Introduction: Early Diagnosis and Appropriate Treatment of Atrial Fibrillation

Atrial fibrillation (AF), the most common sustained arrhythmia, represents a significant burden to patients and healthcare systems. Many patients with AF are asymptomatic and often undiagnosed. Improved detection methods and surveillance have resulted in recognition of asymptomatic and subclinical AF, providing earlier diagnosis. The recent EAST-AFNET 4 and Korean studies have demonstrated early rhythm control (ERC) with antiarrhythmic drugs (AADs) or ablation in patients with AF improves outcomes. The EARLY AF and STOP AF First studies have shown that ERC using ablation can slow AF progression. In the following videos, the authors discuss the evolving AF landscape, with an emphasis on the benefits of early diagnosis and treatment. Historic rate versus rhythm control studies and their limitations are reviewed, followed by recent studies that support the use of ERC alongside usual care including rate control. Discussion of ERC treatment includes the selection of appropriate AADs based on safety, when to choose ablation as first-line therapy, and the complementary use of ablation and AADs. The authors summarize the current guidelines for the use of AADs to treat AF, highlighting the importance of concordance with those guidelines. Patient cases are used to relate the contents of the videos to clinical practice and are supplemented with discussion of the importance of shared decision-making involving the patient in treatment decisions. It is anticipated that this digital publication will enable cardiologists and primary care providers to recognize when early treatment of AF will improve patient outcomes, and to empower them to initiate that treatment accordingly.

Chapter 1: The Evolving Atrial Fibrillation Landscape: Importance of Early Diagnosis and Treatment

Chapter 1 begins with data that show the rising prevalence of atrial fibrillation (AF), which is increasing in tandem with the growing number of older adults, increased survival of people who have cardiovascular (CV) disorders, and the expanding use of wearable and insertable/implantable devices capable of detection. Together, these increases will result in healthcare providers seeing more patients with AF who present at earlier stages of the disease. The panel discussion covers information regarding symptoms that are common to patients with AF as well as information about the important adverse outcomes that may occur in patients with AF, including heart failure, hospitalization, thromboembolism, and death. Notably, these events may reflect either the comorbidities commonly underlying AF, AF itself, or a combination of these conditions. The chapter also introduces the four pillars of therapy-"upstream therapy," rate control, rhythm control, and embolic prevention-with an emphasis on early rhythm control as being optimal. Chapter 1 is summarized as follows.

Chapter 4: Evidence for the Early Use of Ablation and AADs Post-Ablation

Both catheter ablation and antiarrhythmic drugs (AADs) are effective treatments for atrial fibrillation (AF) and can be used individually or as complementary treatments. This chapter discusses the use of ablation for early rhythm control in AF, and the use of AADs post-ablation. Decisions on which therapeutic approach to pursue should be based on shared decision-making with the patient. The chapter reviews data from the CABANA trial, in which the intent-to-treat (ITT) analysis failed to show superiority for ablation versus AADs. Statistical significance was achieved, however, when using the pre-specified per-protocol and pre-treatment analyses. The discussion addresses the fact that data analysis was complicated by several factors: (1) not all members of the group assigned to ablation actually received ablation; (2) the AAD arm included rate control treatment without the use of AADs; (3) there were a large number of crossovers from the AAD arm to the ablation arm; and (4) many ablation-treated participants also used AADs. Results from the CABANA trial showed that ablation was better at preventing AF recurrence than AADs alone. Data from the STOP AF and EARLY AF trials that support the observation of ablation being superior to AADs alone for the reduction of recurrent AF are also reviewed. Many patients who undergo catheter ablation for AF either continue to use or need to restart AADs following ablation. This combination therapy is used by up to 40-50% of people at 1-year post ablation, as is clearly demonstrated by the results from the trials discussed above, in addition to those from the 5A trial, the POWDER AF trial, the AMIO-CAT trial, and a substantial meta-analysis. All these trials are reviewed in this chapter, noting that a variety of differences exist between the randomized clinical trials, including in ablation procedures, follow-up periods, physician experience, and AADs. Chapter 4 is summarized as follows.

Chapter 5: Guideline Recommendations: Which AAD and for Whom?

This chapter discusses the American College of Cardiology/American Heart Association/ Heart Rhythm Society (AHA/ACC/HRS) and European Society of Cardiology (ESC) guidelines for atrial fibrillation (AF) management with particular focus on antiarrhythmic drug (AAD) selection and the identification of individuals for whom AAD treatment is appropriate. Discussion includes AAD indications, when to start an AAD, choosing among AADs, how to minimize proarrhythmic risk, how to determine efficacy, and the use of adjuvant interventions. The indications for all AADs are based on safety; the current AHA/ACC/HRS and ESC guidelines state that the choice of AAD is based on the presence or absence of structural heart disease (SHD), coronary artery disease, or heart failure (HF), with further recommendations in the ESC guidelines based on HF type (e.g., HF with reduced ejection fraction [HFrEF] versus HF with preserved ejection fraction [HFpEF]). The chapter closes with a discussion of the lack of consistent use of guideline-directed care, with a review of supportive data from the recently reported AIM-AF survey-a multinational survey on AF management that involved both cardiologists and electrophysiologists. In AIM-AF, inappropriate drug selection in terms of suitable candidate selection and drug choice occurred with all types of drugs and in most patient groups. Most notable was the overuse of amiodarone in patients without SHD, and the widespread use of sotalol, including its use in patients with HFrEF. Chapter 5 is summarized as follows.

