, 2025-06-26 09:29:00
SAN DIEGO — Building on the success of a growing number of devices employing pulsed field ablation to control treatment-resistant paroxysmal atrial fibrillation (AF), a new spherical device produced the highest rate so far of sustained pulmonary vein isolation and freedom from the arrhythmia at 1 year.
The results, characterized as “unprecedented,” relate to the device’s multielectrode array that can map, pace, and ablate for a single-shot pulmonary vein isolation in most patients, according to Vivek Y. Reddy, MD, director of Cardiac Arrhythmia Services at the Mount Sinai Health System in New York City. Reddy presented data from the PULSAR IDE pivotal trial of the technology at the 2025 annual meeting of the Heart Rhythm Society.
The experimental evidence that ultra-rapid high-voltage electrical pulses provide more consistent and durable pulmonary vein isolation than radiofrequency and other commonly used forms of ablation led to the first approval in the US of a device for pulse field ablation in late 2023. Others quickly followed.
Durable AF Suppression an Unmet Need
Reddy said pulsed field ablation fills an unmet need in cardiology. “Creating durable pulmonary vein isolation is critical to improve the long-term freedom from recurrent atrial arrhythmia,” he said.
The Globe Pulsed Field System (Kardium Inc.) is a globe-shaped device with a diameter of about 30 mm that clinicians navigate to the pulmonary vein ostium with fluoroscopy. There are 122 gold-plated electrodes mounted on the 16 ribs that provide the structure for the sphere.
The multicenter single-arm trial enrolled 164 patients directly into the pivotal trial; 19 others were rolled in from an earlier phase study. All 183 patients had treatment-resistant or treatment-intolerant paroxysmal AF.
On the primary efficacy endpoint of freedom from treatment failure 1 year after the procedure, 78% achieved durable control of AF. The only safety event was a hemorrhagic stroke in a patient with severe hypertension. No procedural safety events were reported.
“The efficacy result is likely approaching the limit of what we can achieve with pulmonary vein isolation alone,” Reddy said.
New Device Maps Electrical Activity
The spherical shape was inspired by preclinical data suggesting higher electrical field strength and greater proximity to cardiac tissue are among the variables that determine the durability of pulmonary vein isolation. However, the Globe Pulse Field device also is able to calculate atrial chamber geometry and map electrical activity in order to deliver pulsed field ablation for what Reddy called “single-shot” pulmonary vein isolation.
In a smaller first-in-human study with the device, 21 patients were assigned to either single-shot ablation or to a sequence of three pulses, but researchers observed no difference in the rate of success (100% in both groups) or in adverse events (zero in both groups). Procedure time was shorter (73.2 vs 93.7 minutes, respectively), and the proportion of patients with durable pulmonary vein isolation (100% vs 30%, respectively) was higher after the “single-shot,” according to Reddy, who was also the senior author of the pilot study.
In the PULSAR IDE trial, the mean mapping time was 9.1 minutes, the mean transpired ablation time was 25.5 minutes, the median left atrial catheter dwell time was 59.9 minutes, and the median procedure time was 95.8 minutes.
In a 33-patient substudy that looked for moderate or severe pulmonary vein narrowing, no such events were seen.
Pulsed field ablation is a nonthermal but irreversible form of ablation that causes cell death by several mechanisms but acts preferentially on myocardial tissue while sparing the esophagus and phrenic nerve, Reddy said.
In the pivotal PULSED AF trial for the first approved pulsed-field ablation device, PulseSelect (Medtronic), 66.2% of patients achieved the composite efficacy endpoint of freedom from procedural failure and recurrence of arrhythmia. PulseSelect is not spherical. This device has nine electrodes and includes mapping and precision delivery of energy, according to promotional descriptions.
Pivotal trials with the subsequently approved FARAPULSE (Boston Scientific) and VARIPULSE (Johnson & Johnson) devices generated similar results using comparable measures of effectiveness. In the ADVENT trial of the FARAPULSE device, 73.3% of patients achieved the primary efficacy endpoint. In the AdmIRE trial of VARIPULSE, roughly 75% of patients reached the primary efficacy endpoint.
Dhanunjaya D.J. Lakkireddy, MD, executive director of the Kansas City Heart Rhythm Institute in Overland Park, Kansas, called the latest data encouraging, but “one has to be cautiously excited about these supersized single-shot systems,” he warned.
Large single-shot devices like Globe Pulsed Field are effective for rapid ablation, but they have the potential for “collateral effects on the atrial and neighboring ventricular myocardium.” The chances of such damage over the long term are “largely unknown.”
Reddy reported financial relationships with more than 50 pharmaceutical and device companies, including Kardium, which provided funding for the PULSAR IDE trial. Lakkireddy reported no relevant conflicts of interest.
Ted Bosworth is a medical journalist in New York City.
