Large trial stopped after third planned interim analysis
A device designed to remove embolic material—fragments of tissue that can be released into the bloodstream during transcatheter aortic valve replacement (TAVR)—did not result in a reduction in the rate of stroke, according to a randomized trial presented at the American College of Cardiology’s Annual Scientific Session (ACC.25).
The BHF PROTECT-TAVI trial is the largest randomized trial assessing the use of a cerebral embolic protection device during TAVR, also known as transcatheter aortic valve implantation or TAVI.
“This large, well-conducted, appropriately powered clinical trial has addressed the question of whether the SENTINEL Cerebral Protection System is effective in an unselected cohort of TAVI patients,” said Rajesh Kharbanda, MD, associate professor of cardiovascular medicine at the University of Oxford, United Kingdom, and the study’s first author. “In our population, a routine strategy of cerebral embolic protection did not reduce the rate of stroke. Our study provides convincing evidence that there is no value in the routine use of this device during TAVI.”
TAVR is a common procedure carried out to treat patients with aortic stenosis, a condition in which the aortic valve becomes narrowed, preventing blood from flowing properly. During TAVR a prosthetic valve is implanted in the diseased valve between the aorta and the heart’s left ventricle. While TAVR carries a good safety record overall, around 2% to 4% of patients have a stroke during or shortly after the procedure, sometimes because calcium or tissue fragments are released when the replacement valve is deployed. About half of such strokes result in permanent disabilities.
Cerebral embolic protection devices are designed to capture embolic material that enters the bloodstream during TAVR, preventing it from reaching the brain and causing a stroke. SENTINEL, the device used in the trial, is the most frequently used embolic protection device in TAVR procedures.
The BHF PROTECT-TAVI trial enrolled 7,635 patients undergoing TAVR for aortic stenosis at 33 centers in the United Kingdom between 2020-2024, representing about 30% of all UK patients who received the procedure in those years. Participants had an average age of 81 years and just under 40% were female. Participants were randomized 1:1 to undergo TAVR with the SENTINEL device or TAVR without cerebral embolic protection.
In a third planned interim analysis, the trial’s primary endpoint—the incidence of stroke at 72 hours post-TAVR or at the time of hospital discharge, if sooner—occurred in 2.1% of patients assigned to the SENTINEL device and in 2.2% of patients assigned to the control group, showing no evidence of a difference between the two study arms. Results for secondary endpoints including all-cause mortality, stroke severity, disabling stroke and cognitive outcomes were also similar between groups. Recruitment for the trial was stopped after the interim analysis based on these findings.
No differences in outcomes were seen in any subgroups that were analyzed.
Researchers said the stroke risk associated with TAVR has decreased over the past decade due to improvements in TAVR devices, implantation techniques and procedural protocols and as operators have become more experienced with the procedure. Although the trial showed current cerebral embolic protection devices do not improve outcomes, Kharbanda said it is possible that next-generation embolic protection devices could potentially reduce stroke risk for certain groups, but further trials would be needed to demonstrate this.
“We need to understand which patients are at higher risk of stroke during TAVR and whether a more stratified approach to delivering therapy to those people is beneficial,” Kharbanda said.
Although the study was limited to the UK, researchers said the broad, national rollout of the trial and its representative patient population likely make the results generalizable to other countries.
The study was funded by British Heart Foundation and by Boston Scientific through an investigator-sponsored grant, but they had no role in the design, conduct or reporting of the study. The trial is sponsored by University of Oxford and the London School of Hygiene & Tropical Medicine coordinated the study.
This study was simultaneously published online in the
New England Journal of Medicine at the time of presentation.
ACC.25 will take place March 29-31, 2025, in Chicago, bringing together cardiologists and cardiovascular specialists from around the world to share the newest discoveries in treatment and prevention. Follow @ACCinTouch, @ACCMediaCenter and #ACC25 for the latest news from the meeting.
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Kharbanda will be available to the media in an embargoed press conference on Sunday, March 30, at 7:00 a.m. CT / 12:00 UTC in Room N226.
Kharbanda will present the study, “Routine Cerebral Embolic Protection in Transcatheter Aortic Valve Implantation: The British Heart Foundation (BHF) PROTECT-TAVI Trial,” on Sunday, March 30, 2025, at 10:00 a.m. CT / 15:00 UTC in the Main Tent, North Hall B.
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