Chapter 2: Rate Versus Rhythm Control

Atrial fibrillation (AF) is a potentially serious health risk, both because of its symptoms and because of its association with an increased risk for heart failure, hospitalization, thromboembolism, and death. Chapter 2 discusses selection of appropriate treatments and when to initiate these therapies. Older trials focused on comparing rate versus rhythm control treatment options for AF. It is now recognized that both rate and rhythm control are important and can be used together. This chapter reviews the historical, pivotal rate versus rhythm control trials that failed to show any overall survival benefit of rhythm over rate control, as well as the trials' now-recognized limitations with respect to modern therapy. In addition, an in-depth discussion of the more recent trials of antiarrhythmic drugs (AAD) and ablation techniques (which have become available since the original rate versus rhythm trials were performed) is included. These updated trials show that when applied to patient- and disease-specific situations, rhythm control can reduce the risk for mortality and hospitalization. The chapter also reviews the guidelines that have been developed to achieve these goals. Chapter 2 is summarized as follows: (1) Rate control is needed (at rest and during exertion) to reduce rate-related symptoms when rhythm control is ineffective or incomplete and to prevent a tachycardia-induced cardiomyopathy. (2) Previous trials with pharmacological therapy alone comparing rate versus rhythm control using the AADs available at that time failed to show any overall survival benefit of rhythm control over rate control. (3) These earlier trials had many methodological limitations and enrolled participants who did not have access to modern therapies. (4) Newer therapies, including those for stroke prevention, dronedarone (the latest approved AAD), and AF ablation, have improved the safety and efficacy of rhythm control strategies.

Chapter 3: Evidence for the Use of Early Rhythm Control to Prevent Atrial Fibrillation Progression

This chapter reviews atrial fibrillation (AF) progression and its associated mechanisms, including comorbidities and AF as contributors to atrial myopathy, and atrial myopathy as a contributing factor to AF progression. In addition, the chapter discusses the concept of comorbidities and atrial myopathy as synergistic contributors to adverse outcomes, the notion of "AF begets AF," and the consequences of AF burden if left untreated. Clinical trials evaluating outcomes with antiarrhythmic drugs (AADs) compared with placebo have demonstrated efficacy, but also reveal a possible proarrhythmic and mortality risk if AAD selection is not appropriate and patients are not correctly identified based on risk factors and comorbidities. Data from ATHENA, the first and only trial to demonstrate that an AAD (dronedarone) can reduce cardiovascular (CV) hospitalizations in people with AF, are reviewed, along with studies reporting on the use of catheter ablation versus AADs for AF rhythm control. Finally, recent data showing a reduction in major adverse outcomes if rhythm control is initiated early are summarized, including results from the EAST-AFNET 4 trial, as well as confirmatory results from several large "real-world" trials. Chapter 3 is summarized as follows.

Chapter 6: AAD Use in Different Patient Populations, and a Patient-Centric Approach to Optimal Patient Management

Associated with longer life expectancy, greater survival of patients with cardiovascular disorders, and increased use of wearable and insertable/implantable devices capable of detection, the frequency of atrial fibrillation (AF) diagnosis is increasing. This chapter describes two representative patient cases that were used to enable a discussion of the evaluation and management of AF in different scenarios. One patient is young and healthy with paroxysmal AF but no major comorbidities (though there is a family history of AF). The other is older with multiple complicating comorbidities. These cases sparked an active discussion among the panelists that demonstrated not only the multitude of considerations when choosing the optimal therapy for each individual, but also the individualistic differences in biases and styles that can exist between experts in the field. The results of these discussions revealed agreement that.

Real-world utilization of the pill-in-the-pocket method for terminating episodes of atrial fibrillation: data from the multinational Antiarrhythmic Interventions for Managing Atrial Fibrillation (AIM-AF) survey

AIMS

Atrial fibrillation (AF) is the most common sustained arrhythmia encountered in clinical practice. Episodes may stop spontaneously (paroxysmal AF); may terminate only via intervention (persistent AF); or may persist indefinitely (permanent AF) (see European and American guidelines, referenced below, for more precise definitions). Recently, there has been renewed interest in an approach to terminate AF acutely referred to as 'pill-in-the-pocket' (PITP). The PITP is recognized in both the US and European guidelines as an effective option using an oral antiarrhythmic drug for acute conversion of acute/recent-onset AF. However, how PITP is currently used has not been systematically evaluated.

METHODS AND RESULTS

The recently published Antiarrhythmic Interventions for Managing Atrial Fibrillation (AIM-AF) survey included questions regarding current PITP usage, stratified by US vs. European countries surveyed, by representative countries within Europe, and by cardiologists vs. electrophysiologists. This manuscript presents the data from this planned sub-study. Our survey revealed that clinicians in both the USA and Europe consider PITP in about a quarter of their patients, mostly for recent-onset AF with minimal or no structural heart disease (guideline appropriate). However, significant deviations exist. See the Graphical abstract for a summary of the data.

CONCLUSION

Our findings highlight the frequent use of PITP and the need for further physician education about appropriate and optimal use of this strategy.

