Time-to-isolation guided titration of freeze duration in 3rd generation short-tip cryoballoon pulmonary vein isolation - Comparable clinical outcome and shorter procedure duration.
BACKGROUND
The optimal freeze duration in cryoballoon pulmonary vein isolation (PVI) is unknown. The 3rd generation cryoballoon facilitates observation of the time-to-isolation (TTI) and thereby enables individualized cryoenergy titration. To evaluate the efficacy of an individualized freeze duration we compared the clinical outcome of patients treated with a TTI-guided ablation protocol to the outcome of patients treated with a fixed ablation protocol.


METHODS
We compared 100 patients treated with the 3rd generation cryoballoon applying a TTI-based protocol (TTI group) to 100 patients treated by a fixed freeze protocol (fixed group). In the fixed group a 240s freeze cycle was followed by a 240s bonus freeze after acute PV isolation. In the TTI group freeze duration was 180s if TTI was ≥30s and reduced to only 120s, if TTI was <30s. In case of a TTI >60s a 180s bonus freeze was applied.


RESULTS
Freedom from atrial arrhythmia recurrence off class I/III antiarrhythmic drugs after one year was not different between the TTI group (73.6%) and the fixed group (75.7%; p=0.75). Mean procedure duration was 85.8±27.3min in the TTI group compared to 115.7±27.1min in the fixed group (p<0.001). Mean fluoroscopy time was 17.5±6.6min in the TTI group and 22.5±9.8min in the fixed group (p<0.001).


CONCLUSIONS
TTI-guided cryoenergy titration leads to reduced procedure duration and fluoroscopy time and appears to be as effective as a fixed ablation strategy. A single 2-minute freeze seems to be sufficient in case of short TTI.
['Pott|Alexander|A|', 'Kraft|Christoph|C|', 'Stephan|Tilman|T|', 'Petscher|Kerstin|K|', 'Rottbauer|Wolfgang|W|', 'Dahme|Tillman|T|']
D000368:Aged D001281:Atrial Fibrillation D016022:Case-Control Studies D017115:Catheter Ablation D003452:Cryosurgery D005260:Female D005500:Follow-Up Studies D006801:Humans D008297:Male D008875:Middle Aged D011667:Pulmonary Veins D012189:Retrospective Studies D013997:Time Factors D016896:Treatment Outcome
Time-to-isolation Cryoballoon Ablation 2-Minute freeze Atrial fibrillation Short tip