2019 Volume 49 Issue 3 Pages 137-142
Objectives: Measurement of flow-mediated vasodilation (FMD) in the brachial artery is widely used to assess endothelial function in humans. The diagnostic criteria for vascular failure based on FMD remain to be established, however. The purpose of this study was to establish diagnostic criteria for endothelial dysfunction based on FMD in the brachial artery.
Methods: Data were obtained from the Flow-mediated Dilation Japan Registry (FDR) and Flow-mediated Dilation Japan (FMD-J) studies, which included 6413 Japanese individuals with no history of cardiovascular disease to determine the cutoff value for normal endothelial function. Next, prospective studies investigating the association between FMD and cardiovascular events in individuals with no history of cardiovascular disease were overviewed to determine the cutoff value for endothelial dysfunction.
Results: Receiver-operating characteristic curve analysis of the data from the FDR and FMD-J studies revealed that the cutoff value with FMD in discriminating individuals aged 30－74 years and with from those with no cardiovascular risk factors was 6.9％ . This indicated that the cutoff value for normal endothelial function was approximately 7％. According to the results of four previous studies investigating the association between FMD and cardiovascular events in individuals with no history of cardiovascular disease, the cutoff values for patients at high risk for cardiovascular events ranged from between 2.9％ to 4.7％, indicating that the cutoff value for endothelial dysfunction was approximately 4％.
Conclusions: Based on these findings, the following criteria for brachial artery FMD-based diagnosis of vascular failure are proposed: ＜ 4.0％ for endothelial dysfunction; ≥ 4.0％ and ＜ 7.0％ for borderline; and ≥ 7.0％ for normal endothelial function.