No Stroke Reduction With Embolic Protection in TAVI, Two Studies Suggest

CHICAGO, IL—Cerebral embolic protection devices are infrequently used during transcatheter aortic valve implantation procedures in the United States, and new data suggest their use does not appear to provide any clinical benefit.

Those are the conclusions of two studies presented this week at TVT 2022: an analysis from the Nationwide Readmissions Database (NRD) and a meta-analysis of published cerebral embolic protection trials.

“Stroke is a feared complication after TAVR, with an incidence of around 2% to 3%,” Aamer Ubaid, MD (University of Missouri-Kansas City), who led the NRD analysis, said during his presentation. The US Food and Drug Administration approved a cerebral embolic protection device (Sentinel; Boston Scientific) in 2017 for use in TAVI, but “whether it really improves clinical outcomes is still uncertain,” he said.

The new NRD study, in fact, showed that there was a trend toward a higher risk of stroke/TIA and ischemic stroke at hospitals that routinely used embolic protection, said Ubaid. However, he urged caution interpreting those findings, noting that the registry-based study is limited by ICD coding and the potential for unmeasured residual confounding.

Sachin Goel, MD (Houston Methodist, TX), who moderated the session, told TCTMD the jury is still out on the benefit of cerebral embolic protection devices for TAVI, but that operators hope to have an answer soon with the PROTECTED-TAVR study. Led by Samir Kapadia, MD (Cleveland Clinic, OH), researchers are randomizing approximately 3,000 patients to cerebral protection with the Sentinel device during TAVI or to TAVI alone. The primary endpoint of the study is the rate of all stroke at 72 hours or upon hospital discharge, and the trial is expected to be completed soon.  

“We’re all eagerly awaiting the results of that trial to learn if embolic protection helps or not,” said Goel.

Two-Thirds of US Hospitals Are Nonusers

In the meantime, investigators are attempting to get a handle on how widely cerebral embolic protection is used and whether its use has provided any clinical benefit in patients who underwent TAVI. In the study led by Ubaid, researchers analyzed NRD data to try to address these questions.

From the database, they identified 41,666 admissions for TAVI at 392 hospitals in 2019. Overall, cerebral protection devices were used infrequently: 258 hospitals (65.8%), which completed 20,939 TAVI procedures, didn’t use cerebral embolic protection at all during their cases. Another 122 hospitals (31.1%), representing 18,143 admissions for TAVI, used cerebral embolic protection only selectively (defined as ≤ 50% of cases). The remaining 12 hospitals (3.1%), representing 2,584 admissions, were classified as routine users of embolic protection (defined as > 50% of cases).

Hospitals that were routine users of embolic protection were more likely to be large and tended to treat more patients with private insurance. The vast majority of routine-use hospitals were metropolitan teaching hospitals.

When compared with hospitals that didn’t use embolic protection at all, there was no difference in the risk of stroke/TIA among hospitals that used a device selectively or routinely. In fact, there was a trend toward a higher risk of stroke/TIA among centers that routinely used embolic protection (OR 1.32; 95% CI 1.00-1.75). With ischemic stroke, there was no significant difference between nonusers and selective users, but again there was a trend toward a higher risk of ischemic stroke among centers that routinely used a device (OR 1.34; 95% CI 0.98-1.83). There were no differences in mortality between the three groups.

The mean cost of hospitalization for TAVI was significantly higher among hospitals that selectively and routinely used embolic protection (approximately $28,000 higher) than hospitals that never used the device.

Ubaid pointed out that the increased risk of neurologic events and higher hospitalization costs “may reflect a higher-risk patient mix rather than increased risk due to cerebral embolic protection device use.” Also, he noted that one of the limitations of the analysis is a lack of granularity, in that they were unable to tease out which type of patients are receiving embolic protection at hospitals who only selectively use the devices.

Meta-analysis Insights

The meta-analysis, which Arpanjeet Kaur, MD (Icahn School of Medicine at Mount Sinai, New York, NY), presented during the same session, included six randomized, controlled trials—DEFLECT III, MISTRAL-C, CLEAN-TAVI, SENTINEL, and REFLECT I and II—testing the TriGUARD (Keystone Heart) and Sentinel devices. The follow-up in the trials, which included 1,016 patients (average age 81.3 years), was 30 days.

The primary outcome of all-cause stroke was not significantly lower among patients treated with embolic protection compared with those who underwent TAVI alone (RR 0.93; 95% CI 0.57-1.53). Similarly, there was no significant difference in mortality with embolic protection. Use of embolic protection appeared to be safe, with no reported differences in major vascular complications, life-threatening/disabling bleeding, or stage II/III acute kidney injury in those who received the device.

Patients at High Risk For Stroke

To TCTMD, Goel noted that he’s practiced at hospitals with very different approaches.  

“I trained at the Cleveland Clinic, and we used embolic protection in everybody,” said Goel. “When I went into clinical practice, we were also using it quite a bit. In fact, we were using it in almost everybody. Then the hospital came back to us after doing their own analysis and showed that to reduce one stroke, we needed to treat something like 267 patients. At the time, the cost was a big issue—it wasn’t covered by insurance. So, a lot of the decision-making was not driven by physicians, and we stopped using it in everybody and only use it selectively.”  

Right now, Goel said they deploy embolic protection primarily in patients with a prior stroke, patients undergoing valve-in-valve TAVI, and patients with bicuspid anatomy.

“These are three groups, in my mind, who are at a higher risk of stroke with TAVI,” he said. “It’s difficult to tease out short of a randomized trial whether these are meaningful reductions in stroke.”

Goel said one aspect to consider with embolic protection is the ability to actually cause cerebrovascular events while delivering the embolic protection device.

“If it takes more than 3 or 4 minutes, in our mind there is a risk of the procedure itself causing an embolic event during the placement of the device,” he said. “We don’t spend more than a few minutes trying to put this in place. If it’s straightforward anatomy, it shouldn’t take very long to deploy. If it’s taking longer, then I think the risks outweigh the benefits.”