New research suggests that cryoablation is a safe and effective approach to closing congenital patent foramen ovale (PFO) in patients with atrial fibrillation (AF) undergoing pulmonary vein isolation (PVI) as part of a single procedure. A study published in the journal Heart Rhythm details this alternative method to the conventional treatment of implementing a percutaneous metal device for PFO closure—which carries the risk of adverse events like infection and arrhythmia.
PFO is associated with a variety of disorders, including cryptogenic stroke, transient ischaemic attack (TIA), migraine and decompression sickness. And, while percutaneous device occlusion is currently the standard therapeutic option for PFO-related ischaemic stroke, there are risks linked to implantation of this permanent device—for example, infection, pericardial effusion, device displacement, thrombus development, and arrhythmia. Furthermore, a metal occluder obstructs future access to the left atrium in interventional treatments like catheter ablation for AF, mitral valve clamping, and left atrial appendage occlusion (LAAO).
The present study in Heart Rhythm outlines the first use of cryoablation—a minimally invasive procedure that uses extreme cold—to induce PFO closure.
Co-lead investigator of the study Jiang Deng (Yongchuan Hospital of Chongqing Medical University, Chongqing, China) noted: “The pursuit of an ideal PFO closure method without a residual device is a compelling endeavour. Our aim was to investigate the efficacy and safety of PFO closure using cryoablation without implantation in patients with atrial fibrillation who underwent PVI. We postulated that cryoablation can also fuse PFO by injuring the primary and secondary septum.”
Co-lead investigator EnRun Wang (First Affiliated Hospital of Chongqing Medical University, Chongqing, China) added: “Although AF and PFO are both risk factors for stroke/TIA, it is difficult to determine whether PFO is involved in the development of stroke when the two disorders co-occur. The advantages of PVI in conjunction with PFO closure are unknown. Our aim was to investigate whether atrial septal (AS) cryoablation could lead to secondary PFO closure in individuals with AF who undergo PVI.”
The study enrolled a group of 22 patients with symptomatic drug-refractory paroxysmal or short-time persistent AF and PFO who were admitted for PVI via cryoablation from the First Hospital of Chongqing Medical University. Eligible patients were divided into the standard PVI-plus-AS cryoablation group and the standard PVI group. The study was designed to determine the PFO closure rate, procedure-related complications, the recurrence of AF, and stroke/TIA events.
Patients who underwent AS cryoablation had a significantly higher rate of successful PFO closure than individuals who only had balloon inflation. There was no difference in procedure-related adverse events, AF recurrence, and ischaemic stroke/TIA events, across both groups.
Nir Flint (Tel Aviv Sourasky Medical Center/Tel Aviv University School of Medicine, Tel Aviv, Israel), co-author of an accompanying editorial commentary, stated: “The notion of a ‘no-footprint,’ device-free, percutaneous PFO closure presents potential benefits. This procedure theoretically mimics the physiologic healing and closure of the PFO by inducing inflammation and scarring, creating an anatomic closure of the interatrial septum. This approach minimises the adverse events associated with artificial materials and allows future interventions if needed.”
Eyal Ben-Assa (Assuta Ashdod University Hospital/Ben Gurion University, Ashdod, Israel), co-author of the commentary, concluded: “This study presents an innovative approach to PFO closure by cryoballoon ablation, showcasing its potential as a device-free alternative. The authors wisely performed this procedure on patients undergoing ablation of AF with a ‘closing-the-door-on-your-way-out’ approach. Whereas preliminary results are promising, further research is needed to enhance efficacy and to confirm safety. This technique could pave the way for new strategies in PFO management, particularly for patients undergoing ablation procedures.”
