First Expandable Cryoballoon Catheter Gets FDA-Approval

Boston Scientific Corporation has announced that the POLARx™ cryoablation system—which features the POLARx™ FIT cryoablation balloon catheter—has received approval from the US Food and Drug Administration (FDA) for the treatment of patients with paroxysmal atrial fibrillation.¹

While traditional ablation procedures require the completion of the time-consuming task of changing out different catheters to find the proper fit, cryoablation is a procedure where an adjustable balloon catheter delivers cryotherapy to the pulmonary vein and freezes the problematic tissue. This creates scarring that blocks irregular electrical signals. The POLARx™ cryoablation system allows physicians to adjust and expand the POLARx™ FIT balloon—sized at 28 mm and expandable to 31 mm—to personally fit the patient’s heart anatomy during an ablation procedure. This feature increases the range of different pulmonary vein anatomies that the physician can treat. The system also allows physicians to create scarring in optimal positions to better treat the tissue of origin in the heart that is causing atrial fibrillation.¹

The approval of this system is supported by results from a global, prospective, non-randomized, single-arm, 12-month long study (FROZEN-AF IDE; ClinicalTrials.gov Identifier: NCT04133168) presented at Heart Rhythm 2023.¹ Researchers enrolled 385 patients with paroxysmal atrial fibrillation to find the safety and efficacy of the POLARx™ cryoablation system. The primary safety endpoint of a composite of acute and chronic primary safety events was achieved throughout the length of the trial (12 months) with an event-free rate of 96.3%.² The primary efficacy endpoint of the rate of freedom from postprocedure treatment failure was 79.9% at the end of the trial. There were also no reports of moderate or severe pulmonary vein stenosis, persistent phrenic nerve palsy, or esophageal fistulas experienced postprocedure.

Fifty of the patients were treated with at least 1 application of the 31 mm cryoballoon and are included in an extension arm substudy for the FIT balloon catheter, which will be followed for 12 months. The substudy has passed the 6 month mark of follow-up and the event-free rate is 100%, with a rate of freedom from postprocedure treatment failure of 88.0%.²

“…the combination of maneuverability and variable balloon sizes makes this system particularly useful in addressing longstanding challenges with varying cardiac anatomies and brings to the table occlusion capabilities physicians aren’t used to seeing with traditional systems,”¹ the study authors wrote. The ability of this device to adapt to a patient’s individual anatomy shows promise in the successful treatment of paroxysmal atrial fibrillation.