Potential Role of Circulating Biomarkers in Peripheral Artery Disease

PURPOSE OF REVIEW: To review evidence on the role of circulating biomarkers associated with lower extremity peripheral artery disease (PAD) and adverse outcomes in people with PAD. RECENT FINDINGS: The ankle-brachial index (ABI) is a non-invasive, guideline-recommended test to diagnose PAD. Circulating biomarkers may offer additional insight into early detection of PAD and risk stratification of adverse events in people with PAD. Observational studies show that higher levels of inflammatory biomarkers (such as C-reactive protein, interleukin-6, soluble intracellular adhesion molecule-1), thrombosis biomarkers (such as D-dimer, fibrinogen), cardiac biomarkers (such as troponin, N-terminal pro-brain natriuretic peptide, lipoprotein A), and omic markers are associated with increased risk of developing PAD. Some of these markers are also associated with severity and adverse outcomes in people with PAD. While association studies have shown links between circulating biomarkers and PAD, no single biomarker or combination of markers is currently guideline-recommended for routine clinical use in diagnosis or management of PAD due to absence of clinical trial data showing that circulating biomarkers definitively improve outcomes in PAD. The current state of biomarkers in PAD suggests that further study is needed to determine whether biomarker-guided therapy will improve diagnosis or clinical outcomes for people at risk and people with PAD.