Methodological and interpretative pitfalls in the noninvasive assessment of vascular endothelial function

Noninvasive assessment of vascular endothelial function, most commonly via brachial artery flow-mediated vasodilation and peripheral arterial tonometry-derived reactive hyperemia index, has become a cornerstone of cardiovascular research. These techniques provide clinically relevant surrogate indices of vascular health and have been associated with future cardiovascular risks. However, their interpretation is complex because they are influenced by a wide range of methodological, physiological, and pathobiological factors. A nuanced understanding of these limitations is essential, particularly in mechanistic and intervention studies.