Background: Coronary endothelial dysfunction, a systemic disorder, represents an early stage of atherosclerosis; RH-PAT is a technique to assess peripheral microvascular endothelial function. Using an EndoPAT, digital pulse volume changes during reactive hyperemia were assessed in 94 patients without obstructive coronary artery disease and either normal (n = 39) or abnormal (n = 55) coronary microvascular endothelial function; EndoScore, a measure of reactive hyperemia, was calculated as the ratio of the digital pulse volume during reactive hyperemia divided by that at baseline. Results: Average EndoScore was lower in patients with coronary endothelial dysfunction compared with those with normal coronary endothelial function (1.27 +/- 0.05 vs. 1.78 +/- 0.08: p < 0.001). An EndoScore <1.35 was found to have a sensitivity of 80% and a specificity of 85% to identify patients with coronary endothelial dysfunction. Conclusion: Digital hyperemic response, as measured by EndoPAT, is attenuated in patients with coronary microvascular endothelial dysfunction, suggesting a role for EndoPAT as a noninvasive test to identify patients with this disorder. |
