Feasibility of a No-Implant Approach to Interatrial Shunts: Preclinical and Early Clinical Studies.

Background: Heart failure with preserved ejection fraction represents a major unmet clinical need with limited treatment options. Recent device therapies under investigation have focused on decompression of the left atrium through an implantable interatrial shunt. Although these devices have shown favorable safety and efficacy signals, an implant is required to maintain shunt patency, which may increase the patient risk profile and complicate subsequent interventions requiring transseptal access. Methods: The Alleviant System is a no-implant approach to creating an interatrial shunt using radiofrequency energy to securely capture, excise, and extract a precise disk of tissue from the interatrial septum. Acute preclinical studies in healthy swine (n = 5) demonstrated the feasibility of the Alleviant System to repeatably create a 7 mm interatrial orifice with minimal collateral thermal effect and minimal platelet and fibrin deposition observed histologically. Results: Chronic animal studies (n = 9) were carried out to 30- and 60-day time points and exhibited sustained shunt patency with histology demonstrating completely healed margins, endothelialization, and no trauma to adjacent atrial tissue. Preliminary clinical safety and feasibility were validated in a first-in-human study in patients with heart failure with preserved ejection fraction (n = 15). All patients demonstrated shunt patency by transesophageal echocardiographic imaging at 1, 3, and 6 months, as well as cardiac computed tomography imaging at 6-month follow-up timepoints. Conclusions: Combined, these data support the safety and feasibility of a novel no-implant approach to creating an interatrial shunt using the Alleviant System. Continued follow-up and subsequent clinical studies are currently ongoing.