in patients with baseline AF episode duration of less than 24 continuous hours compared with those with longer AF episodes (24 hours vs 24-48 hours: hazard ratio [HR], 0.41; 95% CI, 0.21-0.80; P = .009; 24 hours vs 2-7 days: HR, 0.25; 95% CI, 0.14-0.45; P < .001; 24 hours vs >7 days: HR, 0.23; 95% CI, 0.09-0.55; P < .001). Patients with preablation AF episodes limited to less than 24 continuous hours had a significantly lower median (interquartile range) postablation AF burden (0% [0%-0.1%]) compared with those with AF preablation episodes lasting 2-7 days (0.1% [0%-1.0%]; P = .003) and those with AF preablation episodes lasting more than 7 days (1.0% [0%-5.4%]; P = .008). There was no significant difference in arrhythmia recurrence or AF burden between the 3 groups with a baseline AF episode duration of longer than 24 hours.

CONCLUSIONS AND RELEVANCE

In this study, patients with AF episodes limited to less than 24 continuous hours had a significantly lower incidence of arrhythmia recurrence following AF ablation. This suggests that current guidelines for classification of AF may not reflect clinical outcomes.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT01913522.

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.