Sinus rhythm is associated with fewer heart failure symptoms: Insights from the AFFIRM trial

Heart failure and atrial fibrillation: Is atrial fibrillation ablation in heart failure pointless or mandatory?

A vast amount of now well-established clinical and epidemiological data indicates a close, interdependent, and symbiotic association between atrial fibrillation (AF) and heart failure (HF). Both AF and HF, when co-exist in a patient, have serious treatment and prognostic implications. Based on the prevailing knowledge of the topic, various societies have issued a number of guidelines regarding the management of patients with AF and HF. Overall, it is the rhythm control strategy that has shown beneficial effect over the rate control strategy with improvement in symptoms of AF and HF. While antiarrhythmic drugs (AADs) and catheter ablation (CA) may be utilized as rhythm control strategy for AF, both AADs and CA have limitations of their own. Furthermore, with the progress made in various pharmacotherapeutic agents in HF, one could question the utility of CA in HF (i.e., whether ablation is mandatory or pointless in patients who have HF). The purpose of this review is to discuss this very point, focusing on the beneficial, neutral, or detrimental outcome of CA based on the category and class of HF.

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.

Age-dependency of EHRA improvement based on quality of life at diagnosis of atrial fibrillation

BACKGROUND

In this study, the relationship between AF-related quality of life (AFEQT) at baseline in AF-patients and the improvement on perceived symptoms and general state of health (EHRA, European Heart Rhythm Association score) at 12 months was assessed across predefined age categories.

METHODS

Between November 2014 and October 2019 patients diagnosed with AF de novo in four hospitals embedded within the Netherlands Heart Network were prospectively followed for 12 months. These AF-patients were categorized into quartiles based on their AFEQT score at diagnosis and EHRA score was measured at diagnosis and 12 months of follow-up. Stratified analyses were performed using age categories (<65 vs. ≥65 years; <75 vs. ≥75 years).

RESULTS

In total, 203/483 (42.0%) AF-patients improved in EHRA score after 12 months of follow-up. AF-patients in the lowest AFEQT quartile were more likely to improve, compared to patients in the highest AFEQT quartile (OR [95%CI]:4.73 [2.63-8.50]). Furthermore, patients ≥65 years and patients <75 years at diagnosis with lower AFEQT scores at baseline were most likely to improve in EHRA score after 12 months, compared to similarly aged patients with higher AFEQT scores at baseline.

CONCLUSION

The present study indicates that AF-patients with a lower quality of life at diagnosis were most likely to improve their EHRA score after 12 months. This effect was most prominent in patients ≥65 years of age and patients <75 years of age, compared to patients >65 and ≥75 years, respectively. Future research should focus on further defining characteristics of these age groups to enable the implementation of age-tailored treatment.

Coronary artery bypass grafting in low ejection fraction: state of the art

PURPOSE OF REVIEW

As the number of patients with reduced ejection fraction secondary to ischemic cardiomyopathy (ICM) increases, coronary artery bypass grafting is being used with increasing frequency. In this review, we summarize the different operative considerations in this vulnerable patient population.

RECENT FINDINGS

Preoperative optimization with mechanical circulatory support devices, especially in the setting of hemodynamic instability, can reduce perioperative morbidity and mortality. The advantage of advanced techniques, such as off-pump CABG and multiple arterial grafting remains unclear. Concomitant procedures, such as ablation for atrial fibrillation remain important considerations that should be tailored to the individual patients risk profile.

SUMMARY

Despite improvements in perioperative care of patients undergoing CABG, patients with a reduced ejection fraction remain at elevated risk of major morbidity and mortality. Preoperative optimization and careful selection of intraoperative techniques can lead to improved outcomes.

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.

Current Management Strategies in Patients with Heart Failure and Atrial Fibrillation: A Review of the Literature

Heart Failure (HF) and Atrial Fibrillation (AF) are common diseases which lead to significant morbidity and mortality. Each disease can be a challenge to treat clinically, especially when they present together. We performed a review of the literature including clinical trials, metanalyses, and guidelines regarding the management of patients with HF and AF. This review describes the pathophysiologic mechanisms behind each disease state, their associated prognosis, and epidemiologic features. Strategies for prevention of stroke in patients with AF, including use of novel oral anticoagulants as well as prevention of the development of AF are discussed. We review the medical and catheter-based therapies for AF and present an original algorithm for the management of AF in patients with HF.

