Abstract TP483: Transcatheter Aortic Valve Replacement (TAVR) Does Not Improve Cerebral Hemodynamics or Neurocognition in Patients With Severe Aortic Stenosis

Abstract

Objective: To determine if aortic stenosis (AS) is associated with altered cerebral hemodynamics and impaired neurocognition, and whether TAVR improves hemodynamics and cognition. Background: AS results in higher systolic pressure to overcome resistance from the stenotic valve, leading to heart failure and decline in cardiac output. There has been no baseline assessment of CBF with neurocognition in AS, or the effects of valve replacement. Methods: In 40 patients with planned TAVR, transcranial Doppler (TCD) assessed bilateral MCA mean flow velocity (MFV); abnormality was < 30cc/sec. The neurocognitive battery assessed memory, language, attention, visual-spatial skills, and executive function, yielding an average Z-score. Impairment was < 1.5 SD’s below the normative mean. Results: The mean age was 78 years, 59% male, and the mean valve gradient was 46.87%. Mean follow-up was 36 days post-TAVR (range 27 - 55). Before TAVR, the average MFV was 42 cc/sec (SD=10.22), and the mean cognitive score was -0.22 SD’s (range -1.99 to 1.08) below the normative mean. Of the 5 with abnormal MFV’s, none had abnormal cognition (average=0.19 SD’s above the normative mean). After TAVR, the MFV was 43 cc/sec, not different from baseline (p=0.56). The post-TAVR average Z-score was 0.01 SD’s above the normative mean, also not different from baseline (p=0.29). There was no correlation between the change scores in MFV and in neurocognition (r = 0.08, p= 0.69). Conclusions: Among patients with severe AS, there was no correlation at baseline between abnormal MFV’s on TCD and abnormal neurocognition. It was therefore unsurprising that there was little impact of valve replacement on these measures of cerebral blood flow and brain function. Prior assumptions about diminished CBF and the relationship to cognitive function may not be supported.