Non-invasive endothelial function testing and the risk of adverse outcomes: A systematic review andmeta-analysis

Abstract

Objectives We performed a systematic review and meta-analysis to understand the role of flow-mediated dilatation (FMD) of the brachial artery (BA) and peripheral arterial tonometry (PAT) in predicting adverse events, including cardiovascular (CV) events and all-cause mortality. Background FMD of the BA and PAT are non-invasive measures of endothelial function. Impairment of endothelial function is associated with increased CV events. While FMD is the more widely used and studied technique, PAT offers several advantages. The purpose of this systematic review and meta-analysis is to determine whether brachial FMD and PAT are independent risk factors for future CV events and mortality. Methods Multiple electronic data bases were searched for articles relatingFMDor PATtoCVevents. Datawere extracted on study characteristics, study quality, and study outcomes. Relative risks (RRs) from individual studies were combined and a pooled multivariate RR was calculated. Results Thirty-six studies for FMD were included in the systematic review, of which 32 studies consisting of 15, 191 individuals were meta-analysed. The pooled RR of CV events and all-cause mortality per 1% increase in brachial FMD, adjusting for potential confounders, was 0.90 (0.88-0.92). In contrast, only three studies evaluated the prognostic value of PAT forCV events, and the pooled RR per 0.1 increase in reactive hyperaemia index was 0.85 (0.78-0.93). Conclusion BrachialFMDand PAT are independent predictors of CVevents and all-cause mortality. Further research to evaluate the prognostic utility of PATis necessary to compareit with FMDas a non-invasive endothelial function test in clinical practice. © The Author 2014.