Cost-effective strategies in the acute management of atrial fibrillation

Incidence and Determinants of Spontaneous Cardioversion of Early Onset Symptomatic Atrial Fibrillation

Atrial fibrillation (AF) is the most frequent chronic arrhythmia worldwide, and it is associated with significant morbidity and mortality, making it a considerable burden both to patients and the healthcare system. Nowadays, an early attempt to restore sinus rhythm in acute symptomatic AF through electrical or pharmacological cardioversion is the most common approach in the Emergency Department (ED). However, considering the high percentage of spontaneous cardioversion of paroxysmal AF reported by many studies, this approach may not be the ideal choice for all patients. In this manuscript we performed a review of the most relevant studies found in literature with the aim of identifying the main determinants of spontaneous cardioversion, focusing on those easy to detect in the ED. We have found that the most relevant predictors of spontaneous cardioversion are the absence of Heart Failure (HF), a small atrial size, recent-onset AF, rapid Atrial Fibrillatory Rate and the relationship between a previous AF episode and Heart Rate/Blood Pressure. A number of those are utilized, along with other easily determined parameters, in the recently developed "ReSinus" score which predicts the likelihood of AF spontaneous cardioversion. Such identification may help the physician decide whether immediate cardioversion is necessary, or whether to adopt a "watch-and-wait" strategy in the presence of spontaneous cardioversion determinants.

Effectiveness and safety of electrical cardioversion for acute-onset atrial fibrillation in the emergency department: a real-world 10-year single center experience

OBJECTIVE

Despite limited evidence, electrical cardioversion of acute-onset atrial fibrillation (AAF) is widely performed in the emergency department (ED). The aim of this study was to describe the effectiveness and safety of electrical cardioversion of AAF performed by emergency physicians in the ED.

METHODS

All episodes of AAF electrically cardioverted in the ED were retrieved from the database for a 10-year period. Most patients not already receiving anticoagulants were given enoxaparin before the procedure (259/419). Procedural complications were recorded, and the patients were followed-up for 30 days for cardiovascular and hemorrhagic complications.

RESULTS

Four hundred nineteen eligible cases were identified; men represented 69%, and mean age was 61±13 years. The procedure was effective in 403 cases (96.2%; 95.4% in women, 96.5% in men), with considerable differences with respect to the age of the patients, the procedure being effective in 100% of patients aged 18 to 39 and only 68.8% in those >80 years. New ED visits (33/419) were identified within 30 days (31 due to atrial fibrillation/atrial flutter recurrence, 1 due to iatrogenic hypokalemia, 1 due to hypertensive emergency). No strokes, major bleeding, life-threatening arrhythmias or peripheral thromboembolism were recorded. Nine small and mild skin burns were observed.

CONCLUSION

Electrical cardioversion is an effective and safe procedure in the vast majority of patients, albeit less effective in patients aged >80 years. It appears reasonable to avoid anticoagulation in low-risk patients with AAF and administer peri-procedural heparin to all remaining patients. Long-term anticoagulation should be planned on an individual basis, after assessment of thromboembolic and hemorrhagic risk.

A review of the literature on atrial fibrillation: rate reversion or control?

AIMS

The aim of this paper is to review the current literature describing the aetiology of atrial fibrillation and to examine the evidence for rate reversion and rate control.

BACKGROUND

Atrial fibrillation is the most commonly seen arrhythmia within the clinical setting. Treatment depends on severity of symptoms, which are predominantly palpitations and shortness of breath. The primary complications from atrial fibrillation are thrombo-embolic events (such as a pulmonary embolus or stroke).

OBJECTIVES AND METHODS

A comprehensive literature review on atrial fibrillation, rate reversion and rate control was undertaken to examine the incidence of atrial fibrillation, to review research on management of atrial fibrillation and to determine if rate reversion was superior to rate control in the treatment of atrial fibrillation.

