Antiarrhythmic drug therapy after DC cardioversion of chronic atrial fibrillation - rationale and design of the PAFAC trial

Atrial fibrillation (AF) is the most frequent cardiac arrhythmia. However, despite manifold publications reflecting numerous clinical trials about tre atment of AF, the management of this arrhythmia is still under controversia l. discussion, in daily clinical work as well as in research. The present s tudy concentrates on three major questions: 1. How frequent are recurrences of AF in long-term follow-up? Most of the previous studies used the occurr ence of symptoms as a surrogate parameter for recurrences of AF, despite th e expected high rate of asymptomatic relapses. In the present study a daily transtelephonic ECG transmission enables a rhythm monitoring independent o f symptoms. 2. Is the frequency of AF recurrences significantly reduced by antiarrhythmic medication? A direct comparison of class I and III antiarrhy thmic drugs, which still are most frequently used for this indication,and o f placebo will answer this question. 3. How safe is the long-term treatment for the prevention of AF recurrences with special respect to proarrhythmic effects? The daily transtelephonic ECG transmission enables a quantitative and qualitative monitoring of tachy- and bradyarrhythmias independent of s ymptoms. Additionally, the daily analysis of ECG measures may detect parame ters predicting subsequent life threatening arrhythmias. The study design provides a prospective, randomised, double-blind, placebo controlled, multicenter parallel group comparison. In Germany and in the Cz ech Republic about 90 hospitals will include 900 patients with documented c hronic AF, age 18 to 80 years, if they are eligible for electrical cardiove rsion without concomitant antiarrhythmic drug therapy and if they are antic oagulated for at least three weeks prior to inclusion. Neither the size of the left atrium nor the duration of chronic AF are exclusion criteria. A fe w hours after successful electrical cardioversion the patients are randomis ed either to sotalol (2x 160 mg) or quinidine + verapamil (3x 160 mg 3x 80 mg) or placebo. Starting at the day after cardioversion, the patient is ask ed to record and transmit electrocardiograms of one minute duration at leas t once a day using his personal transtelephonic ECG recording unit (Tele-EC G recorder, credit card size), in case of symptoms as often as necessary. T he ECGs can be transmitted at any time by any regular phone without additio nal equipment using a toll free number. A custom made, computer based, full y automated receiving centre is handling the patient calls interactively wi th voice control, including a voice recording of the patient's symptoms. Th e ECG tracings and the patient's voice messages are subsequently computer b ased analysed by experienced technicians. All ECG measures are stored in a database. In case of AF recurrence, any other relevant arrhythmia or additi onal abnormalities (e.g. QT prolongation) the correspondent hospital is imm ediately informed by fax. In case of AF recurrence, a subsequent Holter rec ording discriminates in paroxysmal and permanent AE Study medication is end ed if either permanent AF or the third episode of paroxysmal AF are detecte d or after 12 months of follow-up. Regular follow-up visits are performed m onthly. Major endpoints are the time to first recurrence of AF or the time to death, secondary parameters are the number of AF recurrences, the time t o end of medication and AF related symptoms. The recruitment started in the last days of 1996. Until the end of June 199 8, 424 patients have been randomised. It is expected to end recruitment in spring 1999 and to close the study in spring 2000. Final results will be av ailable in summer 2000.