SNOWMASS, COLO. – New-onset brain lesions arising after transcatheter aortic valve replacement are the largely unacknowledged elephant in the room with regard to the boomingly popular procedure.
Multiple studies utilizing diffusion-weighted MRI have shown roughly a 70% incidence of new brain lesions following transcatheter aortic valve replacement (TAVR). And studies employing full neurocognitive test batteries have consistently shown a relationship between small brain infarcts much like these, cognitive decline, and dementia, Dr. David R. Holmes Jr. said at the Annual Cardiovascular Conference at Snowmass.
“This is an incredibly alarming piece of information. People should be aware of this. There is interest in doing TAVR in younger and younger patients. But there is indeed an issue with unintended consequences. If we take younger and less and less symptomatic patients, their chance of dementia in 20 years is probably going to be increased. We’re going to have to follow these patients for a long period of time to look at that specific endpoint,” noted Dr. Holmes of the Mayo Clinic in Rochester, Minn.
Speaking of unintended consequences, there is also the issue of TAVR-related stroke. Among the more than 27,000 patient records submitted to the Society of Thoracic Surgeons/American College of Cardiology Transcatheter Valve Therapy (TVT) Registry through December 2014, the periprocedural stroke rate was 2.4%. One-year outcomes included 26.2% mortality and a 3.6% stroke rate.
Given that two-thirds of TAVR cases submitted to the TVT registry in 2014 involved patients age 80 or older, with New York Heart Association class III/IV symptoms present in 82%, and 50% of patients rated as being at extreme risk with a predicted 1-year mortality of 50% without intervention, a 3.6% stroke rate can be considered tolerable. But not so in the sort of younger asymptomatic patients with significant aortic stenosis increasingly under discussion as potential candidates for the procedure.
“Stroke rates are the real deal in patients undergoing TAVR. Maybe you’re going to take an asymptomatic person and give them a stroke rather than wait or give a surgical valve replacement,” the cardiologist said.
He predicted that within 10 years, the use of cerebral protection devices will be considered mandatory, not just during TAVR, but during percutaneous coronary intervention, CABG surgery, and probably during atrial fibrillation ablation as well. All of these procedures have been linked to new-onset brain lesions on diffusion-weighted MRI.
Promising new neuroprotection devices include Keystone Heart’s TriGuard, a filter-deflector that covers all three cerebral arteries, has no impact on cerebral blood flow, doesn’t require an additional access site, is supported by excellent safety data, and is approved in Europe but investigational in the United States, Dr. Holmes observed. Efficacy data are coming soon, when the results of the DETECT III (A Prospective Randomized Evaluation of The TriGuard HDH Embolic Deflection Device During Transcatheter Aortic Valve Replacement) will be presented at the ACC scientific sessions on March 15. In that study, 70 patients underwent neurocognitive testing before and 30 days after their TAVR procedure.
“We’re going to be using something – a filter or filter-deflector – in every single patient to prevent the abnormal brain hits that are seen with all of these procedures. The need for brain protection is not going away,” he forecast.
Dr. Holmes, who played a pivotal role in creating the TVT registry during his term as ACC president, pointed out an intriguing registry finding: Through 2014, only 36% of the procedures have been done percutaneously.
“When you go to meetings everybody says, ‘We do them all percutaneously with a dual Perclose.’ But when you look at the data, out of those 27,000 patients only about one-third were done percutaneously. Is that going to be different in the future? Probably. But it’s important to remember that we’re still not doing all that many percutaneous procedures,” the cardiologist said.
He reported serving as a consultant to Boston Scientific.