Perspective on Antiarrhythmic Drug Combinations

Physicians use multiple drugs in combination to treat hypertension, heart failure, diabetes mellitus, angina, hyperlipidemia, and many other cardiovascular conditions and risk factors. However, administering antiarrhythmic drugs (AAD) in combination is rarely discussed. Yet, the possibility of increasing efficacy and/or tolerance and/or safety of AADs (by adding mechanisms, offsetting adverse mechanisms, and/or using lower doses) exists. Unfortunately, this topic has not been reviewed in any contemporary cardiac literature of which we are aware, although information regarding AAD combinations has been published. In conclusion, and accordingly, this review discusses the possibility of using AAD combinations for both ventricular arrhythmias and atrial fibrillation, in which the rationale for such combinations, considerations for such combinations, and supporting literature are covered.

Cardiovascular Benefits of Icosapent Ethyl in Patients With and Without Atrial Fibrillation in REDUCE-IT

Background In REDUCE-IT (Reduction of Cardiovascular Events With Icosapent Ethyl-Intervention Trial), icosapent ethyl (IPE) versus placebo) reduced cardiovascular death, myocardial infarction, stroke, coronary revascularization, or unstable angina requiring hospitalization, but was associated with increased atrial fibrillation/atrial flutter (AF) hospitalization (3.1% IPE versus 2.1% placebo; P=0.004). Methods and Results We performed post hoc efficacy and safety analyses of patients with or without prior AF (before randomization) and with or without in-study time-varying AF hospitalization to assess relationships of IPE (versus placebo) and outcomes. In-study AF hospitalization event rates were higher in patients with prior AF (12.5% versus 6.3%, IPE versus placebo; P=0.007) versus without prior AF (2.2% versus 1.6%, IPE versus placebo; P=0.09). Serious bleeding rates trended higher in patients with (7.3% versus 6.0%, IPE versus placebo; P=0.59) versus without prior AF (2.3% versus 1.7%, IPE versus placebo; P=0.08). With IPE, serious bleeding trended higher regardless of prior AF (interaction P value [Pint]=0.61) or postrandomization AF hospitalization (Pint=0.66). Patients with prior AF (n=751, 9.2%) versus without prior AF (n=7428, 90.8%) had similar relative risk reductions of the primary composite and key secondary composite end points with IPE versus placebo (Pint=0.37 and Pint=0.55, respectively). Conclusions In REDUCE-IT, in-study AF hospitalization rates were higher in patients with prior AF especially in those randomized to IPE. Although serious bleeding trended higher in those randomized to IPE versus placebo over the course of the study, serious bleeding was not different regardless of prior AF or in-study AF hospitalization. Patients with prior AF or in-study AF hospitalization had consistent relative risk reductions across primary, key secondary, and stroke end points with IPE. Registration URL: https://clinicaltrials.gov/ct2/show/NCT01492361; Unique Identifier: NCT01492361.

The Party Should Not Last That Long

Too much food, too much wine, and too many friends. You'll pay the price tomorrow; you shouldn't have let the party last so long. This analogy seems apt with respect to our new understanding of atrial fibrillation (AF) and approaches to AF. The keys to understanding recent advances in the management of AF and improving outcomes on therapies are an appreciation that: (1) AF is often a progressive disorder; (2) its progression is related to the degree of atrial myopathy that is present; (3) atrial myopathy is a consequence of the effects of underlying comorbidities as well as the effect of AF itself (tachycardic effects on the atria); (4) adverse outcomes can be a consequence of AF, the underlying atrial myopathy, as well as direct consequences of any comorbidities present; (5) rhythm control of AF early in its course as well as early and optimal treatment of underlying comorbidities have been associated with improved outcomes (eg, lower mortality, lesser thromboembolism, lesser heart failure, fewer hospitalizations) in recent trials; (6) therapies not available 2 decades ago during the rate- versus rhythm-control trials have played a role in the new treatment approaches and make the old idea that rate control is as good as rhythm control somewhat obsolescent; and (7) these now indicate that optimal and early rhythm control and comorbidity treatment provide the best results for AF patients.

Residual stroke risk despite oral anticoagulation in patients with atrial fibrillation

Background

Oral anticoagulation (OAC) reduces the risk of thromboembolic events in patients with atrial fibrillation (AF); however, thromboembolism (TE) still can occur despite OAC. Factors associated with residual risk for stroke, systemic embolism, or transient ischemic attack events despite OAC have not been well described.

Objective

The purpose of this study was to evaluate the residual risk of thromboembolic events in patients with AF despite OAC.

Methods

A total of 18,955 patients were analyzed in the Outcomes Registry for Better Informed Treatment of Atrial Fibrillation (ORBIT-AF I and II) using multivariable Cox proportional hazard modeling. Mean age was 72 ± 10.7, and 42% were women. There were 451 outcome events.

Results

The risk of TE despite OAC increased with CHA₂DS₂-VASc score: 0.76 (95% confidence interval [CI] 0.63-0.92) events per 100 patient-years for CHA₂DS₂-VASc score <4 vs 2.01 (95% CI 1.81-2.24) events per 100-patient years for CHA₂DS₂-VASc score >4. Factors associated with increased risk were previous stroke or transient ischemic attack (hazard ratio [HR] 2.87; 95% CI 2.30-3.59; P <.001), female sex (HR 1.52; 95% CI 1.24-1.86; P <.001), hypertension (HR 1.50; 95% CI 1.09-2.06; P = .01), and permanent AF (HR 1.47; 95% CI 1.12-1.94; P = .001). When transient ischemic attack was excluded, the results were similar, but permanent AF was no longer significantly associated with thromboembolic events.

