Increased mortality after dronedarone therapy for severe heart failure

Korean Guidelines for Diagnosis and Management of Chronic Heart Failure

The prevalence of heart failure (HF) is skyrocketing worldwide, and is closely associated with serious morbidity and mortality. In particular, HF is one of the main causes for the hospitalization and mortality in elderly individuals. Korea also has these epidemiological problems, and HF is responsible for huge socioeconomic burden. However, there has been no clinical guideline for HF management in Korea. 
The present guideline provides the first set of practical guidelines for the management of HF in Korea and was developed using the guideline adaptation process while including as many data from Korean studies as possible. The scope of the present guideline includes the definition, diagnosis, and treatment of chronic HF with reduced/preserved ejection fraction of various etiologies.

Cardiac metabolism - A promising therapeutic target for heart failure

Both heart failure with reduced ejection fraction (HFrEF) and with preserved ejection fraction (HFpEF) are associated with high morbidity and mortality. Although many established pharmacological interventions exist for HFrEF, hospitalization and death rates remain high, and for those with HFpEF (approximately half of all heart failure patients), there are no effective therapies. Recently, the role of impaired cardiac energetic status in heart failure has gained increasing recognition with the identification of reduced capacity for both fatty acid and carbohydrate oxidation, impaired function of the electron transport chain, reduced capacity to transfer ATP to the cytosol, and inefficient utilization of the energy produced. These nodes in the genesis of cardiac energetic impairment provide potential therapeutic targets, and there is promising data from recent experimental and early-phase clinical studies evaluating modulators such as carnitine palmitoyltransferase 1 inhibitors, partial fatty acid oxidation inhibitors and mitochondrial-targeted antioxidants. Metabolic modulation may provide significant symptomatic and prognostic benefit for patients suffering from heart failure above and beyond guideline-directed therapy, but further clinical trials are needed.

Guidelines on the management of atrial fibrillation in the emergency department: a critical appraisal

Several guidelines often exist on the same topic, sometimes offering divergent recommendations. For the clinician, it can be difficult to understand the reasons for this divergence and how to select the right recommendations. The aim of this study is to compare different guidelines on the management of atrial fibrillation (AF), and provide practical and affordable advice on its management in the acute setting. A PubMed search was performed in May 2014 to identify the three most recent and cited published guidelines on AF. During the 1-week school of the European School of Internal Medicine, the attending residents were divided in five working groups. The three selected guidelines were compared with five specific questions. The guidelines identified were: the European Society of Cardiology guidelines on AF, the Canadian guidelines on emergency department management of AF, and the American Heart Association guidelines on AF. Twenty-one relevant sub-questions were identified. For five of these, there was no agreement between guidelines; for three, there was partial agreement; for three data were not available (issue not covered by one of the guidelines), while for ten, there was complete agreement. Evidence on the management of AF in the acute setting is largely based on expert opinion rather than clinical trials. While there is broad agreement on the management of the haemodynamically unstable patient and the use of drugs for rate-control strategy, there is less agreement on drug therapy for rhythm control and no agreement on several other topics.

Rationales and choices for the treatment of patients with NYHA class II heart failure

Heart failure (HF) in the United States represents a significant burden for patients and a tremendous strain on the healthcare system. Patients receiving a diagnosis of HF can be placed into 1 of 4 New York Heart Association (NYHA) functional classifications; the greatest proportion of patients are in the NYHA class II category, which is defined as patients having a slight limitation of physical activity but who are comfortable at rest, and for whom ordinary physical activity results in symptoms of HF. Because the severity of NYHA class II HF may be perceived as mild or unalarming by this definition, the urgency to treat this type of HF may be overlooked. However, these patients are optimal candidates for active intervention because their HF is at a critical point on the disease progression continuum when untoward changes can be halted or reversed. This review discusses the physiological consequences of NYHA class II HF with reduced ejection fraction and describes recent clinical trials that have demonstrated a therapeutic benefit for patients in this population. In doing so, we hope to establish that patients with NYHA class II disease merit careful attention and to provide reassurance to the treating community that options are available for these patients.

