Normalizing flow-mediated dilation to individual shear stress successfully discriminated moderate from low cardiovascular risk subjects (p=0.041), whereas unadjusted FMD did not (p=0.286).
Cross-Sectional (n=40)
Does adjusting flow-mediated dilation for shear stress stimulus improve the detection of endothelial dysfunction in patients with moderate cardiovascular risk compared to conventional FMD?
Normalizing flow-mediated dilation to individual shear stress improves the sensitivity of ultrasound-based endothelial function testing to detect moderate cardiovascular risk.
valor p: p=0.041
BACKGROUND/AIMS: Although normalization of brachial artery flow-mediated dilation (FMD) to individual shear stress (FMD:shear stress ratio) has been proposed to improve this measure of endothelial function, the clinical utility of FMD normalization has not yet been demonstrated. We tested (1) whether following conventional 5-min forearm occlusion, the FMD:shear stress ratio would discriminate a population with moderate cardiovascular risk (MR) from a low-risk (LR) population, and (2) whether the dose-response profile relating shear stress to FMD would be different between the 2 populations. METHODS: Five different magnitudes of reactive hyperemia-induced shear stress were applied to 20 MR and 20 LR subjects by manipulating forearm cuff occlusion duration. Brachial artery diameters and velocities were measured via high-resolution ultrasound. To quantify the hyperemic stimulus, shear stress area under the curve was individually calculated for the duration of time-to-peak dilation. RESULTS: Following 5-min of forearm occlusion, FMD:shear stress ratio (p = 0.041), but not FMD (p = 0.286), discriminated MR from LR. The slope of the shear stress-FMD regression line was lower in MR compared to the LR (p < 0.001). CONCLUSION: The FMD:shear stress ratio distinguished reduced endothelial function in a population with MR. The dose-response profile of the shear stress-FMD relationship appears to differ between populations of distinct cardiovascular risk.
Padilla et al. (Thu,) conducted a cross-sectional in Moderate cardiovascular risk (n=40). FMD:shear stress ratio vs. Unadjusted FMD was evaluated on Discrimination of moderate from low cardiovascular risk following 5-min forearm occlusion (p=0.041). Normalizing flow-mediated dilation to individual shear stress successfully discriminated moderate from low cardiovascular risk subjects (p=0.041), whereas unadjusted FMD did not (p=0.286).