Early Dronedarone Versus Usual Care to Improve Outcomes in Persons With Newly Diagnosed Atrial Fibrillation

Atrial fibrillation (AF) is the most common sustained arrhythmia encountered in clinical practice, accounting for one-third of arrhythmia-related hospitalizations.1 As many as 1 in 4 people develop AF over their lifetime after the age of 40 years. The prevalence and burden of AF in the United States is substantial; the age-adjusted incidence and prevalence has increased over the last 3 decades. Moreover, the number of Americans with AF is expected to increase 150% by 2050. The goals of care in the treatment of AF include (1) the management and reduction of risk factors, (2) prevention of tachycardia (rate control), (3) prevention of stroke, and (4) improvement of symptoms. Reduction or elimination of symptoms often requires rhythm control. Historically, randomized clinical trials have not demonstrated a mortality or stroke benefit with a rhythm control versus a rate control strategy.

Despite the failure of prior randomized clinical trials to demonstrate the superiority of rhythm control, the recent Early Treatment of Atrial Fibrillation for Stroke Prevention 4 (EAST-AFNET 4) trial demonstrated that early introduction of a comprehensive rhythm-control strategy (within one year of diagnosis) is superior to guideline-based usual care in improving cardiovascular (CV) outcomes at a mean follow-up of 5 years. The EAST-AFNET 4 trial found that early rhythm control reduced the primary outcome of CV death, stroke, hospitalization for heart failure (HF), or acute coronary syndrome (HR 0.79, 96% confidence interval (CI) 0.66-0.94, p = 0.005). EAST-AFNET 4 also demonstrated a reduction in the risk of stroke with early introduction of rhythm control (HR 0.65, 95% CI 0.44-0.98), a finding that was also observed with dronedarone in the ATHENA trial. In addition, maintenance of sinus rhythm has been associated with improved quality of life and increased exercise capacity in some patients. Outside of clinical trials, a quality-of-life study from the Registry on Cardiac Rhythm Disorders Assessing the Control of Atrial Fibrillation (RECORD-AF) found that rhythm control was associated with better quality of life.

There are several antiarrhythmic drugs (AADs) available for rhythm control of AF. Class I antiarrhythmic agents are predominantly limited to younger patients without coronary artery or structural heart disease. Patients with advanced chronic kidney disease, prolonged QT intervals, and/or severe left ventricular hypertrophy should not be treated with sotalol or dofetilide. Even when sotalol or dofetilide can be used, patients are often hesitant to start a medication that requires an inpatient hospitalization for drug loading and laboratory evaluation every 3 months. Amiodarone has been shown to be the most effective AAD for maintaining sinus rhythm in patients with AF; however, based on its side effect profile, amiodarone is only recommended as a first-line agent under specific clinical circumstances. Moreover, despite its efficacy, amiodarone has high rates of discontinuation due to frequent adverse events. In addition to its unfavorable side effects, several studies, including those of patients at risk for sudden cardiac death, have demonstrated an association between amiodarone use and higher mortality, as well as lower functional status. In contrast to amiodarone, dronedarone is a much better tolerated antiarrhythmic medication. In randomized controlled trials, dronedarone has been shown to prevent recurrent AF, improve rate control, and decrease cardiovascular hospitalization in patients with AF.

While there are several completed clinical trials that address treatment strategy in patients with symptomatic and recurrent AF, there are no randomized clinical trials that address treatment for first-detected or new-onset AF. After appropriate evaluation for oral anticoagulation, these patients are often started on an atrioventricular nodal blocking agent (beta-blocker or non-dihydropyridine calcium channel blocker). The investigators hypothesize that earlier administration of a well-tolerated antiarrhythmic drug proven to reduce hospitalization may result in improved quality of life and cardiovascular outcomes in patients with first-detected AF.

Risk Assessment:

Dronedarone is approved by the Food and Drug Administration to reduce the risk of hospitalization for AF in patients with paroxysmal or persistent AF. The efficacy and safety of dronedarone 400 mg twice daily was evaluated in five controlled studies, ATHENA, ANDROMEDA, European Trial in Atrial Fibrillation or Flutter Patients Receiving Dronedarone for the Maintenance of Sinus Rhythm (EURIDIS), ADONIS, and Dronedarone Atrial FibrillatioN study after Electrical Cardioversion (DAFNE), involving more than 6,000 patients with including more than 3200 patients who received dronedarone. As with any therapeutic agent, there are known risks with dronedarone therapy. These risks include hepatic injury, heart failure exacerbation, increased exposure to digoxin, increased plasma concentration of tacrolimus, sirolimus, and other Cytochrome P450, family 3, subfamily A (CYP 3A) substrates, and very rare instances of pulmonary toxicity. The risks of dronedarone are felt to be outweighed by its benefits. The guideline recommendations provided by the European Society of Cardiology and American Heart Association (AHA)/American College of Cardiology (ACC)/Heart Rhythm Society (HRS) are commensurate with this risk benefit assessment.

