Abstract
OBJECTIVE: Experimental studies link oscillatory flow accompanied by flow reversal to impaired endothelial cell function. The relation of flow reversal with vascular function and arterial stiffness remains incompletely defined. APPROACH AND RESULTS: We measured brachial diastolic flow patterns along with vasodilator function in addition to tonometry-based central and peripheral arterial stiffness in 5708 participants (age 47±13 years, 53% women) in the Framingham Heart Study Offspring and Third Generation cohorts. Brachial artery diastolic flow reversal was present in 35% of the participants. In multivariable regression models, the presence of flow reversal was associated with lower flow-mediated dilation (3.9±0.2 versus 5.0±0.2%; P<0.0001) and reactive hyperemic flow velocity (50±0.99 versus 57±0.93 cm/s; P<0.0001). The presence of flow reversal (compared with absence) was associated with higher central aortic stiffness (carotid-femoral pulse wave velocity 9.3±0.1 versus 8.9±0.1 m/s), lower muscular artery stiffness (carotid-radial pulse wave velocity 9.6±0.1 versus 9.8±0.1 m/s), and higher forearm vascular resistance (5.32±0.03 versus 4.66±0.02 log dyne/s/cm(5); P<0.0001). The relations of diastolic flow velocity with flow-mediated dilation, aortic stiffness, and forearm vascular resistance were nonlinear, with a steeper decline in vascular function associated with increasing magnitude of flow reversal. CONCLUSIONS: In our large, community-based sample, brachial artery flow reversal was common and associated with impaired vasodilator function and higher aortic stiffness. Our findings are consistent with the concept that flow reversal may contribute to vascular dysfunction.