Aortic stiffness is an indicator of cognitive dysfunction before and after aortic valve replacement for aortic stenosis

Abstract

Post-cardiac surgical cognitive dysfunction occurs more commonly following valvular procedures. Cognitive function has been related to vascular health status; however, the relation between pre-existent arterial stiffness and perioperative cognitive dysfunction is yet to be defined. The objective of this study was to assess whether aortic stiffness is related to cognitive dysfunction in surgical aortic stenosis (AS) pre- and postoperatively. Between June 2010 and August 2012, patients undergoing aortic valve replacement (AVR) for AS were recruited for inclusion in this prospective observational study. Aortic pulse wave velocity (PWV) was used as a measure of aortic stiffness and cognitive function was assessed using the computerized Cambridge Neuropsychological Test Automated Battery (CANTAB) preoperatively and (409 ± 159 days) post-AVR. Fifty-six patients (age 71 ± 8.4 years) were recruited. Of the total, 50 (89%) completed postoperative follow-up. Pre- and postoperatively, patients with normal PWV (PWV-norm) had significantly superior delayed memory, sustained visual attention and executive function compared with those with high PWV (PWV-high). Immediate memory and decision-making were similar between groups. Postoperatively, improvement in cognitive function was more marked in PWV-high compared with PWV-norm patients. In two models of multiple regression analysis, PWV as a continuous variable was independently related to all preoperative main cognitive components as well as postoperative executive function. PWV as a dichotomous variable was independently related to all pre- and postoperative main cognitive function components. AVR may not be associated with an independent or homogeneous effect on cognitive decline. Aortic PWV might be useful as an additional indicator for cognitive dysfunction before and after surgical intervention for AS.