Prior antiarrhythmic drug use and the outcome of atrial fibrillation ablation

Atrial fibrillation (AF) ablation is generally performed after patients fail antiarrhythmic drug (AAD) therapy. Some patients have drug contraindications or choose to avoid a lifetime of drug therapy. Little is known about the impact of previous drug therapy on ablation outcomes. We evaluated AAD use before AF ablation and its impact on ablation outcomes.

We evaluated freedom from AF after ablation and patients' clinical characteristics by number of AADs failed in 1125 patients undergoing 1504 ablations. We also evaluated reasons why some patients did not receive prior drug therapy. Cox multivariate analysis examined factors predicting ablation failure. Patients failing more drugs before ablation were older (P = 0.001), had a longer duration of AF (P = 0.0001), were more likely female (P = 0.037), had more repeat ablations (P = 0.045), and less paroxysmal AF (P = 0.003). For patients with either paroxysmal or persistent AF, the number of drugs failed predicted AF recurrence (P = 0.0001). Other factors predicting AF recurrence following final ablation included age (P = 0.004), left atrial size (P = 0.002), female gender (P = 0.0001), and persistent AF (P = 0.0001). The reason for not receiving prior drug therapy was medical in 21.5% and patient choice in 78.5%. Number of drugs failed did not influence ablation outcome for patients with long-standing persistent AF (P = 0.352).

For paroxysmal and persistent AF patients undergoing ablation, those failing fewer AADs have different clinical characteristics than those who fail more drugs. Our study also suggests that the more drugs failed pre-ablation, the lower the freedom from AF post-procedure, possibly due to AF progression during drug trials.