With our powers combined: Does the pooled analysis of existing randomized data regarding treatment of atrial fibrillation in heart failure settle the case for catheter ablation?

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A New Therapeutic Framework for Atrial Fibrillation Drug Development

Atrial fibrillation (AF) is a highly prevalent cardiac arrhythmia and cause of significant morbidity and mortality. Its increasing prevalence in aging societies constitutes a growing challenge to global healthcare systems. Despite substantial unmet needs in AF prevention and treatment, drug developments hitherto have been challenging, and the current pharmaceutical pipeline is nearly empty. In this review, we argue that current drugs for AF are inadequate because of an oversimplified system for patient classification and the development of drugs that do not interdict underlying disease mechanisms. We posit that an improved understanding of AF molecular pathophysiology related to the continuous identification of novel disease-modifying drug targets and an increased appreciation of patient heterogeneity provide a new framework to personalize AF drug development. Together with recent innovations in diagnostics, remote rhythm monitoring, and big data capabilities, we anticipate that adoption of a new framework for patient subsegmentation based on pathophysiological, genetic, and molecular subsets will improve success rates of clinical trials and advance drugs that reduce the individual patient and public health burden of AF.

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.

The Evolving Role of Catheter Ablation in Patients With Heart Failure and AF

AF and heart failure are emerging epidemics worldwide. Several recent trials have provided a growing evidence base for the benefits of catheter ablation in this patient group, which are yet to be universally adopted in clinical practice guidelines. This paper provides a summary of recent developments in this field and provides pragmatic advice to the treating physician regarding the appropriate role of catheter ablation in the overall management of patients with comorbid AF and heart failure.

The effects of rhythm control strategies versus rate control strategies for atrial fibrillation and atrial flutter: A systematic review with meta-analysis and Trial Sequential Analysis

Background

Atrial fibrillation and atrial flutter may be managed by either a rhythm control strategy or a rate control strategy but the evidence on the clinical effects of these two intervention strategies is unclear. Our objective was to assess the beneficial and harmful effects of rhythm control strategies versus rate control strategies for atrial fibrillation and atrial flutter.

Methods

We searched CENTRAL, MEDLINE, Embase, LILACS, Web of Science, BIOSIS, Google Scholar, clinicaltrials.gov, TRIP, EU-CTR, Chi-CTR, and ICTRP for eligible trials comparing any rhythm control strategy with any rate control strategy in patients with atrial fibrillation or atrial flutter published before November 2016. Our primary outcomes were all-cause mortality, serious adverse events, and quality of life. Our secondary outcomes were stroke and ejection fraction. We performed both random-effects and fixed-effect meta-analysis and chose the most conservative result as our primary result. We used Trial Sequential Analysis (TSA) to control for random errors. Statistical heterogeneity was assessed by visual inspection of forest plots and by calculating inconsistency (I²) for traditional meta-analyses and diversity (D²) for TSA. Sensitivity analyses and subgroup analyses were conducted to explore the reasons for substantial statistical heterogeneity. We assessed the risk of publication bias in meta-analyses consisting of 10 trials or more with tests for funnel plot asymmetry. We used GRADE to assess the quality of the body of evidence.

Results

25 randomized clinical trials (n = 9354 participants) were included, all of which were at high risk of bias. Meta-analysis showed that rhythm control strategies versus rate control strategies significantly increased the risk of a serious adverse event (risk ratio (RR), 1.10; 95% confidence interval (CI), 1.02 to 1.18; P = 0.02; I² = 12% (95% CI 0.00 to 0.32); 21 trials), but TSA did not confirm this result (TSA-adjusted CI 0.99 to 1.22). The increased risk of a serious adverse event did not seem to be caused by any single component of the composite outcome. Meta-analysis showed that rhythm control strategies versus rate control strategies were associated with better SF-36 physical component score (mean difference (MD), 6.93 points; 95% CI, 2.25 to 11.61; P = 0.004; I² = 95% (95% CI 0.94 to 0.96); 8 trials) and ejection fraction (MD, 4.20%; 95% CI, 0.54 to 7.87; P = 0.02; I² = 79% (95% CI 0.69 to 0.85); 7 trials), but TSA did not confirm these results. Both meta-analysis and TSA showed no significant differences on all-cause mortality, SF-36 mental component score, Minnesota Living with Heart Failure Questionnaire, and stroke.

