ENDOTHELIAL FUNCTION IS ASSOCIATED WITH COGNITION IN CORONARY ARTERY DISEASE

Abstract

Cognitive impairment and particularly subtle deficits in verbal memory are common in patients with coronary artery disease (CAD). Although deterioration may be mitigated by exercise, cognitive response to exercise is heterogeneous. Endothelial dysfunction and arterial stiffness are hallmarks of CAD and may play an important role in impairing the neural adaptation response to exercise. Associations between endothelial function and performance in verbal memory and other cognitive domains were assessed in CAD subjects at baseline and following completion of a 3-month cardiac rehabilitation (CR) program. Verbal memory, visuospatial memory, processing speed, executive function and global cognition were assessed and Z-scores based on age, gender and education were calculated. Endothelial function was measured by reactive hyperemia index (RHI), and arterial stiffness was measured by heart rate corrected augmentation index (AI@75) using peripheral arterial tonometry. Linear regressions were used to determine cross-sectional associations between vascular health indices and cognitive performance. Longitudinal relationships were assessed using linear mixed models. Participants (n=64) were aged 63±7 years, mostly male (70%) and Caucasian (72%) with 16±3 years of education. Lower RHI was significantly associated with poorer verbal memory performance (b=0.28, p=0.02) at entry into CR. After 3 months of CR, an increase in RHI was significantly associated with improvement in processing speed (b [SE]=0.40[0.19], p=0.04) and executive function (b [SE]=0.46[0.21], p=0.03) though there was no significant improvement in verbal memory (b [SE]=0.35[0.20], p=0.09). A decrease in AI@75 was significantly associated with improvement in verbal memory domain Z-scores (b [SE]=-0.01[0.005], p=0.03) over CR. Measures of vascular health may be clinically useful makers of cognitive change, and might provide insight into the effects of exercise on cognitive function in patients with CAD.