Ibutilide Effectiveness and Safety in the Cardioversion of Atrial Fibrillation and Flutter in the Community Emergency Department

Mechanisms of Chemical Atrial Defibrillation by Flecainide and Ibutilide

BACKGROUND

Effective and safe pharmacological approaches for atrial defibrillation offer several potential advantages over techniques like ablation. Pharmacological therapy is noninvasive, involving no risk associated with the procedure or resulting complications. Moreover, acute drug intervention with existing drugs is likely to be low cost and broadly accessible, thereby addressing a central tenet of health equity.

OBJECTIVES

This study aims to investigate ibutilide-mediated action potential prolongation to promote use-dependent effects of flecainide on Na+ channels by reducing the diastolic interval and, consequently, drug unbinding to reduce action potential excitability in atrial tissue and terminate re-entrant arrhythmia.

METHODS

The authors utilize a modeling and simulation approach to predict the specific combinations of sodium- and potassium-channel blocking drugs to chemically terminate atrial re-entry.

RESULTS

Computational modeling and simulation show that acute application of flecainide and ibutilide is a promising example of drug repurposing that may constitute a promising combination for chemical atrial defibrillation.

CONCLUSIONS

We predict the drug concentrations that promote efficacy of flecainide and ibutilide used in combination for atrial chemical defibrillation. We also predict the potential safety pharmacology impact of this drug combination on ventricular electrophysiology.

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.

Bayesian Network Meta-analysis of Randomized Controlled Trials on the Efficacy of Antiarrhythmics in the Pharmacological Cardioversion of Paroxysmal Atrial Fibrillation

PURPOSE

Since atrial fibrillation (AF) is one of the major arrhythmias managed in hospitals worldwide, it has a major impact on public health. The guidelines agree on the desirability of cardioverting paroxysmal AF episodes. This meta-analysis aims to answer the question of which antiarrhythmic agent is most effective in cardioverting a paroxysmal AF.

MATERIALS AND METHODS

A systematic review and Bayesian network meta-analysis, searching MEDLINE, Embase, and CINAHL, were performed, including randomized controlled trials (RCTs) enrolling a population of unselected adult patients with a paroxysmal AF that compared at least two pharmacological regimes to restore the sinus rhythm or a cardioversion agent against a placebo. The main outcome was efficacy in restoring sinus rhythm.

RESULTS

Sixty-one RCTs (7988 patients) were included in the quantitative analysis [deviance information criterion (DIC) 272.57; I² = 3%]. Compared with the placebo, the association verapamil-quinidine shows the highest SUCRA rank score (87%), followed by antazoline (86%), vernakalant (85%), tedisamil at high dose (i.e., 0.6 mg/kg; 80%), amiodarone-ranolazine (80%), lidocaine (78%), dofetilide (77%), and intravenous flecainide (71%). Taking into account the degree of evidence of each individual comparison between pharmacological agents, we have drawn up a ranking of pharmacological agents from the most effective to the least effective.

CONCLUSIONS

In comparing the antiarrhythmic agents used to restore sinus rhythm in the case of paroxysmal AF, vernakalant, amiodarone-ranolazine, flecainide, and ibutilide are the most effective medications. The verapamil-quinidine combination seems promising, though few RCTs have studied it. The incidence of side effects must be taken into account in the choice of antiarrhythmic in clinical practice.

CLINICAL TRIAL REGISTRATION

PROSPERO: International prospective register of systematic reviews, 2022, CRD42022369433 (Available from: https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42022369433 ).

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.

Cardioversion of Post-Ablation Atrial Tachyarrhythmia with Ibutilide and Amiodarone: A Registry-Based Cohort Study