RESULTS

Many studies have been carried out to determine the best treatment for this condition. The choices are currently pharmacological and electrical cardioversion in conjunction with anticoagulant therapy. Drug therapies are not without their problems, especially toxicity and the need for close clinical monitoring. Transaesophageal echocardiography has been used to establish the presence of left atrial thrombi and aims to reduce the anticoagulation time and reduce the risk of thrombo-embolic events. A randomized comparative study of transaesophageal echocardiography and conventional anticoagulation therapy prior to cardioversion demonstrated statistically significant reduction in haemorrhagic events and a shorter time to cardioversion in those in the transaesophageal echocardiography group compared with the conventional group. For those with persistent atrial fibrillation, surgery is an option with valve repair or replacement carried out in conjunction with a bi-atrial surgical ablation.

CONCLUSIONS

The management of atrial fibrillation is dependent on many factors and to date there are no proven clinical rationale for rate control or reversion.

RELEVANCE TO CLINICAL PRACTICE

Atrial fibrillation requires immediate attention in order to avoid thrombo-embolic complications and the use of transaesophageal echocardiography and conventional anticoagulation therapy can significantly reduce these complications.

Spheres of clinical nurse specialist practice influence evidence-based care for patients with atrial fibrillation

PURPOSE

The purpose of this article is to review atrial fibrillation (AF) and its consequences, to present sources of published evidence-based guidelines for management of AF, and to highlight multifaceted clinical nurse specialist (CNS) interventions that promote positive outcomes for patients with AF.

RATIONALE

The number of people with AF is expected to increase from 2.3 million to more than 5 million in the next 50 years. AF is associated with increased mortality, morbidity, healthcare expenditures, and decreased quality of life. Recognition of the growing number of AF cases and adverse consequences of AF led to development of evidence-based guidelines for AF management. Although nurses in diverse settings are accountable for providing evidence-based care for patients with AF, the guidelines have not been widely disseminated to nurses.

DESCRIPTION

This discussion includes a review of the adverse consequences of AF and a summary of management of recently detected AF with a focus on recommendations for nursing activities/interventions that are supported by evidence-based guidelines. Multifaceted strategies directed toward nurses and nursing practice, patients/clients, and organizations/systems that are linked to published CNS competencies and outcomes are highlighted.

OUTCOMES

CNS influence in all 3 spheres of CNS practice promotes positive outcomes that include improved patient/client functioning and self-management, reduced complications of treatment, decreased fragmentation of care, advancement of professional nursing practice, adherence to regulatory standards, and development of patient care processes that are supported by published guidelines.

CONCLUSIONS

With the use of the strategies discussed, clinical nurse specialists, whose spheres of influence include nursing and nursing practice, patients/clients, and organizations/systems, promote improved patient outcomes through implementation of evidence-based guidelines for AF management.

Pharmacological cardioversion of atrial fibrillation: current management and treatment options

Atrial fibrillation (AF) is the most common form of arrhythmia, carrying high social costs. It is usually first seen by general practitioners or in emergency departments. Despite the availability of consensus guidelines, considerable variations exist in treatment practice, especially outside specialised cardiological settings. Cardioversion to sinus rhythm aims to: (i) restore the atrial contribution to ventricular filling/output; (ii) regularise ventricular rate; and (iii) interrupt atrial remodelling. Cardioversion always requires careful assessment of potential proarrhythmic and thromboembolic risks, and this translates into the need to personalise treatment decisions. Among the many clinical variables that affect strategy selection, time from onset is crucial. In selected patients, pharmacological cardioversion of recent-onset AF can be a safely used, feasible and effective approach, even in internal medicine and emergency departments. In most cases of recent-onset AF, pharmacological cardioversion provides an important--and probably more cost effective--alternative to electrical cardioversion, which can then be employed as a second-line therapy for nonresponders. Class IC agents (flecainide or propafenone), which can be safely used in hospitalised patients with recent-onset AF without left ventricular dysfunction, can provide rapid conversion to sinus rhythm after either intravenous administration or oral loading. Although intravenous amiodarone requires longer conversion times, it is still the standard treatment for patients with heart failure. Ibutilide also provides good conversion rates and could be used for AF patients with left ventricular dysfunction (were it not for high costs). For long-lasting AF most pharmacological treatments have only limited efficacy and electrical cardioversion remains the gold standard in this setting. However, a widely used strategy involves pretreatment with amiodarone in the weeks before planned electrical cardioversion: this provides optimal prophylaxis and can sometimes even restore sinus rhythm. Dofetilide may also be capable of restoring sinus rhythm in up to 25-30% of patients and can be used in patients with heart failure. The potential risk of proarrhythmia increases the need for careful therapeutic decision making and management of pharmacological cardioversion. The results of recent trials (AFFIRM [Atrial Fibrillation Follow-up Investigation of Rhythm Management] and RACE [Rate Control versus Electrical Cardioversion for Persistent Atrial Fibrillation]) on rate versus rhythm control strategies in the long term have led to a generalised shift in interest towards rate control. Although carefully designed studies are required to better define the role of pharmacological rhythm control in specific AF settings, this alternative option remains a recommendable strategy for many patients, especially those in acute care.

