Routine versus aggressive upstream rhythm control for prevention of early atrial fibrillation in heart failure: background, aims and design of the RACE 3 study

Updates in the management of atrial fibrillation: Emerging therapies and treatment

OBJECTIVE

The most common and clinically important cardiac arrhythmia is atrial fibrillation (AF), which has a large negative impact on public health due to higher fatalities, morbidity, and healthcare expenditure rates. This study aims to provide valuable insights into the effectiveness and outcomes of various treatment approaches and interventions for AF.

STUDY DESIGN

Systematic review.

METHOD

The most pertinent published research (original papers and reviews) in the scientific literature were searched for and critically assessed using the online, internationally indexed databases PubMed, Medline, and Cochrane Reviews. These studies are summarised in this review. Keywords like "Atrial Fibrillation", "emerging therapies", "treatment", "catheter ablation", and "atrial appendage" were used to search the papers. The papers were researched and examined to be relevant to the topic.

CONCLUSION

A lot of work has gone into enhancing AF management to deal with this expanding public health concern. Significant developments and advances in the treatment of AF during the past few years have aided clinicians in giving AF patients better care. The most recent treatments for AF include medication, catheter ablation, cryo-balloon ablation, and left atrial appendage closure.

miR-135 protects against atrial fibrillation by suppressing intracellular calcium-mediated NLRP3 inflammasome activation

Atrial fibrillation (AF), one of the most common types of arrhythmias, is associated with high morbidity and mortality, seriously endangering human health. Inflammation is closely associated with AF development. Activation of the nucleotide-binding domain-like receptor protein 3 (NLRP3) inflammasome in cardiomyocytes has been shown to promote AF progression. Here, we demonstrate the effect of miR-135 on NLRP3 inflammasome and study the cardioprotective role of miR-135 in AF. We observed that overexpression of miR-135 in mice reduced the AF incidence and duration, and inhibited both excessive activation of NLRP3 inflammasome and the increased intracellular calcium release during AF. However, the inhibitory effect of miR-135 on AF was partly abolished in the presence of a specific agonist of the calcium-sensing receptor (CaSR). We showed in the present study that miR-135 has a protective effect against AF by suppressing intracellular calcium-mediated NLRP3 inflammasome activation, suggesting the potential of miR-135 as a therapeutic agent in the treatment of AF.

Long-term outcome of targeted therapy of underlying conditions in patients with early persistent atrial fibrillation and heart failure: data of the RACE 3 trial

AIMS

The Routine vs. Aggressive risk factor driven upstream rhythm Control for prevention of Early persistent atrial fibrillation (AF) in heart failure (HF) (RACE 3) trial demonstrated that targeted therapy of underlying conditions improved sinus rhythm maintenance at 1 year. We now explored the effects of targeted therapy on the additional co-primary endpoints; sinus rhythm maintenance and cardiovascular outcome at 5 years.

METHODS AND RESULTS

Patients with early persistent AF and mild-to-moderate stable HF were randomized to targeted or conventional therapy. Both groups received rhythm control therapy according to guidelines. The targeted group additionally received four therapies: angiotensin-converting enzyme inhibitors and/or angiotensin receptor blockers (ARBs), statins, mineralocorticoid receptor antagonists (MRAs), and cardiac rehabilitation. The presence of sinus rhythm and cardiovascular morbidity and mortality at 5-year follow-up were assessed. Two hundred and sixteen patients consented for long-term follow-up, 107 were randomized to targeted and 109 to conventional therapy. At 5 years, MRAs [76 (74%) vs. 10 (9%) patients, P < 0.001] and statins [81 (79%) vs. 59 (55%), P < 0.001] were used more in the targeted than conventional group. Angiotensin-converting enzyme inhibitors/ARBs and physical activity were not different between groups. Sinus rhythm was present in 49 (46%) targeted vs. 43 (39%) conventional group patients at 5 years (odds ratio 1.297, lower limit of 95% confidence interval 0.756, P = 0.346). Cardiovascular mortality and morbidity occurred in 20 (19%) in the targeted and 15 (14%) conventional group patients, P = 0.353.

CONCLUSION

In patients with early persistent AF and HF superiority of targeted therapy in sinus rhythm maintenance could not be preserved at 5-year follow-up. Cardiovascular outcome was not different between groups.

TRIAL REGISTRATION NUMBER

Clinicaltrials.gov NCT00877643.

