Efficacy of dofetilide in the treatment of atrial fibrillation-flutter in patients with reduced left ventricular function: a Danish investigations of arrhythmia and mortality on dofetilide (diamond) substudy

Dofetilide for the treatment of premature ventricular complexes and ventricular tachycardia in patients with structural heart disease

BACKGROUND

Dofetilide is a class III antiarrhythmic agent approved for the treatment of atrial fibrillation and atrial flutter. Given the efficacy of other class III agents, it has been used off-label for the treatment of premature ventricular complexes (PVCs) and ventricular tachycardias (VTs).

OBJECTIVE

The purpose of this study was to determine the efficacy and safety of dofetilide for ventricular arrythmias (VAs).

METHODS

In this retrospective cohort study, 81 patients (59 men; age = 60 ± 14 years; LVEF = 0.34 ± 0.16) were admitted for dofetilide initiation to treat PVCs (29), VTs (42) or both (10). A ≥ 80% decrease in PVC burden was defined as a satisfactory response. An ICD was present in 72 patients (89%). Another antiarrhythmic was previously used in 50 patients (62%). Prior catheter ablation had been performed in 33 patients (41%).

RESULTS

During intitiation, dofetilide was discontinued in 12 patients (15%) due to QT prolongation (8) and inefficacy to suppress VAs (4). Among the 32 patients with PVCs who successfully started dofetilide, the mean PVC burden decreased from 20 ± 10% to 8 ± 8% at a median follow-up of 2.6 months (p < .001). PVC burden was reduced by ≥80% in only 11/32 patients (34%). During 7 ± 1 years of follow-up, 41/69 patients (59%) continued to have VAs and received appropriate ICD therapies for monomorphic VTs (35) and polymorphic VT/VF (6) at a median of 8.0 (IQR 2.6-33.2) months. Dofetilide had to be discontinued in 50/69 patients (72%) due to inefficacy or intolerance. The composite outcome of VT/VF recurrence, heart transplantation, or death occurred in 6/12 patients (50%) without dofetilide and 49/69 patients (71%) with dofetilide. The event free survival was similar between patients treated with and without dofetilide (log-rank p = .55).

CONCLUSIONS

Treatment with dofetilide was associated with a decrease in PVCs, however clinically significant suppression occurred in a minority of patients. Dofetilide failed to suppress the occurrence of VTs in a majority of patients.

Atrial Fibrillation and Heart Failure With Reduced Ejection Fraction: New Assessment of an Old Problem

Atrial fibrillation (AF) and heart failure (HF)-specifically, heart failure with reduced ejection fraction (HFrEF)-often coexist, and each contributes to the propagation of the other. This relationship extends from the mechanistic and physiological to clinical syndromes, quality of life, and long-term cardiovascular outcomes. The risk factors for AF and HF overlap and create a critical opportunity to prevent adverse outcomes among patients at greatest risk for either condition. Increasing recognition of the linkages between AF and HF have led to widespread interest in designing diagnostic, predictive, and interventional strategies targeting all aspects of disease, from identifying genetic predisposition to addressing social determinants of health. Advances across this spectrum culminated in updated multisociety guidelines for management of AF, which includes specific consideration of comorbid AF and HF. This review expands on these guidelines by further highlighting relevant clinical trial findings and providing additional context for the evolving recommendations for management in this important and growing population.

External electrical and pharmacological cardioversion for atrial fibrillation, atrial flutter or atrial tachycardias: a network meta-analysis

BACKGROUND

Atrial fibrillation (AF) is the most frequent sustained arrhythmia. Cardioversion is a rhythm control strategy to restore normal/sinus rhythm, and can be achieved through drugs (pharmacological) or a synchronised electric shock (electrical cardioversion).

OBJECTIVES

To assess the efficacy and safety of pharmacological and electrical cardioversion for atrial fibrillation (AF), atrial flutter and atrial tachycardias.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, Conference Proceedings Citation Index-Science (CPCI-S) and three trials registers (ClinicalTrials.gov, WHO ICTRP and ISRCTN) on 14 February 2023.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) at the individual patient level. Patient populations were aged ≥ 18 years with AF of any type and duration, atrial flutter or other sustained related atrial arrhythmias, not occurring as a result of reversible causes.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methodology to collect data and performed a network meta-analysis using the standard frequentist graph-theoretical approach using the netmeta package in R. We used GRADE to assess the quality of the evidence which we presented in our summary of findings with a judgement on certainty. We calculated differences using risk ratios (RR) and 95% confidence intervals (CI) as well as ranking treatments using a P value. We assessed clinical and statistical heterogeneity and split the networks for the primary outcome and acute procedural success, due to concerns about violating the transitivity assumption.

MAIN RESULTS

We included 112 RCTs (139 records), from which we pooled data from 15,968 patients. The average age ranged from 47 to 72 years and the proportion of male patients ranged from 38% to 92%. Seventy-nine trials were considered to be at high risk of bias for at least one domain, 32 had no high risk of bias domains, but had at least one domain classified as uncertain risk, and one study was considered at low risk for all domains. For paroxysmal AF (35 trials), when compared to placebo, anteroapical (AA)/anteroposterior (AP) biphasic truncated exponential waveform (BTE) cardioversion (RR: 2.42; 95% CI 1.65 to 3.56), quinidine (RR: 2.23; 95% CI 1.49 to 3.34), ibutilide (RR: 2.00; 95% CI 1.28 to 3.12), propafenone (RR: 1.98; 95% CI 1.67 to 2.34), amiodarone (RR: 1.69; 95% CI 1.42 to 2.02), sotalol (RR: 1.58; 95% CI 1.08 to 2.31) and procainamide (RR: 1.49; 95% CI 1.13 to 1.97) likely result in a large increase in maintenance of sinus rhythm until hospital discharge or end of study follow-up (certainty of evidence: moderate). The effect size was larger for AA/AP incremental and was progressively smaller for the subsequent interventions. Despite low certainty of evidence, antazoline may result in a large increase (RR: 28.60; 95% CI 1.77 to 461.30) in this outcome. Similarly, low-certainty evidence suggests a large increase in this outcome for flecainide (RR: 2.17; 95% CI 1.68 to 2.79), vernakalant (RR: 2.13; 95% CI 1.52 to 2.99), and magnesium (RR: 1.73; 95% CI 0.79 to 3.79). For persistent AF (26 trials), one network was created for electrical cardioversion and showed that, when compared to AP BTE incremental energy with patches, AP BTE maximum energy with patches (RR 1.35, 95% CI 1.17 to 1.55) likely results in a large increase, and active compression AP BTE incremental energy with patches (RR: 1.14, 95% CI 1.00 to 1.131) likely results in an increase in maintenance of sinus rhythm at hospital discharge or end of study follow-up (certainty of evidence: high). Use of AP BTE incremental with paddles (RR: 1.03, 95% CI 0.98 to 1.09; certainty of evidence: low) may lead to a slight increase, and AP MDS Incremental paddles (RR: 0.95, 95% CI 0.86 to 1.05; certainty of evidence: low) may lead to a slight decrease in efficacy. On the other hand, AP MDS incremental energy using patches (RR: 0.78, 95% CI 0.70 to 0.87), AA RBW incremental energy with patches (RR: 0.76, 95% CI 0.66 to 0.88), AP RBW incremental energy with patches (RR: 0.76, 95% CI 0.68 to 0.86), AA MDS incremental energy with patches (RR: 0.76, 95% CI 0.67 to 0.86) and AA MDS incremental energy with paddles (RR: 0.68, 95% CI 0.53 to 0.83) probably result in a decrease in this outcome when compared to AP BTE incremental energy with patches (certainty of evidence: moderate). The network for pharmacological cardioversion showed that bepridil (RR: 2.29, 95% CI 1.26 to 4.17) and quindine (RR: 1.53, (95% CI 1.01 to 2.32) probably result in a large increase in maintenance of sinus rhythm at hospital discharge or end of study follow-up when compared to amiodarone (certainty of evidence: moderate). Dofetilide (RR: 0.79, 95% CI 0.56 to 1.44), sotalol (RR: 0.89, 95% CI 0.67 to 1.18), propafenone (RR: 0.79, 95% CI 0.50 to 1.25) and pilsicainide (RR: 0.39, 95% CI 0.02 to 7.01) may result in a reduction in this outcome when compared to amiodarone, but the certainty of evidence is low. For atrial flutter (14 trials), a network could be created only for antiarrhythmic drugs. Using placebo as the common comparator, ibutilide (RR: 21.45, 95% CI 4.41 to 104.37), propafenone (RR: 7.15, 95% CI 1.27 to 40.10), dofetilide (RR: 6.43, 95% CI 1.38 to 29.91), and sotalol (RR: 6.39, 95% CI 1.03 to 39.78) probably result in a large increase in the maintenance of sinus rhythm at hospital discharge or end of study follow-up (certainty of evidence: moderate), and procainamide (RR: 4.29, 95% CI 0.63 to 29.03), flecainide (RR 3.57, 95% CI 0.24 to 52.30) and vernakalant (RR: 1.18, 95% CI 0.05 to 27.37) may result in a large increase in maintenance of sinus rhythm at hospital discharge or end of study follow-up (certainty of evidence: low). All tested electrical cardioversion strategies for atrial flutter had very high efficacy (97.9% to 100%). The rate of mortality (14 deaths) and stroke or systemic embolism (3 events) at 30 days was extremely low. Data on quality of life were scarce and of uncertain clinical significance. No information was available regarding heart failure readmissions. Data on duration of hospitalisation was scarce, of low quality, and could not be pooled.

