Coronary sinus electrogram characteristics predicts termination of AF with ablation and long-term clinical outcome.

Introduction- Markers predicting AF termination and freedom from AF/atrial tachycardia (AT) has been proposed. The role of CS electrogram characteristics has not yet been evaluated. Methods- Patients undergoing ablation for persistent AF as part of the Stochastic Trajectory Analysis of Ranked signals mapping study were included. Novel CS electrogram characteristics including CS cycle length variability (CLV) and CS activation pattern stability (APS) and proportion of low voltage zones (LVZs) were reviewed as potential predictors for AF termination on ablation and freedom from AF/AT during follow-up. The relationship between localized driver characteristics and CS electrogram characteristics were also assessed. Results- Sixty-five patients were included. AF termination was achieved in 51 patients and 80% of patients were free from AF/AT during a follow-up of 29.5±3.7 months. CS CLV of <30ms, CS APS of ≥30% and proportion of LVZ <30% showed a high diagnostic accuracy in predicting AF termination on ablation and freedom from AF/AT during follow-up (CS CLV OR 25.6, AUC 0.91; CS APS OR 15.9, AUC 0.94; proportion of LVZs OR 21.4, AUC 0.88). These markers were independent predictors of AF termination on ablation and AF/AT recurrence during follow-up. Ablation of a smaller number of drivers that demonstrate greater dominance strongly correlate with greater CS organization. Conclusions- Novel CS electrogram characteristics were independent predictors of AF termination and AF/AT recurrence during follow-up. These markers can potentially aid in predicting outcomes and guide ablation and follow-up strategies.