Lack of prognostic value of atrial arrhythmia inducibility and change in inducibility status after catheter ablation of atrial fibrillation.

BACKGROUND: Previous studies have suggested a role of atrial arrhythmia inducibility as an endpoint of catheter ablation of atrial fibrillation (AF). The prognostic value of noninducibility after ablation and of a change in inducibility status has not been investigated in large studies.

OBJECTIVE: The purpose of this study was to evaluate the prognostic role of noninducibility and of a change in inducibility status after ablation of AF.

METHODS: We studied 305 consecutive patients with AF (66% paroxysmal) undergoing antral pulmonary vein (PV) isolation plus non-PV triggers ablation. All patients underwent a standardized induction protocol before and after ablation from the coronary sinus and right atrium: 15-beat burst pacing at 250 ms and decrementing to 180 ms (up to 20 μg/min isoproterenol). Inducibility was defined as any sustained AF or organized atrial tachycardia (AT) lasting >2 minutes.

RESULTS: A total of 197 patients (65%) had inducible AF/AT at baseline compared to 118 (39%) after ablation. One hundred seven patients (57%) changed their inducibility status from inducible preablation to noninducible postablation. After 19 ± 7 months of follow-up, 212 patients (70%) remained free from any recurrent AF/AT. Noninducibility of AF/AT postablation (log-rank P = .236) or change in inducibility status (log-rank P = .429) was not associated with reduced risk of recurrent AF/AT. Results were consistent across the paroxysmal and nonparoxysmal subgroups.

CONCLUSION: Noninducibility of atrial arrhythmia or change in inducibility status after PV isolation and non-PV trigger ablation is not associated with long-term freedom from recurrent arrhythmia and should not be used as an ablation endpoint or to support the appropriateness of additional ablation lesion sets.