Reporting of Lost to Follow-Up and Treatment Discontinuation in Pharmacotherapy and Device Trials in Chronic Heart Failure: A Systematic Review

BACKGROUND

Premature treatment discontinuation and loss to follow-up (LTFU) with unknown outcomes leave uncertainty about the true efficacy and safety of a treatment and a lack of confidence in the results of any trial. We reviewed the extent of (and trends over time in) reporting LTFU and treatment discontinuation in large studies in chronic heart failure published since 1990.

METHODS AND RESULTS

Online databases were systematically reviewed to identify randomized controlled clinical trials (RCTs) in chronic heart failure with >400 participants and utilizing all-cause mortality as a component of the primary or secondary end point. Assessments were made of documentation of treatment discontinuation, LTFU, inclusion of and completeness of a Consolidated Standards Of Reporting Trials (CONSORT) diagram, and whether LTFU was differentiated from withdrawal of consent. Sixty-eight trials were identified, with >154 000 participants. Reasons for treatment discontinuation in pharmacotherapy trials were infrequently reported (35%), particularly in a CONSORT diagram (20%). Eighty-three percent of trials reported LTFU, although only 34% of these differentiated LTFU for vital status from withdrawal of consent. Use of a CONSORT diagram increased over time, although reporting of LTFU in the CONSORT diagram remained low overall at 35%.

CONCLUSIONS

Participant flow through RCTs in chronic heart failure has not been uniformly reported, and the use of a complete CONSORT diagram has been low, although it seems to be improving. All study participants should be accounted for within a CONSORT diagram in any RCT to enable the practicing cardiologist to interpret how the results should influence his/her clinical practice.

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Zusammenfassung. Zusammenfassung: Das Vorhofflimmern ist die häufigste supraventrikuläre Rhythmusstörung und entwickelt sich typischerweise bei Patienten mit kardiovaskulären Risikofaktoren oder einer zugrunde liegenden Kardiopathie. Die Bandbreite an Symptomen ist sehr weit und reicht von vollkommen asymptomatischen Patienten bis zur schweren Herzinsuffizienz. Eine korrekte Dokumentation mittels EKG ist unabdingbar für die Diagnose. Für jeden Patienten mit Vorhofflimmern ist eine komplette internistisch-kardiologische Abklärung indiziert. Von zentraler Bedeutung in der Behandlung ist die Thromboembolie-Prophylaxe bei Patienten mit einem erhöhten Risiko für einen Schlaganfall, dies unabhängig von der übrigen Therapie des Vorhofflimmerns. Beim Letzteren ist neben der antiarrhythmischen Therapie die Kontrolle der kardiovaskulären Risikofaktoren sowie die Behandlung einer allfällig vorhandenen Herzinsuffizienz entscheidend. Neben der medikamentösen Rhythmuskontrolle hat sich die Ablationsbehandlung als effektive und sichere alternative Therapieoption etabliert.

Impact of treatment crossovers on clinical outcomes in the rate and rhythm control strategies for atrial fibrillation: Insights from the AFFIRM (Atrial Fibrillation Follow-up Investigation of Rhythm Management) trial

We investigated the rates and reasons for crossover to alternative treatment strategies and its impact on mortality in patients who were enrolled in the Atrial Fibrillation Follow-up Investigation of Rhythm Management (AFFIRM) trial. Over a mean follow-up period of 3.5 years, 842 patients underwent crossover to the alternative treatment arms in AFFIRM. The rate of crossover from rhythm to rate control (594/2,033, 29.2%) was more frequent than the rate of crossover from rate to rhythm control (248/2,027, 12.2%, P < 0.0001). The leading reasons for crossover from rhythm to rate control were failure to achieve or maintain sinus rhythm (272/594, 45.8%) and intolerable adverse effects (122/594, 20.5%). In comparison, the major reasons for crossover from rate to rhythm control were failure to control atrial fibrillation symptoms (159/248, 64.1%) and intolerable adverse effects (9/248, 3.6%). This difference in crossover pattern was statistically significant (P < 0.0001). There was a significantly decreased risk of all-cause mortality (adjusted HR: 0.61, 95% CI: 0.48-0.78, P < 0.0001) and cardiac mortality (adjusted hazard ratio [HR]: 0.61, 95% confidence interval [CI]: 0.43-0.88, P = 0.008) in the subgroup of patients who crossed over from rhythm to rate control as compared to those who continued in rhythm control. There was a nonsignificant trend toward decreased all-cause (adjusted HR: 0.76, 95% CI: 0.53-1.10, P = 0.14) and cardiac mortality (adjusted HR: 0.70, 95% CI: 0.42-1.18, P = 0.18) in patients who crossed over from rate to rhythm control as compared to those who continued rate control.

