Impaired dynamic cerebral autoregulation predicts silent ischemic lesions after carotid artery stenting: A hemodynamic biomarker beyond plaque morphology.

Abstract

Carotid artery stenting (CAS) induces hemodynamic disturbances that may trigger silent cerebral ischemia (ASILs), though the relative contributions of impaired cerebral autoregulation (dCA) versus plaque characteristics remain unclear. In this prospective cohort study, we evaluated 59 patients with severe carotid stenosis undergoing CAS, assessing dCA via transcranial Doppler (TCD) and transfer function analysis (TFA) pre- and post-procedurally, with postoperative MRI to detect ASILs. ASILs occurred in 30.5% (18/59) of patients and were associated with dyslipidemia (P = 0.010) and low-echo plaques (P = 0.022). Critically, the ASILs group exhibited significantly reduced dCA phase in the very low frequency (VLF) range post-CAS (P < 0.001), indicating impaired autoregulation. Multivariate analysis identified postoperative VLF phase (adjusted OR: 0.925, P = 0.002), dyslipidemia (OR: 11.909), and plaque morphology (OR: 10.798) as independent ASILs predictors. ROC analysis demonstrated superior predictive accuracy when combining dCA parameters with clinical/plaque features (AUC = 0.917). These findings establish dCA dysfunction as a key hemodynamic biomarker of ASILs post-CAS, surpassing plaque characteristics alone. Integration of perioperative dCA monitoring with traditional risk stratification may optimize patient selection and neuroprotective strategies during carotid revascularization.