PulseSelect registered an adverse event rate of 0.7%. Medtronic said that marks one of the lowest adverse event rates of any previous FDA investigational device exemption (IDE) trial for AFib ablation or any multi-center PFA study.

The Pulsed AF trial exceeded the threshold for its efficacy performance goal, too. It demonstrated further clinical success through freedom from recurrence of any symptomatic atrial arrhythmias. That totaled at least 80% for each patient cohort.

Medtronic presented findings from Pulsed AF today at the American College of Cardiology’s Annual Scientific Session Together with the World Congress of Cardiology (ACC.23/WCC). It simultaneously published results in Circulation.

The Pulsed AF trial evaluates the safety and effectiveness of PFA technology for AFib ablation. PFA uses pulsed electric fields to efficiently isolate pulmonary veins to treat paroxysmal or persistent AF. Medtronic completed enrollment in November 2021. (Read more about what pulsed-field ablation is here).

Medtronic’s trial evaluates PulseSelect for treating AFib in adult patients. The patients have a history of drug-refractory, recurrent and symptomatic paroxysmal or persistent AFib. It treated 300 patients (150 with paroxysmal AFib and 150 with persistent AFib). The trial enrolled patients across 41 sites in nine countries.

Medtronic reports encouraging safety results

The Pulsed AF study exceeded its performance goal of freedom from a composite of serious procedure- and device-related adverse events. Both patient cohorts reported a 0.7% rate of primary adverse events. Medtronic received no reports of esophageal events, instances of pulmonary vein stenosis or phrenic nerve injury.

Dr. Atul Verma, electrophysiologist and director, Division of Cardiology, McGill University Health Centre in Montreal, served as principal investigator. 

“The results of PFA trials have been highly anticipated among the EP community to help us treat the growing number of AF patients around the world,” Verma said. “The high rate of 80% or more in clinical success and the promising safety and efficiency results from PULSED AF will help establish PFA as an exciting new option for patients.”

PulseSelect demonstrates strong efficacy, too

In addition to promising safety data, Pulsed AF exceeded the threshold for efficacy in both cohorts at 12 months. It demonstrated efficacy performance totaling 66% in paroxysmal AFib patients and 55% in persistent Afib patients.

The endpoint included a composite of measures based on efficacy endpoints across multiple radiofrequency and cryoablation studies. This included freedom from acute procedural failure, arrhythmia recurrence, repeat ablation, direct current cardioversion and left atrial surgery. It also included antiarrhythmic escalation through twelve months, excluding a 3-month blanking period.

Medtronic reported freedom from atrial arrhythmia recurrence at 12 months totaling 70% in the paroxysmal cohort. It totaled 62% in the persistent group. Clinical success — measured by freedom from recurrence of symptomatic atrial arrhythmias — totaled 80% for paroxysmal and 81% for persistent.

“Today’s findings demonstrate a critical achievement in the decade-long commitment we have made to researching PFA and underscores our confidence in the PulseSelect system,” said Rebecca Seidel, president of Medtronic’s Cardiac Ablation Solutions business. “We are taking the same comprehensive approach to PFA that we took with the introduction of the single-shot Arctic Front Advance cryoballoon, and that involves building a deep, extensive body of clinical evidence and strong collaboration with clinicians globally.

“The single-shot PulseSelect System, together with the focal Affera Sphere-9 mapping and ablation catheter, will allow us to offer a complementary suite of PFA technologies to help treat patients with AF and other arrhythmias.”

Analysts react to Medtronic’s PFA progress

BTIG analyst Marie Thibault explained in a report that Medtronic noted more rigorous AFib monitoring and endpoints compared to studies evaluating the Boston Scientific Farapulse and the Biosense Webster Varipulse systems. That may “muddy the comparison” between the early PFA technologies. However, she noted that “we do think PulseSelect can secure FDA approval.”

Thibault also pointed to other PFA devices in Medtronic’s portfolio. That includes the Sphere-9 PFA system thanks to Medtronic’s acquisition of Affera, completed in August 2022.

“We expect PFA technologies to be adopted quickly, as so far they seem to be faster and safer than thermal ablation approaches, and the single-shot approach to pulmonary vein isolation (PVI) is likely to take share from cryoablation,” Thibault said. “Whether efficacy will be improved is still an open question. We remain bullish on PFA as a technology class and note there are several other public and private players developing competing approaches.”

Needham analyst Mike Matson noted that, as results seem to support improved safety with PFA compared to thermal ablation, the efficacy appears similar.

Despite encouraging study results, Matson maintained a “Hold” rating on Medtronic.

“While the Pulsed AF trial results were positive in our view, we maintain our Hold rating on MDT given our expectation of below normal EPS growth in FY24 and FY25,” Matson wrote.