AUTHORS' CONCLUSIONS

Despite the low quality of evidence, this systematic review provides important information on electrical and pharmacological strategies to help patients and physicians deal with AF and atrial flutter. In the assessment of the patient comorbidity profile, antiarrhythmic drug onset of action and side effect profile versus the need for a physician with experience in sedation, or anaesthetics support for electrical cardioversion are key aspects when choosing the cardioversion method.

Prognostic Impact of Sinus Rhythm in Atrial Fibrillation Patients: Separating Rhythm Outcomes From Randomized Strategy Findings From the CABANA Trial

BACKGROUND

Clinically detected atrial fibrillation (AF) is associated with a significant increase in mortality and other adverse cardiovascular events. Since the advent of effective methods for AF rhythm control, investigators have attempted to determine how much these adverse prognostic AF effects could be mitigated by the restoration of sinus rhythm (SR) and whether the method used mattered.

METHODS

The CABANA trial (Catheter Ablation versus Antiarrhythmic Drug Therapy for Atrial Fibrillation) randomized 2204 AF patients to ablation versus drug therapy, of which 1240 patients were monitored in follow-up using the CABANA ECG rhythm monitoring system. To assess the prognostic benefits of SR, we performed a prespecified analysis using Cox survival modeling with heart rhythm as a time-dependent variable and randomized treatment group as a stratification factor.

RESULTS

In the 1240 patient study cohort, 883 (71.2%) had documented AF at some point during their postblanking follow-up. Among the 883 patients, 671 (76.0%) experienced AF within the first year of postblanking follow-up, and 212 (24.0%) experienced their first AF after ≥1 year of postblanking follow-up. The primary CABANA end point (death, disabling stroke, serious bleeding, or cardiac arrest) occurred in 95 (10.8%) of the 883 patients with documented AF and in 29 (8.1%) of the 357 patients with no AF recorded during follow-up. In multivariable time-dependent analysis, the presence of SR (compared with non-SR) was associated with a significantly reduced risk of the primary end point (adjusted hazard ratio, 0.57 [95% CI, 0.38-0.85]; P=0.006; independent of treatment strategy [ablation versus drugs]). Corresponding results for all-cause mortality were adjusted hazard ratio of 0.59 [95% CI, 0.35-1.01]; P=0.053).

CONCLUSIONS

In patients in the CABANA trial with detailed long-term rhythm follow-up, increased time in SR was associated with a clinically consequential decrease in mortality and other adverse prognostic events. The predictive value of SR was independent of the therapeutic approach responsible for reducing the burden of detectable AF.

REGISTRATION

URL: https://clinicaltrials.gov; Unique Identifier: NCT00911508.

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

AIM

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

METHODS

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

STRUCTURE

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

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

AIM

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

METHODS

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

STRUCTURE

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

Left Ventricular Assist Device Emergencies: Diagnosis and Management

Durable left ventricular assist devices (LVADs) are a virtually limitless advanced therapy option for an increasingly growing population of patients with end-stage advanced heart failure. As of 2019, 30% to 40% of all patients diagnosed with heart failure were categorized as New York Heart Association class III or IV. In 2018 more than 3.2 million office visits and 1.4 million emergency department visits carried a primary diagnosis of heart failure. Given the rapid growth of the LVAD population, facility in the diagnosis and management of common perioperative and outpatient LVAD emergencies has become of paramount importance in a variety of clinical settings.

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.

Atrial Fibrillation Occurring During Acute Hospitalization: A Scientific Statement From the American Heart Association

Acute atrial fibrillation is defined as atrial fibrillation detected in the setting of acute care or acute illness; atrial fibrillation may be detected or managed for the first time during acute hospitalization for another condition. Atrial fibrillation after cardiothoracic surgery is a distinct type of acute atrial fibrillation. Acute atrial fibrillation is associated with high risk of long-term atrial fibrillation recurrence, warranting clinical attention during acute hospitalization and over long-term follow-up. A framework of substrates and triggers can be useful for evaluating and managing acute atrial fibrillation. Acute management requires a multipronged approach with interdisciplinary care collaboration, tailoring treatments to the patient's underlying substrate and acute condition. Key components of acute management include identification and treatment of triggers, selection and implementation of rate/rhythm control, and management of anticoagulation. Acute rate or rhythm control strategy should be individualized with consideration of the patient's capacity to tolerate rapid rates or atrioventricular dyssynchrony, and the patient's ability to tolerate the risk of the therapeutic strategy. Given the high risks of atrial fibrillation recurrence in patients with acute atrial fibrillation, clinical follow-up and heart rhythm monitoring are warranted. Long-term management is guided by patient substrate, with implications for intensity of heart rhythm monitoring, anticoagulation, and considerations for rhythm management strategies. Overall management of acute atrial fibrillation addresses substrates and triggers. The 3As of acute management are acute triggers, atrial fibrillation rate/rhythm management, and anticoagulation. The 2As and 2Ms of long-term management include monitoring of heart rhythm and modification of lifestyle and risk factors, in addition to considerations for atrial fibrillation rate/rhythm management and anticoagulation. Several gaps in knowledge related to acute atrial fibrillation exist and warrant future research.

Catheter ablation of atrial fibrillation in heart failure with impaired systolic function: An updated meta-analysis of randomized controlled trials

BACKGROUND

The recent Atrial Fibrillation Management in Congestive Heart Failure With Ablation trial did not reveal any benefit of catheter ablation in patients with atrial fibrillation (AF), advanced heart failure (HF), and severely reduced left ventricular ejection fraction (LVEF). We hypothesized that radiofrequency catheter ablation (RFCA) could improve outcomes in HF patients with AF and impaired left ventricular systolic function (LVEF <50%) as compared with only medical therapy.

METHODS

We searched the literature for randomized clinical trials (RCTs) that compared RFCA to medical therapy in this population.

RESULTS

Compared with the medical therapy group, the RFCA group had significantly less all-cause mortality, HF hospitalization, and AF recurrence rates. The RFCA group had significantly higher peak oxygen consumption (VO 2max ), a better quality of life (Minnesota Living with Heart Failure Questionnaire score), and improved LVEF. However, RFCA for AF failed to reduce all-cause mortality in a specific meta-analysis of four RCTs that enrolled patients with LVEF ≤35%.

CONCLUSION

Compared with medical therapy, RFCA for AF in the setting of HF with impaired systolic function is associated with better clinical (HF hospitalization and all-cause mortality), structural (LVEF improvement), functional (VO 2max ), and quality of life outcomes. However, RFCA for AF failed to reduce all-cause mortality in RCTs that enrolled patients with LVEF ≤35% and thereby indicated the necessary stratification to identify patients who may benefit more from RFCA.

