- Question
- In patients with persistent atrial fibrillation, does adding substrate ablation (complex fractionated electrograms or lines) to pulmonary-vein isolation improve the outcomes of catheter ablation?
- Design
- Randomized, single-masked trial of 589 patients assigned 1:4:4 to three ablation strategies, with 18 months of follow-up.
- Population
- Patients with persistent atrial fibrillation referred for catheter ablation.
- Intervention
- Pulmonary-vein isolation plus ablation of electrograms showing complex fractionated activity (263 patients), or pulmonary-vein isolation plus linear ablation across the left atrial roof and mitral isthmus (259 patients).
- Control
- Pulmonary-vein isolation alone (67 patients).
- Primary outcome
- Freedom from any documented recurrence of atrial fibrillation lasting longer than 30 seconds after a single ablation procedure.
- Results
- At 18 months, 59% of patients assigned to pulmonary-vein isolation alone were free from atrial fibrillation, compared with 49% with added complex fractionated electrogram ablation and 46% with added linear ablation (P=0.15). Procedure time was significantly shorter with isolation alone (P<0.001).
- Safety
- Complications included tamponade (three patients), stroke or transient ischemic attack (three patients), and one atrioesophageal fistula (one patient).
- Conclusion
- Adding linear ablation or ablation of complex fractionated electrograms to pulmonary-vein isolation did not reduce recurrence of persistent atrial fibrillation.
- Why it matters
- It challenged the practice of extending ablation beyond pulmonary-vein isolation in persistent atrial fibrillation, since the larger lesion sets gave no benefit and lengthened the procedure.
Card generated automatically with AI from the abstract of the original publication and the trial registry; every figure was checked against those sources. It may contain errors: verify the data at the source before using it for clinical decisions.
Generated on October 18, 2026