Time Course of Flow-Mediated Dilation and Vascular Endothelial Growth Factor following Acute Stroke.

OBJECTIVES: People after stroke demonstrate alterations in vascular endothelial function measured by flow-mediated dilation. Limited information is available in the literature on possible protective factors following stroke. The aims of the secondary analysis were (1) to characterize the time course of vascular endothelial function using flow-mediated dilation at 72 hours after stroke and 1 week later during inpatient stroke rehabilitation and (2) to determine whether flow-mediated dilation was related to vascular endothelial growth factor, brain-derived neurotrophic factor, or estimated prestroke peak oxygen uptake.
METHODS: Flow-mediated dilation using Doppler ultrasound was assessed in bilateral brachial arteries at the defined time points. Flow-mediated dilation and blood draws occurred on the same day between 7:30 am and 9:00 am following an overnight fast. Enzyme-linked immunosorbent assay was used to quantify plasma vascular endothelial growth factor and brain-derived neurotrophic factor values. A nonexercise estimate was used to calculate prestroke peak oxygen uptake.
RESULTS: We have shown that between-limb differences are evident within 72 hours after stroke and remain 1 week later during inpatient rehabilitation. Higher values for vascular endothelial growth factor were associated with increased flow-mediated dilation at both time points. Higher estimated prestroke peak oxygen uptake was related to flow-mediated dilation. Brain-derived neurotrophic factor was not related to any outcome measures.
CONCLUSIONS: Unique vascular adaptations start early after stroke in the stroke-affected limb and remain through inpatient stroke rehabilitation. Vascular endothelial growth factor and prestroke physical activity may have a protective role in vascular function following stroke. Future work should focus on mechanistic pathways for preservation of vascular health.