Comparison of Non-Invasive Peripheral Vascular Function to Invasive Measures of Coronary Function in Patients with Suspected Coronary Microvascular Dysfunction

This thesis examined whether reactive hyperemia peripheral arterial tonometry (RH-PAT) and flow-mediated dilation (FMD), non-invasive measures of peripheral endothelial function, are associated with coronary microvascular function following multiple pharmacological stimuli in patients with suspected coronary microvascular dysfunction (CMD). Patients with suspected CMD completed peripheral vascular assessments using concurrent RH-PAT and FMD, while coronary microvascular function was measured using the index of microvascular resistance (IMR) and the coronary flow reserve (CFR) during endothelial independent (adenosine), endothelial-dependent (acetylcholine), and sympathetically-mediated (dobutamine) hyperemia. Any abnormality in the IMR and/or CFR during the adenosine and/or acetylcholine trials defined patients with CMD. RH-PAT and FMD were attenuated in patients with CMD (P<0.05). RH-PAT was correlated with the dobutamine IMR and CFR (P<0.05), while FMD was correlated with the adenosine (P<0.05) and acetylcholine IMRs (P<0.05), but not the CFRs. Therefore, this thesis suggests that both RH-PAT and FMD can identify patients with CMD in clinical settings.