Adjustable interatrial shunt for heart failure shows promise in first-in-human trial
A first-in-human study demonstrated early feasibility and safety for an adjustable interatrial shunt designed to regulate left atrial pressure in patients with advanced heart failure. Gregg W. Stone, MD, a professor of cardiology at the Icahn School of Medicine at Mount Sinai, presented the ATHENS-HF data at TCT 2025 and spoke with Cardiovascular Business about the study's findings.
ATHENS-HF evaluated a bi-atrial pressure-sensing shunt from Adona Medical that can be resized over time and provides continuous left and right atrial pressure monitoring. Adjustments to the device are performed in the catheterization lab.
“The shunt itself is made of a shaped memory nitinol, which is coated with an ePTFE material,” Stone said. A non-contact induction loop heats the nitinol, reducing the orifice from 12 mm to 5 mm before it is expanded to the desired size.
Stone reported favorable early safety and feasibility outcomes in the first 10 patients treated at two sites in Tbilisi, Georgia. The cohort consisted largely of advanced heart failure patients with reduced ejection fraction.
“The shunt was implanted successfully in all 10 patients. There were zero major adverse cardiovascular-neurologic events,” Stone said.
After 90-days, nine patients returned for reassessment.
“In nine out of nine patients, we could again adjust the size of the shunt anytime we wanted to, and they all were able to remotely transmit pressures," Stone said. “It worked pretty flawlessly.”
While the study was not designed to evaluate effectiveness, Stone noted encouraging clinical signals.
“Patients tended to feel better, their natriuretic peptides tended to go down,” he said.
Based on these results, a second study, ATLANTIS, is now enrolling approximately 20 patients. It will incorporate improved electronics and systematic shunt-size adjustments according to hemodynamics.
Interatrial shunts offer a new tool to treat heart failure
Stone said interest in interatrial shunt therapy has grown as clinicians look for new ways to manage elevated left atrial pressure, a major driver of heart failure symptoms and hospitalizations.
“There’s a lot of interest in atrial shunts for patients to the heart failure. Atrial shunts create a permanent, small communication between the left atrium and right atrium.”
This mechanism, he said, can redistribute blood from the left atrium when pressures rises, decreasing congestion through an autoregulatory mechanism.
Two earlier shunt systems have completed pivotal trials, but all prior devices used a fixed orifice. Stone said this is a limitation because, “some patients may need a smaller shunt, some patients may need a larger shunt, and the patient's condition may also change over time.” The new device incorporates atrial pressure sensors and a shunt that can be resized after implantation.
The system transmits atrial pressures to the cloud, using a wand in this early stage of development. In the future, Stone expects the transmission of data to be automatically done with a sensor under the patient's bed or with a wand. Patients can take readings at rest or during symptoms, and clinicians can adjust the shunt to meet changing physiologic needs.
Stone also placed the findings in the context of prior shunt research. Earlier trials of fixed-orifice devices have delivered mixed results, with benefits suggested only in certain subgroups. As he summarized, “overall negative results … but in the patients with reduced ejection fraction, they found marked clinical benefits… and so that's undergoing regulatory review right now.”
For patients who remain symptomatic despite guideline-directed therapy, Stone emphasized the unmet need driving innovation in this space.
“These patients have a tremendous clinical need,” he said. “This could be a lifesaving therapy for them.”
First interatrial shunt goes before the FDA
While there are a few of these devices in development, none have U.S. Food and Drug Administration (FDA) clearance. But the first device to be reviewed by the FDA will be discussed Dec. 3 by cardiology experts on the FDA Circulatory System Devices Panel Advisory Committee. The meeting will focus on the V-Wave Ventura Interatrial Shunt System, which gained an FDA breakthrough device designation in 2019.
The FDA has said this permanent implant is the first device of its kind aimed at heart failure patients with reduced ejection fraction (HFrEF). The committee will discuss the merits of the device based on clinical data and make recommendations to the FDA. The FDA usually, but not always, accepts the recommendations of its medical expert committee members.
Johnson & Johnson acquired V-Wave in October 2024 for $600 million, but the final total could reach $1.7 billion if regulatory and commercial milestones are met. FDA approval of the device is a major part of that.
Dave Fornell has covered healthcare for more than 17 years, with a focus in cardiology and radiology. Fornell is a 5-time winner of a Jesse H. Neal Award, the most prestigious editorial honors in the field of specialized journalism. The wins included best technical content, best use of social media and best COVID-19 coverage. Fornell was also a three-time Neal finalist for best range of work by a single author. He produces more than 100 editorial videos each year, most of them interviews with key opinion leaders in medicine. He also writes technical articles, covers key trends, conducts video hospital site visits, and is very involved with social media. E-mail: [email protected]