Rhythm control in selected patients diagnosed with paroxysmal atrial fibrillation (AF) remains a clinically important goal. The role of pacing therapies for maintaining that goal remains unclear, despite considerable study effort. Several pacing strategies have been evaluated to treat AF, including various prevention pacing therapies (PPTs) designed to suppress known triggers of AF. The inconsistent results and difficulty interpreting the results of past studies stems in part from variability in trial designs, patient populations, and end points.

The SAFARI is the largest, multicenter, prospective, randomized clinical trial that aims to address many of the design limitations of previous trials to delineate better the role of PPTs. The primary end point for the study is total AF burden as reported by the device. Patients are selected to include only those with paroxysmal AF and to exclude those without documented arrhythmias. A 1-month postimplant lead stabilization period followed by a 3-month run-in period is incorporated into the design to help exclude patients with no AF after implantation or patients in whom the accuracy of the device reported AF burden is suspect. A suite of 6 PPTs is used to treat multiple different triggers of arrhythmia. Data will be gathered for10 months. Enrollment of 546 patients was completed in January 2005; patient follow-up visits are expected to be completed in November 2005.

By using a study design that addresses the limitations of previous trials, SAFARI will help significantly refine our understanding of the role of pacing to prevent AF.