The significance of pulmonary veins isolation radiofrequency time and the evolution of left atrium volume on a twelve-year observational follow-up of paroxysmal atrial fibrillation patients.

AIMS: Pulmonary vein isolation (PVI) is the treatment of choice of paroxysmal atrial fibrillation (PAF). However, radiofrequency delivery at extra-PV sites may be additionally required. We compared clinical and procedural characteristics of patients undergoing PVI alone versus adjunctive extra-PV substrate modification, at first procedure and repeat procedures for AF recurrence.

METHODS

587 patients with PAF undergoing radiofrequency (RF) ablation were retrospectively included. Extra-PV ablation was performed in case of sustained AF despite PVI, or at re-do procedures without PV conduction recovery. Demographic, clinical and electrophysiological predictors of survival without re-intervention were analysed in patients' groups having undergone one (G1), two (G2) or three or more procedures (G3).

RESULTS

At baseline procedure, PV RF ablation time was shorter in G1 compared to G2/G3 whereas extra-PV RF ablation time was greater in G3 compared to G1. The proportion of patients requiring PV re-isolation decreased with repeat procedures. Smaller LA before procedure 1 (p1) or p2 was associated with PV reconnection at p2. Conversely larger LA before p1 was associated with extra-PV substrate modification at p2. Late re-do procedure timing (>1yr) was associated with increasing LA volume. Only longer PV and total RF time predicted poorer survival free from AF without re-intervention.

CONCLUSION

Longer PV RF time predicted requirement for re-ablation during follow-up. Smaller LA size predicted an increased probability of PV reconnection and decreased extra-PV substrate modification at p2. LA size decreased in patients undergoing early re-intervention, whereas it increased in patients undergoing re-intervention later on suggesting ongoing remodelling or progression.