Conclusions

Rhythm control strategies compared with rate control strategies seem to significantly increase the risk of a serious adverse event in patients with atrial fibrillation. Based on current evidence, it seems that most patients with atrial fibrillation should be treated with a rate control strategy unless there are specific reasons (e.g., patients with unbearable symptoms due to atrial fibrillation or patients who are hemodynamically unstable due to atrial fibrillation) justifying a rhythm control strategy. More randomized trials at low risk of bias and low risk of random errors are needed.

Trial registration

PROSPERO CRD42016051433

Atrial Fibrillation in Heart Failure: a Therapeutic Challenge of Our Times

Atrial fibrillation (AF) and heart failure (HF) are growing cardiovascular disease epidemics worldwide. There has been an exponential increase in the prevalence of AF and HF correlating with an increased burden of cardiac risk factors and improved survival rates in patients with structural heart disease. AF is associated with adverse prognostic outcomes in HF and is most evident in mild-to-moderate left ventricular (LV) dysfunction where the loss of "atrial kick" translates into poorer quality of life and increased mortality. In the absence of underlying structural heart disease, arrhythmia can independently contribute to the development of cardiomyopathy. Together, these 2 conditions carry a high risk of thromboembolism due to stasis, inflammation and cellular dysfunction. Stroke prevention with oral anticoagulation (OAC) remains a mainstay of treatment. Pharmacologic rate and rhythm control remain limited by variable efficacy, intolerance and adverse reactions. Catheter ablation for AF has resulted in a paradigm shift with evidence indicating superiority over medical therapy. While its therapeutic success is high for paroxysmal AF, it remains suboptimal in persistent AF. A better mechanistic understanding of AF as well as innovations in ablation technology may improve patient outcomes in the future. Refractory cases may benefit from atrioventricular junction ablation and biventricular pacing. The value of risk factor modification, especially with regard to obesity, sleep apnea, hypertension and diabetes, cannot be emphasized enough. Close interdisciplinary collaboration between HF specialists and electrophysiologists is an essential component of good long-term outcomes in this challenging population.

Atrial Fibrillation and Heart Failure - Cause or Effect?

There are emerging epidemics of atrial fibrillation (AF) and heart failure in most developed countries, with a significant health burden. Due to many shared pathophysiological mechanisms, which facilitate the maintenance of each condition, AF and heart failure co-exist in up to 30% of patients. In the circumstance where known structural causes of heart failure (such as myocardial infarction) are absent, patients presenting with both conditions present a unique challenge, particularly as the temporal relationship of each condition can often remain elusive from the clinical history. The question of whether the AF is driving, or significantly contributing to the left ventricular (LV) dysfunction, rather than merely a consequence of heart failure, has become ever more pertinent, especially as catheter ablation now offers a significant advancement over existing rhythm control strategies. This paper will review the inter-related physiological drivers of AF and heart failure before considering the implications from the outcomes of recent clinical trials in patients with AF and heart failure.

Use of antiarrhythmic drug therapy and clinical outcomes in older patients with concomitant atrial fibrillation and coronary artery disease

AIMS

Atrial fibrillation (AF) and coronary artery disease (CAD) are common in older patients. We aimed to describe the use of antiarrhythmic drug (AAD) therapy and clinical outcomes in these patients.

METHODS AND RESULTS

We analysed AAD therapy and outcomes in 1738 older patients (age ≥65) with AF and CAD in the Duke Databank for cardiovascular disease. The primary outcomes were mortality and rehospitalization at 1 and 5 years. Overall, 35% of patients received an AAD at baseline, 43% were female and 85% were white. Prior myocardial infarction (MI, 31%) and heart failure (41%) were common. Amiodarone was the most common AAD (21%), followed by pure Class III agents (sotalol 6.3%, dofetilide 2.2%). Persistence of AAD was low (35% at 1 year). After adjustment, baseline AAD use was not associated with 1-year mortality [adjusted hazard ratio (HR) 1.23, 95% confidence interval (CI) 0.94-1.60] or cardiovascular mortality (adjusted HR 1.27, 95% CI 0.90-1.80). However, AAD use was associated with increased all-cause rehospitalization (adjusted HR 1.20, 95% CI 1.03-1.39) and cardiovascular rehospitalization (adjusted HR 1.20, 95% CI 1.01-1.43) at 1 year. This association did not persist at 5 years; however, these patients were at very high risk of death (55% for those >75 and on AAD) and all-cause rehospitalization (87% for those >75 and on AAD) at 5 years.

