1. Department of Cardiovascular Medicine, Tohoku University Graduate School of Medicine, Sendai, Japan; 2. Department of Diagnostic Radiology, Tohoku University, Sendai, Japan; 3. Department of Geriatrics & Gerontology, Division of Brain Science, Institute of Development, Aging and Cancer, Tohoku University, Sendai, Japan; 4. Division of Cardiovascular Surgery, Tohoku University Graduate School of Medicine, Sendai, Japan; 5. Department of Nuclear Medicine and Radiology, Institute of Development, Aging and Cancer, Tohoku University, Sendai, Japan
Aims: The aim of this study was to examine the mechanisms of cognitive impairment and reversibility in elderly patients with severe aortic stenosis (AS) after transcatheter aortic valve implantation (TAVI) with special reference to cerebral blood flow (CBF).
Methods and results: We examined 15 elderly patients with severe AS (mean age 83.2±4.5 years, 12 female) who underwent TAVI. Before and three months after TAVI, we evaluated cognitive function with the Logical Memory II test (LM II), cardiac output (CO) with echocardiography, and CBF with 99mTc single-photon emission computed tomography (SPECT). LM II score and CO were significantly increased after TAVI compared with baseline (p<0.01 for LM II, p<0.005 for CO). Notably, CBF in the local regions, including that in the right hippocampus, was significantly increased after TAVI (p<0.005 at each voxel). The patients with increased CO after TAVI also showed significantly increased CBF in the right hippocampus compared with those without it (p<0.01). Importantly, CBF in the right hippocampus was positively correlated with LM II scores (p<0.05).
Conclusions: These results provide the first evidence that TAVI may improve cognitive functions associated with increased cerebral perfusion especially in the hippocampus in elderly patients with severe AS.