Pulmonary venous isolation versus additional substrate modification as treatment for paroxysmal atrial fibrillation

Background: Pulmonary vein isolation alone is ineffective in maintaining sinus rhythm in up to one third of patients with paroxysmal atrial fibrillation (AF). We compared pulmonary vein antral isolation plus additional limited ablation along the inferoposterior left atrium and epicardially within the adjacent coronary sinus (PVAI + CS) to pulmonary vein antral isolation (PVAI) alone in patients with paroxysmal AF. Methods: Forty-two consecutive patients with paroxysmal AF were prospectively randomized to PVAI vs. PVAI + CS. All patients were seen 3, 6, 12, and 18 months after ablation and underwent 24-h ambulatory Holter monitoring. Results: Following a single procedure, 17 out of 22 patients (77%) remained arrhythmia free off antiarrhythmic medication after PVAI at 18 months vs. 10 out of 20 (50%) after PVAI + CS (p<0.01). After PVAI, three patients had recurrent paroxysmal AF, and two had atrial tachycardia, whereas after PVAI + CS, three patients had recurrent paroxysmal AF, and seven had atrial tachycardia. All patients in the PVAI + CS group with atrial tachycardia who underwent a second procedure were found to have peri-mitral macro-reentry as the underlying mechanism. Eighty-one percent of patients remained arrhythmia free off medication after 1.09 procedures in the PVAI group vs. 80% after 1.35 procedures in the PVAI + CS group (p<0.01). Conclusion: The addition of limited ablation along the inferoposterior left atrium and within the adjacent coronary sinus to PVAI alone did not reduce the recurrence rate of paroxysmal atrial fibrillation and was associated with an increased rate of peri-mitral macro-reentrant atrial tachycardia.