Transcatheter aortic valve implantation improves carotid and vertebral arterial blood flow in patients with severe aortic stenosis: practical role of orthostatic stress test

Abstract

Background: There are no data on the impact of transcatheter aortic valve implantation (TAVI) on carotid and vertebral arterial blood flow. Our aim was to assess the effects of the orthostatic stress test on carotid and vertebral artery blood flow in patients with severe aortic stenosis (AS) undergoing TAVI. Hypothesis: TAVI may have beneficial effect on carotid and vertebral artery flow in patients with severe aortic stenosis. Methods: Thirty carefully selected patients with severe AS undergoing TAVI were enrolled. Peak systolic blood-flow velocity and end-diastolic velocity in the common carotid artery, internal carotid artery, and vertebral artery, as well as spectral analysis of flow pattern with time-averaged maximum velocity (centimeters per second), time-averaged mean velocity (centimeters per second), and flow volume (milliliters per minute) on both sides were measured by duplex ultrasound. Measurements were performed in the supine position and at 1 to 2 minutes after the assumption of the standing position at baseline and 3 months after TAVI. Results: All duplex ultrasound parameters assessed in the supine position have significantly improved in patients after TAVI as compared to baseline (P < 0.001 for all). The orthostatic stress test induced decrease of carotid and vertebral arterial flow velocities in AS patients before and after TAVI. However, the drop in velocities and flow volume was numerically lower after TAVI. Conclusions: TAVI may have some beneficial effect on extracranial artery blood flow by minimalization of its decrease as a response to orthostatic stress.