Dofetilide Dose Reductions and Discontinuation in Obese Compared with Nonobese Patients

ABSTRACT

Dofetilide is an antiarrhythmic agent and primarily eliminated renally. Initial dosing is determined by creatinine clearance, calculated by total body weight in the Cockcroft-Gault equation. To date, there is no evidence comparing the dosing of dofetilide in obese versus nonobese patients. We conducted a retrospective review of 217 adults admitted for dofetilide loading to evaluate the tolerability of dofetilide in obese versus nonobese patients. The rate of dose adjustments, including dose reductions and discontinuations, was compared between obese versus nonobese patients in unadjusted and adjusted analyses. Electrocardiograms were collected throughout the loading period, and calculation of QT intervals was performed. Obese patients did not have a significantly higher frequency of dose adjustments compared with nonobese patients (51.5% vs. 44.8%, P = 0.33). Using total body weight to determine starting doses was associated with great odds of dose adjustments compared with ideal body weight (OR 3.69, P = 0.002) and adjusted body weight (OR 4.46, P = 0.02). Men required significantly fewer dose adjustments compared with women on multivariate analysis (OR 0.53, P = 0.03). Obesity is not associated with an increase in the rate of dose adjustments. Total body weight should be used with caution to calculate initial doses of dofetilide in women because it may lead to a higher rate of dose adjustments compared with ideal body weight. Additional studies are needed to confirm the optimal method for selecting starting doses of dofetilide in women, particularly those with a body mass index of ≥30.

Attaining sinus rhythm mediates improved outcome with early rhythm control therapy of atrial fibrillation: the EAST - AFNET 4 trial

Aims

A strategy of systematic, early rhythm control (ERC) improves cardiovascular outcomes in patients with atrial fibrillation (AF). It is not known how this outcome-reducing effect is mediated.

Methods and results

Using the Early treatment of Atrial Fibrillation for Stroke prevention Trial (EAST—AFNET 4) data set, potential mediators of the effect of ERC were identified in the total study population at 12-month follow up and further interrogated by use of a four-way decomposition of the treatment effect in an exponential model predicting future primary outcome events. Fourteen potential mediators of ERC were identified at the 12-month visit. Of these, sinus rhythm at 12 months explained 81% of the treatment effect of ERC compared with usual care during the remainder of follow up (4.1 years). In patients not in sinus rhythm at 12 months, ERC did not reduce future cardiovascular outcomes (hazard ratio 0.94, 95% confidence interval 0.65–1.67). Inclusion of AF recurrence in the model only explained 31% of the treatment effect, and inclusion of systolic blood pressure at 12 months only 10%. There was no difference in outcomes in patients who underwent AF ablation compared with those who did not undergo AF ablation.

Conclusion

The effectiveness of early rhythm control is mediated by the presence of sinus rhythm at 12 months in the EAST-AFNET 4 trial. Clinicians implementing ERC should aim for rapid and sustained restoration of sinus rhythm in patients with recently diagnosed AF and cardiovascular comorbidities.

The 2020 ESC atrial fibrillation guidelines for atrial fibrillation catheter ablation, CABANA, and EAST

Prior randomised clinical trials (RCTs) have suggested that rhythm control offers no benefit compared to accepting AF and instituting rate control in terms of all-cause mortality, CV mortality and sudden death; as a consequence, the ESC AF guidelines have recommended rhythm control for reducing AF-related symptoms and improving quality of life. The Early Treatment of Atrial Fibrillation for Stroke Prevention Trial (EAST-AFNET 4) evaluated whether a more up-to-date rhythm control management strategy provides a benefit in mortality or stroke rates while the Catheter Ablation vs Antiarrhythmic Drug Therapy for Atrial Fibrillation (CABANA) trial evaluated whether catheter ablation was better than drug therapy in preventing a composite of death, disabling stroke, serious bleeding or cardiac arrest. This document critically reviews the recommendations of the 2020 ESC guidelines for the management of AF in the light of these two landmark trials, both of which have underlined the safety of contemporary rhythm control treatment. Considering the safety of the different strategies in modern AF treatment, a personalized approach taking into account the specific patient profile and preferences of the individual patient is needed.

Pharmacologic Rate versus Rhythm Control for Atrial Fibrillation in Heart Failure Patients

Atrial fibrillation (AF) and Heart failure (HF) constitute two frequently coexisting cardiovascular diseases, with a great volume of the scientific research referring to strategies and guidelines associated with the best management of patients suffering from either of the two or both of these entities. The common pathophysiological paths, the adverse outcomes, the hospitalization rates, and the mortality rates that occur from various reports and trials indicate that a targeted therapy to the common background of these cardiovascular conditions may reverse the progression of their interrelating development. Among other optimal treatments concerning the prevalence of both AF and HF, the introduction of rhythm and rate control strategies in the guidelines has underlined the importance of sinus rhythm and heart rate control in the prevention of deleterious complications. The use of these strategies in the clinical practice has led to a debate about the superiority of rhythm versus rate control. The current guidelines as well as the published randomized trials and studies have not proved that rhythm control is more beneficial than the rate control treatments in the terms of survival, all-cause mortality, hospitalization rates, and quality of life. Therefore, the current therapeutic strategy is based on the therapy guidelines and the clinical judgment and experience. The aim of this review was to elucidate the endpoints of pharmacologic randomized clinical trials and the clinical data of each antiarrhythmic or rate-limiting medication, so as to promote their effective, individualized, evidence-based clinical use.

Longitudinal QTc Stability and Impact of Baseline Cardiac Rhythm on Discharge Dose in Dofetilide-treated Patients

BACKGROUND

Dofetilide suppresses AF in a dose-dependent fashion. The protective effect of AF against QT_c prolongation induced torsades de pointe and transient post-cardioversion QT_c prolongation may result in dofetilide under-dosing during initiation. Thus, the optimal timing of cardioversion for AF patients undergoing dofetilide initiation to optimize discharge dose remains unknown as does the longitudinal stability of QT_c .

OBJECTIVE

To evaluate the impact of baseline rhythm on dofetilide dosing during initiation and assess the longitudinal stability of QT_c-all (Bazzett, Fridericia, Framingham, and Hodges) over time.

METHODS

Medical records of patients who underwent pre-planned dofetilide loading at a tertiary care center between January 2016-2019 were reviewed.

RESULTS

A total of 198 patients (66±10 years, 32% female, CHADS₂ -Vasc 3 [2-4]) presented for dofetilide loading in either AF (59%) or SR (41%). Neither presenting rhythm, nor spontaneous conversion to SR impacted discharge dose. The cumulative dofetilide dose prior to cardioversion moderately correlated (r=0.36; p=0.0001) with discharge dose. Post-cardioversion QT_c-all prolongation (p<0.0001) prompted discharge dose reduction (890±224mcg vs 552±199mcg; p<0.0001) in 30% patients. QT_c-all in SR prolonged significantly during loading (p<0.0001). All patients displayed QT_c-all reduction (p<0.0001) from discharge to short-term (46 [34-65] days) that continued at long-term (360 [296-414] days) follow-ups. The extent of QT_c-all reduction over time moderately correlated with discharge QT_c-all (r=0.54-0.65; p<0.0001).

CONCLUSION

Dofetilide initiation prior to cardioversion is equivalent to initiation during SR. Significant QT_c reduction proportional to discharge QT_c is seen over time in all dofetilide-treated patients. QT_c returns to pre-loading baseline during follow-up in patients initiated in SR. This article is protected by copyright. All rights reserved.

Rate versus rhythm control for atrial fibrillation: from AFFIRM to EAST-AFNET 4 - a paradigm shift

The clinical choice between rate or rhythm control therapies has been debated over the years. In 2002, the AFFIRM trial demonstrated that the rhythm-control strategy had no survival advantage over the rate-control strategy. Eighteen years later, EAST-AFNET 4 showed that the rhythm-control approach is better than rate control in reducing adverse cardiovascular outcomes in patients with a recent diagnosis of atrial fibrillation (AF). During the time between AFFIRM and EAST-AFNET 4, rhythm control understanding, specifically ablation, improved, while rate-control strategies remained the same possibly leading to the change in results seen in EAST-AFNET 4. This review seeks to evaluate the rate- and rhythm-control strategies, focusing on the important clinical trials in the past two decades. These trials have shown great advancement in AF management; however, the search for the best approach to controlling AF and minimizing the burden of symptoms is still a work in progress and needs further research.

