Rethinking the reasons to treat atrial fibrillation? The role of dronedarone in reducing cardiovascular hospitalizations

Abstract

The management of patients with atrial fibrillation has changed considerably over the past decade, largely because of data derived from clinical trials. Although studies comparing strategies of rate control vs. rhythm control consistently failed to demonstrate the benefit of a rhythm control strategy, to argue that rhythm control is of no value to argue with imprecision. AFFIRM, the largest of the rate vs. rhythm trials, showed, in multivariate analysis, that those patients who stayed in sinus rhythm had a reduced mortality, although this was offset by the use of antiarrhythmic drugs.1 In contrast, although no benefit of a rhythm control strategy was found in the AF-CHF study (in which all patients had left ventricular dysfunction and the predominant antiarrhythmic drug used was amiodarone), there was also no trend towards increased mortality with the use of antiarrhythmic therapy.2 Despite negative outcomes in terms of mortality, rhythm control does have some benefits. Analyses of patients who were able to maintain sinus rhythm (as opposed to being randomized to a rhythm control strategy regardless of outcome) does appear to show a benefit of rhythm control, at least in terms of quality of life.3 In addition, there are many patients with atrial fibrillation in whom the arrhythmia is clearly associated with unpleasant or intolerable symptoms and these patients benefit symptomatically from restoration of sinus rhythm. Antiarrhythmic drugs remain problematic, however, given their side effects and propensity for significant proarrhythmia. Until recently, clinical trials of antiarrhythmic drugs in patients with atrial fibrillation concentrated on suppression of the arrhythmia as determined by freedom from atrial fibrillation at a predetermined endpoint (usually 1 year or less) or by measuring time to first symptomatic recurrence. Data from antiarrhythmic trials that utilize daily transtelephonic monitoring and from interrogation of permanent pacemakers reveal a high prevalence of …