The first in-human trials of a no-implant approach to interatrial shunting to alleviate heart failure symptoms have shown a signal that the procedure reduces peak exercise wedge pressure in recipients a month afterward, according to early trial results.
Colin M. Barker, MD, reported 30-day results of 31 patients who had no-implant interatrial shunting for heart failure across three studies, at the Society for Cardiovascular Angiography & Interventions scientific sessions. The studies included patients with HF with preserved and reduced ejection fraction (HFpEF and HFrEF).
Dr. Colin M. Barker
“At 30 days, there was a response with a decrease in the wedge pressures both at rest and at peak exercise, and that was consistent through all three of these initial trials,” Dr. Barker said. In all 33 patients who have been treated to date, there were no major adverse cardiac and cerebrovascular or thromboembolic events through 1 month. (Two of the patients weren’t included in the results Dr. Barker presented.)
The three studies he reported on were the Alleviate-HF-1 (n = 15), Alleviate-HF-2 (n = 11) for patients with HFpEF, and Alleviate-HFrEF (n = 5). The average patient age was 67 years, and all were New York Heart Association class II, III, or IV with elevated peak pulmonary capillary wedge pressure (PCWP).
The device that creates the no-implant shunt as “not very exotic, but it is very effective, and what it does is create a very predictable, reproducible atrial septostomy” between the left and right atria. The device obtains “almost a biopsy” that’s 7 mm in diameter. “There’s no hardware or foreign bodies left inside the patient,” said Dr. Barker, director of interventional cardiology at Vanderbilt University in Nashville, Tenn. “There’s a natural healing process at the rims after the radiofrequency ablation has been done.” Femoral access was used.
Study participants were also asked to complete the Kansas City Cardiomyopathy Questionnaire (KCCQ) at baseline and at 1 and 3 months across all three studies, and at 6 months in the Alleviate-HF-1 study. “Just as important is how patients feel,” Dr. Barker said. KCCQ overall summary scores increased at each time interval across all three studies.
“Durability has been proven with multiple different imaging modalities,” Dr. Barker added, explaining that CT scans in 10 of 10 shunts demonstrated patency through 12 months, and 15 of 15 at 6 months. He noted that none of the created shunts have closed yet. At 6 months, the average shunt measured 7.5 mm (± 1.1 mm, n = 22), left atrial diameter decreased 2.4 mm (P = .031) in HFpEF patients, and no significant changes were observed in right ventricular fractional area change or right atrial volume index.
None of the septostomies have had to be closed or enlarged to date, Dr. Barker said. “We are creating an atrial septal defect that we have a lot of comfort and experience with closing with other devices if need be, but that hasn’t been an issue,” he said. “As of now, it’s one size, but as you can imagine, one-size-fits-all is not the way this will go, and this does allow for variations in size ultimately.”
Kirk N. Garratt, MD, director of the Center for Heart and Vascular Health at Christiana Care in Newark, Del., noted that the approach to unload the left atrium “is novel, but I think is becoming well accepted in the advanced HF population. There remain questions about long-term consequences of an intentional interatrial shunt – what happens to pulmonary flow dynamics and the like – but to date the impact of this approach has been favorable.
Dr. Kirk N. Garratt
“The liabilities that come with an implanted device in the septal space, both in terms of the durability of the shunt and the impact that it would have on the ability to perform other transseptal procedures, is overcome with this approach,” he added.
Dr. Barker disclosed he is an advisory board member and consultant to Alleviant Medical. Dr. Garratt is an advisory board member for Abbott.