Conclusion

Patients with AF have a residual risk of TE with increasing CHA₂DS₂-VASc score despite OAC. Key risk markers include previous stroke/transient ischemic attack, female sex, hypertension, and permanent AF.

Understanding Antiarrhythmic Drug Efficacy for the Clinical Practitioner: There Is More than Meets the Eye

Determining if a medication is effective should be easy: Either the condition is or is not improved. However, the truth is often more complex than that, including in the antiarrhythmic drug (AAD) management of atrial fibrillation. In clinical trials, AAD efficacy is usually determined by the time to first atrial fibrillation recurrence. Another AAD efficacy endpoint, in patients with cardiac implantable electrical devices, is a reduction of atrial fibrillation burden. Other cardiovascular outcomes have included hospitalization, heart failure, and cardiovascular or total mortality. In clinical practice AADs, for atrial fibrillation, are prescribed to reduce symptoms/improve quality of life, which usually correlate with reduced atrial fibrillation frequency, duration, and beneficial hemodynamic effects in certain patient subgroups. Time to first recurrence is not a reliable predictor of clinical efficacy endpoints in practice. This article presents a review for the practitioner of AAD efficacy endpoints in clinical trials versus those in clinical practice and why such differences are present.

Drug Interactions Affecting Antiarrhythmic Drug Use

Antiarrhythmic drugs (AAD) play an important role in the management of arrhythmias. Drug interactions involving AAD are common in clinical practice. As AADs have a narrow therapeutic window, both pharmacokinetic as well as pharmacodynamic interactions involving AAD can result in serious adverse drug reactions ranging from arrhythmia recurrence, failure of device-based therapy, and heart failure, to death. Pharmacokinetic drug interactions frequently involve the inhibition of key metabolic pathways, resulting in accumulation of a substrate drug. Additionally, over the past 2 decades, the P-gp (permeability glycoprotein) has been increasingly cited as a significant source of drug interactions. Pharmacodynamic drug interactions involving AADs commonly involve additive QT prolongation. Amiodarone, quinidine, and dofetilide are AADs with numerous and clinically significant drug interactions. Recent studies have also demonstrated increased morbidity and mortality with the use of digoxin and other AAD which interact with P-gp. QT prolongation is an important pharmacodynamic interaction involving mainly Vaughan-Williams class III AAD as many commonly used drug classes, such as macrolide antibiotics, fluoroquinolone antibiotics, antipsychotics, and antiemetics prolong the QT interval. Whenever possible, serious drug-drug interactions involving AAD should be avoided. If unavoidable, patients will require closer monitoring and the concomitant use of interacting agents should be minimized. Increasing awareness of drug interactions among clinicians will significantly improve patient safety for patients with arrhythmias.

AIM-AF: A Physician Survey in the United States and Europe

Background

Guideline recommendations are the accepted reference for selection of therapies for rhythm control of atrial fibrillation (AF). This study was designed to understand physicians’ treatment practices and adherence to guidelines.

Methods and Results

The AIM‐AF (Antiarrhythmic Medication for Atrial Fibrillation) study was an online survey of clinical cardiologists and electrophysiologists that was conducted in the United States and Europe (N=629). Respondents actively treated ≥30 patients with AF who received drug therapy, and had received or were referred for ablation every 3 months. The survey comprised 96 questions on physician demographics, AF types, and treatment practices. Overall, 54% of respondents considered guidelines to be the most important nonpatient factor influencing treatment choice. Across most queried comorbidities, amiodarone was selected by 60% to 80% of respondents. Other nonadherent usage included sotalol by 21% in patients with renal impairment; dofetilide initiation (16%, United States only) outside of hospital; class Ic agents by 6% in coronary artery disease; and dronedarone by 8% in patients with heart failure with reduced ejection fraction. Additionally, rhythm control strategies were frequently chosen in asymptomatic AF (antiarrhythmic drugs [AADs], 35%; ablation, 8%) and subclinical AF (AADs, 38%; ablation, 13%). Despite guideline algorithms emphasizing safety first, efficacy (48%) was selected as the most important consideration for AAD choice, followed by safety (34%).

Conclusions

Despite surveyed clinicians recognizing the importance of guidelines, nonadherence was frequently observed. While deviation may be reasonable in selected patients, in general, nonadherence has the potential to compromise patient safety. These findings highlight an underappreciation of the safe use of AADs, emphasizing the need for interventions to support optimal AAD selection.

Predictors of dronedarone plasma drug concentrations and effect on atrial fibrillation/atrial flutter recurrence: Analyses from the EURIDIS and ADONIS studies

BACKGROUND

In this post hoc analysis, we assessed patient characteristics as predictors of dronedarone trough concentrations and characterized the relationship of trough concentrations of dronedarone with its efficacy and safety.

HYPOTHESIS

Dronedarone is recommended as a 400 mg twice daily dose taken orally with meals. We hypothesize that drug concentration/bioavailability of dronedarone, measured as above- and below-median trough concentrations, does not impact the efficacy outcomes.