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.

Pharmacological update: New drugs in cardiac practice: A critical appraisal

Cardiac practice involves the application of a range of pharmacological therapies. An anesthesiologist needs to keep pace with the rampant drug developments in the field of cardiovascular medicine for appropriate management in both perioperative and intensive care set-up, to strengthen his/her role as a perioperative physician in practice. The article reviews the changing trends and the future perspectives in major classes of cardiovascular medicine.

Antiarrhythmic Drug Therapy for Atrial Fibrillation

Atrial fibrillation (AF) is the most frequently encountered arrhythmia. Prevalence increases with advancing age and so as its associated comorbidities, like heart failure. Choice of pharmacologic therapy depends on whether the goal of treatment is maintaining sinus rhythm or tolerating AF with adequate control of ventricular rates. Antiarrhythmic therapy and conversion of AF into sinus rhythm comes with the side effect profile, and we should select best antiarrhythmic therapy, individualized to the patient. New antiarrhythmic drugs are being tested in clinical trials. Drugs that target remodeling and inflammation are being tested for their use as prevention of AF or as upstream therapy.

Potassium currents in the heart: functional roles in repolarization, arrhythmia and therapeutics

This is the second of the two White Papers from the fourth UC Davis Cardiovascular Symposium Systems Approach to Understanding Cardiac Excitation-Contraction Coupling and Arrhythmias (3-4 March 2016), a biennial event that brings together leading experts in different fields of cardiovascular research. The theme of the 2016 symposium was 'K⁺ channels and regulation', and the objectives of the conference were severalfold: (1) to identify current knowledge gaps; (2) to understand what may go wrong in the diseased heart and why; (3) to identify possible novel therapeutic targets; and (4) to further the development of systems biology approaches to decipher the molecular mechanisms and treatment of cardiac arrhythmias. The sessions of the Symposium focusing on the functional roles of the cardiac K⁺ channel in health and disease, as well as K⁺ channels as therapeutic targets, were contributed by Ye Chen-Izu, Gideon Koren, James Weiss, David Paterson, David Christini, Dobromir Dobrev, Jordi Heijman, Thomas O'Hara, Crystal Ripplinger, Zhilin Qu, Jamie Vandenberg, Colleen Clancy, Isabelle Deschenes, Leighton Izu, Tamas Banyasz, Andras Varro, Heike Wulff, Eleonora Grandi, Michael Sanguinetti, Donald Bers, Jeanne Nerbonne and Nipavan Chiamvimonvat as speakers and panel discussants. This article summarizes state-of-the-art knowledge and controversies on the functional roles of cardiac K⁺ channels in normal and diseased heart. We endeavour to integrate current knowledge at multiple scales, from the single cell to the whole organ levels, and from both experimental and computational studies.

The State of the Art: Atrial Fibrillation Epidemiology, Prevention, and Treatment

As the most common sustained arrhythmia in adults, atrial fibrillation (AF) is an established and growing epidemic. To provide optimal patient care, it is important for clinicians to be aware of AF's epidemiological trends, methods of risk reduction, and the various available treatment modalities. Our understanding of AF's pathophysiology has advanced, and with this new understanding has come advancements in prevention strategies as well as pharmacological and nonpharmacological treatment options. Following PubMed and MEDLINE searches for AF risk factors, epidemiology, and therapies, we reviewed relevant articles (and bibliographies of those articles) published from 2000 to 2016. This "state-of-the-art" review provides a comprehensive update on the understanding of AF in the world today, contemporary therapeutic options, and directions of ongoing and future study.

