Medtronic Highlights Improved Results with Affera PFA Technology

Medtronic has announced encouraging clinical outcomes from two studies evaluating its pulsed field ablation (PFA) technologies. These studies focused on the Affera family of solutions, including the latest Sphere-360 single-shot PFA catheter and the Sphere-9, a dual-energy focal PFA and mapping catheter. The findings were presented at the Heart Rhythm Society (HRS) 2025 Annual Meeting in San Diego, alongside additional data regarding Medtronic’s OmniaSecure defibrillation lead.
Affera’s technologies have been integrated into Medtronic’s broader PulseSelect PFA system, the first FDA-cleared platform specifically for treating atrial fibrillation (AFib). This integration allows for comprehensive visualization and electroanatomical mapping during procedures. Medtronic acquired Affera in August 2022 through a $1 billion deal, expanding its leadership in cardiac electrophysiology. In 2024, the company also secured FDA approval to explore the use of this system for ventricular tachycardia (VT) treatment.
Rebecca Seidel, president of Medtronic’s Cardiac Ablation Solutions business, emphasized the company’s dedication to innovation and patient care. “These results represent a significant step forward as we work to advance treatment options and solidify our leadership in electrophysiology,” she stated.

The Sphere-360 catheter, currently under investigation, is designed to simplify AFib procedures through efficient, durable ablations using pulsed field energy. Its unique design features a large, flexible lattice tip that delivers energy across its surface without requiring multiple rotations, a step that distinguishes it from traditional technologies. Additionally, it employs the smallest sheath size (8.5 Fr) among single-shot PFA devices.
A year-long, multi-center trial evaluating Sphere-360 in patients with paroxysmal AFib showed an impressive 88% rate of freedom from arrhythmia recurrence. Moreover, the device achieved durable pulmonary vein isolation (PVI) in 98% of targeted veins. No safety events were recorded among patients treated with the most optimized waveform settings. Medtronic plans to launch a pivotal U.S. trial for Sphere-360 later this year.
Dr. Vivek Reddy, director of cardiac arrhythmia services at Mount Sinai Health System, praised the system’s performance, noting its intuitive integration and potential to streamline procedures without sacrificing precision. He highlighted that Sphere-360’s design allows for efficient circumferential lesions without requiring catheter rotation, with a strong safety and efficacy profile.
The Sphere-9 catheter, another Affera innovation, utilizes a smaller 9 mm nitinol lattice tip to deliver both radiofrequency (RF) and pulsed field energy. In contrast to the Sphere-360, which is intended to address larger areas around the pulmonary veins, the Sphere-9 catheter is built for more precise, focal treatments — an important feature for performing linear ablations that are often paired with PVI when managing persistent AFib.

A detailed sub-analysis from the Sphere Per-AF IDE study showed that the Sphere-9 could safely and successfully create linear lesions, helping to boost the chances of sustaining a normal heart rhythm. Findings from the broader Sphere Per-AF trial ultimately supported the FDA’s approval of the Affera system in October 2024, reinforcing Medtronic’s leadership in the field of cardiac ablation therapy.