STAND: Ultrasound of Cerebral Blood Flow During First Verticalization in Acute Stroke-A Prospective Case-Control Study.

The optimal timing for mobilizing patients during the acute phase of ischemic stroke remains unclear. Prior research has produced conflicting results, often neglecting the impact of upstream arterial stenosis on cerebral blood flow. This study aimed to determine whether early transition to a seated position in the acute phase of ischemic stroke influences intracranial hemodynamics, particularly in patients with significant carotid stenosis. In a prospective, bi-centric, 1:1 case-control observational study (NCT04180826), we continuously and non-invasively monitored cerebral and systemic hemodynamics during the first authorized transition from supine to a sitting position in patients with ischemic stroke of the carotid territory. Cases were defined as those with homolateral carotid stenosis >50% by NASCET criteria. The primary outcome was a >10% reduction in mean flow velocity (MFV) in the homolateral middle cerebral artery (MCA). Of 42 screened patients, 36 were included (19 controls, 17 cases). A significant (>10%) MFV drop occurred in 9/17 cases (53%) versus 1/19 controls (5%; p = 0.012). Notably, cases with an MFV drop showed no compensatory systemic response (no rise in blood pressure or heart rate). Multivariate analysis revealed that a shorter time from stroke onset to sitting (coefficient = -2.793, p = 0.016) and being a case (coefficient = -6.283, p = 0.004) independently predicted an MFV decrease >10%. Additional factors associated with significant MFV decline in cases included the absence of a blood pressure increase after verticalization, lower hemoglobin (p = 0.007), and higher BNP levels (p = 0.024). Early sitting in the acute phase of ischemic stroke is more frequently associated with marked MFV reductions in patients with carotid stenosis, potentially due to impaired systemic hemodynamic adaptation. These findings underscore the importance of individualized mobilization strategies based on vascular and systemic factors.