Results from the PROTECT H2H trial, a global clinical study comparing two embolic protection devices for protection against stroke in patients undergoing transcatheter aortic valve implantation (TAVI) has shown comparable performance between the investigational Emboliner (Emboline) device and Sentinel (Boston Scientific).
Adam Greenbaum (Emory School of Medicine, Atlanta, USA) presented the findings of the trial during a late-breaking trials session at the American College of Cardiology’s annual scientific session (ACC.26; 28–30 March, New Orleans, USA).
“For the primary endpoint of death from any cause, stroke or kidney failure at 30 days, the investigational Emboliner device and the approved Sentinel device performed nearly identically,” Greenbaum said. “Findings for the secondary endpoint of stroke alone were also nearly identical—and, at about 2% in both arms, are the lowest rates of stroke that have been achieved in a trial of this size.”
Studies suggest that stroke during TAVI occurs during 3% of procedures within 30 days, and that patients also have an elevated risk of stroke for two years following the procedure, compared with patients matched by age and sex who had not undergone TAVI.
The Sentinel Cerebral Protection System is US Food and Drug Administration (FDA)-approved to be used with the TAVI catheter like a filter, to capture the TAVI-generated debris and keep it from getting into the bloodstream and to the brain. To date, however, studies have not shown that its use in TAVI reduces strokes or patient deaths within 30 days of the procedure.
“While the Sentinel is a great advance in the field, it leaves open the question of whether preventing other downstream effects of TAVI-generated debris—for example, in the gut, the legs, the kidneys—could improve patient outcomes,” Greenbaum said.
The Emboliner embolic protection system is an investigational full-body filter designed to capture TAVI-generated debris and prevent it from getting into the arteries that carry blood not only to the brain but also to other organs and tissues. The device is a soft, mesh sleeve designed to capture all debris in the descending aorta. It has a port to allow passage of the transcatheter valve and other devices.
The Protect H2H randomised trial was designed to directly compare the safety and effectiveness of the Sentinel and Emboliner devices in patients undergoing TAVI. The study enrolled 522 patients (average age 79 years, 33% women) in the USA, Germany and Brazil. All of the patients had severe aortic stenosis and were randomly assigned to undergo TAVI with protection provided by either the Sentinel or the Emboliner device.
Patients’ other health conditions included prior stroke (9%), high blood pressure (84%) and atrial fibrillation (25%), all of which were similar across both groups. The trial’s primary endpoint was a composite of death from any cause, stroke or kidney failure within 30 days of the procedure.
Key secondary endpoints were stroke within 30 days and the number of debris particles larger than 150 microns (roughly the size of a dust mite or a grain of table salt) that the filter captured. Patients were followed up on discharge from the hospital after their procedure and again at 30 days. Results at 30 days showed that 4.9% of patients whose procedure was performed using the Emboliner device had experienced a primary endpoint event, compared with 5% of those whose procedure was performed using the Sentinel device.
The secondary endpoint of stroke at 30 days occurred in 2% of patients in the Emboliner group and 2.1% of those in the Sentinel group. The number of adverse events such as bleeding and blood clots was similar in both groups.
In other findings, the Emboliner device captured three times as many debris particles larger than 150 microns as the Sentinel device did (93 vs. 31), and almost twice as many total particles (1,575 vs. 801), including some as small as 40 microns (less than the width of a human hair), Greenbaum said.
“While the trial was not powered to detect differences in terms of other outcomes from debris elsewhere. Any embolic debris during TAVI is neutral at best, potentially harmful, and it would therefore be intuitive that as long as the system is safe and easy to use, the more debris captured, the better,” he said.
The Emboliner also had fewer issues with placement. Operators were unable to position the catheter in the protective filter in the patient’s body prior to placing the replacement heart valve in only 4% of patients in the Emboliner group compared with 13% in the Sentinel group, Greenbaum said.
A limitation of the study is that it provides no information about patient outcomes beyond the 30-day follow-up period. In addition, the trial was not large enough to identify whether the incidence of kidney failure differed between the two groups.
The study was funded by Emboline, the manufacturer of the Emboliner embolic protection system.
