Boston Scientific Advisory: Cardiac Cryoablation System

Impacted Models

POLARx and POLARxFIT cryoablation catheter used in conjunction with the SMARTFREEZE console.

Issue Summary

Since commercial introduction of the POLARx Cryoablation System in 2020, Boston Scientific has received seven reports worldwide of AE fistula occurring after atrial fibrillation ablations, four of these reports have resulted in patient death. Boston Scientific reports to date this cryoballoon ablation system has been used in approximately 69,000 cases worldwide.

After a thorough review of the individual cases, including available data from the consoles, there were no identifiable product performance related concerns noted. However, some of the operators did report a higher frequency and intensity of cryoablation applications, than studied in the FROzEN AF clinical trial, which likely contributed to the outcomes. Therefore, Boston Scientific is updating their product instructions for use to mitigate the risk for this life-threatening complication.

Appropriate regulatory agencies including the FDA have been notified of these updates.

Boston Scientific Recommendations

Review the instructions for use updates and specifically, the table for cryoablation parameters that specifies the ideal number of applications, balloon temperature, and duration of ablation lesions, for use of their system. Notably, their recommendations are different from those of other manufacturers of cryoablation technologies, as their balloon is different.

Most importantly:

• Utilize the minimum number of cryoablation applications necessary to achieve PV isolation, and avoid immediately repeating ablations in the same location
• Stop the ablation if the balloon temperature decreases to -65C

HRS Recommendations

HRS strongly encourages its members who use the POLARx cryoablation system worldwide to read and follow the updated Boston Scientific Instructions for use of their system. At present, there is no indication that their system is not safe and effective, if used in accordance with the instructions for use.

One key message from the analysis and from parameters reported in the FROzEN AF clinical trial is that this cryoballoon ablation system is different from other cryoballoon ablation systems and should be treated as such – requiring individual learning curve with this system.

Reporting Adverse Reactions or Quality Problems

Adverse reactions or quality problems experienced with the use of this product should be reported to the FDA’s MedWatch.

Adverse Event Reporting program either online, by regular mail or by fax.

• Complete and submit the report Online: www.fda.gov/medwatch/report.htm
• Regular Mail or Fax: Download form or call 1-800-332-1088 to request a reporting form, then complete and return to the address on the pre-addressed form, or submit by fax to 1-800-FDA-0178

If further support is required, contact your local Boston Scientific sales professional.