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. 2023 Jan;108(1):103-110.
doi: 10.1113/EP090502. Epub 2022 Nov 20.

Changes in cerebral autoregulation and vasoreactivity after surgical aortic valve replacement: a prospective study

Tiago Pedro  1 , Andreia Costa  2   3 , Juliana Ferreira  4 , Ana Luísa Rocha  2   3 , Elson Salgueiro  5   6 , Gilberto Pereira  2   4 , Elsa Azevedo  2   3   4 , Pedro Castro  2   3   4
Affiliations

Changes in cerebral autoregulation and vasoreactivity after surgical aortic valve replacement: a prospective study

Tiago Pedro et al. Exp Physiol. 2023 Jan.

Abstract

New findings: What is the central question of this study? How are dynamic cerebral autoregulation and brain vasoreactivity influenced by severe aortic stenosis and its surgical treatment? What are the main findings and their importance? Dynamic cerebral autoregulation is preserved in the long term in patients with severe aortic stenosis and does not change after surgical aortic valve replacement. However, carbon dioxide vasoreactivity is impaired in these patients.

Abstract: Surgical aortic valve replacement (SAVR) alters the natural course of severe aortic stenosis (AS). In this study, we aimed to determine the effects of the disease on dynamic cerebral autoregulation and vasoreactivity (VR) and to assess their changes after SAVR. We recruited 23 patients diagnosed with severe AS eligible for SAVR and 15 healthy matched controls. AS patients had lower mean VR to CO2 (P = 0.005) than controls, but dynamic cerebral autoregulation was preserved. Cerebral haemodynamics showed no significant change after SAVR. Patients with smaller baseline aortic valve areas presented with smaller low frequency phase changes after surgery (P = 0.016). Severe AS does not seem to impact dynamic cerebral autoregulation but does reduce VR to CO2 . SAVR does not alter cerebral autoregulation nor vasoreactivity.

Keywords: aortic valve stenosis; cerebral autoregulation; transcranial Doppler ultrasound.

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Conflict of interest statement

The authors have no relevant conflicts of interest to declare.

Figures

FIGURE 1
FIGURE 1
Averaged transfer function parameters for pre‐surgery, post‐surgery, and control patients. (a) Coherence; (b) gain; (c) phase. Dotted lines indicate standard deviation
FIGURE 2
FIGURE 2
Mean cerebral blood flow velocity (CBFV), end‐tidal CO2 and normalized mean arterial pressure (MAP) during hypercapnia and hypocapnia states for pre‐surgery, post‐surgery and control patients. Dotted lines indicate standard deviation. TCD, transcranial Doppler
FIGURE 3
FIGURE 3
Example of a T2‐weighted MRI sagittal scan of the middle cerebral artery (MCA). The white box indicates the zoomed area showing the lumen of the M1 portion of the MCA
See this image and copyright information in PMC

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