How best to manage nonvalvular atrial fibrillation is controversial. One option is restoring normal sinus rhythm through anti-arrhythmic medications and cardioversion. The rhythm control method relieves symptoms and delays or prevents chronic atrial fibrillation. However, only approximately 50 percent of patients who receive this treatment have a normal sinus rhythm after six months to one year, and the strategy for preventing thromboembolic events has not been established. The other option is rate control, which is easier to achieve than rhythm control and improves hemodynamics. The disadvantage is that it allows atrial fibrillation to persist and may not relieve its symptoms. Opolski and associates compared the risks and benefits of rate control versus rhythm control in patients with atrial fibrillation.
This prospective, randomized, open, multi-center clinical trial involved six cardiology centers. Participants were 50 to 75 years of age and had between seven days and two years of persistent atrial fibrillation. Exclusion criteria were extensive and included documented inefficiency, intolerance to or contraindications to antiarrhythmic medications, and an identifiable reversible cause for atrial fibrillation. Participants were randomized to receive rate or rhythm control treatments. Rate control was achieved through rate-slowing therapies, and the effectiveness was assessed using repeat 24-hour Holter monitors. The rhythm control group received serial cardioversion and antiarrhythmic medications (the specific medication varied among patients) using a stepwise protocol. Both groups received anticoagulation following the established guidelines. Main outcome measures were death from any cause, thrombo embolic complications, and intracranial or other major hemorrhage.
The study involved 205 patients (101 in the rate control group and 104 in the rhythm control group). The mean observation period for the study was 1.7 years. At the end of this period, 63.5 percent of patients in the rhythm control group remained in sinus rhythm. The two groups, however, did not show significantly different main outcomes. The incidence of hospitalization was significantly lower in the rate control group compared with the rhythm control group. Both groups showed improvement in their New York Heart Association functional class. The rhythm control group had a significant improvement in exercise tolerance compared with the rate control group.
The authors conclude that there are no significant differences in major end points between rate control and rhythm control treatment of chronic atrial fibrillation. They add that physicians should base their choice of therapy on the individual patient’s needs.