METHODS

Average trough concentrations (Ctrough_avg ) across multiple timepoints were calculated for each patient, and patient Ctrough_avg values were categorized as below-median or above-median concentrations. The effect of patient baseline characteristics on dronedarone Ctrough_avg was assessed in the below-median versus above-median groups. The effect of dronedarone in each Ctrough_avg group versus placebo on risk of first atrial fibrillation/atrial flutter (AF/AFL) recurrence and safety was also evaluated.

RESULTS

Overall, 1795 plasma samples were available from 507 dronedarone-treated patients. An above-median Ctrough_avg was associated with age ≥75 years, female sex, lower weight, higher pacemaker use, and higher oral anticoagulant use. The risk of adjudicated first AF/AFL recurrence was significantly lower with dronedarone versus placebo in the below-median (hazard ratio [HR]: 0.71; 95% confidence interval [CI]: 0.56-0.91; p = .0054) and above-median groups (HR: 0.63; 95% CI: 0.50-0.81; p = .0002). No difference in risk of AF/AFL recurrence was observed between the above- and below-median groups. Safety and tolerability of dronedarone were similar between groups.

CONCLUSION

Significant reduction in AF/AFL recurrence was observed in patients treated with dronedarone versus placebo, regardless of dronedarone concentrations above or below the median value.

The Importance of Atrial Fibrillation's Associated Comorbidities as Clinical Presentation and Outcome Contributors

Atrial fibrillation (AF) has a heterogeneous clinical presentation. It can occur: (a) in the presence or absence of detectable heart disease, and, (b) with or without relatedsymptoms. Its prognosis in terms of thromboembolismand mortality is most benign when applied to young individuals (aged less than 60 years) without clinical orechocardiographic evidence of cardiopulmonary disease [termed "lone AF"]. However, by virtue of aging or because of the development of concomitant cardiovascular disorders, patientsmove out of the lone AF category over time, accompanied by increased risks for thromboembolism and mortality. Thus, underlying and/or associated comorbidities must play an important role in the presentation and consequences of patients with AF. While, no doubt, most clinicians likely appreciate that the majority of the AF patients they see have associated cardiovascular, pulmonary, metabolic, endocrinologic, genetic, and/or other disorders, it is not clear how much they appreciate that these disorders directly relate to the presenting symptoms and to the risks from AF in addition to their role as risk factors (or markers) for AF. This issue is the subject of this review manuscript.

Risk of Major Bleeding in Patients With Atrial Fibrillation Taking Dronedarone in Combination With a Direct Acting Oral Anticoagulant (From a U.S. Claims Database)

Dronedarone may increase exposure and the risk of major bleeding when prescribed with a direct oral anticoagulant (DOAC). This retrospective cohort study examined the risk of the first occurrence of major bleeding (hospitalization or emergency room visit for gastrointestinal [GI] bleeding, intracranial hemorrhage [ICH], or bleeding at other sites) among new users of apixaban, dabigatran, and rivaroxaban in patients with AF ≥18 years (January 1, 2007 to September 30, 2017) from the United States Truven Health MarketScan claims, comparing concomitant users of dronedarone to DOAC alone users in patients with atrial fibrillation (AF). No increased risk of major bleeding was associated with use of dronedarone and apixaban (adjusted Hazard Ratio [aHR]: 0.69 [95% confidence interval [CI]: 0.40, 1.17], p = 0.16), a modestly increased risk of GI bleeding but not overall bleeding was associated with use of dronedarone and dabigatran (aHR bleeding: 1.18 [95% CI: 0.89, 1.56], p = 0.26; aHR GI bleeding: 1.40 [95% CI: 1.01, 1.93]; p = 0.04) and an increased risk of overall bleeding, driven by GI bleeding, was associated with use of dronedarone and rivaroxaban (aHR bleeding: 1.31 [95% CI: 1.01, 1.69]; p = 0.04; aHR GI bleeding: 1.39 [95% CI: 0.98, 1.95]; p = 0.06), compared to each DOAC respectively. There was no increased risk of ICH associated with combined use of dronedarone and any DOAC. Prospective analyses, preferably randomized controlled studies, are needed to further explore the risk of major bleeding with concomitant use of DOACs and CYP3A4/P-gp inhibitors such as dronedarone.

Cardiovascular benefits outweigh risks in patients with atrial fibrillation in REDUCE-IT (Reduction of Cardiovascular Events with Icosapent Ethyl-Intervention Trial)

Background/Introduction

REDUCE-IT, a multinational, double-blind trial, randomized 8179 statin-treated patients with controlled low density lipoprotein cholesterol, elevated triglycerides, and cardiovascular (CV) risk, to icosapent ethyl (IPE) 4 grams/day or placebo. IPE reduced the primary (CV death, myocardial infarction [MI], stroke, coronary revascularization, hospitalization for unstable angina) and key secondary (CV death, MI, stroke) endpoints 25% and 26%, respectively (each p&lt;0.0001), and individual components including stroke (28%), MI (31%), cardiac arrest (48%), and sudden cardiac death (31%) (all p≤0.01). With IPE, bleeding was greater (11.8% vs 9.9%; p=0.006), serious bleeding trended higher (2.7% vs 2.1%; p=0.06), and atrial fibrillation/flutter (AF/F) hospitalization endpoints increased (3.1% vs 2.1%; p=0.004).

