Trial results for a study evaluating the 31 mm POLARx FIT cryoballoon in Atrial Fibrillation were posted on ClinicalTrials.gov on 2025-12-04, indicating that 86% of pulmonary veins achieved Grade 4 occlusion and a 79% single shot success rate.
Background
Atrial fibrillation (AFib) is the most common sustained cardiac arrhythmia, characterized by irregular and often rapid heartbeats that can lead to symptoms such as palpitations, shortness of breath, and fatigue. It significantly increases the risk of stroke, heart failure, and other cardiovascular complications. Current treatment strategies include medication for rate and rhythm control, and catheter ablation. Cryoballoon ablation is a widely used technique for pulmonary vein isolation (PVI), a cornerstone of AFib treatment, where extreme cold is used to create lesions that block abnormal electrical signals originating from the pulmonary veins. The effectiveness of cryoballoon ablation is closely tied to the ability to achieve complete and durable PVI, often assessed by the extent of lesion creation and the degree of vein occlusion.
Trial design
This completed study, identified as Phase NA, enrolled 20 participants with Atrial Fibrillation. The trial aimed to prospectively evaluate the extent of antral lesions created by the 31 mm balloon size of the novel POLARx FIT cryoballoon catheter. Investigators performed pre- and post-ablation high-definition 3D maps to quantify the lesion extent in patients with paroxysmal atrial fibrillation.
Key results
The trial results focused on the performance characteristics of the 31 mm POLARx FIT cryoballoon:
- The percentage of ablated left atrial posterior wall with the 31 mm balloon size POLARx FIT was a mean of 35.4% with a Standard Deviation of 13.8%.
- The percentage of pulmonary veins with Grade 4 occlusion using the 31 mm balloon size POLARx FIT was 86%.
- The percentage of pulmonary veins with a single shot success rate using the 31 mm POLARx FIT cryoablation catheter was 79%.
What this means
The posted results provide insights into the performance of the 31 mm POLARx FIT cryoballoon in patients with atrial fibrillation. The finding that 86% of pulmonary veins achieved Grade 4 occlusion suggests a high rate of acute procedural success in isolating the pulmonary veins, which is a critical goal of AFib ablation. A 79% single shot success rate further indicates the efficiency of the device in achieving isolation with a single application. The mean percentage of ablated left atrial posterior wall at 35.4% (SD 13.8%) provides a quantitative measure of the lesion size created by the cryoballoon. These data collectively suggest that the 31 mm POLARx FIT cryoballoon is effective in creating significant lesions and achieving high rates of pulmonary vein occlusion and single shot success, which are important indicators for durable AFib treatment outcomes.
Source
The information regarding these trial results was obtained from ClinicalTrials.gov, a public database of clinical studies. The results for the study NCT05881733, titled "Effect of a Bigger Cryoballoon on the Total Antral Lesion Size: Evaluation of POLARx FIT", were posted on 2025-12-04 on clinicaltrials.gov.