Year in Review: Pulsed-Field Ablation Again Tops Heart Rhythm News

Pulsed-field ablation (PFA), which was first approved in the United States early in 2024, continued to drive news within the field of heart rhythm disorders this past year, with evidence around left atrial appendage occlusion (LAAO) and conduction-system pacing also continuing to accumulate.

Mina Chung, MD (Cleveland Clinic, OH), president of the Heart Rhythm Society (HRS), told TCTMD that PFA has largely displaced thermal modalities (radiofrequency and cryoballoon) for most atrial fibrillation (AF) ablation procedures.

“We’ve seen a lot of encouraging results for its efficacy, improving durability and, especially, safety,” she said. “I think that’s where the most important aspect has come in and has expanded our scope of application to patients that may have been excluded due to higher risk.”

Due to its mechanism of action and specificity for myocardial tissue, PFA carries lower risks of damage to surrounding structures, preventing atrioesophageal fistula, pulmonary vein stenosis, and phrenic nerve paralysis.

In 2025, two large registry studies—NEMESIS-PFA and MANIFEST-US—highlighted the overall safety of PFA but also revealed small risks of rarer complications like coronary vasospasm, hemolysis, and renal dysfunction. Use of the Varipulse PFA system (Johnson & Johnson MedTech) was halted for about a month early in the year in response to four neurovascular events, with a company investigation indicating that risk of such events “may increase if a high number of ablations, the stacking of ablations, and/or ablations outside of the pulmonary veins are delivered.”

The field also saw additional randomized trials of PFA, including the first sham-controlled trial (PFA-SHAM) and head-to-head comparisons of the Farapulse system (Boston Scientific) against cryoballoon (SINGLE SHOT CHAMPION) and radiofrequency (BEAT PAROX-AF) energy sources.

New PFA catheters continue to come out, including those that can deliver both pulsed-field and radiofrequency energy, and there is emerging evidence that PFA may be useful for treating ventricular tachycardia.

“We’re still looking forward to many more improvements, including improvements in incorporating high-density electroanatomic mapping with the catheters,” Chung said. “This is an exciting time for electrophysiology.”

The HRS recently announced that it will be developing a PFA data collection platform to gather real-world procedural results. It will incorporate advanced automation, artificial intelligence (AI), and electronic health record integration to reduce burden on participating sites.

The new platform “could be transformative” when it comes to tracking the results of PFA, including complications and patient outcomes, Chung said, adding that the aim is to launch some pilot sites in early 2026 and eventually ramp up to full implementation by 2027.

Ablation in Ambulatory Surgical Centers

The US Centers for Medicare & Medicaid Services (CMS) delivered big news for electrophysiologists in November by adding cardiac catheter ablation to its list of covered procedures when performed in ambulatory surgical centers (ASCs).

The announcement, spelled out in the 2026 Hospital Outpatient Prospective Payment System (OPPS) and Ambulatory Surgical Center (ASC) Payment System final rule, came shortly before the HRS and the American College of Cardiology (ACC) released a scientific statement laying out guiding principles around the performance of ablation in ASCs—a “guardrails type of document,” according to Chung. Earlier in the year, HRS/ACC released a statement on same-day discharge after ablation.

“Expanding PFA into ASCs is unquestionably a win for patient access, but it also creates an important downstream policy question,” Chung said. “CMS needs to ensure that broadening site-of-service options doesn’t inadvertently destabilize reimbursement in the hospital setting, where the most complex EP patients are treated and where the cost structure is fundamentally different.”

The goal of HRS, she continued, “is to widen access without undermining the capacity of hospitals to deliver high-acuity rhythm care. AF ablation catheters, imaging and mapping equipment, and anesthesia needs can be complex; we do not want the use of these efficacy- and safety-enhancing technologies to diminish due to a need to reduce costs in an ASC or in a hospital outpatient setting.”

Chung noted that not all patients who require an ablation will be suitable for treatment at an ASC.

“We need to assure that appropriate patients are selected for doing these procedures in ASCs; that good clinical practice and standards are upheld, including standards for the facility, physician, and staffing requirements; and that discharge requirement criteria, emergency care plans, and transfer protocols are in place.”

New LAAO, Anticoagulation Insights

In 2025, the Society for Cardiovascular Angiography and Interventions (SCAI) and the HRS released their first practice guideline on LAAO, following up on a 2023 expert consensus statement.

The year also included news around a US Food and Drug Administration warning about air embolism risks with some access systems for the Watchman FLX device (Boston Scientific); potential differences in longer-term outcomes between the Amplatzer Amulet (Abbott) and Watchman 2.5 or Watchman FLX devices in SWISS-APERO; and antithrombotic therapy choices after LAAO in the EMERGE LAA postapproval study.

One of TCTMD’s top stories of 2025 covered the results of the CLOSURE-AF trial, in which LAAO failed to meet criteria for noninferiority compared with standard medical care that included anticoagulation in high-risk patients with AF. The rate of stroke, systemic embolism, cardiovascular/unexplained death, or major bleeding was higher in the LAAO arm (16.82 vs 13.27 per 100 person-years).

Additional data on the comparison of LAAO with oral anticoagulation are on the way from trials like CHAMPION-AF and CATALYST in lower-risk patients and LAAOS-4 in higher-risk patients. “It goes to show you that we’re still very concerned over the very high-risk patients,” Chung said. In that group, she added, “you wonder about the rest of the atrium that may have substrate and milieu for thrombus generation outside of the left atrial appendage.”

Regarding LAAO, Chung said, “we’re not at the end of the story yet.”

Following publication of the OPTION trial results late in 2024, this year also saw additional data informing the management of patients after successful AF ablation. The standard approach has been to keep these patients on long-term oral anticoagulation, but researchers have started to explore whether patients with a low burden of AF after the procedure can either forego anticoagulation altogether or use it as-needed in response to monitoring with wearable or implantable devices (as in the ongoing REACT-AF trial).

In OCEAN, which included low-risk patients randomized after successful AF ablation, outcomes over 3 years were similar in those treated with aspirin and those treated with rivaroxaban (Xarelto; Bayer/Janssen). And in ALONE-AF, which included patients who were free from atrial arrhythmia recurrences for at least a year after ablation, stopping versus continuing oral anticoagulation lowered the risk of stroke, systemic embolism, or major bleeding through 2 years of follow-up.

Conduction-System Pacing and More

Among other developments in heart rhythm disorders, Chung pointed to the continued accumulation of data on conduction-system pacing. In patients who require cardiac resynchronization therapy (CRT), for instance, left bundle branch pacing provided better results compared with traditional biventricular pacing in the randomized HeartSync-LBBP trial and left bundle branch area pacing performed better than biventricular pacing in the nonrandomized International Collaborative LBBAP Study (I-CLAS).

Moreover, in patients with atrioventricular block who didn’t have an indication for CRT, conduction-system pacing reduced pacing-induced cardiomyopathy and the need for a biventricular CRT upgrade compared with ventricular septal pacing in the randomized CSPACE trial.

The year also saw continuing developments in the use of AI for ECG analysis, particularly when integrated into wearable devices. Chung highlighted the FDA clearance that Google received for its “loss of pulse detection” feature integrated into its Pixel Watch 3; a loss of pulse triggers a call to emergency medical services.

“That’s really exciting,” Chung said, touting a focus of HRS on improving outcomes after sudden cardiac arrest. The society has a task force working on sudden cardiac arrest, CPR and automated external defibrillator education, and implementation of the HEARTS Act, which aims to prevent sudden cardiac arrest in young people. The American Heart Association launched a sudden cardiac arrest task force in 2025 as well.