Eight RCTs (812 participants) were included. Some studies included two or more comparisons of differing pacing sites. Six studies (621 participants) assessed overdrive pacing; of these, four study arms assessed biatrial pacing, five right atrial pacing and two left atrial pacing. Two studies 191 participants) assessed fixed high-rate pacing; of these, two study arms assessed biatrial pacing and one right atrial pacing.
Overdrive pacing.
Overdrive biatrial pacing and right atrial pacing both reduced the incidence of post-operative atrial fibrillation compared with the control; the ORs were 2.6 (95% CI: 1.4, 4.8) and 1.8 (95% CI: 1.1, 2.7), respectively.
The incidence of atrial fibrillation with overdrive left atrial pacing (28%) was not significantly different from that of patients assigned to the control (39%) (P=0.2). The authors considered these studies to be underpowered for assessing efficacy.
Fixed high-rate pacing.
The odds of atrial fibrillation occurring was 2.5 times lower in the group that received fixed high-rate biatrial pacing compared with the odds of atrial fibrillation occurring in the control group (OR 2.5, 95% CI: 1.3, 5.1).
The incidence of atrial fibrillation with fixed high-rate right atrial pacing (29%) was not significantly different from that of patients assigned to the control (33%) (P=0.7). The authors considered this study to be underpowered for assessing efficacy.
Complications.
The authors stated that the complications reported in the studies were similar to those described after heart surgery. No study reported problems related to the placement or removal of atrial electrodes.