Pulse Biosciences Aims to Redefine AFib Ablation with FDA Trial Nod

HAYWARD, CA – December 18, 2025 – Pulse Biosciences has secured a critical go-ahead from the U.S. Food and Drug Administration (FDA) to begin a pivotal clinical trial for its novel cardiac ablation system, a move that could significantly alter the treatment landscape for millions suffering from a common heart rhythm disorder. The company announced it received Investigational Device Exemption (IDE) approval to initiate its NANOPULSE-AF study, which will evaluate the nPulse Cardiac Catheter System for treating paroxysmal atrial fibrillation (PAF).

The approval allows the Hayward-based bioelectric medicine company to test its proprietary Nanosecond Pulsed Field Ablation (nsPFA) technology in a multicenter U.S. study, representing a major step toward bringing a potentially safer and more efficient ablation solution to a rapidly growing market.

The Quest for a Safer Heart Fix

Atrial fibrillation (AFib) is the most prevalent cardiac arrhythmia worldwide, affecting tens of millions and significantly increasing the risk of stroke, heart failure, and mortality. Paroxysmal AF, characterized by intermittent, self-terminating episodes, is a common form of the condition that often progresses if left untreated. For decades, catheter ablation has been a cornerstone of rhythm control therapy, using thermal energy—either intense heat (radiofrequency) or extreme cold (cryoablation)—to create scar tissue in the heart and block the erratic electrical signals that cause AFib.

While effective, these thermal methods carry inherent risks due to their non-selective nature. The energy can damage adjacent non-cardiac structures, leading to rare but potentially devastating complications. These include atrioesophageal fistula, an often-fatal tear between the heart and the esophagus, and phrenic nerve injury, which can cause paralysis of the diaphragm. Complication rates for traditional ablation hover between 2% and 5%, with risks including cardiac tamponade (bleeding around the heart) and stroke.

The recent emergence of Pulsed Field Ablation (PFA) has been hailed as a breakthrough. Standard PFA uses microsecond-long electrical pulses to selectively destroy heart muscle cells through a process called electroporation, largely sparing other tissues. However, even these first-generation PFA systems are not without concerns. Studies have noted that the high-voltage energy can still generate significant heat, leading to potential blood clot formation, and some reports have flagged issues like microbubble formation and device-related complications.

The Nanosecond Difference: Precision Over Power

Pulse Biosciences is betting that the future lies in an even more refined approach: nanosecond PFA. The company’s nPulse system delivers ultra-short electrical pulses, on the order of nanoseconds rather than microseconds. This fundamental difference is designed to achieve cell death with meaningfully lower total energy, further enhancing tissue selectivity and potentially minimizing the collateral damage and thermal side effects seen with other systems.

"Unlike existing systems, which rely on microsecond energy delivery, our nanosecond PFA platform is designed to deliver meaningfully lower total energy with the potential to further reduce collateral injury to surrounding structures," said Dr. David Kenigsberg, Chief Medical Officer, Electrophysiology at Pulse Biosciences. He emphasized that the system is "specifically designed for pulmonary vein isolation," a key goal of AFib ablation.

The nPulse Cardiac Catheter itself incorporates an innovative design intended to streamline the procedure. It aims to create a complete, circumferential lesion around the pulmonary veins—the common source of AFib triggers—in a single, brief energy application. This could eliminate the tedious process of repositioning the catheter multiple times to create overlapping point-by-point lesions, a hallmark of many radiofrequency procedures.

Dr. Vivek Reddy, Director of Cardiac Arrhythmia Services at the Mount Sinai Fuster Heart Hospital, NY, and principal investigator of the study, highlighted the system's potential from his hands-on experience. "Based on my extensive hands-on experience with the nPulse Cardiac Catheter, the combination of a differentiated nanosecond pulsed-field energy source and thoughtful catheter design has the potential to deliver effective lesion formation with a favorable safety profile, while simplifying workflow in the EP lab," he stated.

A Pivotal Step in a Competitive Market

The FDA's IDE approval is more than a regulatory hurdle; it's a major validation of Pulse Biosciences' preclinical and early human data. The company has already been gathering real-world evidence in Europe, where an ongoing feasibility study has enrolled 150 patients with promising initial results. The new NANOPULSE-AF study will be a single-arm, prospective trial enrolling up to 145 patients with drug-resistant PAF across as many as 30 medical centers in the U.S. and Europe.

This milestone positions Pulse Biosciences to challenge established giants in the multi-billion-dollar cardiac ablation market. Companies like Medtronic, Boston Scientific, and Johnson & Johnson have already launched or are developing their own microsecond PFA systems, making the field intensely competitive. Success in the NANOPULSE-AF trial could allow Pulse to leapfrog these first-generation PFA technologies by offering a next-generation platform with a superior safety and efficiency profile.

"This FDA IDE approval is a major milestone for Pulse Biosciences and is a testament to the strength of our preclinical and human clinical data," said Paul LaViolette, Co-Chairman and CEO of Pulse Biosciences. "With the support of leading electrophysiologists, we believe our proprietary nanosecond PFA represents a next-generation energy modality with the potential to improve the safety, effectiveness, and efficiency of AF ablation through a simpler, clinician-friendly procedure."

The company anticipates sharing follow-up data from the study in 2026, which will be crucial for its path toward commercial approval. As the medical community increasingly adopts catheter ablation as a first-line therapy for AFib, the demand for safer and more reliable technologies is at an all-time high. The NANOPULSE-AF study will now put the promise of nanosecond precision to the test, with the potential to set a new standard for how atrial fibrillation is treated for years to come.