AT EUROPCR 2015
PARIS (FRONTLINE MEDICAL NEWS) – Using the TriGuard embolic protection device during transcatheter aortic valve implantation resulted in a fivefold reduction in the incidence of new postprocedural neurologic deficits, compared with unprotected TAVI in the randomized DEFLECT III trial.
Moreover, TriGuard-protected TAVI patients showed a 44% reduction in the volume of new brain lesions on diffusion-weighted MRI at discharge, coupled with a 45% greater likelihood of freedom from any cerebral ischemic lesions, compared with the unprotected controls, Dr. Andreas Baumbach reported at the annual congress of the European Association of Percutaneous Cardiovascular Interventions.
The TriGuard is a filter/deflector device that covers all three cerebral arteries, and thus all brain territories. It consists of a single-wire nitinol frame and mesh filter with a pore size of 130 microns, enabling it to deflect cerebral emboli during TAVI while allowing maximal blood flow. The device is approved and commercially available in Europe but remains investigational in the United States
TriGuard is delivered by a 9 Fr sheath from the femoral artery and maintained during the TAVI procedure by a stabilizer in the innominate artery. Although introducing an additional element into TAVI raises the theoretic possibility of safety concerns, no safety signal was seen in DEFLECT III . In-hospital rates of death, stroke, bleeding, acute kidney injury, and major vascular complications didn’t differ between TriGuard recipients and controls in the 85-patient study.
TriGuard is designed to address an emerging concern as TAVI’s popularity soars and the procedure is extended to younger, lower–surgical risk patients: namely, the high rate of new embolic lesions seen on brain imaging post procedure. Such lesions have been linked to cognitive decline, noted Dr. Baumbach, professor of interventional cardiology at the University of Bristol (England).
Focusing on outcomes in the 89% of TriGuard recipients whose device remained in position and thus provided complete three-vessel coverage throughout TAVI, he said that group had significantly fewer new neurologic deficits on the National Institutes of Health Stroke Scale at discharge than the control group, by a margin of 3.1% versus 15.4%. Twenty-seven percent of the TriGuard group had no new ischemic brain lesions at discharge as determined by diffusion-weighted MRI, compared with 11.5% of controls who underwent TAVI with no cerebral protection. The TriGuard group also had significantly better scores at discharge on the Montreal Cognitive Assessment and on a delayed memory task.
Of particular importance was the finding that 30 days post procedure the TriGuard group was 2.27-fold more likely to have recovered normal cognitive function, compared with unprotected controls, the cardiologist continued. What that means is that 45% of the TriGuard group had an age-normalized Montreal Cognitive Assessment score greater than 26 out of a possible 30, compared with just 20% of controls.
Another intriguing finding was that roughly 10% of patients in both study arms developed new cerebral emboli between their discharge and 30-day follow-up brain imaging studies. By definition, such emboli can’t be prevented using the TriGuard, but this finding identifies the postprocedural period as one of continued elevated embolic risk, Dr. Baumbach said.
DEFLECT III was a 13-center, 30-day, exploratory, prospective, randomized trial designed to establish benchmark rates for the upcoming larger pivotal REFLECT randomized trial. Simultaneous with Dr. Baumbach’s presentation in Paris, the final DEFLECT III results were published online (Eur. Heart J. 2015 May 19. [ doi:10.1093/eurheartj/ehv191 ]). Session cochair Dr. Stephan Windecker of the University of Bern (Switzerland) noted that there’s a discrepancy between imaging results, which identify brain lesions in 70% or more of patients post-TAVI, and the vastly lower stroke rate – roughly 3% – associated with TAVI in contemporary series. He asked Dr. Baumbach how this can be reconciled: Is imaging too sensitive, or are cardiologists missing lots of smaller strokes?
“What we’ve learned is the emboli we see have a large spectrum of clinical sequelae,” Dr . Baumbach replied. “Of course, the volume of lesions you have in the brain matters, but so does the location of the infarct. Volume alone doesn’t give us the whole answer regarding the severity of these lesions. But what is clear after this study is that we cannot ignore these lesions. They may not produce overt stroke that we as cardiologists are able to detect, but they certainly produce neurologic deficits that a neurologist can see, and they do so in about 15% of unprotected procedures. And this has been seen with surgical aortic valve replacement as well.”
He reported serving on the scientific advisory board for and receiving research grants from Keystone Health, which produces TriGuard.
