Antiarrhythmic drug therapy in the prophylaxis of symptomatic paroxysmal atrial fibrillation/flutter. Rationale and design of the SOPAT trial

The indication to treat symptomatic paroxysmal atrial fibrillation is discu ssed controversely. Successful medical treatment may result in the reductio n of symptoms by improving hemodynamics in a reduction of thromboembolic ev ents. However, several antiarrhythmic drugs are also known to increase the risk of proarrhythmic events. A randomized, double-blind, and placebo-controlled multicenter trial with 100 0 patients to be recruited was designed to compare the effects of two antia rrhythmic drugs frequently used in Germany for the treatment of atrial fibr illation, Sotalol and the fixed combination of chinidin and verapamil (Cord ichin(R)). Patients with symptomatic paroxysmal atrial fibrillation/atrial flutter will be observed for a period of one year. The occurrence of paroxy smal atrial fibrillation is documented by transtelephonic ECG monitoring. P atients will document an ECG once daily, and recording is mandatory in case of symptoms. ECGs are transmitted to a central data base for analysis. This clinical trial is designed to answer the following questions: (1) What is the average rate of spontaneous events of symptomatic atrial fibrillati on? (2) Is it possible to reduce the frequency of symptomatic events by chr onic antiarrhythmic drug administration? (3) What is the long-term frequenc y for the occurrence of severe side-effects under antiarrhythmic medication ? The primary endpoint is defined as the time to first recurrence of symptoma tic arrhythmia after reaching steady state plasma concentrations of the stu dy medication. The trial started in November 1997 and is planned to be finished by the end of 1999.