Patients with recurrence of atrial tachyarrhythmia after catheter ablation for atrial fibrillation or atrial flutter constitute a rapidly growing cohort, but study-driven treatment recommendations are lacking. The present study aimed to compare the cardioversion success of ibutilide and amiodarone in patients with post-ablation atrial tachyarrhythmia. We included all episodes of post-ablation atrial tachyarrhythmia in patients treated with either intravenous ibutilide or amiodarone at an academic emergency department from 2010 to 2018. The primary endpoint was the conversion to sinus rhythm. The conversion rates were stratified by arrhythmia type, and multivariable cluster-adjusted logistic regression was used to estimate the effect of ibutilide and amiodarone on cardioversion success, given as the odds ratio (OR) with 95% confidence intervals (95% CI). In total, 109 episodes of 72 patients were analyzed. The conversion rates were 37/49 (76%) for ibutilide and 16/60 (27%) for amiodarone. Compared to amiodarone, ibutilide was associated with higher odds of conversion (multivariable cluster-adjusted OR 5.6, 95% CI 1.3–24.3). The cardioversion success of ibutilide was the highest in atrial flutter (crude OR 19.5, 95% CI 3.4–112.5) and focal atrial tachycardia (crude OR 8.3, 95% CI 1.5–47.2), but it was less pronounced in atrial fibrillation (crude OR 4.5, 95% CI 1.2–17.2). Randomized trials are warranted to confirm our findings.

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.

Safety and Efficacy of Ibutilide for Acute Pharmacological Cardioversion of Rheumatic Atrial Fibrillation

INTRODUCTION

Ibutilide is indicated for acute cardioversion of nonvalvular atrial fibrillation (AF). However, its efficacy and safety in the pharmacological cardioversion of rheumatic AF are unknown.

METHODS

Patients with mild-to-moderate rheumatic mitral valve (MV) disease with symptomatic, paroxysmal, or persistent AF were included in the analysis. Intravenous ibutilide was administered at doses tailored to body weight (0.5-2.0 mg) for over 10 min. The primary end point was efficacy, assessed as the rate of conversion of AF to sinus rhythm. The secondary end point was safety, including arrhythmic events and death within 24 h of drug initiation.

RESULTS

From June 2016 to October 2018, 165 patients (94 with mitral stenosis, 23 with mitral regurgitation, 11 with mixed MV disease, and 37 with MV replacement) received ibutilide (mean dose 0.90 ± 0.54 mg). Ibutilide successfully converted AF to sinus rhythm in 127/165 (76.9%) patients, with a conversion time of 7.9 ± 4.1 min. The QTc increased from 419.9 ± 15.8 to 487.5 ± 34 ms after ibutilide administration (p < 0.001). The mean change in QTc after ibutilide administration (∆QTc) was 72.01 ± 36.03. There were no deaths, but 3 patients (1.8%) developed torsades de pointes (TdP) requiring defibrillation 55 ± 37 min after infusion.

CONCLUSION

Ibutilide cardioverted 77% of rheumatic AF to sinus rhythm, indicating its potential as a clinically useful option for pharmacological cardioversion of rheumatic AF. TdP is a potentially serious adverse event that requires careful monitoring.

A randomized, controlled comparison of electrical versus pharmacological cardioversion for emergency department patients with acute atrial flutter

BACKGROUND

Acute atrial flutter has one-tenth the prevalence of acute atrial fibrillation in the emergency department (ED) but shares many management strategies. Our aim was to compare conversion from acute atrial flutter to sinus rhythm between pharmacological cardioversion followed by electrical cardioversion (Drug-Shock), and electrical cardioversion alone (Shock-Only).

METHODS

We conducted a randomized, blinded, placebo-controlled comparison of attempted pharmacological cardioversion with IV procainamide followed by electrical cardioversion if necessary, and placebo infusion followed by electrical cardioversion. We enrolled stable patients with a primary diagnosis of acute acute atrial flutter at 11 academic EDs. The primary outcome was conversion to normal sinus rhythm.

FINDINGS

From July 2013 to October 2018, we enrolled 76 patients, and none were lost to follow-up. Comparing the Drug-Shock to the Shock-Only group, conversion to sinus rhythm occurred in 33 (100%) versus 40 (93%) (absolute difference 7.0%; 95% CI - 0.6 to 14.6; P = 0.25). Median time to conversion from start of infusion in the Drug-Shock group was 24 min (IQR 21-82) but only 9 (27%) cases were converted with IV procainamide. Patients in both groups had similar outcomes at 14 days; there were no strokes or deaths.