CONCLUSIONS

In older patients with AF and CAD, antiarrhythmic therapy was associated with increased rehospitalization at 1 year. Overall, these patients are at high risk of longer-term hospitalization and death. Safer, better-tolerated, and more effective therapies for symptom control in this high-risk population are warranted.

How much atrial fibrillation causes symptoms of heart failure?

INTRODUCTION

Patients with atrial fibrillation (AF) are more symptomatic than patients with sinus rhythm. However, it is unknown what per cent of time spent in AF is associated with symptoms.

METHODS

We used a limited access dataset from the Atrial Fibrillation Follow-up Investigation of Rhythm Management trial. Patients had their current rhythm and New York Heart Association (NYHA) class recorded at baseline and at every follow-up visit. The ratio of number of visits when patients were in AF to the total number of visits was used as a surrogate measure of AF burden. The median number of visits was 12 per patient. We grouped patients labelled as class 0 and I by NYHA as having no symptoms and NYHA II or III as having symptoms. Furthermore, we calculated mortality and the prevalence of symptoms depending on the per cent of visits when they had AF.

RESULTS

Of 4060 patients enrolled in the trial, 74 had no follow-up visits and were excluded; the remaining 3986 patients were analysed. Patients who had no or little AF throughout the study (0-20%) had the lowest prevalence of symptoms. Prevalence of symptoms increased with greater per cent of time spent in AF. Specifically, symptoms became more prevalent when AF burden reached 20-40%. Mortality was similar regardless of proportion of visits when patients were in AF.

CONCLUSIONS

Higher AF burden is associated with higher prevalence of symptoms. The increment became significant when patients were in AF at 20-40% of visits.

Atrial fibrillation in heart failure: an innocent bystander?

Heart failure (HF) and atrial fibrillation (AF) frequently coexist and each complicates the course of the other. The purpose of this review is to analyse the prognostic impact of AF in patients with HF and assess whether there is an advantage in targeting therapies towards the maintenance of sinus rhythm (SR) in this cohort of patients. The presence of AF in patients with HF has been reported to be independently associated with an increase in mortality in many studies and this increased risk is observed in those with both preserved and impaired LV systolic function. The optimal strategy for targeting AF in patients with HF is unclear but recent randomised controlled studies indicate no significant prognostic advantage associated with a rhythm control strategy as compared to a rate control strategy. A number of small studies have investigated the role of both cardiac resynchronization therapy (CRT) and AF catheter ablation for the maintenance of / conversion to SR in patients with HF with initial promising results although larger randomised controlled studies will need to be performed to define the role of these modalities in the treatment of this cohort and whether preliminary benefits observed in these studies translate to improvements in longer term prognosis. Finally, there has been a focus on modifying the arrhythmogenic atrial substrate and neurohormonal milieu by pharmacological means in order to prevent AF although it remains to be seen whether this approach proves to be efficacious with improvements in clinically relevant outcomes.

Predictors and risk of pacemaker implantation after the Cox-maze IV procedure

BACKGROUND

The incidence of and causes for permanent pacemaker implantation (PPM) after surgical arrhythmia procedures remain poorly understood because of the varied lesion patterns and energy sources reported in small series. This study characterized the incidence, indications, and risk factors for PPM after the Cox-maze IV (CMIV) procedure when performed as either a lone or a concomitant procedure.

METHODS

A retrospective analysis of 340 patients undergoing a CMIV as either a lone (n = 112) or a concomitant (n = 228) procedure was conducted. The incidence, indication, and variables associated with PPM implantation within 1 year of the operation were assessed. Follow-up was conducted at 30 days and 1 year and was 90% complete.

RESULTS

The incidence of PPM after a lone CMIV procedure was 5%. Patients with concomitant cardiac operations had a nonsignificant increase in PPM insertion at 30 days (11% vs 5%, p = 0.14) and 1 year (15% vs 6%, p = 0.06) when compared with lone CMIV patients. Of patients who required pacemakers, sinus node dysfunction was present in 79% (35/44) of patients in the entire series and in 88% (8/9) after lone CMIV. After PPM, 84% (37/44) of patients remained paced at last follow-up. Multivariate analysis identified age (odds ratio = 1.10 [1.06-1.14], p < 0.001) as the only variable associated with higher risk of a PPM after any CMIV procedure.