2016 Guidelines of the Taiwan Heart Rhythm Society and the Taiwan Society of Cardiology for the management of atrial fibrillation

Atrial fibrillation (AF) is the most common sustained arrhythmia. Both the incidence and prevalence of AF are increasing, and the burden of AF is becoming huge. Many innovative advances have emerged in the past decade for the diagnosis and management of AF, including a new scoring system for the prediction of stroke and bleeding events, the introduction of non-vitamin K antagonist oral anticoagulants and their special benefits in Asians, new rhythm- and rate-control concepts, optimal endpoints of rate control, upstream therapy, life-style modification to prevent AF recurrence, and new ablation techniques. The Taiwan Heart Rhythm Society and the Taiwan Society of Cardiology aimed to update the information and have appointed a jointed writing committee for new AF guidelines. The writing committee members comprehensively reviewed and summarized the literature, and completed the 2016 Guidelines of the Taiwan Heart Rhythm Society and the Taiwan Society of Cardiology for the Management of Atrial Fibrillation. This guideline presents the details of the updated recommendations, along with their background and rationale, focusing on data unique for Asians. The guidelines are not mandatory, and members of the writing committee fully realize that treatment of AF should be individualized. The physician's decision remains most important in AF management.

Atrial Electrophysiological Remodeling and Fibrillation in Heart Failure

Heart failure (HF) causes complex, chronic changes in atrial structure and function, which can cause substantial electrophysiological remodeling and predispose the individual to atrial fibrillation (AF). Pharmacological treatments for preventing AF in patients with HF are limited. Improved understanding of the atrial electrical and ionic/molecular mechanisms that promote AF in these patients could lead to the identification of novel therapeutic targets. Animal models of HF have identified numerous changes in atrial ion currents, intracellular calcium handling, action potential waveform and conduction, as well as expression and signaling of associated proteins. These studies have shown that the pattern of electrophysiological remodeling likely depends on the duration of HF, the underlying cardiac pathology, and the species studied. In atrial myocytes and tissues obtained from patients with HF or left ventricular systolic dysfunction, the data on changes in ion currents and action potentials are largely equivocal, probably owing mainly to difficulties in controlling for the confounding influences of multiple variables, such as patient’s age, sex, disease history, and drug treatments, as well as the technical challenges in obtaining such data. In this review, we provide a summary and comparison of the main animal and human electrophysiological studies to date, with the aim of highlighting the consistencies in some of the remodeling patterns, as well as identifying areas of contention and gaps in the knowledge, which warrant further investigation.

Atrial fibrillation in heart failure with preserved ejection fraction: Insights into mechanisms and therapeutics

Atrial fibrillation (AF) and heart failure (HF) often coexist, and the outcomes of patients who have both AF and HF are considerably worse than those with either condition in isolation. Heart failure with preserved ejection fraction (HFpEF) is a heterogeneous clinical entity and accounts for approximately one-half of current HF. At least one-third of patients with HFpEF are burdened by comorbid AF. The current understanding of the relationship between AF and HFpEF is limited, but the clinical implications are potentially important. In this review, we explore 1) the pathogenesis that drives AF and HFpEF to coexist; 2) pharmacologic therapies that may attenuate the impact of AF in HFpEF; and 3) future directions in the management of this complex syndrome.

Antiarrhythmic Drug Therapy to Avoid Implantable Cardioverter Defibrillator Shocks

Implantable cardioverter defibrillators (ICDs) are effective in the prevention of arrhythmic sudden cardiac death. Many patients receiving an ICD are affected by heart failure and are at risk of ventricular arrhythmias, which may lead to appropriate shocks. On the other hand, in this population the incidence of atrial fibrillation, giving rise to inappropriate ICD shocks, is high. Accordingly, ICD discharges occur frequently and many patients with an ICD will need concomitant antiarrhythmic drug therapy to avoid or reduce the frequency of shocks. Therapeutic agents such as β-blockers, class I or class III antiarrhythmic drugs effectively suppress arrhythmias, but may have side-effects. Some drugs could eventually influence the function of ICDs by altering defibrillation or pacing threshold. Few prospective randomised trials are available, but current data suggest that amiodarone is most effective for prevention of appropriate or inappropriate ICD shocks. This review article summarises current knowledge regarding the antiarrhythmic management of patients with ICDs.

