Cerebral protection device use did not reduce the risk of stroke or delirium in patients undergoing transcatheter aortic valve replacement (TAVR), according to a new registry analysis recording 1,564 cases in Germany.
Use of such a device was associated with lower in-hospital mortality, however, despite not preventing brain damage. The device used was Boston Scientific’s Claret Sentinel dual filter, which is currently the only approved and commercially available cerebral embolic protection (CEP) device.
The study was published in the Jan. 25 issue of JACC: Cardiovascular Interventions, and the lead author was Peter Stachon, MD, from the University of Freiburg, Germany. The authors had no relevant relationships to disclose.
Despite procedural improvements in recent years, peri-interventional stroke is still a “feared complication” for TAVR patients, with a stroke rate of around 2%, the researchers said. Up to 84% experience silent strokes after TAVR due to embolic shower, although the significance of these lesions is unknown, they added.
Most early strokes after TAVR are due to cardiac embolism during valve implantation – an adverse event against which CEP devices are purported to protect by either filtering or diverting cardiac emboli during procedure. Prevention of stroke is an important aim for TAVR.
Nevertheless, encouraging results in smaller single-center studies have not been replicated in randomized controlled trials, the researchers said. The scarce evidence over reduction in clinically apparent strokes means use of these devices remains controversial, they said.
They, therefore, set out to assess a large data set of 41,654 isolated transfemoral TAVR procedures performed in Germany between 2015 and 2017 based on data extracted from a nationwide billing database collected by the Research Data Center of the Federal Bureau of Statistics (DESTATIS). Of these procedures, 3.8% used cerebral protection devices.
The primary endpoint was in-hospital mortality, while secondary endpoints included acute kidney injury, permanent pacemaker implantation, mechanical ventilation of more than 48 hours, length of hospital stay, post-procedural delirium, stroke and total reimbursement.
A propensity score comparison was performed to compare outcomes that may be related to the use of cerebral protection devices.
The use of a cerebral protection device did not reduce stroke risk (adjusted risk difference [aRD]; +0.88%; 95% confidence interval [CI]: -0.07% to 1.83%; p = 0.069).
It also failed to reduce the risk of developing delirium (aRD: +1.31%; 95% CI: -0.28% to 2.89%; p = 0.106), which is a key sign of acute brain failure.
Although brain damage could not be prevented with the protection devices, in-hospital mortality was lower (aRD: -0.76; 95% CI: -1.46% to -0.06%; p = 0.034), the researchers said.
Patients undergoing transfemoral TAVR with embolic protection devices were younger than those in procedures without a cerebral device (median 80.6 vs. 81.1 years), but they were at a slightly increased risk of in-hospital mortality, according to the European System for Cardiac Operative Risk Evaluation score (EuroSCORE) (logistic EuroSCORE 14.7 vs. 13.8).
Those who received devices were also more often in New York Heart Association functional class III or IV (63% vs. 49.2%) and had a higher incidence rate of carotid disease (8.4% vs. 5.7%), although renal disease was less frequent.
“The basic concept of protecting from embolism is reasonable,” Stachon and team said.
They added that real-world use of these devices is still low, although use did rise from 256 cases in 2015 to 821 in 2017 in the dataset.
They, therefore, called for further technical development and confirmation of improved outcomes in randomized controlled trials, as well as more research into which patient subgroups may benefit – a factor which could be determined using typical risk factors.
“The routine use of cerebral protection device cannot be recommended without further randomized controlled trials,” they urged.
In an accompanying editorial, Cleveland Clinic’s Samir R. Kapadia, MD, and Amar Krishnaswamy, MD, said “intuitively, [CEP] device use during TAVR makes sense,” adding that the reduction in mortality for the device group was intriguing.
“Although the authors ponder that this reduction could be the result of those patients with CEP being treated at larger centers, it could be that patients with CEP had smaller strokes (which confer a lower mortality risk), though this is of course strictly conjectural and there are no data provided to know whether this is possible,” they said.
In response to the researchers’ call for more definitive clinical data, the editorialists insisted the Boston Scientific’s ongoing 3,000-patient 1:1 randomized trial PROTECTED TAVR (Stroke Protection With Sentinel During Transcatheter Aortic Valve Replacement) – on which Krishnawamy is the principal investigator – will “provide the answer” as to whether CEP does reduce stroke rates.
“Although a solid evidence-based foundation is necessary for us to feel confident in the benefits of the medical procedures that we provide our patients, hopefully the current rational data gaps do not overshadow what appears to be an appropriate intuition regarding CEP in TAVR,” said Kapadia and Krishnaswamy.
“For the sake of our patients, hopefully the PROTECTED TAVR trial will bridge this gap.”
Stachon P, Kaier K, Heidt T, et al. The Use and Outcomes of Cerebral Protection Devices for Patients Undergoing Transfemoral Transcatheter Aortic Valve Replacement in Clinical Practice. JACC Cardiovasc Interv 2021;14:161-8.
Kapadia SR, Amar Krishnaswamy. Cerebral Embolic Protection in Transcatheter Aortic Valve Replacement: Connecting Intuition and Proof. JACC Cardiovasc Interv 2021;14:169-71.