Simard T, Jung R, Labinaz A, et al. - Using a large, real-world cohort of patients (n = 1,141) undergoing angiography for assessment of coronary artery disease, researchers report the factors, both analytical and biological, influencing the quantification of adenosine in humans, given the potential clinical implications of adenosine biology. Findings revealed no significant influence of traditional cardiovascular risk factors on plasma adenosine; however, a possible correlation of advancing age and of the presence of obstructive coronary artery disease with lower adenosine levels was suggested. In addition, significant implications of the degree of intra- and inter-subject variance of adenosine was shown for biomarker use as a prognosticator of cardiovascular outcomes and as an endpoint in clinical investigations.