CONCLUSIONS

The risk of PPM implantation after a lone CMIV is 5% and increases with age. The need for a PPM after a CMIV is largely due to SA node dysfunction, which appears unlikely to recover. These data should help physicians counsel patients regarding the perioperative risks associated with the CMIV.

Rate versus rhythm control for management of atrial fibrillation in clinical practice: results from the Outcomes Registry for Better Informed Treatment of Atrial Fibrillation (ORBIT-AF) registry

BACKGROUND

All patients with atrial fibrillation (AF) require optimization of their ventricular rate. Factors leading to use of additional rhythm control in clinical practice have not been thoroughly defined.

METHODS

The ORBIT-AF registry enrolled patients with AF from a broad range of practice settings and collected data on rate versus rhythm control, as indicated by the treating physician. Multivariable logistic regression analysis was performed to identify factors associated with each strategy.

RESULTS

Of 10,061 patients enrolled, 6,859 (68%) were managed with rate only control versus 3,202 (32%) with rhythm control. Patients managed with rate control were significantly older and more likely to have hypertension, heart failure, prior stroke, and gastrointestinal bleeds. They also had fewer AF-related symptoms (41% with no symptoms vs 31% for rhythm control). Systemic anticoagulation was prescribed for 5,448 (79%) rate-control patients versus 2,219 (69%) rhythm-control patients (P < .0001). After multivariable adjustment, patients with higher symptom scores (severe symptoms vs. none, OR 1.62, 95% CI 1.41-1.87) and those referred to electrophysiologists (OR 1.64, 95% CI 1.45-1.85) were more likely to be managed with a rhythm control strategy.

CONCLUSIONS

In this outpatient registry of US clinical practice, the majority of patients with AF were managed with rate control alone. Patients with more symptoms and who were treated by an electrophysiologist were more likely to receive rhythm-control therapies. A significant proportion of AF patients, regardless of treatment strategy, were not treated with anticoagulation for thromboembolism prophylaxis.

Cost considerations in the management of atrial fibrillation - impact of dronedarone

Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia. It is associated with significant morbidity and mortality. At the societal level, AF carries an enormous cost. Strategies aimed at reducing AF morbidity and mortality and containing the associated fiscal burden are of paramount importance. This review will discuss AF treatment strategies and economics, focusing on the impact of dronedarone, a novel antiarrhythmic agent.

Dronedarone: an overview

Atrial fibrillation (AF) is the most common arrhythmia encountered in clinical practice. Until recently, a rhythm control strategy for AF has been limited by drug toxicity and side-effects, and landmark AF trials have shown that such a strategy is not superior to a rate control one. New antiarrhythmic drugs, free of undesired effects, would enhance the rhythm control strategy, with the possibility of sinus rhythm restoration and maintenance. One of the promising drugs recently approved for clinical use is dronedarone. This drug has amiodarone-like antiarrhythmic and electrophysiological properties, despite it having a modified structure and lacking an iodine moiety. Thus, dronedarone lacks amiodarone's organ toxicity (including adverse thyroid and pulmonary effects). The efficacy of dronedarone has been investigated in several clinical trials, proving its effect in the prevention of AF recurrence, rate control in paroxysmal/persistent and permanent AF, reduction of cardiovascular hospitalization or death from any cause, and others. Indirect comparisons with amiodarone, as well as one head-to-head study of the two drugs, indicate that the relative safety of dronedarone may be at a cost of its lower antiarrhythmic efficacy compared with amiodarone.

Novel pharmacological targets for the rhythm control management of atrial fibrillation

Atrial fibrillation (AF) is a growing clinical problem associated with increased morbidity and mortality. Development of safe and effective pharmacological treatments for AF is one of the greatest unmet medical needs facing our society. In spite of significant progress in non-pharmacological AF treatments (largely due to the use of catheter ablation techniques), anti-arrhythmic agents (AADs) remain first line therapy for rhythm control management of AF for most AF patients. When considering efficacy, safety and tolerability, currently available AADs for rhythm control of AF are less than optimal. Ion channel inhibition remains the principal strategy for termination of AF and prevention of its recurrence. Practical clinical experience indicates that multi-ion channel blockers are generally more optimal for rhythm control of AF compared to ion channel-selective blockers. Recent studies suggest that atrial-selective sodium channel block can lead to safe and effective suppression of AF and that concurrent inhibition of potassium ion channels may potentiate this effect. An important limitation of the ion channel block approach for AF treatment is that non-electrical factors (largely structural remodeling) may importantly determine the generation of AF, so that "upstream therapy", aimed at preventing or reversing structural remodeling, may be required for effective rhythm control management. This review focuses on novel pharmacological targets for the rhythm control management of AF.