Purpose

To evaluate the effects of IPE on the risk of CV events and safety measures in patients by either history of AF/F or in-study occurrence of positively adjudicated AF/F hospitalization.

Methods

Conduct post hoc efficacy and safety subgroup analyses of patients with or without either baseline history of AF/F or in-study adjudicated AF/F hospitalization, including hospitalization for ≥24 hours; AF/F not meeting endpoint criteria were reported as adverse events.

Results

Patients with (n=751; 9.2%) AF/F history at baseline (vs without; n=7428; 90.8%) (Figure 1), or those with (n=211; 2.6%) positively adjudicated in-study AF/F hospitalization endpoints (vs without; n=7968; 97.4%) (Figure 2), had higher event rates of primary, key secondary, and fatal or nonfatal stroke endpoints, but relative risk reductions with IPE were not significantly different (all interaction p-values [pint]=ns). Similar reductions were observed with IPE across the prespecified endpoint testing hierarchy in patients with or without AF/F history or in-study hospitalization endpoints. Patients with baseline AF/F history had similar relative risk for in-study occurrence of AF/F hospitalization with IPE versus placebo (pint=0.21) but had greater absolute risk (12.5% vs 6.3%, IPE vs placebo) vs patients without baseline AF/F history (2.2% vs 1.6%, IPE vs placebo); i.e., recurrent AF/F in those with a prior history of AF/F was more prevalent than de novo AF/F. Serious bleeding trended higher regardless of AF/F history or in-study AF/F hospitalization endpoints (all pint=ns); absolute risk of serious bleeding was greater in patients with AF/F history at baseline (7.3% vs 6.0%) vs those without a baseline history of AF/F (2.3% vs 1.7%), and serious bleeding also trended higher in patients with in-study AF/F hospitalization (8.7% vs 6.0%) vs without (2.5% vs 2.0%) [all IPE vs placebo].

Conclusion

REDUCE-IT patients with AF/F history or in-study AF/F hospitalization endpoints had greater CV risk, but similar relative risk reduction in primary, key secondary, and fatal or nonfatal stroke endpoints with IPE.

Funding Acknowledgement

Type of funding sources: Private company. Main funding source(s): Amarin Pharma, Inc.

Antiarrhythmic Drugs for Atrial Fibrillation: Selected Features of Ventricular Repolarization That Facilitate Proarrhythmic Torsades de Pointes and Favor Inpatient Initiation

The management approaches to patients with atrial fibrillation (AF) include rhythm-control strategies for those patients who are symptomatic despite rate control and for selected others in whom sinus rhythm is necessary for reasons beyond current symptoms (including commercial pilots, those who are felt likely to develop symptoms as comorbidities progress, and more). First-line therapies among the rhythm-control options are antiarrhythmic drugs (AADs). For many AADs, their initiation in-hospital is either a requirement or strongly advised- especially when the patient is in AF. This article explores some of the rationale behind this requirement to give clinicians a better understanding of the reasons for this undesired inconvenience.

Shared decision-making in atrial fibrillation: patient-reported involvement in treatment decisions

AIMS

To determine the extent of shared decision-making (SDM), during selection of oral anticoagulant (OAC) and rhythm control treatments, in patients with newly diagnosed atrial fibrillation (AF).

METHODS AND RESULTS

We evaluated survey data from 1006 patients with new-onset AF enrolled at 56 US sites participating in the SATELLITE substudy of the Outcomes Registry for Better Informed Treatment of Atrial Fibrillation (ORBIT II). Patients completed surveys at enrolment and at 6-month follow-up. Patients were asked about who made their AF treatment decisions. Shared decision-making was classified as one that the patient felt was an autonomous decision or a shared decision with their healthcare provider (HCP). Approximately half of patients reported that their OAC treatment decisions were made entirely by their HCP. Compared with those reporting no SDM, patients reporting SDM for OAC were more often female (47.2% vs. 38.4%), while patients reporting SDM for rhythm control were more often male (62.2% vs. 57.6%). The most important factors cited by patients during decision-making for OAC were reducing stroke and bleeding risk, and their HCP's recommendations. After adjustment, patients with self-reported understanding of OAC, and rhythm control options, had higher odds of having participated in SDM [odds ratio (OR) 2.54, confidence interval (CI): 1.75-3.68 and OR 2.36, CI: 1.50-3.71, both P ≤ 0.001, respectively].

CONCLUSION

Shared decision-making is not widely implemented in contemporary AF practice. Patient understanding about available therapeutic options is associated with a more than a two-fold higher likelihood of SDM, and may be a potential target for future interventions.

Antiarrhythmic Medication for Atrial Fibrillation (AIM-AF) study: A physician survey of antiarrhythmic drug (AAD) treatment practices and guideline adherence in the EU and USA

Funding Acknowledgements

Type of funding sources: Private company. Main funding source(s): Sanofi

Introduction

The 2020 European Society of Cardiology and the 2019 USA (AHA/ACC/HRS) guidelines recommend the use of AADs for rhythm control in patients with symptomatic AF. This study sought to understand AAD treatment practices and adherence to guidelines across the EU and the USA.

