The use of antiarrhythmic medications to maintain normal sinus rhythm in patients with atrial fibrillation is a common practice. Because type I antiarrhythmic drugs such as quinidine and procainamide appear to increase mortality when used for this purpose, sotalol has become a frequently prescribed alternative. Southworth and associates conducted a meta-analysis to compare efficacy and safety in maintaining normal sinus rhythm in patients with chronic atrial fibrillation in quinidine, sotalol and control studies.
The three principle inclusion criteria for the meta-analysis consisted of treatment of long-term atrial fibrillation, use of a randomized trial design and inclusion of mortality data and/or normal sinus rhythm maintenance data at three, six or 12 months. Two investigators screened all potential studies for inclusion.
Efficacy rates in the quinidine studies varied, depending on the length of follow-up, ranging from 55 to 91 percent after three months to 29 to 52 percent after 12 months. In the sotalol studies, the three- and six-month efficacy rates were similar, but no data were available at the 12-month follow-up. The maintenance of normal sinus rhythm in patients in the control group was much lower—5 to 28 percent after 12 months. Although quinidine and sotalol were significantly more successful in maintaining normal sinus rhythm than control, approximately 50 percent of patients had recurrent atrial fibrillation within the first six months despite treatment. However, mortality rates did not differ significantly across groups, although long-term therapy with sotalol or quinidine tended to increase mortality.
The authors conclude that the data do not support the use of sotalol as a safer alternative to quinidine in the maintenance of sinus rhythm in patients with chronic atrial fibrillation. Other antiarrhythmic drugs such as amiodarone are becoming more popular, and studies using no therapy other than that aimed at rate control are also being investigated.