Anticoagulation management in clinical practice: preventing stroke in patients with atrial fibrillation

Atrial fibrillation (AF) is a major and widely recognized risk factor for cardioembolic stroke. Prophylactic therapy for the prevention of stroke in patients with AF is often achieved through oral anticoagulation, specifically with warfarin, which has been used for this purpose for more than 50 years. Although warfarin therapy is effective when implemented appropriately, it is often underutilized and requires consistent monitoring to ensure both safety in avoiding bleeding and efficacy in preventing strokes. Because the burden of AF-related stroke continues to rise, healthcare professionals need to understand the strengths and limitations of current and emerging treatment options. This review outlines current practices for managing the risk of stroke with anticoagulation in patients with AF, and discusses how new oral anticoagulants may affect clinical practice.

Upstream therapies for management of atrial fibrillation: review of clinical evidence and implications for European Society of Cardiology guidelines. Part I: primary prevention

Atrial fibrillation (AF) is associated with significant morbidity and mortality. It is also a progressive disease secondary to continuous structural remodelling of the atria due to AF itself, to changes associated with ageing, and to deterioration of underlying heart disease. Current management aims at preventing the recurrence of AF and its consequences (secondary prevention) and includes risk assessment and prevention of stroke, ventricular rate control, and rhythm control therapies including antiarrhythmic drugs and catheter or surgical ablation. The concept of primary prevention of AF with interventions targeting the development of substrate and modifying risk factors for AF has emerged as a result of recent experiments that suggested novel targets for mechanism-based therapies. Upstream therapy refers to the use of non-antiarrhythmic drugs that modify the atrial substrate- or target-specific mechanisms of AF to prevent the occurrence or recurrence of the arrhythmia. Such agents include angiotensin-converting enzyme inhibitors (ACEIs), angiotensin receptor blockers (ARBs), statins, n-3 (ω-3) polyunsaturated fatty acids, and possibly corticosteroids. Animal experiments have compellingly demonstrated the protective effect of these agents against electrical and structural atrial remodelling in association with AF. The key targets of upstream therapy are structural changes in the atria, such as fibrosis, hypertrophy, inflammation, and oxidative stress, but direct and indirect effects on atrial ion channels, gap junctions, and calcium handling are also applied. Although there have been no formal randomized controlled studies (RCTs) in the primary prevention setting, retrospective analyses and reports from the studies in which AF was a pre-specified secondary endpoint have shown a sustained reduction in new-onset AF with ACEIs and ARBs in patients with significant underlying heart disease (e.g. left ventricular dysfunction and hypertrophy), and in the incidence of AF after cardiac surgery in patients treated with statins. In the secondary prevention setting, the results with upstream therapies are significantly less encouraging. Although the results of hypothesis-generating small clinical studies or retrospective analyses in selected patient categories have been positive, larger prospective RCTs have yielded controversial, mostly negative, results. Notably, the controversy exists on whether upstream therapy may impact mortality and major non-fatal cardiovascular events in patients with AF. This has been addressed in retrospective analyses and large prospective RCTs, but the results remain inconclusive pending further reports. This review provides a contemporary evidence-based insight into the role of upstream therapies in primary (Part I) and secondary (Part II) prevention of AF.

CARTO-guided vs. NavX-guided pulmonary vein antrum isolation and pulmonary vein antrum isolation performed without 3-D mapping: effect of the 3-D mapping system on procedure duration and fluoroscopy time

PURPOSE

Pulmonary vein antrum isolation (PVAI) guided by intracardiac echocardiography and a roaming circular mapping catheter is an effective treatment modality for atrial fibrillation. Unfortunately, the complexity of this technique leads to long procedure times and high fluoroscopy exposure. This study examined the effect of two different mapping systems on the procedural characteristics and clinical outcomes of PVAI for atrial fibrillation.

