FDA Approves Ablation Catheter for Atrial Fibrillation

The US Food and Drug Administration (FDA) has approved a new ablation catheter billed by its maker as the first such device on the U.S. market “that enables direct and real-time measurement of contact force” during procedures.

The Thermocool Smarttouch from the Johnson & Johnson company Biosense Webster markets itself for use in patients suffering from drug-resistant paroxysmal atrial fibrillation (AF), sustained monomorphic ischemic ventricular tachycardia, and Type I atrial flutter.

During catheter ablation, doctors insert a catheter through a small incision in the groin and push it up a blood vessel to the upper-left chamber of the heart. They then use radiofrequency energy to create lesions that block the faulty electrical impulses that can cause heart rhythm disorders.

Stable contact force from the radiofrequency energy applied to the heart wall during catheter ablation improves outcomes, according to a Biosense press release, which further noted that excess contact can result in tissue injuries and complications while insufficient contact can result in incomplete lesion formation and the need for additional treatment.

Normally, the contact between catheter tip and tissue must be estimated via indirect measures such as electrogram parameters and impedance. The Smarttouch, however, provides direct, real-time feedback on contact force via graphic display.

Researchers evaluated the Smarttouch as part of the SMART-AF Trial, a 12-month study with 172 subjects (72% male and 28% female) conducted at 21 treatment centers across the United States.

Overall success rates 1 year after treatment were 74%. However, in cases where the physician performing the procedure stayed within the targeted contact force range at least 85% of the time, 1-year success rates were much higher: 88%.

The biggest reported complications were 4 cases of tamponade.

“The Thermocool Smarttouch Catheter is an important new device that will benefit the electrophysiology community, as it will enable us to more precisely control the amount of contact force applied to the heart wall when creating lesions during catheter ablation,” said Andrea Natale, MD, primary investigator of the SMART-AF Trial and Executive Medical Director of the Texas Cardiac Arrhythmia Institute at St. David’s Medical Center in Austin, TX. “Data from the SMART-AF Trial demonstrated that consistent and stable application of contact force has a significant impact on patient outcomes. The use of contact force-sensing technology has emerged as a critical tool in delivering optimal outcomes in the treatment of patients with atrial fibrillation and represents a major advancement for the clinical community.”

AF, the most common heart rhythm disorder, afflicts 3 million Americans and will likely become more common as the population ages. It leads to an estimated 88,000 deaths in the U.S. each year by increasing the risk of conditions that range from heart valve disease, sleep apnea, and chronic fatigue to congestive heart failure and stroke.

Ablation was once hoped to offer a permanent cure for most AF patients, but recent studies — particularly those focusing on ablation as a first-line therapy — have documented high rates of recurrence in the 2 years after surgery, in part because of the incomplete lesion formation the Smarttouch is designed to reduce.