Rhythm control in atrial fibrillation

Many patients with atrial fibrillation have substantial symptoms despite ventricular rate control and require restoration of sinus rhythm to improve their quality of life. Acute restoration (ie, cardioversion) and maintenance of sinus rhythm in patients with atrial fibrillation are referred to as rhythm control. The decision to pursue rhythm control is based on symptoms, the type of atrial fibrillation (paroxysmal, persistent, or long-standing persistent), patient comorbidities, general health status, and anticoagulation status. Many patients have recurrent atrial fibrillation and require further intervention to maintain long term sinus rhythm. Antiarrhythmic drug therapy is generally recommended as a first-line therapy and drug selection is on the basis of the presence or absence of structural heart disease or heart failure, electrocardiographical variables, renal function, and other comorbidities. In patients who continue to have recurrent atrial fibrillation despite medical therapy, catheter ablation has been shown to substantially reduce recurrent atrial fibrillation, decrease symptoms, and improve quality of life, although recurrence is common despite continued advancement in ablation techniques.

Is Heart Rate a Norepiphenomenon in Heart Failure?

There has been an increased focus on heart rate as a target in the management of cardiovascular disease and more specifically in heart failure with preserved ejection fraction in recent years with several studies showing the benefit of a lower resting heart rate on outcomes. This review paper examines the pathophysiology behind the benefits of lowering heart rate in heart failure and also the evidence for and against the pharmacological agents available to achieve this.

The use of dronedarone for recurrent ventricular tachycardia: a case report and review of the literature

Background

Dronedarone is a benzofuran derivative resembling amiodarone that was intended to reduce the iodine-associated tissue deposition and organ toxicity seen with the latter. The utility of dronedarone for patients with ventricular arrhythmias has not been thoroughly evaluated. We present our experience with its use to treat refractory ventricular tachycardia storm and review the literature.

Case presentation

An 85 year-old gentleman with multiple medical comorbidities including ischemic and non-ischemic cardiomyopathy with severe biventricular systolic dysfunction presented with ventricular tachycardia storm. Therapeutic options were limited given his frail medical status, failures of sotalol, mexilitine, and catheter ablation therapies along with drug-toxicities from amiodarone. Dronedarone was thus considered as off-label use following informed consent. The patient unfortunately developed fatal multisystem organ failure including acute severe hepatotoxicity from dronedarone.

Conclusion

Novel therapies for drug-refractory ventricular arrhythmias are long overdue given the limitations of available pharmacologic and non-pharmacologic options. Off-label use of antiarrhythmic agents such as dronedarone is considered a treatment of last-resort in patients who otherwise have no therapeutic options. Given the paucity of reported cases regarding dronedarone for the treatment of ventricular tachyarrhythmias, no conclusive recommendations can be made at this time aside from words of caution. Despite the potential ventricular antiarrhythmic effects of dronedarone, careful patient evaluation is required to identify those at greatest risk of drug-related adverse events particularly in those patients with significant comorbidities such as advanced hepatic, renal, and cardiovascular disease.

Drugs That May Cause or Exacerbate Heart Failure: A Scientific Statement From the American Heart Association

Heart failure is a common, costly, and debilitating syndrome that is associated with a highly complex drug regimen, a large number of comorbidities, and a large and often disparate number of healthcare providers. All of these factors conspire to increase the risk of heart failure exacerbation by direct myocardial toxicity, drug-drug interactions, or both. This scientific statement is designed to serve as a comprehensive and accessible source of drugs that may cause or exacerbate heart failure to assist healthcare providers in improving the quality of care for these patients.

Antiarrhythmic Drug Therapy for Rhythm Control in Atrial Fibrillation

Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia and affects over 33 million people worldwide. AF is associated with stroke and systemic thromboembolism, unpleasant symptoms and reduced quality of life, heart failure, and increased mortality, and treatment of AF and its complications are associated with significant cost. Antiarrhythmic drugs (AADs) can suppress AF, allowing long-term maintenance of sinus rhythm, and have the potential to relieve symptoms and reverse or prevent adverse effects associated with AF. However, large randomized controlled studies evaluating use of AADs have not demonstrated a clear benefit to maintaining sinus rhythm, and AADs often have significant limitations, including a modest rate of overall success at maintaining sinus rhythm, frequent side effects, and potentially life-threatening toxicities. Although some of the currently available AADs have been available for almost 100 years, better tolerated and more efficacious AADs have recently been developed both for long-term maintenance of sinus rhythm and for chemical cardioversion of AF to sinus rhythm. Advances in automated AF detection with cardiac implantable electronic devices have suggested that AADs might be useful for suppressing AF to allow safe discontinuation of anticoagulation in select patients who are in sinus rhythm for prolonged periods of time. AADs may also have synergistic effects with catheter ablation of AF. This review summarizes the pharmacology and clinical use of currently available AADs for treatment of AF and discusses novel AADs and future directions for rhythm control in AF.

Update on atrial fibrillation

Atrial fibrillation (AF) is the most common arrhythmia with a substantial effect on individual morbidity and mortality as well as healthcare expenditure. The management of AF is complex and fraught with many uncertain and contentious issues. We have seen substantial progress in AF management in the last two decades including better understanding of the epidemiology, genomics, monitoring, drug and non-pharmacological treatment of the arrhythmia, its complications and stroke risk reduction. In this review, we present a comprehensive discussion on AF with emphasis on most recent updates.

Faster drug approval: challenges for safety

INTRODUCTION

More rapid drug premarketing procedures pose a challenge for regulatory agencies in terms of innovation and improving real-world safety and effectiveness Areas covered: This review considers the blockbuster drugs used over the previous fifteen years with adverse reactions after marketing, the elements and time span of risk identification and the measures implemented or considered, based on the existing literature and reports from the agencies Expert opinion: Risk prediction is founded on several factors: randomization, sample size, a well-established endpoint for safety, use of a comparator rather than placebo and a longer Phase-III period, in which a serious illness may be identified by early signs of alteration in the primary parenchyma with the latest biochemical, instrumental and imaging techniques. In comparative non-inferiority evaluations, increased safety should be preferred, with the exception of drugs that may be useful in serious or life-threatening diseases for which there are few or no effective existing therapies. A period of restricted use may be required to test and dispense new drugs, as well as to implement specific methods for the early detection of adverse events. It is important not to regard a new medicine axiomatically as the best treatment before it comes into wide use.

Falling Cardiovascular Mortality in Heart Failure With Reduced Ejection Fraction and Implications for Clinical Trials

OBJECTIVES

This study examined the trends in the relative contributions of cardiovascular and noncardiovascular mortality to total mortality according to use of beta-blockers in clinical trials of patients with heart failure with reduced ejection fraction (HF-REF).

BACKGROUND

With the increasingly widespread use of disease-modifying therapies, particularly beta-blockers, in HF-REF, the proportion of patients dying from cardiovascular causes is likely to be decreasing.

METHODS

In a systematic review, 2 investigators independently searched online databases to identify clinical trials including >400 patients with chronic heart failure published between 1986 and 2014 and that adjudicated cause of death. Trials were divided into 3 groups on the basis of the proportion of patients treated with a beta-blocker (<33% [low], 33% to 66% [medium], and >66% [high]). Percentages of total deaths adjudicated as cardiovascular or noncardiovascular were calculated by weighted means and weighted standard deviations. Weighted Student t tests were used to compare results between groups.

