Delayed flow-mediated vasodilation and carotid atherosclerosis

Background: In a previous study, we identified temporally distinct post-ischemic flow-mediated dilation (FMD) patterns comparing the standard clinical measurement time of 50s post cuff release with measurement at 2 min. The comparison revealed a cohort with the highest FMD at 50s (Early FMD), another cohort with the highest FMD at 2 min (Late FMD), and a third cohort with no FMD (Absent FMD). The aim of this study was to examine whether these temporally distinct FMD patterns associated with different degrees of carotid atherosclerosis. Materials and Methods: One-hundred-twenty-four free-living caucasian subjects, participating in a cardiovascular disease prevention campaign, were enrolled. FMD was measured at 50s, 2 min, and 3 min after forearm ischemia. The Intima-media thickness (IMT) of the common carotid artery was measured, and the artery was evaluated for the presence and number of carotid plaques. Results: Fifty-seven subjects had Early FMD, 34 had Late FMD and 33 had Absent FMD. The three groups were comparable for age, sex and cardiovascular risk factors. The number of plaques in the carotid arteries, and IMT, increased progressively from Early, to Late, and to Absent FMD (p<0.03), indicating that the FMD pattern is an independent predictive variable for IMT and carotid atherosclerosis. Conclusions: The present study demonstrates that temporal patterns associated with the degree of atherosclerosis of the carotid arteries. Patients with delayed vasodilation (Late FMD) had a higher degree of atherosclerosis than those with early vasodilation (Early FMD), and subjects with no post-ischemic vasodilation (Absent FMD) had the most atherosclerosis.