LEFT ATRIAL ELECTROANATOMIC SUBSTRATE AS A PREDICTOR OF ATRIAL FIBRILLATION RECURRENCE AFTER CIRCULAR RADIOFREQUENCY PULMONARY VEINS ISOLATION. OBSERVATIONAL PROSPECTIVE STUDY RESULTS

Aim. To evaluate an extent of left arrial (LA) electroanatomical substrate (EAS) by the method of high density contact mapping in patients with atrial fibrillation (AF) and estimate its impact on recurrence rate following circular radiofrequency pulmonary veins (PV) isolation in prospective observational study.

Material and methods. Totally 181 high symptomatic subjects with paroxysmal (142 pts) and persistent (39 pts) AF, who underwent circular RF PVI were enrolled. We created and prospectively analyzed LA electroanatomical high density bipolar maps. Bipolar signals ≤0.75mV, associated with local conduction velocity delay <1 m/s were tagged on LA maps and considered as EAS. Relative EAS areas outside PV ostia were consistently measured. All of the patients were followed up at least for 3 years and AF recurrence rate and redo procedures were recorded.

Results. A mean relative EAS area was 13.8±10.3% and 32.6±18.5% in patients with paroxysmal and persistent AF, respectively (P=0,02). During a mean follow-up of 32±7 months, AF recurrence was diagnosed in 69 (38%) of patients. Following a redo ablation in 51 (28%) of patients, subsequent AF recurrence developed in 31 pts (19%). Multivariate analysis showed that only relative EAS areas was independently associated with AF recurrence (HR 1.05, CI 95% 1.02-1.09, P=0.002) and ach 10% increase in the extent of relative EAS area was associated with a 1.6-fold elevation of AF recurrence rate after the index ablation. But the impact of the EAS on clinical outcome after redo ablation was even higher (HR =1,09, p=0,0018) and each 10% increase in the extent of relative EAS area was associated with a 2.4-fold elevation of AF recurrence rate after a redo ablation.

Conclusion. The present study suggests that an extent of LA EAS in patients undergoing PVI — is a significant and independent predictor of AF recurrence. This data can have important role for further development and personalization of strategy of interventional treatment in patients with AF.

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