Complex Fractionated Atrial Electrograms (CFAEs)
CFAEs were first described by NademaneeĀ et al. (21) as a pattern of continuous atrial activity originating from areas of functional block and slow conduction, and pivot points of reentrant waves. The STAR AF (Substrate and Trigger Ablation for Reduction of Atrial Fibrillation) trial (22) found PVI + CFAEs ablation had higher freedom from AF when compared to PVI or CFAEs ablation alone after one or two procedures. A similar conclusion was derived from a meta-analysis by Hayward et al. (23). However, additional substrate modification was not found to have any benefit over PVI and ablation of non-PV triggers in a subsequent study (24). Verma et al. conducted the STAR AF II (Approaches to Catheter Ablation for Persistent Atrial Fibrillation) trial (25) with a larger sample size, and no reduction in the recurrence rate of AF was observed when CFAEs ablation was performed in addition to PVI. Although CFAE ablation is associated with an increase in intraprocedural AF termination (26), it does not provide any incremental benefit over PVI alone in the reduction of long-term AF recurrence and is associated with longer procedural and fluoroscopy times (27). (Figure 2)