Method

An online physician survey of cardiologists, cardiac electrophysiologists and interventional electrophysiologists (N = 569) was conducted in the USA, Germany, Italy and the UK. All respondents were actively treating ≥10 AF patients who received drug therapy and/or who had received or were referred for ablation. This extensively detailed survey explored questions on physician demographics, AF types, and drug treatment and ablation practices.

Results: Of the responses obtained

(1) Amiodarone was used frequently across co-morbidity categories (highest use in those with heart failure with reduced left ventricular ejection fraction [LVEF] [80%]), including in those in which it is not indicated for initial therapy (minimal or no structural heart disease: 26%). Other deviations from guideline recommendations, include: class 1C drugs were used with structural heart disease, including coronary artery disease (CAD) (average class 1C use in CAD-related comorbidities: 6%); sotalol was used with renal dysfunction (22%); and drugs such as sotalol and dofetilide were initiated out of hospital (56% and 17% of respondents, respectively). (2) Nonetheless, a majority of respondents (53%) considered guidelines as the most important non-patient factor in influencing their choice of AF management. (3) Rhythm control was selected more frequently as primary therapy for paroxysmal AF (PAF) (59% of patients) while rate control was used more often for persistent AF (53%). (4) For PAF, AADs were preferred as 1st line more often than ablation, especially if PAF was infrequent and mildly symptomatic (59% of respondents) while ablation was preferred more if frequent symptomatic PAF and for recurrent persistent AF. (5) Rhythm control (AAD or ablation) was chosen in notable numbers for asymptomatic AF and subclinical AF (AADs: 36% and 37%, respectively; ablation: 9% and 14%, respectively). (6) AAD use for those with a first or recurrent episodes of symptomatic AF was 60% or 47%, respectively. (7) Efficacy and safety were chosen as the most important considerations for choice of specific rhythm control therapy (49% and 33%, respectively), and reduction of mortality and cardiovascular hospitalisation (23%) were as important as maintaining sinus rhythm (26%) for rhythm therapy goals.

Conclusions

Although surveyed clinicians consider guidelines important, deviations in patient types and treatments chosen that compromise safety or were not indicated were common. Findings suggest a lack of understanding of the pharmacology and safe use of AADs, highlighting an important need for further education. Abstract Figure.

Relation of Antecedent Symptoms to the Likelihood of Detecting Subclinical Atrial Fibrillation With Inserted Cardiac Monitors

Atrial fibrillation (AF) comes to attention clinically during an evaluation of symptoms, an evaluation of its adverse outcomes, or because of incidental detection during a routine examination or electrocardiogram. However, a notable number of additional individuals have AF that has not yet been clinically apparent or suspect-subclinical AF (SCAF). SCAF has been recognized during interrogation of pacemakers and defibrillators. More recently, SCAF has been demonstrated in prospective studies with long-term monitors-both external and implanted. The REVEAL AF trial enrolled a demographically "enriched" population that underwent monitoring for up to 3 years with an insertable cardiac monitor. SCAF was noted in 40% by 30 months. None of these patients had AF known before the study; however, some had nonspecific symptoms common to patients with known AF. The current study assessed whether patients with versus without such symptoms were more likely to have SCAF detected. We found that only palpitations had an association with AF detection when controlling for other baseline symptoms (hazard ratio 1.61 (95% confidence interval 1.12 to 2.32; p = 0.011). No other prescreening symptoms evaluated were associated with an increased likelihood of SCAF detection although patients without detected SCAF had an even higher frequency of symptoms than those with detected SCAF. Thus, REVEAL AF demonstrated that the presence of palpitations is associated with an increased likelihood of SCAF whereas other common symptoms are not; and, symptoms, per se, may more likely be consequent to associated disorders than they are a direct consequence of SCAF.

"Pill in the Pocket" Antiarrhythmic Drugs for Orally Administered Pharmacologic Cardioversion of Atrial Fibrillation

The therapy of atrial fibrillation often involves the use of a rhythm control strategy, in which 1 or more antiarrhythmic drugs (AAD), ablative procedures, and/or hybrid approaches involving both of these options are utilized in an attempt to restore and maintain sinus rhythm. For chronic therapy, an AAD is taken daily. However, for patients with symptomatic but infrequent, acute, but nondestabilizing episodes, the use of an AAD only at the time of an episode that can quickly restore sinus rhythm, generally as an out-patient, without the burden of a daily drug regimen, may be better. This is called "pill-in-the-pocket" therapy. This manuscript reviews the "pill-in-the-pocket" concept, traces its development from its origins using quinidine, to its expansion using class IC AADs, to the more recent investigation of ranolazine for this purpose. Who should get it, what it involves, its efficacy rates and concerns are all discussed.

The Link Between CHA2DS2-VASc Score and Thromboembolic Risk in Patients Without Known Atrial Fibrillation: Are We Missing a Silent Culprit?

Stroke is a leading cause of morbidity and mortality. The majority of strokes are ischemic and a subset of these are due to atrial fibrillation (AF). Other etiologies include a variety of cardiovascular disorders. The CHA₂DS₂-VASc score is a validated stroke prediction tool for patients with non-valvular AF. However, it has also been shown to predict increased risk for stroke or thromboembolism in the absence of AF. Given how common subclinical AF (SCAF) is when looked for in patients with elevated CHA₂DS₂-VaSc scores who are not known to have AF, (especially when implanted monitors are used), the stroke/thromboembolism risk that has been associated with CHA₂DS₂-VASc scores absent known AF may be an overestimate of the true risk due to the likely presence of SCAF in some of the subjects included. This has not yet been adequately addressed in the literature. Finally, the risk of a left atrial thromboembolic event is a consequence of the altered atrial anatomy and physiology (atrial cardiomyopathy) that may result from comorbid disorders and AF itself, or, additively from both - whether or not the AF has been already recognized clinically.