Atrial fibrillation: rate control versus maintenance of sinus rhythm

Atrial fibrillation is a common tachyarrhythmia encountered in clinical practice. Management has become increasingly complex as the therapeutic options have multiplied. Two basic strategies are available: rhythm control with or without pharmacologic manipulation, and rate control with anticoagulation. To date, no randomized controlled trial that compares the two strategies has been completed, although the Atrial Fibrillation Follow-Up Investigation of Rhythm Management (AFFIRM) trial is underway. This review outlines the rationale for each of the two basic treatment strategies, providing an overview of the advantages and disadvantages of each. Included are clinical criteria used in selecting the appropriate treatment plan.

Intravenous antiarrhythmic agents

Intravenous antiarrhythmic drugs can be used as diagnostic tools; for example, adenosine can be used to reveal the underlying rhythm in narrow QRS tachycardia. Newer class III antiarrhythmic agents, like ibutilide and dofetilide, are effective at the conversion of acute atrial fibrillation; however, electrical cardioversion is still the most effective method for restoration of sinus rhythm in persistent atrial fibrillation. Lidocaine and bretylium in the treatment and prevention of ventricular tachyarrhythmia are de-emphasized because of inefficacy, safety concerns (lidocaine), or shortage of drug (bretylium). Procainamide is effective for stable ventricular tachycardia, and amiodarone is effective in the treatment of shock-refractory ventricular fibrillation. Adrenergic blockade is likely important in the management of tachyarrhythmias, particularly in electrical storm, but more data will be necessary to establish its role.

Cost effectiveness of therapies for atrial fibrillation. A review

Atrial fibrillation is the most common supraventricular tachyarrhythmia encountered in clinical practice, affecting over 5% of persons over the age of 65 years. A common pathophysiological mechanism for arrhythmia development is atrial distention and fibrosis induced by hypertension, coronary artery disease or ventricular dysfunction. Less frequently, atrial fibrillation is caused by mitral stenosis or other provocative factors such as thyrotoxicosis, pericarditis or alcohol intoxication. Depending on the extent of associated cardiovascular disease, atrial fibrillation may produce haemodynamic compromise, or symptoms such as palpitations, fatigue, chest pain or dyspnoea. Arrhythmia-induced atrial stasis can precipitate clot formation and the potential for subsequent thromboembolism. Comprehensive management of atrial fibrillation requires a multifaceted approach directed at controlling symptoms, protecting the patient from ischaemic stroke or peripheral embolism and possible conversion to or maintenance of sinus rhythm. Numerous randomised trials have demonstrated the efficacy of warfarin--and less so aspirin (acetylsalicylic acid)--in reducing the risk of embolic events. Furthermore, therapeutic strategies exist that can favourably modify symptoms by restoring and maintaining sinus rhythm with cardioversion and antiarrhythmic prophylaxis. However, the risks and benefits of various treatments is highly dependent on patient-specific features, emphasising the need for an individualised approach. This article reviews the findings of cost-effectiveness studies published over the past decade that have evaluated different components of treatment strategies for atrial fibrillation. These studies demonstrate the economic attractiveness of acute management options, long term warfarin prophylaxis, telemetry-guided initiation of antiarrhythmic therapy, approaches to restore and maintain sinus rhythm, and the potential role of transoesophageal echocardiographic screening for atrial thrombus prior to pharmacological or electrical cardioversion. Further, we discuss the merits and limitations of the cost-effectiveness analyses in the context of overall treatment strategies. Finally, we identify areas that will require additional research to achieve the goal of effective and economically efficient management of atrial fibrillation.