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Cognitive brain impairment before TAVR prevalent in aortic stenosis
Comprehensive neurocognitive assessment shows significant cognitive brain impairment before transcatheter aortic valve replacement in patients with aortic stenosis, according to data published in the Journal of American College of Cardiology.
According to the study, the results of the SENTINEL trial underscore the importance of pre-interventional testing and MRI in any research investigating postsurgical cognitive outcomes in patients with CVD.
“Despite cardiovascular efficacy and improvement in quality of life, most previous studies of TAVR and the brain have focused on procedure-related ischemic injury,” Ronald M. Lazar, PhD, from the department of neurology at the University of Alabama at Birmingham, and colleagues wrote. “The stroke rate may have declined marginally as the TAVR technology has evolved, but questions have emerged about the significance of micro-embolic producing silent infarction resulting in clinically covert events, including changes in cognition.”
Impairment analysis
The researchers analyzed 234 patients from the SENTINEL trial who received cognitive assessments of attention, processing speed, executive function, and verbal and visual memory to determine baseline neurocognition before TAVR and study its correlation with pre-TAVR brain imaging.
Lazar and colleagues based z scores on normative means and standard deviations, combined into a primary composite z score.
Using 3T scanners with a T2 fluid-attenuated inversion recovery sequence, the researchers obtained brain MRIs pre-TAVR.
Scores –1.5 standard deviation below the normative mean were considered impairment.
The relationship between neurocognitive z scores and T2 lesion volume were assessed using correlation and regression analyses.
The researchers found that the mean composite z score was –0.65 standard deviation below the normative mean among the cohort.
Domain scores ranged from –0.15 standard deviation for attention to –1.32 standard deviation for executive function, according to the study.
Compared with the normative reference, impaired scores were more prevalent in the composite z score (13.2%; P = .019), executive function (41.9%; P < .001), verbal memory (P < .001) and visual memory (P < .001), Lazar and colleagues wrote.
There were significant negative correlations in the regression model between fluid-attenuated inversion recovery lesion volume and baseline cognition.
“There is a great degree of preprocedural cognitive impairment among older, high-surgical risk patients with planned TAVR than previously known,” the researchers wrote. “Moreover, this impairment is related to pre-TAVR cerebral lesions burden that is affected by cerebrovascular risk factors. Determining whether patients have lower surgical risk have comparable degrees of cognitive loss requires further research.”
Measurement difficult
“Why is it so difficult to measure a clinical effect of a protection device that appears to work well from a technical perspective,” Steffen Massberg, MD and Axel Bauer, MD, from the Medizinische Klinik und Poliklinik I, Klinikum der Universität München, Ludwig Maximilians University, Munich, wrote in a related editorial. “The authors speculate that pre-existing neurocognitive impairment might cause a ‘floor effect,’ with new procedure-related lesions having little to no additional impact on an already damaged brain. While this explanation appears plausible, the positive relationship between pre-existing white matter disease and new lesion volume is somewhat contradictory.” – by Dave Quaile
Disclosures: The SENTINEL study was funded by Claret Medical. Lazar reports he is a consultant for and holds stock in Claret Medical. Please see the study for all other authors’ relevant financial disclosures. Massberg and Bauer report no relevant financial disclosures.