Follow-Ups Completed in Medtronic STOP-AF Trial


July 17, 2009

July 17, 2009 – Medtronic announced today the completion of a 12-month follow-up in the STOP-AF (Sustained Treatment of Paroxysmal Atrial Fibrillation) clinical trial evaluating the first cryoballoon catheter technology designed to treat paroxysmal atrial fibrillation: the Medtronic Arctic Front CryoAblation Catheter System.

After the study data are analyzed and filed with regulatory authorities, the results will be shared at an upcoming medical meeting. The system is approved for use in Europe, Australia and Hong Kong and is under investigational use in the U.S.

The Arctic Front system uses cryoablation, or freezing, to ablate heart tissue between the pulmonary veins and the left atrium. A coolant is released into the catheter’s balloon causing the balloon to freeze and ablate the heart tissue. Freezing helps the balloon maintain contact with the tissue being ablated.

“This catheter is designed to allow physicians to more efficiently and easily ablate than with a single tip ablation procedure,” said Kevin Wheelan, M.D., chief of staff at Baylor Heart and Vascular in Dallas and investigator in the STOP-AF trial. “In this trial, the cryoballoon's stability simplified the process for these types of cardiac ablation procedures.”

Medtronic recently acquired CryoCath LP and Ablation Frontiers LLC, which along with their existing EP Systems diagnostic and RF ablation catheters, collectively form Medtronic’s AF Solutions division.

The Medtronic Arctic Front CryoAblation Catheter System technologies used in the STOP-AF trial include: the Arctic Front cryoballoon catheter, which inflates and fills with coolant to ablate between the pulmonary veins and the left atrium; the FlexCath Steerable Sheath, which helps deliver and position the cryocatheter in the left atrium; the Freezor MAX Cardiac CryoAblation Catheter, which is a single-point catheter used to provide additional ablations; and the CryoConsole, which houses the coolant, electrical and mechanical components that run the catheter during a cryotherapy procedure.

This pivotal trial is studying the safety and efficacy of the Medtronic Arctic Front CryoAblation Catheter System in paroxysmal AF patients as compared to drug therapy. Patients were randomized to receive ablation therapy or common drug treatments. For every three patients enrolled, approximately two received an ablation and one was randomly assigned to the drug therapy group. Twenty-five U.S. and Canadian centers enrolled 245 patients who were followed for at least 12 months after the ablation procedure. Results will be submitted in consideration for FDA approval for the Medtronic Arctic Front CryoAblation Catheter System.

For more information: