This is a brief overview of information related to FDA’s approval to market this product. See the links below to the Summary of Safety and Effectiveness Data (SSED) product labeling for more complete information on this product, its indications for use, and the basis for FDA’s approval.

Product Name: Boston Scientific Cardiac Cryoablation System and Accessories, consisting of: POLARx Cryoablation Balloon Catheter, POLARx FIT Cryoablation Balloon Catheter, SMARTFREEZE Cryoablation System Console
PMA Applicant: Boston Scientific Corporation
Address: 4100 Hamline Avenue North, St. Paul, MN
Approval Date: August 8, 2023
Approval Letter: Approval Letter

What is it?

Boston Scientific Cardiac Cryoablation System and Accessories are balloon-tipped catheters that use cold energy (gas) to treat people with symptomatic recurrent paroxysmal atrial fibrillation (PAF) who do not respond to medicine (drug refractory).

How does it work?

A doctor puts the balloon-tipped catheter through a small cut in a vein in the groin and moves the tip of the catheter up to the heart. The balloon is then inflated with cold gas at the opening of a vein that carries blood from the lung to the heart (pulmonary vein). The cold balloon is used to freeze (ablate) the heart tissue and block electrical signals that cause abnormal heart rhythms. This is repeated to treat all the pulmonary veins. The catheter is removed after treatment.

When is it used?

The Boston Scientific Cardiac Cryoablation System using the POLARx Cryoablation Balloon Catheters is indicated for the treatment of people with drug refractory, recurrent symptomatic paroxysmal atrial fibrillation (PAF). These catheters may be used as an alternative to medicine or other ablation catheters for treatment of recurrent symptomatic PAF.

What will it accomplish?

In a clinical study, 404 people with drug refractory, recurrent symptomatic PAF were selected to participate. At the completion of the study, 317 people were available for analysis one year after treatment. Of the 317 patients treated with the POLARx cryoablation catheter, 127 people (59.9%) did not experience an atrial fibrillation, atrial flutter, or atrial tachycardia recurrence one year after treatment. In addition, the clinical study was expanded to assess the safety and effectiveness of the POLARx FIT cryoablation catheter, which is intended to be used for people with cardiac anatomy that is not suited to the POLARx catheter. Fifty patients with drug refractory, recurrent symptomatic PAF were selected to participate in the additional study. The observed procedural success rate was 100% at 3 months after the procedure.

When should it not be used?

The catheters should not be used in people who have:

• An active systemic infection.
• A myxoma or an intracardiac thrombus (blood clot in the heart).
• A prosthetic heart valve (mechanical or tissue).
• Had a recent ventriculostomy (incision into a ventricle of the heart) or atriotomy (surgical opening of atrium).
• Pulmonary vein stents.
• Cryoglobulinemia, the presence of abnormal proteins in the blood.
• Conditions where insertion into or manipulation in the atrium (chamber in the heart) is unsafe.
• An intra-atrial septal patch or any other surgical intervention in or adjacent to the intra-atrial septum.
• An interatrial baffle or path.
• Hypercoagulopathy or an inability to tolerate anticoagulation therapy during an electrophysiology procedure.
• A contraindication to an invasive electrophysiology procedure where insertion or manipulation of a catheter in the cardiac chambers is deemed unsafe.
• A percutaneous left atrial appendage occlusion device, an alternate therapy to prevent stroke when in atrial fibrillation.

Additional information (including warnings, precautions, and adverse events):

• Summary of Safety and Effectiveness Data (SSED)
• Labeling
• PMA Database entry