Cerebral Hemodynamic Changes in Older Adults With Cognitive Complaints According to the Presence of Peripheral Artery Disease.

Abstract

Objective: As a systemic expression of atherosclerosis, peripheral artery disease (PAD) has the potential to alter cerebral hemodynamics in elderly individuals presenting with cognitive concerns. However, how PAD status shapes the longitudinal trajectory of cerebral hemodynamics has not been well characterized.

Methods: We conducted a single-center longitudinal observational study enrolling 132 participants (21 controls, 39 mild cognitive impairment, 72 mild Alzheimer's disease). All participants underwent transcranial Doppler (TCD) ultrasonography, ankle-brachial index (ABI) measurement, brain MRI, and cognitive assessments at baseline and follow-up (~13.45 months). PAD was defined as ABI < 0.90. Bilateral mean flow velocity (MFV), pulsatility index (PI), and resistance index (RI) of the middle cerebral artery (MCA) were tracked longitudinally across both time points.

Results: PAD was identified in 13 participants (9.8%). Baseline TCD parameters, vascular risk factors, white matter lesions on brain MRI, and cognitive measures were comparable between groups. At follow-up, the PAD group showed significantly higher MCA MFV after age adjustment (left p < 0.001; right p = 0.005). MFV increased in the PAD group (left +16.45 cm/s) but decreased in the non-PAD group (left -3.37 cm/s), with a significant between-group difference. PI and RI did not change in either group. Cognitive and functional outcomes were similar across groups throughout the study.

Conclusion: These findings identify PAD as a condition associated with progressive MCA MFV elevation in the context of preserved cognition, implying that subclinical cerebrovascular changes are detectable by TCD before overt clinical worsening. Future research involving larger cohorts and extended follow-up is required to determine whether such hemodynamic changes forecast eventual cognitive deterioration.