Effect of Intensive Blood Pressure Lowering on Incident Atrial Fibrillation: A Systematic Review and Meta-Analysis

The effect of intensive versus standard blood pressure (BP) lowering on the risk of atrial fibrillation (AF) is uncertain. Intensive BP lowering is associated with a lower risk of AF among patients with hypertension. We searched PubMed, EMBASE, and CENTRAL (inception to June 5, 2020) for randomized controlled trials evaluating the effect of intensive versus standard (target systolic BP < 140 mmHg) BP lowering on incident AF. We assessed heterogeneity using the I2 statistic then used fixed-effects meta-analysis models to report pooled treatment effects and 95% confidence intervals. We also tested for publication bias by three funnel plot-based methods. The quality of each study was assessed with the Cochrane Risk of Bias tool. We assessed 16 candidate studies for eligibility from 2,312 published articles, but only three randomized clinical trials were eligible for inclusion and included a combined 12,219 participants with hypertension: Cardio-Sis (Studio Italiano Sugli Effetti Cardiovascolari del Controllo della Pressione Arteriosa Sistolica), ACCORD-BP (Action to Control Cardiovascular Risk in Diabetes Blood Pressure trial), and SPRINT (Systolic Blood Pressure Intervention Trial). The target systolic BP in the intensive BP arm was <120 mmHg for participants in SPRINT and ACCORD-BP, but <130 mmHg for participants in Cardio-Sis. Participants randomized to intensive BP lowering had significantly lower risk of incident AF compared with those randomized to standard BP lowering (AF incidence 2.2% vs. 3.0%, respectively; pooled hazard ratio (95% confidence interval): 0.74 (0.59 - 0.93)). Intensive BP lowering is associated with a significantly lower risk of incident AF in patients with hypertension. These findings add to the current evidence supporting the benefits of intensive BP control.

Adjunctive Vein of Marshall Ethanol Infusion During Atrial Fibrillation Ablation: A Systematic Review and Meta-Analysis

Introduction

Catheter ablation (CA) for atrial fibrillation (AF) can be associated with limited efficacy. Due to its autonomic innervation, the vein of Marshall (VOM) is an attractive target during AF ablation. In this meta-analysis, we aimed to evaluate the efficacy and safety of adjunctive ethanol infusion of VOM (VOM-EI) in AF ablation.

Methods

We performed a comprehensive literature search for studies that evaluated the efficacy and safety of VOM-EI in AF ablation compared to AF catheter ablation alone. The primary outcome of interest was late (≥3 months) AF or atrial tachycardia (AT) recurrence. The secondary outcomes included acute mitral isthmus bidirectional block (MIBB) and procedural complications (pericardial effusion, stroke, or atrio-esophageal fistula). Pooled relative risk (RR) and corresponding 95% confidence intervals (CIs) were calculated using the random-effects model.

Results

A total of four studies, including 804 AF patients (68.2% with persistent AF, the mean age of 63.5±9.9 years, 401 patients underwent VOM-EI plus CA vs. 403 patients who had CA alone), were included in the final analysis. VOM-EI group was associated with a lower risk of late AF/AT recurrence (RR:0.63; 95% CI:0.46-0.87; P = 0.005), and increased probability to achieve acute MIBB (RR:1.39; 95% CI:1.08-1.79; P = 0.009) without an increase in procedural complications (RR:1.05; 95% CI:0.57-1.94; P = 0.87).

Conclusions

Our meta-analysis demonstrated that adjunctive VOM-EI strategy is more effective than conventional catheter ablation with similar safety profiles.

Catheter ablation superiority over the pharmacological treatments in atrial fibrillation: a dedicated review

Atrial fibrillation globally affects roughly 33.5 million people, making it the most common heart rhythm disorder. It is a crucial arrhythmia, as it is linked with a variety of negative outcomes such as strokes, heart failure and cardiovascular mortality. Atrial fibrillation can reduce quality of life because of the potential symptoms, for instance exercise intolerance, fatigue, and palpitation. There are different types of treatments aiming to prevent atrial fibrillation and improve quality of life. Currently, the primary treatment for atrial fibrillation is pharmacology therapy, however, these still show limited effectiveness, which has led to research on other alternative strategies. Catheter ablation is considered the second line treatment for atrial fibrillation when the standard treatment has failed. Moreover, catheter ablation continues to show significant results when compared to standard therapy. Hence, this review will argue that catheter ablation can show superiority over current pharmacological treatments in different aspects. It will discuss the most influential aspects of the treatment of atrial fibrillation, which are recurrence and burden of atrial fibrillation, quality of life, atrial fibrillation in the setting of heart failure and mortality and whether catheter ablation can be the first line treatment for patients with atrial fibrillation.

Heart failure and atrial flutter: a systematic review of current knowledge and practices

While the interplay between heart failure (HF) and atrial fibrillation (AF) has been extensively studied, little is known regarding HF and atrial flutter (AFL), which may be managed differently. We reviewed the incidence, prevalence, and predictors of HF in AFL and vice versa, and the outcomes of treatment of AFL in HF. A systematic literature review of PubMed/Medline and EMBASE yielded 65 studies for inclusion and qualitative synthesis. No study described the incidence or prevalence of AFL in unselected patients with HF. Most cohorts enrolled patients with AF/AFL as interchangeable diagnoses, or highly selected patients with tachycardia‐induced cardiomyopathy. The prevalence of HF in AFL ranged from 6% to 56%. However, the phenotype of HF was never defined by left ventricular ejection fraction (LVEF). No studies reported the predictors, phenotype, and prognostic implications of AFL in HF. There was significant variation in treatments studied, including the proportion that underwent ablation. When systolic dysfunction was tachycardia‐mediated, catheter ablation demonstrated LVEF normalization in up to 88%, as well as reduced cardiovascular mortality. In summary, AFL and HF often coexist but are understudied, with no randomized trial data to inform care. Further research is warranted to define the epidemiology and establish optimal management.

Atrial fibrillation in patients with systolic heart failure: pathophysiology mechanisms and management

Heart failure (HF) and atrial fibrillation (AF) demonstrate a constantly increasing prevalence during the 21^st century worldwide, as a result of the aging population and the successful interventions of the clinical practice in the deterioration of adverse cardiovascular outcomes. HF and AF share common risk factors and pathophysiological mechanisms, creating the base of a constant interrelation. AF impairs systolic and diastolic function, resulting in the increasing incidence of HF, whereas the structural and neurohormonal changes in HF with preserved or reduced ejection fraction increase the possibility of the AF development. The temporal relationship of the development of either condition affects the diagnostic algorithms, the prognosis and the ideal therapeutic strategy that leads to euvolaemia, management of non-cardiovascular comorbidities, control of heart rate or restoration of sinus rate, ventricular synchronization, prevention of sudden death, stroke, embolism, or major bleeding and maintenance of a sustainable quality of life. The indicated treatment for the concomitant HF and AF includes rate or/and rhythm control as well as thromboembolism prophylaxis, while the progress in the understanding of their pathophysiological interdependence and the introduction of the genetic profiling, create new paths in the diagnosis, the prognosis and the prevention of these diseases.

Sex-Specific Prevalence, Incidence, and Mortality Associated With Atrial Fibrillation in Heart Failure

OBJECTIVES

This study sought to investigate the mortality associated with atrial fibrillation (AF) in men and women with heart failure (HF) according to the sequence of presentation and rhythm versus rate control.

BACKGROUND

The sex-specific epidemiology of AF in HF is sparse.

METHODS

Using the Danish nationwide registries, all first-time cases of HF were identified and followed for all-cause mortality from 1998 to 2018.

RESULTS

Among 252,988 patients with HF (mean age: 74 ± 13 years, 45% women), AF presented before HF in 54,064 (21%) and on the same day in 27,651 (11%) individuals, similar in women and men. Among patients without AF, the cumulative 10-year incidence of AF was 18.7% (95% confidence interval [CI]: 18.2% to 19.1%) in women and 21.3% (95% CI: 21.0% to 21.6%) in men. On follow-up (mean: 6.2 ± 5.8 years), adjusted mortality rate ratios were 3.33 (95% CI: 3.25 to 3.41) in women and 2.84 (95% CI: 2.78 to 2.90) in men if AF antedated HF, 3.45 (95% CI: 3.37 to 3.56) in women versus 2.76 (95% CI: 2.69 to 2.83) in men when AF and HF were diagnosed concomitantly, and 4.85 (95% CI: 4.73 to 4.97) in women versus 3.89 (95% CI: 3.80 to 3.98) in men when AF developed after HF. Compared with rate control for AF, a rhythm-controlling strategy was associated with lowered mortality in inverse probability-weighted models across all strata and in both sexes (hazard ratios: 0.75 to 0.83), except for women who developed AF after HF onset (hazard ratio: 1.03).

