Level 2: Mid-level evidence
Rhythm control strategies for atrial fibrillation (AF) have not been shown to be generally more beneficial compared with rate control. Most patients with rhythm control will have some amount of intermittent AF that necessitates anticoagulation. The principal benefit is for patients who cannot tolerate the symptoms of AF.
A recent randomized trial compared dronedarone (400 mg twice daily) with placebo in 4,628 patients (mean age 72 years) with paroxysmal or persistent AF or flutter (N Engl J Med. 2009;360:668-678; available at content.nejm.org/cgi/content/full/360/7/668, accessed May 12, 2009). All patients had at least one additional risk factor, including age 70 years or older, arterial hypertension, diabetes, previous stroke, transient ischemic attack or systemic embolism, left atrial diameter ³50 mm, or left ventricular ejection fraction £40%. At mean follow-up of 21 months, dronedarone was associated with lower rates of hospitalization for any cardiovascular event (29.3% vs. 36.9%, P <.001, NNT 14) or for AF (14.6% vs. 21.9%, P <.001, NNT 14). Cardiovascular mortality was also lower for the dronedarone group (2.7% vs. 3.9%, P =.03, NNT 84), but the difference in all-cause mortality was not significant (5% vs. 6%). About 30% of patients in each group discontinued treatment due to adverse events. Dronedarone was associated with significantly more bradycardia, QT-interval prolongation, GI problems, and skin-related events.