Effect of Temporary Interruption of Warfarin Due to an Intervention on Downstream Time in Therapeutic Range in Patients With Atrial Fibrillation (from ORBIT AF)

The aim of this study was to quantify time in therapeutic range (TTR) before and after a temporary interruption of warfarin due to an intervention in the Outcomes Registry for Better Informed Treatment of atrial fibrillation (AF). AF patients on warfarin who had a temporary interruption followed by resumption were identified. A nonparametric method for estimating survival functions for interval censored data was used to examine the first therapeutic International Normalized Ratio (INR) after interruption. TTR was compared using Wilcoxon signed rank test. Cox proportional hazards model was used to investigate the association between TTR in the first 3 months after interruption and subsequent outcomes at 3 to 9 months. Of 9,749 AF patients, 71% were on warfarin. Over a median (IQR) follow-up of 2.6 (1.8 to 3.1) y, 33% of patients had a total of 3,022 temporary interruptions. The first therapeutic INR was recorded within 1 week in 35.0% (95% confidence interval 32.6% to 37.4%), 2 weeks in 54.6% (52.2% to 57.0%), 30 days in 70.0% (67.9% to 72.1%) and 90 days in 91.3% (90.0% to 92.5%) of patients. Compared with pre-interruption, TTR 3 months after interruption was significantly lower (61.1% [36.6% to 85.0%] vs 67.6% [50.0% to 81.3%], p <0.0001). A 10 unit increment in the TTR in the first 3 months after interruption was associated with a lower risk of major bleeding [Hazard ratio 0.91 (0.85 to 0.97), p = 0.005]. This association was noted in patients who received bridging anticoagulation, but not in those who did not. In conclusion, temporary interruption of warfarin is common, and nearly half of these patients had subtherapeutic INR after 2 weeks. Lower TTR in the first 3 months after interruption was associated with higher incidence of major bleeding in patients who received bridging anticoagulation.

Detection of Previously Unrecognized (Subclinical) Atrial Fibrillation

Atrial fibrillation (AF) has been associated with increased morbidity and mortality, even when symptoms are absent and the arrhythmia is unrecognized (e.g., subclinical AF [SCAF]). Despite substantial evidence demonstrating an association between AF and adverse outcomes, the role of mass screening for previously unrecognized SCAF, such that its individual and population risks may be reduced by prophylactic therapy, remains uncertain. Many AF screening strategies exist, from pulse palpation and single-use devices to implanted cardiac monitors; however, existing guidelines are insufficient in specifying who to screen and for how long. In general, higher age, more (and more severe) comorbidities, and longer monitoring periods are associated with greater detection of SCAF. Herein we review the significance of previously unrecognized SCAF and current status of SCAF detection methods. We then propose a clinical approach to help clinicians incorporate AF screening into their practice. In conclusion, we report that SCAF may not be rare, that inserted cardiac monitors have the highest yield of SCAF detection, that clinical concern regarding SCAF is appropriate, but that evidence for therapy mandates is still being collected.

Patterns of oral anticoagulation use with cardioversion in clinical practice

BACKGROUND

Cardioversion is common among patients with atrial fibrillation (AF). We hypothesised that novel oral anticoagulants (NOAC) used in clinical practice resulted in similar rates of stroke compared with vitamin K antagonists (VKA) for cardioversion.

METHODS

Using the Outcomes Registry for Better Informed Treatment of Atrial Fibrillation II, patients with AF who had a cardioversion, follow-up data and an AF diagnosis within 6 months of enrolment were identified retrospectively. Clinical outcomes were compared for patients receiving a NOAC or VKA for 1 year following cardioversion.

RESULTS

Among 13 004 patients with AF, 2260 (17%) underwent cardioversion. 1613 met the inclusion criteria for this analysis. At the time of cardioversion, 283 (17.5%) were receiving a VKA and 1330 (82.5%) a NOAC. A transoesophageal echocardiogram (TOE) was performed in 403 (25%) cardioversions. The incidence of stroke/transient ischaemic attack (TIA) at 30 days was the same for patients having (3.04 per 100 patient-years) or not having (3.04 per 100 patient-years) a TOE (p=0.99). There were no differences in the incidence of death (HR 1.19, 95% CI 0.62 to 2.28, p=0.61), cardiovascular hospitalisation (HR 1.02, 95% CI 0.76 to 1.35, p=0.91), stroke/TIA (HR 1.18, 95% CI 0.30 to 4.74, p=0.81) or bleeding-related hospitalisation (HR 1.29, 95% CI 0.66 to 2.52, p=0.45) at 1 year for patients treated with either a NOAC or VKA.

CONCLUSIONS

Cardioversion was a low-risk procedure for patients treated with NOAC, and there were statistically similar rates of stroke/TIA 30 days after cardioversion as for patients treated with VKA. There were no statically significant differences in death, stroke/TIA or major bleeding at 1 year among patients treated with NOAC compared with VKA after cardioversion.