Abstract Body (Do not enter title and authors here):
Background:
A major challenge in improving atrial fibrillation (AF) ablation is understanding variability in patient’s response to ablation. While some are long-term responders, others recur within a month. Some of this variability may be attributed to progression of AF despite short-term success manifested by acute termination. Our objective was to use our rich clinical database to identify predictors of differential response to ablation.

Method:
We studied 597 consecutive patients with drug-refractory AF, enrolled prospectively for a uniform AF ablation strategy at Stanford Health. We applied logistic regression to 73 clinical variables to identify features associated with freedom from AF or atrial tachycardia (AT) at 1-3 years.

Results:
Patients (N=597) were 65.4±10.4 years, 29.0% female, BMI 29.6 kg/m2, 60.1% with non-paroxysmal AF, and 68.8% at de novo ablation. N=253 (42.4%) recurred at 1 year, N=101 (16.9%) within 1-3 years, and N=243 (40.7%) were free of AF beyond 36 months. One year success in adjusted analyses was associated with fatigue, prior ablation, PVI approach, beta-blocker usage, digoxin usage, and GDMT usage. AF progression at 3 years was associated in adjusted analyses with post-ablation asthma and post-ablation usage of direct oral anticoagulants. In addition, pre-ablation stroke and presenting rhythm was associated with both outcomes.

Conclusion:
In a large prospective AF registry, we identified features which differed between patients with 1-year success and 3-year success, as well as factors shared between endpoints. This data may provide mechanistic insights and help to guide and personalize ablation.