CONCLUSIONS

More than half of all men and women with HF will develop AF during their clinical course, with prognosis associated with AF being worse in women than men. Further studies are needed to understand the underlying mechanisms.

Total thoracoscopic ablation in patients with atrial fibrillation and left ventricular dysfunction

Objective

To evaluate the effectiveness and safety of totally thoracoscopic ablation (TTA) in patients with left ventricular (LV) dysfunction for treatment of atrial fibrillation (AF) refractory to antiarrhythmic drug (AAD) therapy.

Methods

Between January 2012 and December 2018, 31 patients underwent TTA with drug-refractory AF and preoperative left ventricular ejection fraction (LVEF) <50% were included. Of the 31 patients, 8 received additional catheter ablation with an electrophysiologic study within 3 months after TTA. The rhythm outcome was obtained by 12-lead electrocardiography or 24-hour Holter monitoring.

Results

The patient cohort had a mean age of 54.9 ± 9.0 years and consisted of 51.6% with persistent AF (n = 16), 45.2% with long-standing persistent AF (n = 14), and 3.2% with paroxysmal AF (n = 1). No patients died during the follow-up period. Compared with baseline, mean postoperative LVEF at 3 months (interquartile range [IQR], 2-6 months) increased significantly (from 39.7 ± 6.1% to 53.6 ± 9.3%; P < .001). At 25 months (IQR, 14-45 months), LVEF was sustained or further improved (from 39.7 ± 6.1% to 58.1 ± 7.5%; P < .001). The rate of sinus rhythm state was 93.5% (29 of 31), and freedom from arrhythmias off AADs after the final procedure was 61.3% (19 of 31) at a median follow-up of 32 months (IQR, 24-54 months).

Conclusions

TTA is a safe and effective procedure that improves LV function and restores sinus rhythm in AF patients with LV dysfunction.

Catheter Ablation of Atrial Fibrillation in Heart Failure: from Evidences to Guidelines

PURPOSE OF REVIEW

Catheter ablation of atrial fibrillation in heart failure seems to be the way to improve the quality of life, life expectance, and prognosis. In this review, we outline the growing role of this therapy and which patients can benefit from it.

RECENT FINDINGS

While previous studies comparing rate control and rhythm control had not demonstrated the superiority of rhythm control in the prognosis of patients with atrial fibrillation and heart failure, recent findings seem to demonstrate that catheter ablation of atrial fibrillation reduces mortality and hospitalization for heart failure and improves the quality of life, when compared to medical therapy alone. An early rhythm-control strategy in atrial fibrillation may reduce cardiovascular death, stroke, hospitalization for HF, or acute coronary syndrome. Catheter ablation in heart failure is an effective and safe solution to obtain a rhythm control and, therefore, to improve outcomes. A better selection of the patients could help to avoid futile procedures and to identify patients requiring a closer follow-up, to redo procedures, or the addition of antiarrhythmic drugs.

A randomized ablation-based atrial fibrillation rhythm control versus rate control trial in patients with heart failure and high burden atrial fibrillation: The RAFT-AF trial rationale and design

Heart failure (HF) and atrial fibrillation (AF) are 2 cardiac conditions that are increasing in prevalence and incidence. The 2 conditions frequently coexist, and are associated with increased morbidity and mortality. Catheter ablation of AF has been successfully performed in patients with HF, with an improvement in HF and AF, when compared to amiodarone, but further data is required to compare this to rate control. OBJECTIVES: The primary objective is to determine whether AF treated by catheter ablation, with or without antiarrhythmic drugs reduces all-cause mortality and hospitalizations for HF as compared with rate control in patients with HF and a high burden AF. METHODS: This is a multi-center prospective randomized open blinded endpoint (PROBE) study. Patients with NYHA class II-III HF (HF with reduced ejection fraction (<35%) or HF with preserved ejection fraction), and high burden AF are included in the trial. Patients are randomized to either rate control or catheter ablation-based AF rhythm control in a 1:1 ratio. Patients in the rate control group receive optimal HF therapy and rate control measures to achieve a resting hazard ratio (HR) < 80 bpm and 6-minute walk HR < 110 bpm. Patients randomized to catheter ablation-based AF rhythm control group receive optimal HF therapy and one or more aggressive catheter ablation, which include PV antral ablation and LA substrate ablation with or without adjunctive antiarrhythmic drug. The primary outcome is a composite of all-cause mortality and hospitalization for heart failure defined as an admission to a health care facility. The sample size is 600. Enrolment has been completed.

Outpatient initiation of dofetilide: insights from the complexities of atrial fibrillation management during the COVID-19 lockdown

Background

At peak COVID-19 lockdown, patients with symptomatic atrial fibrillation (AF) were faced with an equipoise between a palliative rate-control versus cautious rhythm-control strategy, including hospitalization for initiation of antiarrhythmic drug/s (AADs) and cardiac procedures which was impossible due to hospitalization restrictions.

Objectives

We aimed to evaluate the efficacy and safety of outpatient initiation of dofetilide in patients with AF using cardiac implantable electronic devices (CIEDs) for rhythm and QTc interval monitoring.

Methods

Adult patients with symptomatic AF with prior failure or intolerance to other AADs were enrolled if they were willing to in-office insertion of implantable loop recorders or already implanted with pacemakers or defibrillators capable of remote monitoring. Exclusion criteria were known medical contraindications of dofetilide and unable to provide consent. After making a shared management decision, dofetilide was initiated in a physician office, and rhythm and QTc intervals were monitored by ECGs and CIEDs. Patients were followed to assess the efficacy and safety of the treatment.

Results

The study cohort comprised of 30 patients, age 76 ± 7 years (mean ± standard deviation), 10 female (33%), CHA₂DS₂-VASc score 3.25 ± 1.3, ejection fraction 63.45% ± 8.52, and QTc interval 431.68 ± 45.09 ms. From 22 (73%) patients in AF at presentation, SR was restored in 14 (64%) patients after 4 doses of dofetilide. At 46 ± 59 days of follow-up, maintenance of SR in total 22 (73%) patients without cardiac adverse effects was accomplished.

Conclusion

Effective and safe outpatient initiation of dofetilide during the extenuating circumstance of COVID-19 lockdown was possible in patients with AF who had CIEDs.

Management of tachyarrhythmias in pregnancy - A review

The most common arrhythmias detected during pregnancy include sinus tachycardia, sinus bradycardia, and sinus arrhythmia, identified in 0.1% of pregnancies. Isolated premature atrial or ventricular arrhythmias are observed in 0.03% of pregnancies. Arrhythmias may become more frequent during pregnancy or may manifest for the first time.

Comparison of Outcomes After Ablation of Atrial Fibrillation in Patients With Heart Failure With Preserved Versus Reduced Ejection Fraction

Catheter ablation improves outcomes in atrial fibrillation (AF) patients with heart failure (HF) with reduced ejection fraction (HFrEF). We sought to evaluate the efficacy and safety of catheter ablation of AF in HF patients with a preserved ejection fraction (HFpEF). We performed a retrospective study of all patients who underwent de novo radiofrequency catheter ablation enrolled in the UC San Diego AF Ablation Registry. The primary outcome was recurrence of all atrial arrhythmias on or off antiarrhythmic drugs (AAD). Of 547 total patients, 51 (9.3%) had HFpEF, 40 (7.3%) had HFrEF, and 456 (83.4%) were without HF. There was no difference in recurrence of atrial arrhythmias on or off AAD (Adjusted Hazard Ratio [AHR] 1.92 [95% CI 0.97 to 3.83] for HFpEF vs HFrEF and AHR 0.90 [95% CI 0.59 to 1.39] for HFpEF vs no HF) or off AAD (AHR 1.96 [95% CI 0.99 to 3.90] for HFpEF vs HFrEF and AHR 1.14 [95% CI 0.74 to 1.77] for HFpEF vs no HF). There was also no difference in rates of all-cause hospitalizations (AHR 1.80 [95% CI 0.97 to 3.33] for HFpEF vs HFrEF and AHR 2.05 [95% CI 1.30 to 3.23] for HFpEF vs no HF) or rates of all-cause mortality (AHR 0.53 [95% CI 0.05 to 6.11] for HFpEF vs HFrEF and AHR 2.46 [95% CI 0.34 to 17.92] for HFpEF vs no HF). There were no significant differences in AAD use (p = 0.176) or procedural complications between groups (p = 0.980). In conclusion, there were no significant differences in arrhythmia-free survival between patients with HFpEF and HFrEF that underwent catheter ablation of AF.