Antiarrhythmic drugs in patients with early persistent atrial fibrillation and heart failure: results of the RACE 3 study

AIMS

Maintaining sinus rhythm in patients with persistent atrial fibrillation (AF) is challenging. We explored the efficacy of class I and III antiarrhythmic drugs (AADs) in patients with persistent AF and mild to moderate heart failure (HF).

METHODS AND RESULTS

In the RACE 3 trial, patients with early persistent symptomatic AF and short history of mild to moderate HF with preserved or reduced left ventricular ejection fraction (LVEF) were randomized to targeted or conventional therapy. Both groups received AF and HF guideline-driven treatment. Additionally, the targeted-group received mineralocorticoid receptor antagonists, statins, angiotensin-converting enzyme inhibitors and/or receptor blockers, and cardiac rehabilitation. Class I and III AADs could be instituted in case of symptomatic recurrent AF. Eventually, pulmonary vein isolation could be performed. Primary endpoint was sinus rhythm on 7-day Holter after 1-year. Included were 245 patients, age 65 ± 9 years, 193 (79%) men, AF history was 3 (2-6) months, HF history 2 (1-4) months, 72 (29.4%) had HF with reduced LVEF. After baseline electrical cardioversion (ECV), 190 (77.6%) had AF recurrences; 108 (56.8%) received class I/III AADs; 19 (17.6%) flecainide, 36 (33.3%) sotalol, 3 (2.8%) dronedarone, 50 (46.3%) amiodarone. At 1-year 73 of 108 (68.0%) patients were in sinus rhythm, 44 (40.7%) without new AF recurrences. Maintenance of sinus rhythm was significantly better with amiodarone [n = 29/50 (58%)] compared with flecainide [n = 6/19 (32%)] and sotalol/dronedarone [n = 9/39 (23%)], P = 0.0064. Adverse events occurred in 27 (25.0%) patients, were all minor and reversible.

CONCLUSION

In stable HF patients with early persistent AF, AAD treatment was effective in nearly half of patients, with no serious adverse effects reported.

Effects of a simple cardiac rehabilitation program on improvement of self-reported physical activity in atrial fibrillation - Data from the RACE 3 study

BACKGROUND AND AIM

Physical inactivity is associated with an increased prevalence of atrial fibrillation (AF). We aim to evaluate whether cardiac rehabilitation (CR) motivates patients to become and stay physical active, and whether CR affects sinus rhythm maintenance and quality of life (QoL) in patients with persistent AF and moderate heart failure.

METHODS

In the Routine versus Aggressive risk factor driven upstream rhythm Control for prevention of Early atrial fibrillation in heart failure study patients were randomized to conventional or targeted therapy. Targeted therapy contained next to optimal risk factor management a 3-month CR program, including self-reported physical activity and counseling. Successful physical activity was assessed in the targeted group, defined as activity of moderate intensity ≥ 150 min/week, or ≥ 75 min/week of vigorous intensity. AF was assessed at 1 year on 7-days Holter monitoring, QoL using general health, fatigue and AF symptom questionnaires.

RESULTS

All 119 patients within the targeted group participated in the CR program, 106 (89%) completed it. At baseline 80 (67%) patients were successfully physical active, 39 (33%) were not. NTproBNP was lower in active patients. During 1-year follow-up physical active patients stayed active: 72 (90%) at 12 weeks, 72 (90%) at 1 year. Inactive patients became active: at 12 weeks 25 (64%) patients and 30 (77%) at 1 year. No benefits were seen on sinus rhythm maintenance and QoL for successful physical active patients.

CONCLUSION

In patients with persistent AF and moderate heart failure participation in CR contributes to improve and to maintain physical activity.

Progress in heart failure management in the Netherlands and beyond: long-term commitment to deliver high-quality research and patient care

Heart failure (HF) remains a major global problem. In the Netherlands, 1.5–2.0% of the total population is diagnosed with HF. Over 30,000 HF patients are admitted annually in the Netherlands, and this number is expected to further increase given the ageing population and the chronic nature of HF. Despite ongoing efforts to reduce the burden of HF, morbidity and mortality rates of this disease remain high. However, several new treatment modalities have become available or are expected to become available in the coming years. This review will provide an overview of HF research conducted in the Netherlands (often in an international setting) that may have clinical consequences for diagnosis, treatment and prevention of HF, and will also evaluate outcomes of larger clinical trials that have been conducted in the Netherlands.