INTERPRETATION

This trial found that the Drug-Shock strategy is potentially superior but that either approach to immediate rhythm control in the ED for patients with acute acute atrial flutter is highly effective, rapid, and safe in restoring sinus rhythm and allowing patients to go home and return to normal activities. Unlike the case of atrial fibrillation, we found that IV procainamide alone was infrequently effective.

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.

Diagnostic Performance of Emergency Physician Gestalt for Predicting Acute Appendicitis in Patients Age 5 to 20 Years

OBJECTIVES

Pediatric appendicitis remains a challenging diagnosis in the emergency department (ED). Available risk prediction algorithms may contribute to excessive ED imaging studies. Incorporation of physician gestalt assessment could help refine predictive tools and improve diagnostic imaging decisions.

METHODS

This study was a subanalysis of a parent study that prospectively enrolled patients ages 5 to 20.9 years with a chief complaint of abdominal pain presenting to 11 community EDs within an integrated delivery system between October 1, 2016, and September 30, 2018. Prior to diagnostic imaging, attending emergency physicians enrolled patients with ≤5 days of right-sided or diffuse abdominal pain using a Web-based application embedded in the electronic health record. Predicted risk (gestalt) of acute appendicitis was prospectively entered using a sliding scale from 1% to 100%. As a planned secondary analysis, we assessed the performance of gestalt via c-statistics of receiver operating characteristic (ROC) curves; tested associations between gestalt performance and patient, physician, and facility characteristics; and examined clinical characteristics affecting gestalt estimates.

RESULTS

Of 3,426 patients, 334 (9.8%) had confirmed appendicitis. Physician gestalt had excellent ROC curve characteristics (c-statistic = 0.83, 95% confidence interval = 0.81 to 0.85), performing particularly well in the low-risk strata (appendicitis rate = 1.1% in gestalt 1%-10% range, negative predictive value of 98.9% for appendicitis diagnosis). Physicians with ≥5 years since medical school graduation demonstrated improved gestalt performance over those with less experience (p = 0.007). All clinical characteristics tested, except pain <24 hours, were significantly associated with physician gestalt value (p < 0.05).

CONCLUSION

Physician gestalt for acute appendicitis diagnosis performed well, especially in low-risk patients and when employed by experienced physicians.

Emergency Department Management of Recent-Onset Atrial Fibrillation

Atrial fibrillation (AF) is the most common tachyarrhythmia managed in the emergency department (ED). Visits to the ED for a presentation of AF have been increasing in recent years, with an admission rate that exceeds 60% in the United States and contributes substantially to health care costs. Recent-onset AF-defined as symptom onset less than 48 hr-is a common ED presentation for which rate control or acute electrical or pharmacological cardioversion may be appropriate treatment modalities depending on patient-specific circumstances. The focus of this review is to discuss the current recommendations regarding the management of recent-onset nonvalvular AF in the ED, discuss medication administration considerations, and identify implementation strategies in the ED to optimize throughput and reduce hospital admissions.

Redressing Underrecognition of "Cold Drink Heart": Patients Teaching Physicians about Atrial Fibrillation Triggered by Cold Drink and Food

In this essay I tell the story of insightful patients from around the world with cold-drink atrial arrhythmias, particularly atrial fibrillation (AF). This common condition has received little research attention and remains unknown to many physicians. The under-representation of "cold drink heart" in the literature led me and a colleague a few years ago to publish a case report on this topic in an open-access journal. I included my email address so that physicians and researchers could contact me. Although I sought a physician audience, the report struck a chord with patients. Sixteen individuals have since written me to express their gratitude for having received medical validation of the causal connection they had made between swallowing cold drink or food and their episodes of paroxysmal AF. The validation was all the more important because of their physicians' prevalent disregard of the link, making them miss out on the opportunity to partner with their patients in AF management by trigger avoidance. I explain here how these patients have handled their cold-drink AF and connect their reports with the few published in the literature. These rich email exchanges illustrate how eager patients can be for an explanation of their medical condition and for an opportunity to manage their symptoms. These communications also remind us about the important role patients play in physician education. These email-writing patients have done us all a great service by teaching about the precipitants, prevention, and underrecognition of cold-drink atrial arrhythmias.

