PFO - Patent Foramen Ovale clinical trials

A Comparison of Biodegradable and Metal Occluders in Patients With PFO and Migraine

Migraine is one of the most common chronic neurological disorders, posing a significant global public health concern. Patent Foramen Ovale (PFO) is the most common congenital heart anomaly in adults. Mechanisms linking PFO to migraine include cortical spreading depression, vascular active substance theory, impaired cerebral autoregulation, and genetic susceptibility. Understanding these mechanisms holds promise for overcoming challenges in the prevention and treatment of migraines in PFO patients. At least 11 observational studies, comprising 1,632 subjects, described the efficacy of PFO closure in cryptogenic stroke. Of these, 34% had migraines, and percutaneous PFO closure reportedly reduced migraine days by 81% (with a reduction of over 50% in monthly migraine days). Prospective randomized controlled trials (PRIMA and PREMIUM trials) assessing the Amplatzer® PFO Occluder showed significant benefits in most secondary endpoints, with a pooled analysis indicating its safety and effectiveness compared to medical therapy.While traditional metal PFO closure studies suggest symptom relief, reports also mention potential new-onset or worsened migraines post-closure. Proposed mechanisms include platelet activation, microthrombus formation, nickel allergy, and septal deformation or stretching inducing the release of migraine-related vascular active substances. However, these theories are closely tied to the presence of permanent metal implants. Addressing these concerns, the MemoSorb® biodegradable PFO Occluder system, approved by the National Medical Products Administration (NMPA) in September 2023, offers an innovative solution. Developed collaboratively by the National Biomedical Materials Engineering Technology Research Center, Professor Wang Yunbing's team, Professor Pan Xiangbin's team from Fuwai Hospital, Chinese Academy of Medical Sciences, and HeartTech Medical, this groundbreaking technology represents a shift from metal to degradable materials. The occluder serves as a temporary bridge post-implantation, gradually degrading with endothelialization, facilitating comprehensive self-repair. This intervention concept theoretically avoids the lifelong complications associated with traditional metal occluders, effectively reducing postoperative symptoms like migraines and dizziness. To assess and compare the treatment outcomes, especially in relieving migraines, a prospective, single-blind, randomized controlled study has been designed for patients with patent foramen ovale and migraine, comparing the novel biodegradable occluder with the metal occluder.