Abstract Number: Esoc2026a1827 Age-Dependent Effects of Post-Recanalisation Flow Asymmetry on Dynamic Cerebral Autoregulation After Ischaemic Stroke

Abstract Background and aims Cerebral autoregulation maintains brain perfusion despite blood pressure fluctuations. Our aim is to identify clinical variables associated with dynamic cerebral autoregulation (dCA) early after a successfully treated ischaemic stroke. Methods This prospective single-centre pilot study enrolled patients with MCA ischaemic stroke treated with effective recanalisation (mTICI ≥2b). Within 24 hours of thrombectomy, bilateral transcranial Doppler and continuous blood pressure monitoring were performed. dCA was assessed using Transfer Function Analysis by an in-house software compliant with CARNet guidelines. Univariable and multivariable linear regression models were used to explore associations with Very Low Frequency (VLF) phase shift (PS). Results Twenty-six patients were included (median age 70 years; 65% male; median baseline NIHSS 15). In multivariable models, age emerged as the main determinant of VLF-PS (estimate −0.90 per year, 95% CI −1.55 to −0.26; p=0.008). Mean flow velocity (MFV) ratio (stroke/contralateral side) was not independently associated with VLF phase shift; however, a significant interaction between age and MFV ratio was observed (p=0.049), indicating that flow asymmetry was associated with lower PS predominantly in older patients. Age was not associated with MFV ratio. MFV ratio 1.3 (i.e. ≥30% higher velocity in the treated side) showed a borderline independent association with reduced VLF-PS (estimate −19.7 degrees, 95% CI −40.6 to 1.1; p=0.062). A trend toward higher VLF-PS was observed in patients with hypertension (p=0.082). Conclusions Early impairment of dCA after successful thrombectomy is primarily age-related. Post-reperfusion flow asymmetry (hyperperfusion) seems associated with worse autoregulation, mainly in older patients, potentially reflecting delayed adaptation of vasodilatory mechanisms after recanalisation. Conflict of interest Matteo Paolucci: nothing to disclose; Giacomo Urbinati: nothing to disclose; Ludovica Migliaccio: nothing to disclose; Mauro Gentile: nothing to disclose; Giorgia Arnone: nothing to disclose; Stefano Forlivesi: nothing to disclose; Andrea Zini: received funding for the study by Fondazione Carisbo 2023