Relation between Digital Peripheral Arterial Tonometry and Brachial Artery Ultrasound Measures of Vascular Function in Patients with Coronary Artery Disease and in Healthy Volunteers

摘要

Digital peripheral arterial tonometry (PAT) is an emerging, non-invasive method to assess vascular function. The physiology underlying this phenotype, however, remains unclear. Therefore, we evaluated the relationship between digital PAT and established brachial artery ultrasound measures of vascular function under basal conditions and following reactive hyperemia. Using a cross-sectional study design, digital PAT and brachial artery ultrasound with pulsed wave Doppler were simultaneously completed at baseline and following reactive hyperemia in both individuals with established coronary artery disease (n=99) and healthy volunteers at low cardiovascular disease risk (n=40). Under basal conditions, the digital pulse volume amplitude demonstrated a significant positive correlation with the brachial artery velocity-time integral, that was independent of arterial diameter, in both the healthy volunteer (rs=0.64, P<0.001) and coronary artery disease (rs=0.63, P<0.001) cohorts. Similar positive relationships were observed with baseline brachial artery blood flow velocity and blood flow. In contrast, no relationship between the reactive hyperemia-evoked digital PAT ratio and either brachial artery flow-mediated dilation or shear stress was observed in either cohort (P=NS). In conclusion, these findings demonstrate that digital PAT measures of vascular function more closely reflect basal blood flow in the brachial artery than reactive hyperemia-induced changes in arterial diameter or flow velocity, and the presence of vascular disease does not modify the physiology underlying the digital PAT phenotype.