Boston Scientific Takes the Lead in Pulsed Field Ablation Race

Pulsed field ablation (PFA) has been touted as a promising new ablation modality for the treatment of atrial fibrillation (AF) – and Boston Scientific may have just taken the lead in a race for PFA market share.

Positive 12-month results from the pivotal ADVENT trial of the company's Farapulse PFA system were presented at the annual meeting of the European Society of Cardiology on Sunday and published in The New England Journal of Medicine.

Boston Scientific acquired Farapulse last year. The device, designed to deliver a nonthermal treatment in which electric fields selectively ablate heart tissue in patients with atrial fibrillation (AF), has a CE mark already. Analysts suspect the 12-month results from the ADVENT trial are likely to help the company win FDA approval in 2024.

In this multicenter, prospective and randomized controlled trial, 607 patients in the United States with paroxysmal AF who had previously been unsuccessfully treated with at least one anti-arrhythmic drug were enrolled.

The ADVENT trial results weren't perfect, however. The study did show that pulsed field ablation with the Farapulse device is non-inferior to standard of care thermal ablation (radiofrequency and cryoballoon) at 12 months, which was the primary endpoint. The device did not meet the secondary effectiveness endpoint for superiority.

Farapulse PFA was also non-inferior to thermal ablation for the primary safety endpoint, even though there was one death in the PFA arm from mechanical trauma and puncture. The PFA arm had one transient ischemic attack, two cardiac tamponade/perforation, one pericarditis, and one vascular access complication. The thermal arm of the study had one stroke, one pulmonary edema, and two vascular access complications.

"While any patient death is alarming, the presenter pointed out that a real-world European Farapulse registry has shown just one death out of 1,568 patients (0.06%)," Marie Thibault, a medtech analyst at BTIG, wrote in her report Sunday. "We do not think the death in the ADVENT trial is a major cause for concern about the technology."

On the secondary safety endpoint, which measured change in the cross-sectional area of the pulmonary veins at 90 days, the pulsed field ablation device was superior to thermal ablation. The ADVENT trial also showed that the mean procedure time was significantly shorter with PFA (mean of 29.2 minutes with a standard deviation of 14.3 minutes) compared to the thermal arm (mean of 50 minutes with a standard deviation of 24.6 minutes).

"With PFA offering a faster ablation approach that is at least as effective and safe as the standard of care even though operators had little experience with the new technology, we expect U.S. electrophysiologists will adopt PFA as enthusiastically as their peers in Europe," Thibault wrote, noting that FDA approval for Farapulse is anticipated in 2024. "We think these results were in line with to slightly better than many investors expected, though we expect some focus on the death in the PFA arm."

Mike Matson, a medtech analyst at Needham & Co., also pointed out that the ADVENT trial design could provide a marketing advantage to Boston Scientific.

"While ADVENT is a randomized trial comparing PFA with Farapulse to [radiofrequency and cryoballoon], [Boston Scientific's] key competitors' PFA trials are not randomized controlled trials," Matson wrote in his report Monday. "We think that ADVENT's more rigorous design provides a marketing advantage to [Boston Scientific] since the trial hit its primary safety and efficacy non-inferiority endpoints and its secondary safety superiority endpoint."

The Farapulse device received CE mark in 2021 and has been used to treat more than 25,000 patients globally to date.

"Excellent overall clinical performance of the FARAPULSE PFA System was seen in this study, particularly the high rate of freedom from atrial arrhythmias and the very low rate of safety events, which is impressive given the rigor of the trial design and monitoring protocols utilized," said Vivek Reddy, MD, study principal investigator and electrophysiologist at Mount Sinai Hospital, New York. "These highly anticipated findings, together with extensive prior data from Europe, solidify PFA therapy with this system as a preferred ablative treatment modality."

The race for pulsed field ablation market share is intense

Treating AF with ablation (electrophysiology/EP) is an $8 billion market with a long runway, according to Travis Steed, a medtech analyst at Bank of America. Steed estimates that only about 15% of the eligible 2.5 million U.S. patients with AF are currently being treated with ablation (worldwide, around 650,000 ablations versus 35 million patients with AF, he notes).

In a February 24 report, Steed wrote that pulsed field ablation looks to be safer and faster and could potentially revolutionize the way ablations are done today and expand the market. The key question comes down to data, as PFA must continue to prove durability and safety in line with thermal-based options such as radiofrequency ablation or cryoablation, the analyst noted.

"Our doc conversations suggest that physicians want to see data on each platform as all PFA systems are not created equal," Steed wrote.

In March, Medtronic received a CE mark for its Affera mapping and ablation system, which includes the Sphere-9 catheter and the Affera Prism-1 mapping software. Together, Medtronic said the full system creates a new paradigm in electrophysiology through the integration of the Sphere-9 pulsed field ablation, radiofrequency, and high-density mapping catheter, which maps and ablates atrial arrhythmias (fast, abnormal heart rhythms) and provides real-time feedback through mapping and navigation software.

The Sphere-9 catheter, coupled with the integrated mapping and navigation system, is designed to quickly generate sophisticated electro-anatomical maps allowing the physician to deliver wide-area focal ablation lesions of choice between radiofrequency or pulsed field ablation, based on the patient and procedure needs. Given its size, the all-in-one catheter's nitinol 9mm ablation tip has the potential to require fewer focal ablation lesion applications that may result in lower procedure times than standard irrigated ablation catheters, Medtronic said. The mapping software is designed to enable an optimized user experience by delivering streamlined insights and feedback to support procedure performance.

Read more about the competitive landscape of pulsed field ablation, including private players, here.