AT CRT 2018

WASHINGTON (FRONTLINE MEDICAL NEWS) – All transcatheter aortic valve replacement devices generate debris into the bloodstream, including debris larger than 1 mm, but the amount of the debris differs between devices, according to a study based on collections from a cerebral embolic protection system.

“The quantity of the debris measured by different methods and techniques revealed more debris in patients receiving the Evolut R or Lotus TAVR [transcatheter aortic valve replacement] devices than in patients receiving a Sapien 3 or Sapien XT prosthesis,” reported Tobias Schmidt, MD, a cardiologist at Asklepios Klinik St. Georg, Hamburg, Germany.

The finding was based on data derived from the SENTINEL IDE and SENTINEL H studies, which were conducted to evaluate whether capture of debris by the Sentinel Cerebral Protection System (CPS) during TAVR procedures reduces risk of stroke and other embolic events. Of the 526 patients participating in these studies, Dr. Schmidt presented histopathological and histomorphological data from 246 patients at CRT 2018 sponsored by the Cardiovascular Research Institute at Washington Hospital Center. The primary results of the SENTINEL studies were presented previously.

Of the 246 patients, 145 (59%) received a Sapien 3 device, 40 (16%) received an Evolut R, 36 (14%) received a Lotus, and 25 (10%) received a Sapien XT. Particle features based on histopathological and histomorphological analyses were compared. A multivariate analysis was conducted to test for interaction with the amount of debris according to patient demographics and procedural characteristics, which differed for the devices evaluated.

Debris was captured in essentially all patients (99%) and with every TAVR device. On automated histomorphometry, the Lotus device had significantly higher median particle counts relative to the Evolut R (P = .004), the Sapien S3 (P less than .001), and the Sapien XT (P = .02) devices. When stratified by particle size, the Evolut R generated significantly more particles greater than 500 mcm than either the Sapien S3 or the Sapien XT (both P less than .05).

For particle sizes greater than 1 mm, there were significantly higher counts for both the Lotus and Evolut R (both P less than .05) relative to the Sapien S3, but Dr. Schmidt emphasized all devices generated at least some debris this size and that particles greater than 1 mm were retrieved from 53% of all patients. Similarly, when median total particle area was calculated by histomorphometry, the Lotus (P = .0007) and Evolut R (P = .0009) devices were more likely to have particles greater than 1 mm than the Sapien devices, but again, debris with a large total particle area was retrieved from at least some patients in all device groups.

There were significant differences in patient demographics and procedural characteristics by device. For example, patients receiving an Evolut R were significantly more likely than those receiving the Lotus or Sapien S3 valves to have undergone dilation prior to TAVR. Patients receiving the Sapien XT were significantly older than patients receiving any of the other valve types.

In an effort to control for these differences, “multivariate analysis was performed to text for interaction with the amount of debris captured,” Dr. Schmidt explained. “This analysis showed that transcatheter valve type was the only significant predictor for the morphometric findings.”

In this study, most of the debris was found to come from the vascular bed, but foreign body debris and debris from myocardium was also identified. One hypothesis for the greater debris from the Lotus and Evolut R devices is that these are positionable, raising the possibility that manipulation of the devices was the source of the debris, according to Dr. Schmidt. However, this hypothesis needs verification.

One message from this study is that “capture of debris is universal across different transcatheter valve types,” Dr. Schmidt said, adding that this “supports the benefit of using a CPS device in all TAVR procedures.”

Several commentators, including Jeffrey Popma, MD , director of the Interventional Cardiology Clinical Service at Beth Israel Deaconess Hospital, Boston, observed that it would be inappropriate to conclude that the greater debris observed in this study would necessarily translate into a difference in risk of embolic events for the devices evaluated with or without a CPS device. He and others emphasized no relationship to clinical risk was demonstrated in this study.

Dr. Schmidt reports no potential conflicts of interest.

SOURCE:Schmidt T et al. CROI 2018.