A novel standardized bio-feedback test for cognitive and neuromuscular performance with the CortexTrainer shows improvements within one month after TAVR in elderly severe aortic stenosis patients

Background Transcatheter aortic valve replacement (TAVR) is the treatment of choice for elderly patients or high-risk patients with severe symptomatic aortic valve stenosis with improved symptoms, morbidity and mortality in the follow-up. However, increasing attention is given to the role of frailty and cognitive dysfunction as risk factors, which may limit the therapeutic benefit of TAVR in certain patients. Cardiovascular guidelines recommend taking such comorbidities into account pre and post TAVR. By contrast, quantification of cognitive and neuromuscular function in patients with aortic stenosis before and after causal treatment is not well established. Purpose To validate a novel, easy to perform, standardized bio-feedback protocol testing four cognitive and neuromuscular domains using the CortexTrainer in patients with compensated symptomatic severe aortic valve stenosis before, shortly after and one month after TAVR. Methods N=120 patients consecutive patients scheduled for TAVR (81±1 yrs) were enrolled in a prospective monocentric observational registry. They were tested shortly before the procedure, shortly after as well as one month later as outpatients at the follow-up visit. Their test results were compared to N=70 healthy volunteers of different ages. The CortexTrainer was used to perform a standardized 10-minute supervised exam containing four distinct test domains: 1. postural stability test (sway way, in mm), 2. reaction test (hands vs. feet, in ms), 3. complex movement task (chasing a ball on screen, in % success), and 4. complex neurocognitive task (on-screen trail making test, TMT, in seconds). In addition, Barthel index, frailty scales, MMSE, paper-pen trail making test and clinical data were recorded. Results The 70 study control subjects without aortic valve stenosis showed a linear decrease of neuromuscular performance and postural stability with increasing age. Compared to age-matched control patients, TAVR patients were significantly worse with respect to sway way, reaction time, chase success and TMT, but also had a high inter-individual variability. After one month follow-up, TAVR was not associated with significant differences in Barthel index, Edmonton frailty scale, essential frailty scale, MMSE, handgrip strength and paper-pen TMT. However, in the CortexTrainer standardized assessment, stand stability (sway way 1263±227 vs. 1851±267mm, p=0.006), mean pedal reaction time (192±20 vs. 259±20ms, p=0.021), complex task success rate (p=0.029) and bio-feedback TMT (96±5 vs. 111±4 seconds, p=0.001) were improved. Data are mean±SEM, statistics are t-test and ANOVA for repeated measurements. Conclusion Standardized neuromuscular and cognitive performance measures of control subjects showed a decline with increasing age. Importantly, performance in TAVR recipients was even lower than in age-matched controls. Following TAVR, improved performance in all assessed tasks was seen after 1 month.