Paradigm shifts in pathophysiology and management of atrial fibrillation-a tale of the RACE trials in the Netherlands

In the past 20 years the Netherlands-based RACE trials have investigated important concepts in clinical atrial fibrillation (AF). Their scope ranged from rhythm versus rate control to early or delayed cardioversion and also included early comprehensive management of AF in two trials, one focusing on early 'upstream therapy' and risk factor management and the other on integrated chronic nurse-led care. Studies were mostly triggered by simple clinical observations including futility of electrical cardioversion in persistent AF; many patients with permanent AF tolerating day-after-day 'uncontrolled' resting heart rates of up till 110 beats/min; patients being threatened more by vascular risks than AF itself; and insufficient guideline-based treatments for AF. Also the observation that recent-onset atrial fibrillation generally converts spontaneously, obviating cardioversion, triggered one of the studies. The RACE trials shifted a number of paradigms and by that could change the AF guidelines. The initial 'shock-and-forget' attitude made place for increased attention for anticoagulation, and in turn, broader vascular risks were recognised. In a nutshell, the adage eventually became: 'look beyond the ECG, treat the patient'.

Antiarrhythmic drugs for atrial fibrillation: Imminent impulses are emerging

Rhythm and rate strategies are considered equivalent for the management of atrial fibrillation (AF). Moreover, both strategies are intended for improving symptoms and quality of life. Despite the clinical availability of several antiarrhythmic drugs (AAD) the alternatives for the patient with comorbidities are significantly fewer because of the concern regarding many adverse effects, including proarrhythmias. The impetuous development of AF ablation gave rise to a false impression that AAD are a second line therapy. All these statements reflect, in fact, the weakness of the classical paradigm and classification regarding AAD and the gap between the current knowledge of AF mechanism and determinants and the "classical" AAD non-discriminatory action. A new paradigm in development of effective and safe AAD is based on modern knowledge of vulnerable parameters involved in the genesis and perpetuation of AF. New AAD will target specific triggers of AF and ion currents which are expressed preferentially in fibrillatory atrium. Such targets will include repolarizing currents and channels, as ultrarapid potassium current, two pore potassium current, the acetylcholine-gated potassium current, small-conductance calcium-dependent potassium channels, but, also, molecular targets involved in intracellular calcium kinetics, as Ca2+-calmodulin-dependent protein kinase, ryanodine receptors and non-coding miRNA. New mechanistic discoveries link AF to inflammation and modern anti-cytokine drugs. There is still a long way to win between basic research and clinical practice, but, without any doubt, antiarrhythmic drug therapy will remain and develop as a cornerstone therapy for AF not in conflict, but complementary and alternative to interventional therapy.

Atrial thrombogenesis in atrial fibrillation : Results from atrial fibrillation models and AF-patients

Atrial fibrillation (AF) is the most common cause of thromboembolic complications. The risk of suffering a thromboembolic complication depends on the accompanying cardiac risk factors and the patient's age. For patients who have an increased risk, which is now classified using the CHA2DS2-VASc score, initiation of long-term oral anticoagulation is the first-line treatment. In AF, thrombi arise in the left atrial appendage. The present review will summarize the basic pathophysiology of thrombogenesis in AF and will provide the molecular basis of a process called prothrombotic endocardial remodeling. Despite oral anticoagulation being a central component of therapy, the present results can be used to support concomitant therapy with statins, angiotensin II blockers, etc. to inhibit atrial thromogenesis.

A clinical approach to arrhythmias revisited in 2018 : From ECG over noninvasive and invasive electrophysiology to advanced imaging

Understanding arrhythmias and their treatment is not always easy. The current straightforward approach with catheter ablation and device therapy is an amazing achievement, but does not make management of underlying or other cardiac disease and pharmacological therapy unnecessary. The goal of this paper is to describe how much of the knowledge of the 1980s and early 1990s can and should still be applied in the modern treatment of patients with arrhythmias. After an introduction, this review will focus on paroxysmal atrial fibrillation and a prototype of ‘idiopathic’ ventricular arrhythmias, two diseases with a striking similarity, and will discuss the arrhythmogenesis. The ECG continues to play an important role in diagnostics. Both diseases are associated with a structurally normal heart; the autonomic nervous system plays an important role in triggering arrhythmias at both the atrial and ventricular level.

