The incremental value of brachial flow-mediated dilation measurements in risk stratification for incident cardiovascular events: A systematic review

Adequate risk assessment for cardiovascular disease (CVD) is essential as a guide to initiate drug treatment. Current methods based on traditional risk factors could be improved considerably. Although brachial flow-mediated dilation (FMD) predicts subsequent cardiovascular events, its predictive value on top of traditional risk factors is unknown. We performed a systematic review to evaluate the incremental predictive value of FMD on top of traditional risk factors in asymptomatic individuals. Using PubMed and reference tracking, three studies were identified that reported on the incremental value of FMD using change in the area under the curve (AUC). Two large cohort studies found no improvement in AUC when FMD was added to traditional risk prediction models, whereas one small case-control study found an improvement. One study used the net reclassification improvement (NRI) to assess whether FMD measurement leads to correct risk stratification in risk categories. Although this study did not find an improvement in AUC, the NRI was statistically significant. Based on the reclassification results of this study, FMD measurement might be helpful in risk prediction. Evidence supporting the use of FMD measurement in clinical practice for risk stratification for CVD on top of traditional risk factors is limited, and future studies are needed.