Assessment of peripheral vascular endothelial function with finger arterial pulse wave amplitude

Background Abnormalities in pulse wave amplitude (PWA) have been described in subjects with atherosclerosis and may be a marker of future cardiac events. We evaluated the relationship between changes in PWA of the finger and peripheral endothelial function. Methods We performed measurements of PWA with a novel finger plethysmograph (peripheral arterial tonometry [PAT]) and compared the findings with a simultaneous noninvasive measurement of peripheral endothelial function with brachial artery ultrasound scanning (BAUS) in 89 subjects. The PAT hyperemia ratio was defined as the ratio of PWA during reactive hyperemia relative to the baseline. Flow-mediated dilation (FMD) was defined by BAUS as the ratio of the brachial artery diameter during reactive hyperemia relative to the baseline. Sixty-eight subjects underwent exercise myocardial perfusion imaging (ExMPI). Results Fifty-four men and 35 women were examined. There was a linear relationship between the PAT hyperemia ratio and FMD during the same episode of reactive hyperemia (r = 0.55, P < .0001). Subjects in the lowest FMD quartile had the lowest PAT hyperemia ratio, whereas subjects in the highest FMD quartile had the highest PAT hyperemia ratio (P < .001 for trend). Similar to BAUS, the PAT hyperemia ratio was more impaired in subjects with cardiovascular risk factors and in subjects with ExMPI studies that were indicative of coronary artery disease. Conclusions Assessment of PWA with PAT demonstrates patterns of abnormality similar to that of BAUS assessment of FMD. PWA during reactive hyperemia is influenced by factors known to affect endothelial function, including cardiovascular risk factors and coronary artery disease. These findings support the concept that analysis of PWA with PAT during reactive hyperemia may be used to study peripheral vascular endothelial function.