Associations of carotid flow velocity with cerebral perfusion and cerebral small vessel disease: a community-based prospective study.

Objectives: To explore the associations of carotid artery hemodynamic parameters with cerebral perfusion and cerebral small vessel disease (CSVD) in a healthy population.

Methods: A total of 654 participants from the Kailuan community were included after those with incomplete data or carotid stenosis ≥ 50% were excluded. Carotid ultrasound was used to measure the peak carotid flow velocity (PSV), end-diastolic velocity (EDV), resistance index (RI), pulsatility index (PI) and carotid intima-media thickness (IMT) of the common carotid artery (CCA) and internal carotid artery (ICA). MRI was performed to assess cerebral perfusion and CSVD features, including white matter hyperintensities (WMH), lacunes (LA), cerebral microbleeds (CMB), and enlarged perivascular spaces (EPVS). Multivariate regression models were used to analyze the associations of carotid hemodynamics with cerebral perfusion and CSVD.

Results: CCA-EDV was positively associated with whole-brain perfusion (β = 0.14, p = 0.017) and regional perfusion in gray matter (GM) (β = 0.16, p = 0.012), frontal (β = 0.15, p = 0.014), parietal (β = 0.19, p = 0.006), temporal (β = 0.14, p = 0.020), and hippocampus (β = 0.12, p = 0.034), but no significant associations were found between CCA-EDV and white matter (WM) perfusion. A higher CCA-EDV was associated with a lower risk of LA (OR = 0.93, p = 0.029). The CCA-PSV was negatively correlated with the total CSVD score (OR = 0.99, p = 0.047). No significant associations were detected between other carotid hemodynamic parameters and LA, CMB, EPVS, WMH, or total CSVD score.

Conclusions: Carotid artery hemodynamic parameters, especially the CCA-EDV, are closely related to cerebral perfusion and the development of CSVD. Reductions in total and regional cerebral perfusion, along with an increased LA burden, were associated with decreased CCA-EDV.