Risk Factor Management in Atrial Fibrillation

Atrial fibrillation (AF) is the most common clinical arrhythmia and is associated with increased morbidity and mortality. There is growing evidence that numerous cardiovascular diseases and risk factors are associated with incident AF and that lone AF is rare. Beyond oral anticoagulant therapy, rate and rhythm control, therapy targeting risk factors and underlying conditions is an emerging AF management strategy that warrants better implementation in clinical practice. This review describes current evidence regarding the association between known modifiable risk factors and underlying conditions and the development and progression of AF. It discusses evidence for the early management of underlying conditions to improve AF outcomes. It also provides perspective on the implementation of tailored AF management in daily clinical practice.

Effect of Aggressive Blood Pressure Control on the Recurrence of Atrial Fibrillation After Catheter Ablation

Background:

Radiofrequency catheter ablation for atrial fibrillation has become an important therapy for AF; however, recurrence rates remain high. We proposed to determine whether aggressive blood pressure (BP) lowering prevents recurrent atrial fibrillation (AF) after catheter ablation in patients with AF and a high symptom burden.

Methods:

We randomly assigned 184 patients with AF and a BP >130/80 mm Hg to aggressive BP (target <120/80 mm Hg) or standard BP (target <140/90 mm Hg) treatment before their scheduled AF catheter ablation. The primary outcome was symptomatic recurrence of AF/atrial tachycardia/atrial flutter lasting >30 seconds, determined 3 months beyond catheter ablation by a blinded end-point evaluation.

Results:

The median follow-up was 14 months. At 6 months, the mean systolic BP was 123.2±13.2 mm Hg in the aggressive BP treatment group versus 135.4±15.7 mm Hg ( P <0.001) in the standard treatment group. The primary outcome occurred in 106 patients, 54 (61.4%) in the aggressive BP treatment group compared with 52 (61.2%) in the standard treatment group (hazard ratio=0.94; 95% confidence interval, 0.65–1.38; P =0.763). In the prespecified subgroup analysis of the influence of age, patients ≥61 years of age had a lower primary outcome event rate with aggressive BP (hazard ratio=0.58; 95% confidence interval, 0.34–0.97; P =0.013). There was a higher rate of hypotension requiring medication adjustment in the aggressive BP group (26% versus 0%).

Conclusions:

In this study, this duration of aggressive BP treatment did not reduce atrial arrhythmia recurrence after catheter ablation for AF but resulted in more hypotension.

Clinical Trial Registration:

URL: http://www.clinicaltrials.gov . Unique identifier: NCT00438113.

The burden of proof: The current state of atrial fibrillation prevention and treatment trials

Atrial fibrillation (AF) is an age-related arrhythmia of enormous socioeconomic significance. In recent years, our understanding of the basic mechanisms that initiate and perpetuate AF has evolved rapidly, catheter ablation of AF has progressed from concept to reality, and recent studies suggest lifestyle modification may help prevent AF recurrence. Emerging developments in genetics, imaging, and informatics also present new opportunities for personalized care. However, considerable challenges remain. These include a paucity of studies examining AF prevention, modest efficacy of existing antiarrhythmic therapies, diverse ablation technologies and practice, and limited evidence to guide management of high-risk patients with multiple comorbidities. Studies examining the long-term effects of AF catheter ablation on morbidity and mortality outcomes are not yet completed. In many ways, further progress in the field is heavily contingent on the feasibility, capacity, and efficiency of clinical trials to incorporate the rapidly evolving knowledge base and to provide substantive evidence for novel AF therapeutic strategies. This review outlines the current state of AF prevention and treatment trials, including the foreseeable challenges, as discussed by a unique forum of clinical trialists, scientists, and regulatory representatives in a session endorsed by the Heart Rhythm Society at the 12th Global CardioVascular Clinical Trialists Forum in Washington, DC, December 3-5, 2015.