RESULTS

Sixty-six trials met the inclusion criteria with a total of 136,182 patients and 32,140 deaths. There was a sequential increase in the percentage of noncardiovascular deaths with increasing beta-blocker use from 11.4% of all deaths in trials with low beta-blocker use to 19.1% in those with high beta-blocker use (p < 0.001).

CONCLUSIONS

In trials of patients with HF-REF, the proportion of deaths adjudicated as cardiovascular has decreased. Cardiovascular mortality, and not all-cause mortality, should be used as an endpoint for trials of new treatments for HF-REF.

[Arrhythmia in adults with congenital heart disease : Acute and long-term management]

During the last few decades, the management of cardiac arrhythmias in adult patients with congenital heart disease (CHD) has undergone a significant change from a conservative, mainly pharmacological approach, to interventional techniques such as catheter ablation or device implantation (pacemakers, implantable cardioverter defibrillators [ICD]). The long-term efficacy of these strategies is as dependent on the hemodynamic status of the patient and the type of arrhythmia as it is on the underlying heart defect and any preceding surgery. Pharmacological agents and electrical cardioversion are at the forefront of treatment for tachyarrhythmias. Individualized thromboprophylaxis plays an important role in acute and in long-term management. Catheter ablation seems to show a more favorable outcome compared with a pharmacological approach in the long-term management of supraventricular tachyarrhythmias. Surgical procedures, including arrhythmia surgery (such as the Fontan conversion operation), may improve the arrhythmia. In symptomatic patients with bradyarrhythmias, such as sinus node dysfunction, pacemaker implantation is usually indicated. In the management of ventricular arrhythmias catheter ablation is also increasingly used. This is dominated by the individual risk stratification for the prevention of sudden cardiac death (SCD). However, the ICD is still the therapeutic cornerstone in most cases. The management of cardiac arrhythmias in adult CHD patients should be performed at specialized centers where all aspects of diagnosis and treatment are covered.

Dronedarone: Basic Pharmacology and Clinical Use

Dronedarone is the newest antiarrhythmic drug approved for the maintenance of sinus rhythm in patients with nonpermanent atrial fibrillation (AF). It is a multi-channel blocker with diverse electrophysiologic properties. Dronedarone decreases the incidence of AF recurrence and the ventricular rate during recurrence. Dronedarone decreases rates of cardiovascular hospitalizations in patients with paroxysmal and persistent AF. Dronedarone increases mortality in patients with permanent AF and those with moderate-severe heart failure, and should thus be avoided in these populations. Dronedarone is less effective than amiodarone but also has less toxicity. Direct comparison with other antiarrhythmic drugs is not available.

The combined effects of ranolazine and dronedarone on human atrial and ventricular electrophysiology

INTRODUCTION

Pharmacological rhythm control of atrial fibrillation (AF) in patients with structural heart disease is limited. Ranolazine in combination with low dose dronedarone remarkably reduced AF-burden in the phase II HARMONY trial. We thus aimed to investigate the possible mechanisms underlying these results.

METHODS AND RESULTS

Patch clamp experiments revealed that ranolazine (5μM), low-dose dronedarone (0.3μM), and the combination significantly prolonged action potential duration (APD90) in atrial myocytes from patients in sinus rhythm (prolongation by 23.5±0.1%, 31.7±0.1% and 25.6±0.1% respectively). Most importantly, in atrial myocytes from patients with AF ranolazine alone, but more the combination with dronedarone, also prolonged the typically abbreviated APD90 (prolongation by 21.6±0.1% and 31.9±0.1% respectively). It was clearly observed that neither ranolazine, dronedarone nor the combination significantly changed the APD or contractility and twitch force in ventricular myocytes or trabeculae from patients with heart failure (HF). Interestingly ranolazine, and more so the combination, but not dronedarone alone, caused hyperpolarization of the resting membrane potential in cardiomyocytes from AF. As measured by confocal microscopy (Fluo-3), ranolazine, dronedarone and the combination significantly suppressed diastolic sarcoplasmic reticulum (SR) Ca(2+) leak in myocytes from sinus rhythm (reduction by ranolazine: 89.0±30.7%, dronedarone: 75.6±27.4% and combination: 78.0±27.2%), in myocytes from AF (reduction by ranolazine: 67.6±33.7%, dronedarone: 86.5±31.7% and combination: 81.0±33.3%), as well as in myocytes from HF (reduction by ranolazine: 64.8±26.5% and dronedarone: 65.9±29.3%).