METHODS

Referred patients underwent PVAI using a magnetic-based 3-dimensional (3-D) mapping (CARTO® System; group 1), a current-based system (EnSite NavX™; group 2), or fluoroscopy without 3-D mapping (group 3) between February 2004 and November 2009.

RESULTS

Data were analyzed from 71 patients in group 1, 165 patients in group 2, and 197 patients in group 3. Baseline characteristics and measured long-term outcomes did not differ between the groups. Although patients in group 1 were more likely to undergo a concurrent flutter ablation (P = 0.01), they had significantly shorter procedure time, fluoroscopy time, and radiofrequency energy delivery time compared with group 2 and 3 patients. No difference was detected among the groups with respect to recurrence, mean time to recurrence, or number of PVAI procedures.

CONCLUSIONS

Use of a magnetic-based 3-D mapping system, which allows precise spatial localization of the ablation catheter, was associated with significantly lower procedure time, fluoroscopy duration, and radiofrequency energy delivery time during catheter ablation for atrial fibrillation compared with a current-based system and ablation performed without 3-D mapping, although measured short- and long-term clinical outcomes were similar.

The impact of surgical ablation in patients with low ejection fraction, heart failure, and atrial fibrillation

OBJECTIVE

Surgical ablation procedures that use the Cox-Maze procedure lesion set were shown to be very effective. However, many surgeons are reluctant to perform the procedure, especially in high-risk patients such as those with reduced left ventricular (LV) function. This study explored the potential impact of the Cox-Maze III/IV procedure on patients with low ejection fraction (EF<40%) and symptoms of heart failure experiencing atrial fibrillation (AF) who present for cardiac surgery.

METHODS

A prospective study whereby patients with persistent or long-standing persistent AF who had surgical ablation were followed. Echocardiograms (echo) were obtained; patients with preoperative EF <40% were included. Health-related quality of life (HRQL-SF-12) and AF symptom severity were obtained at baseline and follow-up. Rhythm was captured by electrocardiogram (EKG) and 24-h Holter.

RESULTS

In the past 5 years, 482 patients had surgical ablation (424 full Cox-Maze) of whom 44 patients met the inclusion criteria; however, two patients did not have an available follow-up echo, leaving 42 patients for analysis. Mean age was 61.1 ± 12.9 years, and additive European System for Cardiac Operative Risk Evaluation (EuroSCORE) of 7.5 ± 3.1. There was one operative death, there were no strokes or transient ischemic attacks (TIAs) at follow-up, and EF improved from 30 ± 5.0% to 45 ± 13.0% at a mean of 1.5 ± 11.3 months, postoperatively. The return to NSR at time of follow-up echo was 86% (35/40). The physical functioning HRQL scores improved (37.0 ± 12.3 to 46.8 ± 9.1, p = 0.02) at 12 months (population norm = 38.1 ± 9.9) with a significant improvement in symptom severity. Kaplan-Meier event-free survival at 24 months was 87% (confidence interval (CI): 80.4-91.6) (events considered were redo valve replacement, ventricular assist device or death).

CONCLUSIONS

This is a unique study assessing a high-risk group of patients. Surgical ablation in patients with low EF can be performed in a safe and effective way without added operative risk. Given the potential long-term clinical advantages of a successful surgical ablation in patients with low EF and heart failure, we believe that surgical ablation should be considered in such patients when they present to surgery.

Early management of atrial fibrillation: from imaging to drugs to ablation

Atrial fibrillation (AF) is the most common cardiac arrhythmia, and is responsible for the highest number of rhythm-related disorders and cardioembolic strokes worldwide. Early management of this condition will lower the risk of AF-associated morbidity and mortality. Targeted drug therapy has an important role in preventing the progression of AF through modification of the substrate. Discovery of the role of pulmonary veins as a trigger has been an important breakthrough, leading to the development of pulmonary vein ablation-an established curative therapy for drug-resistant AF. Identifying the underlying reasons for the abnormal firing of venous cardiomyocytes and the widespread progressive alterations of atrial tissue found in persistent AF are challenges for the future. Novel imaging techniques may help to determine the right time for intervention, provide specific targets for ablation, and judge the efficacy of treatment. If new developments can successfully address these issues, the knowledge acquired as a result will have a vital role in preclinical and early management of AF.