Pharmacologic Cardioversion of Recent-Onset Atrial Fibrillation and Flutter in the Emergency Department: A Systematic Review and Network Meta-analysis

STUDY OBJECTIVE

We conduct a systematic review and Bayesian network meta-analysis to indirectly compare and rank antidysrhythmic drugs for pharmacologic cardioversion of recent-onset atrial fibrillation and atrial flutter in the emergency department (ED).

METHODS

We searched MEDLINE, EMBASE, and Web of Science from inception to March 2019, limited to human subjects and English language. We also searched for unpublished data. We limited studies to randomized controlled trials that enrolled adult patients with recent-onset atrial fibrillation or atrial flutter and compared antidysrhythmic agents, placebo, or control. We determined these outcomes before data extraction: rate of conversion to sinus rhythm within 4 hours, time to cardioversion, rate of significant adverse events, and rate of thromboembolism within 30 days. We extracted data according to Preferred Reporting Items for Systematic Reviews and Meta-analyses network meta-analysis and appraised selected trials with the Cochrane review handbook.

RESULTS

The systematic review initially identified 640 studies; 19 met inclusion criteria. Eighteen trials that randomized 2,069 atrial fibrillation patients provided data for atrial fibrillation conversion rate outcome. Bayesian network meta-analysis using a random-effects model demonstrated that antazoline (odds ratio [OR] 24.9; 95% credible interval [CrI] 7.4 to 107.8), tedisamil (OR 12.0; 95% CrI 4.3 to 43.8), vernakalant (OR 7.5; 95% CrI 3.1 to 18.6), propafenone (OR 6.8; 95% CrI 3.6 to 13.8), flecainide (OR 6.1; 95% CrI 2.9 to 13.2), and ibutilide (OR 4.1; 95% CrI 1.8 to 9.6) were associated with increased likelihood of conversion within 4 hours compared with placebo or control. Overall quality was low, and the network exhibited inconsistency.

CONCLUSION

For pharmacologic cardioversion of recent-onset atrial fibrillation within a 4-hour ED visit, there is insufficient evidence to determine which treatment is superior. Several agents are associated with increased likelihood of conversion within 4 hours compared with placebo or control. Limited data preclude any recommendation for cardioversion of recent-onset atrial flutter. Further high-quality study is necessary.

[Atrial Flutter: up-to-date Problem Evaluation with Clinical Positions]

The review provides current ideas about the etiology and prevalence of atrial flutter (AF), mechanism and substrate of arrhythmogenesis, and principles of clinical and electrophysiological classification of this arrhythmia. Methods for conservative and surgical treatments of AF, including their comparative aspect, are described in detail. The review presented recent data on efficacy and potential risks of different approaches to reversing the arrhythmia. The authors indicated a need for early diagnosis and strict control of the sinus rhythm in AF, which would help a successful intervention not only to completely cure the existing arrhythmia but also to prevent other heart rhythm disorders, primarily atrial fibrillation.

2018 Focused Update of the Canadian Cardiovascular Society Guidelines for the Management of Atrial Fibrillation

The Canadian Cardiovascular Society (CCS) Atrial Fibrillation Guidelines Committee provides periodic reviews of new data to produce focused updates that address clinically important advances in atrial fibrillation (AF) management. This 2018 Focused Update addresses: (1) anticoagulation in the context of cardioversion of AF; (2) the management of antithrombotic therapy for patients with AF in the context of coronary artery disease; (3) investigation and management of subclinical AF; (4) the use of antidotes for the reversal of non-vitamin K antagonist oral anticoagulants; (5) acute pharmacological cardioversion of AF; (6) catheter ablation for AF, including patients with concomitant AF and heart failure; and (7) an integrated approach to the patient with AF and modifiable cardiovascular risk factors. The recommendations were developed using the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) standards. Individual studies and literature were reviewed for quality and bias; the literature review process and evidence tables are included as Supplementary Material and are available on the CCS Web site. Details of the updated recommendations are presented, along with their background and rationale. This document is linked to an updated summary of all CCS AF guidelines recommendations, from 2010 to the present 2018 Focused Update, which is provided in the Supplementary Material.