CONCLUSIONS

Electrophysiological measurements during exposure to ranolazine alone or in combination with low-dose dronedarone showed APD prolongation, cellular hyperpolarization and reduced SR Ca(2+) leak in human atrial myocytes. The combined inhibitory effects on various currents, in particular Na(+) and K(+) currents, may explain the anti-AF effects observed in the HARMONY trial. Therefore, the combination of ranolazine and dronedarone, but also ranolazine alone, may be promising new treatment options for AF, especially in patients with HF, and merit further clinical investigation.

Atrial fibrillation management: evaluating rate vs rhythm control

Atrial fibrillation (AF) is an increasing global issue leading to increased hospitalizations, adverse health related events and mortality. This review focuses on the management of atrial fibrillation, in particular in the past decade, comparing two major strategies, rate or rhythm control. We evaluate the evidence for each strategy, pharmacological options and the increasing utilization of invasive techniques, in particular catheter ablation and use of implantable cardiac pacing devices. Pharmacological comparative trials evaluating both strategies have shown rate control being non-inferior to rhythm control for clinical outcomes of mortality and other cardiovascular events (including stroke). Catheter ablation techniques, involving radiofrequency ablation and recently cryoablation, have shown promising results in particular with paroxysmal AF. However, persistent AF provides ongoing challenges and will be a particular focus of continued research.

Guidelines for Potassium Channel Blocker Use

This article summarizes recommendations for the clinical use of antiarrhythmic drugs for the treatment and prevention of atrial and ventricular arrhythmias based on current guideline and consensus documents. The choice of antiarrhythmic drug is based on the efficacy and safety profile and influenced by the presence or absence of structural heart disease. Because of its adverse side-effect profile, amiodarone is recommended for the management of atrial fibrillation only when other agents have failed or are contraindicated. For treatment of symptomatic ventricular arrhythmias in the setting of structural heart disease, amiodarone is generally the preferred agent.

Diagnostic Evaluation and Follow-Up of Patients with Atrial Fibrillation

In this article, a review of the diagnostic evaluation and outpatient follow-up of patients with atrial fibrillation is presented. After exploring details of symptoms, past medical history, quality of life, and physical exam findings, diagnostic tools are then discussed. Furthermore, important considerations after the initial diagnosis and treatment of patients with atrial fibrillation are discussed.

Rate Versus Rhythm Control for Atrial Fibrillation

Treatment of patients with symptomatic atrial fibrillation (AF) with antiarrhythmic drug therapy in general improves their symptom scores and exercise tolerance; however, large randomized trials have failed to show a mortality benefit with a rhythm-control compared with a rate-control strategy. Catheter ablation in patients who have failed or not tolerated medical therapy has been shown to alleviate symptoms and improve quality of life. However, catheter ablation cannot undo the structural remodeling that contributed to the arrhythmia in the first place. Patients should be alerted to modifiable factors that may decrease the likelihood of unchecked structural remodeling and AF recurrence.

The current approach of atrial fibrillation management

Atrial fibrillation (AF) is the most commonly encountered arrhythmia in clinical practice. Aging populations coupled with improved outcomes for many chronic medical conditions has led to increases in AF diagnoses. AF is also known to be associated with an increased risk of adverse events such as transient ischemic attack, ischemic stroke, systemic embolism, and death. This association is enhanced in select populations with preexisting comorbid conditions such as chronic heart failure. The aim of this review is to highlight the advances in the field of cardiology in the management of AF in both acute and long-term settings. We will also review the evolution of anticoagulation management over the past few years and landmark trials in the development of novel oral anticoagulants (NOACs), reversal agents for new NOACs, nonpharmacological options to anticoagulation therapy, and the role of implantable loop recorder in AF management.