Current challenges in sudden cardiac death prevention

Ischemic heart disease and non-ischemic dilated cardiomyopathy are the most common causes of arrhythmic sudden cardiac death (SCD). Implantable cardioverter defibrillator (ICD) therapy is the only strategy that proved to be effective in preventing SCD in high-risk individuals while the role of antiarrhythmic drugs is limited to symptoms relief. Current guidelines recommend selecting candidates to ICD implantation based on etiology, symptoms of heart failure (NYHA class), and severely depressed left ventricular ejection fraction, but these parameters are neither sensitive nor specific. The review addresses the mechanisms of SCD in patients with heart failure of either ischemic or non-ischemic etiology, risk stratification, and strategies for prevention of SCD in the clinical practice (including optimization of heart failure therapy, avoidance of triggering factors, antiarrhythmic drugs, ICD therapy, early resuscitation, and public access defibrillators).

Antiarrhythmic and cardiac electrophysiological effects of SZV-270, a novel compound with combined Class I/B and Class III effects, in rabbits and dogs

Cardiovascular diseases are the leading causes of mortality. Sudden cardiac death is most commonly caused by ventricular fibrillation (VF). Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia and a major cause of stroke and heart failure. Pharmacological management of VF and AF remains suboptimal due to limited efficacy of antiarrhythmic drugs and their ventricular proarrhythmic adverse effects. In this study, the antiarrhythmic and cardiac cellular electrophysiological effects of SZV-270, a novel compound, were investigated in rabbit and canine models. SZV-270 significantly reduced the incidence of VF in rabbits subjected to coronary artery occlusion/reperfusion and reduced the incidence of burst-induced AF in a tachypaced conscious canine model of AF. SZV-270 prolonged the frequency-corrected QT interval, lengthened action potential duration and effective refractory period in ventricular and atrial preparations, blocked I _Kr in isolated cardiomyocytes (Class III effects), and reduced the maximum rate of depolarization (V _max) at cycle lengths smaller than 1000 ms in ventricular preparations (Class I/B effect). Importantly, SZV-270 did not provoke Torsades de Pointes arrhythmia in an anesthetized rabbit proarrhythmia model characterized by impaired repolarization reserve. In conclusion, SZV-270 with its combined Class I/B and III effects can prevent reentry arrhythmias with reduced risk of provoking drug-induced Torsades de Pointes.

Dofetilide Initiation and Implications of Deviation From the Standard Protocol - A Real World Experience

Background

Manufacturer/federal drug administration (FDA) recommends inpatient initiation of dofetilide with the manufacturer providing an initiation algorithm. The outcomes of algorithm deviation have not been reported outside of clinical trials.

Objective

We sought to perform a chart review of all the patients admitted for inpatient initiation of dofetilide to report on the incidence of protocol deviations and their implications.

Methods

We performed a retrospective review of all patients over a 15-month periodwho were initiated on dofetilide for the very first time or reinitiated on dofetilide after a break of three months or more at our institution. We assessed data about patients who were given dofetilide without adherence to the protocol (i.e. protocol deviation).

Results

A total of 189 patients were included in the study with a median age of 66 ± 9 years. Mean baseline QTc interval was 436 ± 32 msec, and 61% (116/189) were in atrial fibrillation (AF) at the time of dofetilide initiation. In 9% (17/189) of patients, the drug was discontinued due to intolerance or inefficacy. Therapy in 49% (93/189) of patients was noted to deviate from manufacturer recommended protocol with deviations more than once in some patients during the same hospitalization. Baseline QTc exceeding 440 msec(>500msec in conduction abnormalities) was the most frequent deviation (25%; 47/189).Ventricular tachyarrhythmia occurred in 4% (7/189) of patients, did not differ between patients, and occurred with and without protocol deviations (5% vs 2%; p = 0.27).

Conclusions

In our retrospective study, there were frequent deviations from the manufacturer-recommended algorithm guidelines for dofetilideinitation, primarily due to prolonged baseline QTc interval. The impact of these protocol deviations on drug discontinuation was uncertain; however, significant adverse events were higher in the deviation group compared to the group that fully adhered to the protocol. Further multicenter studies are warranted to clarify our findings.

Atrial arrhythmias in heart failure with a reduced ejection fraction

PURPOSE OF REVIEW

Atrial arrhythmias are common among individuals with heart failure with a reduced ejection fraction (HFrEF). This review describes management options for these arrhythmias and discusses emerging clinical data supporting catheter ablation.

RECENT FINDINGS

Several recent clinical trials indicate that catheter ablation is superior to pharmacologic therapy for management of symptomatic atrial fibrillation in the setting of HFrEF. Restoration and maintenance of sinus rhythm appears to have the greatest benefit with regard to ejection fraction improvement among individuals with a nonischemic heart failure etiology and minimal left ventricular fibrosis.

SUMMARY

A rhythm control strategy should be strongly considered in patients with HFrEF, especially when the atrial arrhythmia is symptomatic or is present at the time of a heart failure diagnosis. Catheter ablation may be the preferred strategy for maintenance of sinus rhythm in this patient population.

Dronedarone treatment following cardioversion in patients with atrial fibrillation/flutter: A post hoc analysis of the EURIDIS and ADONIS trials

INTRODUCTION

The phase 3 EURIDIS and ADONIS studies evaluated dronedarone for atrial fibrillation (AF)/atrial flutter (AFL) recurrence in patients with nonpermanent AF. Here we assessed whether patient characteristics and/or treatment outcomes in these studies differed based on the need for cardioversion before randomization.

METHODS

Time to adjudicated first AF/AFL recurrence, symptomatic recurrence, cardiovascular hospitalization/death, and AF hospitalization, and safety were assessed by cardioversion status.

RESULTS

Of 1237 patients randomized (2:1 dronedarone:placebo), 364 required baseline cardioversion (dronedarone 243, placebo 121). Patients requiring cardioversion had a greater prevalence of cardiovascular comorbidities and shorter times to first AF/AFL recurrence compared with those not requiring cardioversion. Dronedarone was associated with longer median time to first AF/AFL recurrence vs placebo regardless of cardioversion status (cardioversion: 50 vs 15 days, hazard ratio [HR] 0.76; 95% confidence interval [CI], 0.59-0.97; P = .02; non-cardioversion: 150 vs 77 days, HR 0.76; 95% CI, 0.64-0.90; P < .01). Dronedarone was similarly associated with prolonged median time to symptomatic recurrence vs placebo in the cardioversion (347 vs 87 days, HR 0.65; 95% CI, 0.49-0.87) and non-cardioversion (288 vs 120 days, HR 0.74; 95% CI, 0.62-0.90) populations. Risk of cardiovascular hospitalization/death and first AF hospitalization was lower with dronedarone vs placebo regardless of cardioversion status, but differences were not statistically significant. The safety of dronedarone was similar in both groups.

CONCLUSION

Patients requiring baseline cardioversion represent a distinct population, having more underlying cardiovascular disease and experiencing a shorter time to AF/AFL recurrences. Dronedarone was associated with improved efficacy vs placebo regardless of cardioversion status.

Pharmacological management of atrial fibrillation in patients with heart failure with reduced ejection fraction: review of current knowledge and future directions

Introduction: Both heart failure with reduced ejection fraction (HFrEF) and atrial fibrillation (AF) independently cause significant morbidity and mortality. The two conditions commonly coexist and AF in the setting of HFrEF is associated with worse mortality, hospitalizations, and quality of life compared to HFrEF without AF. Despite the large burden of these conditions, there is no clear optimal management strategy for when they occur together.Areas covered: This review focuses on the pharmacological management of AF in HFrEF. Studies were identified through PubMed search of relevant keywords. The authors review key clinical trials that have influenced management strategies and guidelines. The authors focus on the classes of drugs used to treat AF for both rate and rhythm control strategies including beta-blockers, digoxin, amiodarone, and dofetilide. Additionally, the authors discuss select non-antiarrhythmic medications that affect AF in HFrEF. The authors highlight the strengths and weakness of the data supporting the use of these medications and suggest future directions.Expert opinion: The pharmacological treatment of AF in HFrEF will need further refinement alongside the emerging role of catheter ablation. Novel HF medications and antiarrhythmics offer new tools to prevent the development of AF, as well as for rate and rhythm control strategies.

