An updated look at the use of cerebral embolic protection devices during TAVR
While stroke rates during transcatheter aortic valve replacement (TAVR) have greatly declined over the past decade, they remain a significant challenge. There were high hopes that cerebral embolic protection devices could help lower these rates, but the data have been mixed.
To find out where things are at with this technology, Cardiovascular Business spoke to Akriti Gupta, MD, MSc, an assistant professor of interventional and structural cardiology at Cedars-Sinai and executive associate editor of the JACC journals, during the Transcatheter Cardiovascular Therapeutics (TCT) 2024 meeting.
"Stroke is a very important complication that occurs in the context of TAVR. When TAVR started, the stroke rate was in the range of 3.5 to 5%. Now we are down to about 2.5% in the last few years because of new iterations of the technology, operator experience and patient selection. So we've made a lot of progress, but I think the challenge is that we have plateaued in the 2.5% range," Gupta explained.
Her discussion focused on the ongoing debate regarding the effectiveness of cerebral embolic protection devices, particularly the Sentinel device, and emerging clinical data from large-scale trials.
The challenge of stroke in TAVR and the embolic protection landscape
"Patients who do end up getting stroke have such higher burdens of morbidity and mortality, and obviously we want to do whatever we can to reduce stroke. So cerebral protection intuitively makes sense because you can install devices that are going to capture all the debris that dislodges when we deploy the TAVR device," Gupta said.
She noted that several protection devices have come and gone over the years, but there are a few that are still alive on the market. One of them is the Boston Scientific Sentinel device, which has FDA and CE mark approvals. Another is TriGuard, which only has CE mark approval to be sold and marketed in Europe. While observational data suggest potential benefits to using these devices, randomized clinical trials have not yet demonstrated clear clinical efficacy, Gupta explained.
Gupta said several new cerebral protection devices are in development. The ProtEmbo device, an arch deflector, is currently undergoing clinical trials. Other devices aim to provide broader coverage than Sentinel’s partial protection, addressing gaps in embolic capture.
The most significant trial, PROTECTED TAVR, randomized 3,000 patients globally to receive either Sentinel protection or no protection. The trial found no significant reduction in the primary endpoint—stroke within 72 hours or discharge. However, there was a reduction in disabling stroke, a secondary endpoint. Analysts suggest the trial may have been underpowered due to lower-than-expected stroke rates.
Geographic disparities and future research on TAVR cerebral protection
A key finding from PROTECTED TAVR data presented at TCT 2024 was a statistically significant reduction in stroke rates among U.S. patients, but not international cohorts, Gupta said. The reason for this remains unclear, and further investigation is needed to determine whether specific patient subgroups might benefit more from embolic protection.
Looking ahead, the upcoming BHF PROTECTED TAVI trial in Europe, enrolling 7,000 patients, aims to expand the evidence base. Plans to combine data from PROTECTED TAVR and BHF PROTECTED TAVI may help identify subpopulations that derive greater benefit from cerebral protection.
Cost-effectiveness considerations
One of the major debates surrounding embolic protection is cost-effectiveness. Registry data from over 400,000 U.S. TAVR patients suggest Sentinel reduces stroke risk by only 0.12%. Given the high cost of deploying Sentinel versus the economic burden of stroke care, the number needed to treat remains a critical consideration, Gupta said.
However, the filters are doing their job and she sees evidence of what would have become emboli in the brain after every procedure.
"It's absolutely doing its job, but if it is leading to real reduction in stroke remains to be seen," Gupta explained.
She said one issue with the clinical understanding of stroke and emboli in the brain is that we do not know the impact on cognition over the long term. If there is enough data suggesting these devices are "moving the needle on cognitive dysfunction and subclinical stroke," she thinks it could help "justify the expense" to clinicians and health systems.
With declining stroke rates in TAVR, some operators argue that cerebral protection is becoming less necessary, while others advocate for its use to reduce stroke risks even marginally. Additionally, subclinical strokes and cognitive dysfunction remain concerns, and future research may determine whether embolic protection offers long-term cognitive benefits.
As technology advances and larger trials yield new data, the role of cerebral embolic protection in TAVR will continue to evolve, informing both clinical practice and healthcare policy.
Dave Fornell has covered healthcare for more than 17 years, with a focus in cardiology and radiology. Fornell is a 5-time winner of a Jesse H. Neal Award, the most prestigious editorial honors in the field of specialized journalism. The wins included best technical content, best use of social media and best COVID-19 coverage. Fornell was also a three-time Neal finalist for best range of work by a single author. He produces more than 100 editorial videos each year, most of them interviews with key opinion leaders in medicine. He also writes technical articles, covers key trends, conducts video hospital site visits, and is very involved with social media. E-mail: dfornell@innovatehealthcare.com