Ultrasound measure of endothelium-dependent vasodilation used as a vascular health biomarker.
Flow-mediated dilation measures the percentage increase in brachial artery diameter during reactive hyperaemia after a period of arterial occlusion, reflecting endothelial nitric-oxide-mediated vasodilator function. It is widely used as a surrogate marker of cardiovascular risk, but an observed absolute change in FMD is itself a surrogate endpoint; translating it into hard cardiovascular event risk requires borrowing an external epidemiological model rather than being measured directly in the same dataset.
This guide was auto-drafted and is pending editorial review.