Current pharmacotherapeutic strategies for cardiac arrhythmias in heart failure

Introduction: Heart failure (HF) affects over 6 million Americans and is the most common cause of hospital readmissions in the United States. Cardiac arrhythmias are common comorbidities seen in patients with HF and are associated with an increase in morbidity and mortality. Pharmacotherapeutic agents along with device and ablation therapies are the mainstays of treatment for cardiac arrhythmias in HF.Areas covered: An extensive literature review of articles and clinical trials on PUBMED on the topic of pharmacotherapy for cardiac arrhythmias in heart failure was conducted. This review article summarizes the above literature to describe the prevalence of the various types of arrhythmias in HF, the recommended pharmacotherapies for the treatment of these arrhythmias in HF and the evidence that supports these recommendations.Expert opinion: Cardiac arrhythmias are common in HF and are the leading cause of death in this patient population. The management of cardiac arrhythmias in HF is challenging. Pharmacotherapy is the primary though increasingly adjunctive therapy for most cardiac arrhythmias. Further, antiarrhythmic drugs must be used with caution in this patient population due to their potential adverse effects.

Antiarrhythmics for maintaining sinus rhythm after cardioversion of atrial fibrillation

BACKGROUND

Atrial fibrillation is the most frequent sustained arrhythmia. Atrial fibrillation often recurs after restoration of normal sinus rhythm. Antiarrhythmic drugs have been widely used to prevent recurrence. This is an update of a review previously published in 2006, 2012 and 2015.

OBJECTIVES

To determine the effects of long-term treatment with antiarrhythmic drugs on death, stroke, drug adverse effects and recurrence of atrial fibrillation in people who had recovered sinus rhythm after having atrial fibrillation.

SEARCH METHODS

We updated the searches of CENTRAL, MEDLINE and Embase in January 2019, and ClinicalTrials.gov and WHO ICTRP in February 2019. We checked the reference lists of retrieved articles, recent reviews and meta-analyses.

SELECTION CRITERIA

Two authors independently selected randomised controlled trials (RCTs) comparing any antiarrhythmic drug with a control (no treatment, placebo, drugs for rate control) or with another antiarrhythmic drug in adults who had atrial fibrillation and in whom sinus rhythm was restored, spontaneously or by any intervention. We excluded postoperative atrial fibrillation.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed quality and extracted data. We pooled studies, if appropriate, using Mantel-Haenszel risk ratios (RR), with 95% confidence intervals (CI). All results were calculated at one year of follow-up or the nearest time point.

MAIN RESULTS

This update included one new study (100 participants) and excluded one previously included study because of double publication. Finally, we included 59 RCTs comprising 20,981 participants studying quinidine, disopyramide, propafenone, flecainide, metoprolol, amiodarone, dofetilide, dronedarone and sotalol. Overall, mean follow-up was 10.2 months.All-cause mortalityHigh-certainty evidence from five RCTs indicated that treatment with sotalol was associated with a higher all-cause mortality rate compared with placebo or no treatment (RR 2.23, 95% CI 1.03 to 4.81; participants = 1882). The number need to treat for an additional harmful outcome (NNTH) for sotalol was 102 participants treated for one year to have one additional death. Low-certainty evidence from six RCTs suggested that risk of mortality may be higher in people taking quinidine (RR 2.01, 95% CI 0.84 to 4.77; participants = 1646). Moderate-certainty evidence showed increased RR for mortality but with very wide CIs for metoprolol (RR 2.02, 95% CI 0.37 to 11.05, 2 RCTs, participants = 562) and amiodarone (RR 1.66, 95% CI 0.55 to 4.99, 2 RCTs, participants = 444), compared with placebo.We found little or no difference in mortality with dofetilide (RR 0.98, 95% CI 0.76 to 1.27; moderate-certainty evidence) or dronedarone (RR 0.86, 95% CI 0.68 to 1.09; high-certainty evidence) compared to placebo/no treatment. There were few data on mortality for disopyramide, flecainide and propafenone, making impossible a reliable estimation for those drugs.Withdrawals due to adverse eventsAll analysed drugs increased withdrawals due to adverse effects compared to placebo or no treatment (quinidine: RR 1.56, 95% CI 0.87 to 2.78; disopyramide: RR 3.68, 95% CI 0.95 to 14.24; propafenone: RR 1.62, 95% CI 1.07 to 2.46; flecainide: RR 15.41, 95% CI 0.91 to 260.19; metoprolol: RR 3.47, 95% CI 1.48 to 8.15; amiodarone: RR 6.70, 95% CI 1.91 to 23.45; dofetilide: RR 1.77, 95% CI 0.75 to 4.18; dronedarone: RR 1.58, 95% CI 1.34 to 1.85; sotalol: RR 1.95, 95% CI 1.23 to 3.11). Certainty of the evidence for this outcome was low for disopyramide, amiodarone, dofetilide and flecainide; moderate to high for the remaining drugs.ProarrhythmiaVirtually all studied antiarrhythmics showed increased proarrhythmic effects (counting both tachyarrhythmias and bradyarrhythmias attributable to treatment) (quinidine: RR 2.05, 95% CI 0.95 to 4.41; disopyramide: no data; flecainide: RR 4.80, 95% CI 1.30 to 17.77; metoprolol: RR 18.14, 95% CI 2.42 to 135.66; amiodarone: RR 2.22, 95% CI 0.71 to 6.96; dofetilide: RR 5.50, 95% CI 1.33 to 22.76; dronedarone: RR 1.95, 95% CI 0.77 to 4.98; sotalol: RR 3.55, 95% CI 2.16 to 5.83); with the exception of propafenone (RR 1.32, 95% CI 0.39 to 4.47) for which the certainty of evidence was very low and we were uncertain about the effect. Certainty of the evidence for this outcome for the other drugs was moderate to high.StrokeEleven studies reported stroke outcomes with quinidine, disopyramide, flecainide, amiodarone, dronedarone and sotalol. High-certainty evidence from two RCTs suggested that dronedarone may be associated with reduced risk of stroke (RR 0.66, 95% CI 0.47 to 0.95; participants = 5872). This result is attributed to one study dominating the meta-analysis and has yet to be reproduced in other studies. There was no apparent effect on stroke rates with the other antiarrhythmics.Recurrence of atrial fibrillationModerate- to high-certainty evidence, with the exception of disopyramide which was low-certainty evidence, showed that all analysed drugs, including metoprolol, reduced recurrence of atrial fibrillation (quinidine: RR 0.83, 95% CI 0.78 to 0.88; disopyramide: RR 0.77, 95% CI 0.59 to 1.01; propafenone: RR 0.67, 95% CI 0.61 to 0.74; flecainide: RR 0.65, 95% CI 0.55 to 0.77; metoprolol: RR 0.83 95% CI 0.68 to 1.02; amiodarone: RR 0.52, 95% CI 0.46 to 0.58; dofetilide: RR 0.72, 95% CI 0.61 to 0.85; dronedarone: RR 0.85, 95% CI 0.80 to 0.91; sotalol: RR 0.83, 95% CI 0.80 to 0.87). Despite this reduction, atrial fibrillation still recurred in 43% to 67% of people treated with antiarrhythmics.

AUTHORS' CONCLUSIONS

There is high-certainty evidence of increased mortality associated with sotalol treatment, and low-certainty evidence suggesting increased mortality with quinidine, when used for maintaining sinus rhythm in people with atrial fibrillation. We found few data on mortality in people taking disopyramide, flecainide and propafenone, so it was not possible to make a reliable estimation of the mortality risk for these drugs. However, we did find moderate-certainty evidence of marked increases in proarrhythmia and adverse effects with flecainide.Overall, there is evidence showing that antiarrhythmic drugs increase adverse events, increase proarrhythmic events and some antiarrhythmics may increase mortality. Conversely, although they reduce recurrences of atrial fibrillation, there is no evidence of any benefit on other clinical outcomes, compared with placebo or no treatment.