Tailored treatment strategies: a new approach for modern management of atrial fibrillation

Atrial fibrillation (AF) is not benign. Cardiovascular diseases and risk factors differ importantly amongst patients. Careful phenotyping with the aim to start tailored therapy may improve outcome and quality of life. Furthermore, structural remodelling plays an important role in initiation and progression of AF. Therapies that interfere in the remodelling processes are promising because they may modify the atrial substrate. However, success is still limited probably due to variations in the underlying substrate in individual patients. The most favourable effects of lifestyle changes on success of rhythm control have been demonstrated in obese patients with AF. Differences in genotype may also play an important role. Common gene variants have been associated with recurrence of AF after electrical cardioversion, antiarrhythmic drug therapy and catheter ablation. Therefore, both phenotyping and genotyping may become useful for patient selection in the future. Beside the choice of rate or rhythm control, and type of rhythm control, prevention of complications associated with AF may also differ depending on genotype and phenotype. Efficacy of stroke prevention has been well established, but bleeding remains a clinically relevant problem. Risk stratification is still cumbersome, especially in low-risk patients and in those with a high bleeding risk. The decision whether to start anticoagulation (and if so which type of anticoagulant) or, alternatively, to implant an occlusion device of the left atrial appendage may also be improved by genotyping and phenotyping. In this review, we will summarize new insights into the roles of phenotype and genotype in generating more tailored treatment strategies in patients with AF and discuss several patient-tailored treatment options.

Antiarrhythmic therapy of atrial fibrillation: are we treating too late?

Atrial fibrillation (AF) is associated with increased risk for stroke, heart failure and mortality. The causality between worse prognosis and AF is not clear at this time and AF may just be expression of underlying heart disease that by itself is associated with increased morbidity and mortality. AF is characterized by progression from rare paroxysmal episodes to permanent AF. It has been well recognized that maintenance of sinus rhythm with either antiarrhythmic drugs or catheter ablation is easier to achieve if treatment is established early on. In addition to the established indication of symptomatic improvement, the focus of AF management is shifting to earlier intervention to prevent cardiovascular complications. This concept is currently under investigation in the ongoing EAST trial. Early treatment initiation is desirable from a pathophysiologic perspective. This includes consequent prevention and treatment of AF risk factors, efforts for early diagnosis, and stroke prevention according to the CHA2DS2-VASc score. As long as no data support prognostic advantages with "aggressive" rhythm control therapy it remains reserved for symptomatic patients, since both, medication and catheter ablation, convey a significant risk for complications.

Impact of atrial fibrillation on exercise capacity in heart failure with preserved ejection fraction: a RELAX trial ancillary study

BACKGROUND

Atrial fibrillation (AF) is common among patients with heart failure and preserved ejection fraction (HFpEF), but its clinical profile and impact on exercise capacity remain unclear. RELAX (Phosphodiesterase-5 Inhibition to Improve Clinical Status and Exercise Capacity in HFpEF) was a multicenter randomized trial testing the impact of sildenafil on peak VO2 in stable outpatients with chronic HFpEF. We sought to compare clinical features and exercise capacity among patients with HFpEF who were in sinus rhythm (SR) or AF.

METHODS AND RESULTS

RELAX enrolled 216 patients with HFpEF, of whom 79 (37%) were in AF, 124 (57%) in SR, and 13 in other rhythms. Participants underwent baseline cardiopulmonary exercise testing, echocardiogram, biomarker assessment, and rhythm status assessment before randomization. Patients with AF were older than those in SR but had similar symptom severity, comorbidities, and renal function. β-blocker use and chronotropic indices were also similar. Despite comparable left ventricular size and mass, AF was associated with worse systolic (lower EF, stroke volume, and cardiac index) and diastolic (shorter deceleration time and larger left atria) function compared with SR. Pulmonary artery systolic pressure was higher in AF. Patients with AF had higher N-terminal pro-B-type natriuretic peptide, aldosterone, endothelin-1, troponin I, and C-telopeptide for type I collagen levels, suggesting more severe neurohumoral activation, myocyte necrosis, and fibrosis. Peak VO2 was lower in AF, even after adjustment for age, sex, and chronotropic response, and VE/VCO2 was higher.

CONCLUSIONS

AF identifies an HFpEF cohort with more advanced disease and significantly reduced exercise capacity. These data suggest that evaluation of the impact of different rate or rhythm control strategies on exercise tolerance in patients with HFpEF and AF is warranted.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT00763867.

Impact of atrial fibrillation on outcomes in heart failure

The prevalence of atrial fibrillation (AF) and heart failure increases with advancing age. It is estimated that the annual incidence of AF in the general heart failure population is approximately 5%, whereas as many as 40% of patients with advanced heart failure have AF. The goals of therapy in patients with heart failure and AF are symptom control and prevention of arterial thromboembolism. The adverse hemodynamic events of AF may lead to symptom deterioration and reduced exercise capacity. This review addresses the impact of AF on heart failure outcomes as they pertain to prognosis and management.