The ADMIRE pivotal trial has provided valuable insights into the use of pulsed-field ablation (PFA) for treating paroxysmal atrial fibrillation (AF), demonstrating both its safety and effectiveness. This cutting-edge technique employs a variable-loop PFA catheter, which allows for shorter procedure durations and reduced fluoroscopy exposure.
“The ADMIRE trial confirmed that the variable-loop PFA catheter is safe and effective, showcasing shorter procedure and PFA application times, along with minimal fluoroscopy use,” the researchers reported in *Circulation*.
Atrial fibrillation, a common heart rhythm disorder, can lead to serious complications like stroke and heart failure. Paroxysmal AF, characterized by intermittent episodes, is particularly difficult to treat. Traditional ablation methods have limitations, including extended recovery periods and higher radiation exposure for both patients and medical staff.
As reported by medicaldialogues, earlier clinical trials of PFA systems for AF treatment have shown promise, suggesting that PFA can reduce the complications associated with traditional thermal ablation while maintaining efficacy. However, the lack of an integrated mapping system—a standard tool in modern electrophysiology—has hindered lesion creation and procedural efficiency. To address this, a novel variable-loop PFA catheter has been developed, integrating with an electroanatomic mapping system for real-time, nonfluoroscopic guidance, lesion indexing, and catheter-tissue proximity feedback.
In this context, Dr. Vivek Y. Reddy and colleagues at the Helmsley Electrophysiology Center, Mount Sinai Fuster Heart Hospital, New York, conducted the ADMIRE trial. This multicenter, single-arm study, approved by the FDA under an investigational device exemption, assessed the long-term safety and efficacy of the integrated PFA system in a large cohort of U.S. patients with symptomatic paroxysmal AF resistant to drug treatment.
Using the PFA catheter and an electroanatomic mapping system, patients underwent pulmonary vein isolation. The primary safety endpoint was the incidence of major adverse events within seven days post-ablation. The primary effectiveness endpoint was a composite measure over 12 months, including freedom from documented episodes of atrial arrhythmias, failure to achieve vein isolation, use of non-study catheters, repeat procedures (excluding one redo during the blanking period), or the need for new antiarrhythmic drugs or cardioversion post-blanking.
Key findings from the study include:
– A total of 277 patients (mean age 61.5 years; 64.3% male) underwent PFA across 30 centers.
– Over 25% of the procedures were performed without fluoroscopy. Median times for the procedure, fluoroscopy, and PFA application were 81.0, 7.1, and 31.0 minutes, respectively.
– The primary adverse event rate was 2.9%, with pericardial tamponade being the most common complication.
– The primary effectiveness endpoint at 12 months was 74.6%.
– After the blanking period, 75.4% of patients were free from atrial arrhythmia recurrence.
– Significant improvements in quality of life were reported as early as three months post-procedure, alongside a reduction in healthcare usage.
The ADMIRE trial confirms that pulsed-field ablation with the variable-loop catheter is a promising option for treating paroxysmal AF.
“This innovative technique, with its shorter procedure times and reduced fluoroscopy exposure, has the potential to greatly enhance patient outcomes and quality of life for those affected by this common heart condition,” the researchers concluded.