Pharmacologic and Nonpharmacologic Management of Atrial Fibrillation

Atrial fibrillation (AF) is the most common arrhythmia and its management may be organized into risk stratification and/or treatment of heart failure, stroke prevention, and symptom control. At the core of symptom control, treatment is tailored to either allow AF continue with controlled heart rates, so-called rate control, versus restoring and maintaining sinus rhythm or rhythm control. Rate control strategies mainly use rate-modulating medications, whereas rhythm control treatment includes therapy aimed at restoring sinus rhythm, including pharmacologic and direct current cardioversion, as well as maintenance of sinus rhythm, including antiarrhythmic medications and ablation therapy.

Calcium/calmodulin-dependent protein kinase II causes atrial structural remodeling associated with atrial fibrillation and heart failure

BACKGROUND

Atrial fibrillation (AF) is sustained by reentrant mechanisms that depend, in part, on atrial structural remodeling. Increased Ca2+/calmodulin-dependent protein kinase II (CaMKII) activity occurs in persistent AF. A general consensus has been that electrophysiological actions of CaMKII must be the contributing factor, but electrical remodeling in AF differs considerably with electrophysiological effects of CaMKII. CaMKII has been associated with structural remodeling in several tissues, but not the cardiac atria. The role of CaMKII in sustaining AF remains undefined.

OBJECTIVE

The purpose of this study was to assess the effects of CaMKII on AF-related structural remodeling.

METHODS

We evaluated the objective in a porcine AF-heart failure model using atrial gene transfer of the CaMKII inhibitory peptide CaMKIIn. We used conventional methods including in vivo electrophysiological study, telemetry, western blot, echocardiography, and histology to quantify rhythm, function, microstructure, and signaling pathways relevant to CaMKII and structural remodeling.

RESULTS

CaMKII levels and activity increased progressively in the early stages of AF-heart failure. Inhibiting CaMKII preserved atrial contractile function and attenuated atrial hypertrophy, fibrosis, and apoptosis but did not affect inflammation or myolysis. These effects were accompanied by significantly decreased phosphorylation of HDAC4, decreased expression of p38MAP-kinase, and alterations in the phosphorylation pattern and relative ratios of JNK isoforms.

CONCLUSION

Our findings suggest that CaMKII mediates signaling pathways related to atrial contractile function and structural remodeling in AF. CaMKII inhibition is potentially a novel therapy for AF. These findings are of importance because no clinically relevant mediators of either atrial contractile function or structural remodeling have yet been identified.

Implication of Preoperative Existence of Atrial Fibrillation on Hemocompatibility-Related Adverse Events During Left Ventricular Assist Device Support

BACKGROUND

Hemocompatibility-related adverse events (HRAEs) are substantial issues in patients with left ventricular assist devices (LVADs). Atrial fibrillation (AF) is associated with worse prognosis in patients with heart failure (HF), but its effect on HRAEs following LVAD implantation remain uncertain.Methods and Results:Data from the Japanese Mechanically Assisted Circulatory Support registry of consecutive patients who received HeartMate II LVADs and were followed for 1 year were retrospectively reviewed. Among 190 patients, 23 had AF and 167 had sinus rhythm. The AF group had comparable baseline characteristics with the non-AF group except for their higher age (53 vs. 42 years, P<0.001). Following LVAD implantation, most cases of AF (73%) persisted. Antiplatelet therapy, anticoagulation therapy, and LVAD speed following LVAD implantation were comparable between groups (P>0.05 for all). The 1-year survival free from HRAEs was comparable between groups (83% vs. 76%, P=0.52). Event rates of the breakdown of HRAEs were comparable between groups except for a relatively higher rate of surgically managed pump thrombosis in the AF group (0.16 vs. 0.04, incidence rate ratio 3.75, 95% confidence interval 0.87-16.1, P=0.075). These trends still remained with propensity score-matched comparison.

CONCLUSIONS

Existence of AF had no effect on the development of HRAEs following LVAD implantation. The need to aggressively treat AF before or after LVAD implantation needs further investigation.

Atria-selective antiarrhythmic drugs in need of alliance partners

Atria-selective antiarrhythmic drugs in need of alliance partners. Guideline-based treatment of atrial fibrillation (AF) comprises prevention of thromboembolism and stroke, as well as antiarrhythmic therapy by drugs, electrical rhythm conversion, ablation and surgical procedures. Conventional antiarrhythmic drugs are burdened with unwanted side effects including a propensity of triggering life-threatening ventricular fibrillation. In order to solve this therapeutic dilemma, 'atria-selective' antiarrhythmic drugs have been developed for the treatment of supraventricular arrhythmias. These drugs are designed to aim at atrial targets, taking advantage of differences in atrial and ventricular ion channel expression and function. However it is not clear, whether such drugs are sufficiently antiarrhythmic or whether they are in need of an alliance partner for clinical efficacy. Atria-selective Na⁺ channel blockers display fast dissociation kinetics and high binding affinity to inactivated channels. Compounds targeting atria-selective K⁺ channels include blockers of ultra rapid delayed rectifier (Kv1.5) or acetylcholine-activated inward rectifier K⁺ channels (Kir3.x), inward rectifying K⁺ channels (Kir2.x), Ca²⁺-activated K⁺ channels of small conductance (SK), weakly rectifying two-pore domain K⁺ channels (K_2P), and transient receptor potential channels (TRP). Despite good antiarrhythmic data from in-vitro and animal model experiments, clinical efficacy of atria-selective antiarrhythmic drugs remains to be demonstrated. In the present review we will briefly summarize the novel compounds and their proposed antiarrhythmic action. In addition, we will discuss the evidence for putative improvement of antiarrhythmic efficacy and potency by addressing multiple pathophysiologically relevant targets as possible alliance partners.

Invasive therapies for patients with concomitant heart failure and atrial fibrillation

Atrial fibrillation (AF) and heart failure (HF) are two clinical entities that can present either separately or concurrently. One entity can lead to the other and vice versa as AF can not only be the underlying etiology of HF but also exacerbate HF due to other cardiac diseases. Besides prevention of cerebral and systemic embolism and elimination of AF-related symptoms, restoration of sinus rhythm for AF patients helps to avoid or reduce HF, irrespective of their underlying heart disease. Successful rates of medical therapy for AF are low in persistent AF, and much lower in long-standing AF, while invasive procedures for AF yield promising results. In this review, the authors evaluate the value of invasive therapies for HF patients complicated with non-valvular AF. We examine this clinical problem by interpreting the relationships between these two entities: the mechanism of tachycardia-induced cardiomyopathy (TIC), past opinions about rhythm control and rate control of AF, discrimination of HF-related AF and AF-induced HF, how to identify the AF patients that could benefit from invasive therapies, and how to select invasive therapies for different AF patients and peri-operative treatments.

Pharmacist-Managed Inpatient Dofetilide Initiation Program: Description and Adherence Rate Post-Root Cause Analysis

The aim of this article is to describe the pharmacist-managed dofetilide initiation program at Maine Medical Center (MMC), assess the adherence rate to 8 core clinical metrics, and review adverse effects before and after a root cause analysis (RCA). Core clinical metrics included pharmacist note entered within 4 hours of dose administration, dose chosen correctly per renal function, QTc measurements obtained and reviewed 2 hours after each dose, appropriate dose adjustment per the most recent QTc measurement, documentation of patient education, and assessment of conduction abnormality, drug-drug interactions, and serum potassium and magnesium concentrations. The primary outcome was adherence rate to all 8 core clinical metrics before and after the RCA. The safety outcome was the total number of adverse events. One hundred patients undergoing elective dofetilide initiation were evaluated: 50 pre-RCA and 50 post-RCA. Adherence rate to all core metrics was 14% in the pre-RCA group and 44% in the post-RCA group (P < .001). Torsade de pointes occurred 3 times in the pre-RCA group and never in the post-RCA group. After the RCA, adherence to MMC's pharmacist-managed inpatient dofetilide initiation program significantly improved.

Atrial Fibrillation Ablation Should Be First-line Therapy in Patients with Heart Failure Reduced Ejection Fraction

Catheter ablation for atrial fibrillation in patients with heart failure with reduced ejection fraction is associated with improvement in patient-centered outcomes, such as mortality, heart failure readmission, and atrial fibrillation recurrence, compared with standard medical therapy with or without device therapy. The evidence is not as robust in patients with atrial fibrillation and heart failure with preserved ejection fraction.