Prospective Randomized Study to Assess the Efficacy of Site and Rate of Atrial Pacing on Long-term Progression of Atrial Fibrillation in Sick Sinus Syndrome: Septal Pacing for Atrial Fibrillation Suppression Evaluation (SAFE) Study
Background—Atrial-based pacing is associated with lower risk of atrial fibrillation (AF) in sick sinus syndrome (SSS) compared with ventricular pacing; nevertheless, the impact of site and rate of atrial pacing on progression of AF remains unclear. We evaluated whether long-term atrial pacing at right atrial (RA) appendage versus low RA septum with(ON) or without(OFF) a continuous atrial overdrive pacing algorithm can prevent the development of persistent AF.
Methods and Results—We randomized 385 patients with paroxysmal AF and SSS in whom a pacemaker was indicated to pacing at RA appendage-ON (n=98), RA appendage-OFF (n=99), RA septum-ON (n=92) or RA septum-OFF (n=96). The primary outcome was the occurrence of persistent AF (AF documented at least 7 days apart or need for cardioversion). Demographics data were homogenous across each of pacing site (RA appendage/RA septal) and atrial overdrive (ON/OFF). After a mean follow-up of 3.1-years, persistent AF occurred in 99 patients (25.8%, annual rate of persistent AF: 8.3%). Alternative site pacing at the RA septum versus conventional RA appendage (HR=1.18; 95%CI: 0.79-1.75, P=0.65) or continuous atrial overdrive pacing ON versus OFF (HR=1.17; 95%CI: 0.79-1.74, P=0.69) did not prevent the development of persistent AF.
Conclusions—In patients with paroxysmal AF and SSS requiring pacemaker implantation, an alternative atrial pacing site at the RA septum or continuous atrial overdrive pacing did not prevent the development of persistent AF.
Clinical Trial Registration Information—ClinicalTrials.gov. Identifier: NCT00419640.
- Received January 29, 2013.
- Revision received June 1, 2013.
- Accepted June 14, 2013.