Tung R, et al. Late Breaking Clinical Trials: Clinical Innovations. Presented at: Heart Rhythm 2022; April 29-May 1, 2022; San Francisco (hybrid meeting).
Tung R, et al. Late Breaking Clinical Trials: Clinical Innovations. Presented at: Heart Rhythm 2022; April 29-May 1, 2022; San Francisco (hybrid meeting).
A novel catheter-based cardioneural ablation procedure reduced symptoms of vasovagal syncope by as much as 80% for patients with symptoms despite medical intervention and behavioral modification who did not desire permanent pacing.
Early published reports of cardioneural ablation have shown promise for the relief of autonomically mediated bradycardia; however, cases are typically performed on a compassionate basis and there is a paucity of data on of multicenter experiences, according to Roderick Tung, MD, FHRS, chief of cardiology at the University of Arizona College of Medicine, Phoenix.
“When we do catheter ablation, we are usually going after an arrhythmia, usually tachycardia,” Tung said during a press conference at Heart Rhythm 2022. “To use the same catheter tools and try to do neuromodulation is a paradigm shift. There is a particular group of patients that is relatively young and may experience a simple faint, which we call vasovagal syncope. Those people have a very severe cardioneural reflex. There are few good solutions for autonomic bradycardia. There is behavioral modification and medial therapy has failed. The idea that we can take a catheter and rebalance the neural wiring of the autonomic state of the heart is very novel.”
In a retrospective, nonrandomized study, Tung and colleagues analyzed data from 76 cardioneural ablation procedures performed for 71 patients across 13 U.S. centers from 2016 to 2022. The mean age of patients was 47 years and 51% were women. Of the procedures, 63% were performed as concomitant with primary ablation (86% AF/atrial flutter ablation; 7% ventricular tachycardia or premature ventricular contraction; and 7% supraventricular tachycardia).
Within the cohort, 82% remained free from syncope after a single procedure at a median of 8.5 months, showing a reduction of median episodes (6 to 0 episodes; P < .001) after cardioneural ablation. Researchers observed an increase in heart rate of more than 5 bpm in 70% of patients. Five patients underwent repeat ablations.
“By ablating six unique areas where the nervous system plugs into the heart, we were able to change the milieu of the heart and show acceleration of the heart rate after the procedure,” Tung said. “Those patients went on to have 80% freedom from fainting.”
Tung noted there are several limitations; there is currently no standard of care for cardioneural ablation and there was no uniformity in diagnosis, approach and follow-up. The duration of therapeutic effect is unknown and a multicenter, randomized, sham-controlled trial is needed to learn more, he said.
The rate of complications was low, Tung said.
“There were two patients who had some stunting of the heart rhythm that ordinarily would take a pacemaker, but many of them would get a pacemaker anyway,” Tung said. “It is an interesting study. There is no labeling for this and it is not FDA-approved, but we were able to accumulate these as-needed, compassionate-basis [cases] that have been done across different centers.”
Daniel J. Cantillon, MD, FACC, FHRS
This is an exploratory study that sets the sets the groundwork for more prospective, structured studies that have more clearly defined inclusion criteria, exclusion criteria and more structured diagnostic and referral criteria. These are patients have failed conventional therapies for these fainting disorders — abortive maneuvers and lifestyle modifications that we counsel our patients about, which, generally speaking, are very effective for most people diagnosed with these syndromes. There were some adverse events after ablation, including junctional rhythms, and that is a little concerning. Some of these structures are near normal conductive systems in the heart. If we are seeing junctional bradycardia, one has to wonder what the implications are. More information that needs to be flushed out, even with this dataset.
There is a definite need for some patients who have particularly aggressive, neurally mediated fainting disorders that have failed conventional therapy. This is a patient population for whom we sometimes struggle to meet their needs. The concept of an advanced procedural option is something worth exploring. I hesitate because of the complexity of the autonomic nervous system and the mixed experiences with other neuromodulation treatments. There is variation in how a patient experiences these disorders; the authors also acknowledged there is no standardized approach here.
The next step would be a more structured prospective study, with a more refined understanding of what the procedural goals are, the workflow and how they are applying this ablation strategy.
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