Catheter ablation increases cerebral blood flow and cognitive function in elderly patients with atrial fibrillation

Abstract Background Atrial fibrillation (AF) has been considered to have an increased risk for cognitive impairment independent of a stroke and a silent micro-infarction. The mechanism of this interaction is unclear. One of the potential explanations is brain hypoperfusion due to a reduced cardiac output. To date, there are no reports focusing on the cerebral blood flow and cognitive impairment in patients undergoing AF ablation. Purpose The purpose of this study was to investigate whether catheter ablation of AF would increase cerebral blood flow and restore cognitive impairment. Methods AF patients aged 75 years or older with mild or more cognitive impairment were selected. The assessment of cognitive function using Mini-Mental State Examination (MMSE) and Hasegawa's Dementia Scale-Revised (HDS-R), and measurement of cerebral blood flow using 99mTc-ECD SPECT imaging were examined before and 3 months after ablation. Results A total of 25 elderly patients (mean age 83, 14 males and 11 females) were included in this study. Of them, 23 patients had persistent AF. Twenty-three patients (92%) maintained sinus rhythm after ablation. There was a significant improvement in MMSE score (from 24.6±4.5 to 25.9±4.0, p<0.05) and HDS-R (from 23.2±5.5 to 24.8±5.1, p<0.05) after ablation. Cerebral blood flow also significantly increased after ablation (right lobe: from 34.4±4.6 to 38.5±4.4 ml/100g/min, p<0.01, left lobe: from 35.3±9.7 to 38.8±3.7 ml/100g/min, p<0.01). Overall average cerebral blood flow increased by 10.1±9.4% after ablation. There was a positive correlation between the changes in MMSE score and the changes in cerebral blood flow (r=0.65, p<0.05). Conclusion AF ablation in elderly patients increased cerebral blood flow and cognitive function. AF ablation would be one of the therapeutic options to improve cognitive function in elderly patients with cognitive impairment.