Endothelial dysfunction is an early marker of cardiovascular disease. Flow-mediated dilation is the reference non-invasive method for endothelial assessment but remains operator-dependent. Infrared thermography offers a non-contact approach to evaluate peripheral thermal responses during reactive hyperemia; however, the reproducibility of thermal parameters and optimal occlusion protocols remain unclear.
This study evaluates the repeatability of thermal video-derived parameters in 30 participants during reactive hyperemia, using a new protocol of two successive brachial cuff occlusions (1 min and 3 min) and assesses their relationship with radial artery ultrasound measurements. We assess repeatability using coefficient of variation and intraclass correlation coefficient.
The 3-min occlusion improves repeatability, while Nadir-to-Peak parameters show the best reproducibility for fingertip two-hand referencing method, while cold peripheral responses reduce repeatability, particularly at the fingertip. Current data remain insufficient to draw firm conclusions on the relationship with radial artery ultrasound.
These findings support infrared thermography as a complementary tool for peripheral vascular assessment and raise the question of whether it could discriminate endothelial dysfunction in clinical populations, such as breast cancer patients.