36 Impact of atrial fibrillation termination on long term outcome in persistent atrial fibrillation patients undergoing ACQMAP guided ablation

Introduction An acute response to ablation (arrhythmia termination or cycle length prolongation) is often presented as evidence of the significance of non-pulmonary vein (PV) mechanisms for AF maintenance and is an attractive procedural end point. Objectives To investigate whether acute AF termination with ablation predicts long-term freedom from arrhythmia recurrence. Methods We conducted a retrospective analysis of 100 patients who have undergone AcQMap (Acutus Medical) guided catheter ablation for AF at 3 UK centres. Acute success was defined as a spontaneous conversion to sinus rhythm (SR) during the ablation procedure. Long-term success was defined as freedom from any documented arrhythmia after a 3-month blanking period. Results Mean follow up was 11 ±4 months. Baseline characteristics were well matched between groups except that a higher proportion of those with acute success were in SR at baseline (n=11, 28%, vs. n=6, 10%, p=0.022). During follow up, 68% (27/40) of patients with acute termination were free of arrhythmia recurrence compared with 50% (30/60) of those who required DCCV, a non-statistically significant difference of 0.18, p = 0.083. Binomial logistic regression was performed to evaluate the combined effect of acute termination and baseline SR on long-term outcome. The logistic regression model was not statistically significant (χ2 = 3.857, p = 0.145). For those undergoing first time procedures (n=81) ablation to SR vs DCCV freedom from recurrent arrhythmia was 74% vs 51% (p=0.041). In those in AF at baseline (n=83) ablation to SR vs DCCV freedom from recurrent arrhythmia was 69% vs 56% (p=0.048). Conclusion The relationship between acute ablation to SR and long-term outcome is unclear but may be important for certain subgroups. More work is needed to fully explore the significance of this endpoint. Conflict of Interest None