Abstract 11084: Procedural Parameters During Cryoballoon Ablation Predict Early Pulmonary Vein Reconnection and Atrial Fibrillation Recurrence

Abstract

Introduction: Cryoballoon ablation (CBA) is an established procedure for the management of atrial fibrillation (AF). We sought to assess procedural parameters as predictors of early PV reconnection and AF recurrence following CBA. Methods: 119 patients undergoing CBA for AF were included. Balloon temperature (BT) recorded by the console during CBA targeting each of the four pulmonary veins (PV) was monitored to determine the time needed to reach -15°C and -40°C from the start of the freeze. BT at 30 seconds (s), 60 s and the temperature nadir point were also recorded. Rewarming (thaw) time from the nadir point to 0 °C, was also determined. PVs were assessed for early reconnection and patients were followed for arrhythmia recurrence. Results: Early PV reconnection was identified in 39 (8.3%) of 471 PVs. BT was significantly colder in the absence of early PV reconnection (30 s: -33.5°C vs -29.5°C, p=0.001; 60 s: -41°C vs -36.5°C, p<0.001; nadir: -47°C vs -41.5°C, p<0.001). Early PV reconnection was associated with significantly shorter time to reach -15°C and -40°C (12s vs 14.5s, p=0.023; and 46s vs 75s, p=0.005) and longer rewarming time (7s vs 5.75s, p=0.012) (Panel A). A logistic regression model with the procedural parameters was created to predict early PV reconnection and the corresponding ROC analysis had an AUC=0.71 (Panel B). During an average follow-up period of 559 days, AF recurrence occurred in 51 (49%) patients. Kaplan Meier analysis showed better arrhythmia free survival for patients in whom BT decreased below -40°C in all PVs and patients who had no early PV reconnections, compared to patients where BT below -40°C was not achieved in at least one PV (Log Rank = 6.3, p=0.012) and patients who had PV reconnections (Log Rank = 4.1, p=0.043) (Panel C). Conclusions: Slower BT decline, warmer BT nadir, and faster rewarming time predict early PV reconnection. A lower rate of AF recurrence was associated with absence of early PV reconnections and achieving a BT below -40 °C in all PVs.