Benefit Assessment:

While there are no completed randomized clinical trials to guide selection or initiation of rhythm control therapies in patients with first-detected AF, there are recent trials that suggest benefit with both dronedarone antiarrhythmic therapy and early-initiation of rhythm control in persons with AF. the recent EAST-AFNET 4 trial demonstrated that early introduction of a comprehensive rhythm-control strategy (within one year of diagnosis) is superior to usual guideline-recommended care in improving cardiovascular (CV) outcomes at 5 years. The median time from new-onset AF to randomization in the EAST-AFNET4 trial was 36 days. The trial found that early rhythm control reduced the primary outcome of CV death, stroke, hospitalization for HF, or acute coronary syndrome (HR 0.79, 95% confidence interval 0.66-0.94, p = 0.005). EAST-AFNET 4 also demonstrated a reduction in the risk of stroke with early introduction of rhythm control (HR 0.65, 95% CI 0.44-0.98), a finding that was also observed with dronedarone in the ATHENA trial. Thus, the investigators hypothesize that early initiation of dronedarone in patients with new-onset AF will lead to a reduction in CV hospitalization or death.

Overall Design:

Dronedarone is approved by the Food and Drug Administration to reduce the risk of CV hospitalization in patients with AF or atrial flutter. However, it is unknown if dronedarone (or any antiarrhythmic medication) can reduce CV hospitalization or death in patients with first-detected AF. This trial has been designed to address this important question. In order to facilitate the trial enrollment, data collection, and a generalizability to clinical practice, the CHANGE AFIB study has been designed as an open-label pragmatic clinical trial nested within the Get With The Guidelines (GWTG) Atrial Fibrillation registry. At present the overall GWTG program is being implemented in over 2,300 hospitals across the U.S. and is comprised of over 9 million patient records, with an estimated 650,000 new patient records entered per year. The trial will utilize the existing GWTG registry network, data collection architecture, and experience to facilitate both enrollment and conduct of the trial.

The comparator arm will be "usual care." Thus, this study will compare usual care plus dronedarone versus usual care alone. In most patients, the investigators anticipate usual care to include an atrioventricular nodal blocking agent (beta-blocker, non-dihydropyridine calcium channel blocker, or digoxin) without an antiarrhythmic. As dronedarone has anti-adrenergic rate controlling properties, a low dose of beta-blocker or calcium-channel blocker is recommended in the USPI when starting dronedarone. In the dronedarone arm concomitant digoxin use will be contraindicated due to P-gp interaction based upon data from the PALLAS trial. All patients will receive oral anticoagulation for stroke prevention according to current guideline recommendations.

CHANGE AFIB will leverage several critical advantages as a pragmatic clinical trial. Data collection will be integrated into the Get With The Guidelines AFIB registry. The use of the GWTG-AFIB registry will also enhance subject recruitment and ensure the enrollment of a diverse group of patients. The randomized intervention will be compared with usual care thus further enhancing generalizability. Follow-up visits will be minimized to reduce patient burden. Moreover, follow-up visits will have "windows" to accommodate variation in follow-up intervals at different centers.

Justification for Study Drug Intervention and Dose:

Dronedarone is a non-iodinated benzofuran similar to amiodarone but is not associated with thyroid or pulmonary toxicity in randomized clinical trials or post-marketing observational studies. Dronedarone has electrophysiological characteristics spanning all 4 Vaughan-Williams anti-arrhythmic classes, with primarily class III effects. Initial trials suggested that dronedarone prolonged the time to recurrence of AF and reduced cardiovascular death and hospitalization.

The landmark ATHENA trial evaluated the efficacy and safety of dronedarone in patients with atrial arrhythmias (atrial fibrillation or atrial flutter). This trial did not include patients with a recent history of New York Heart Association (NYHA) class IV heart failure or recent hospitalization for decompensated heart failure (<4 weeks). Approximately, 30% of the ATHENA population had NYHA class I-III heart failure. ATHENA demonstrated that dronedarone 400 mg twice daily (in combination with background therapy) reduced the combined endpoint of CV hospitalization or death from any cause by 24% (p<0.001) compared with placebo. Of course, the ATHENA trial was not conducted in the special population of patients with a new diagnosis of AF. There are no randomized trials or guideline recommendations for antiarrhythmic therapy at the time of first-detected AF. A subgroup analysis from the ATHENA trial suggests that optimal outcomes may be achieved in those patients with shorter duration of AF (time from diagnosis). Similar observations have also been made in patients undergoing other forms of rhythm control, including catheter ablation. In this trial, patients with first-detected AF will be randomized to dronedarone on top of usual care versus usual care alone. Patients randomized to the intervention arm will be prescribed and treated with Dronedarone 400 mg bid. This dose has been chosen as it is the Food and Drug Administration approved dose as well as the dose recommended in current international guidelines. Dronedarone has also been shown to be an effective rate control agent as well. In the ERATO study treatment with dronedarone 400 mg twice daily let to a mean reduction of 24.5 beat/min in patients with permanent AF when compared with placebo. In the EURIDIS/ADONIS studies the mean difference in patients with paroxysmal/persistent AF during AF recurrence was 14 beats/min. Moreover, the dronedarone treated patients experienced improved rate control without any reduction in exercise tolerance as measured by maximal exercise.