Cerebral Autoregulation in Transcatheter Aortic Valve Implantation Patients

Francesca Gelpi1, Vlasta Bari1, Beatrice Cairo1, Sara Pugliese2, Martina Aunguissola2, Beatrice De Maria3, Elena Acerbi4, Mattia Squillace4, Marco Ranucci2, Francesco Bedogni4, Alberto Porta1
1Department of Biomedical Sciences for Health, University of Milan, 2Department of Cardiothoracic, Vascular Anaesthesia and Intensive Care, IRCCS Policlinico San Donato, 3IRCCS Istituti Clinici Scientifici Maugeri, Milan, 4Department of Clinical and Interventional Cardiology, IRCCS Policlinico San Donato


Transcatheter aortic valve implantation (TAVI) is a minimally invasive treatment for patients with severe aortic stenosis. TAVI can affect cerebral circulation; however, little is known on the modification of the control mechanism that guarantees a constant cerebral blood flow despite arterial pressure (AP) variation, namely cerebral autoregulation (CA). Thus, this exploratory study aims to investigate CA before and after TAVI. In 11 patients (age: 78±6 yrs, 3 females, 8 males) scheduled for TAVI, we assessed CA indexes one day before (PRE) and within 7 days after the procedure (POST) via CA indexes derived from spontaneous variations of mean AP (MAP) and mean cerebral blood velocity (MCBv) such as the transfer function gain and phase, squared coherence and autoregulation index (ARI). Traditional time domain indexes such as mean and variance of MAP and MCBv were computed as well. Markers were computed in PRE and POST conditions at supine resting (REST) and during active standing (STAND).
None of the time and frequency domain indexes varied across time points and experimental conditions. However, some CA indexes showed a tendency towards an amelioration of cerebrovascular control after TAVI. Indeed, during STAND we observed a tendency toward a post-procedural decrease of the MCBv variance and a more positive phase lead of MCBv to MAP changes. In additional, ARI increased from 4.5±3.4 to 7±1.8 and from 4.7±2.9 to 6.7±2.1, respectively at REST and STAND. Our preliminary data indicate that TAVI has no impact on CA, but they suggest enlarging the population to check whether some tendencies could be confirmed.