Acetylcholine versus cold pressor testing for evaluation of coronary endothelial function
Fig 1
Correlations between in coronary artery diameter changes in response to acetylcholine (Ach) and cold pressor testing (CPT) (n = 163).
Data are plotted as percent changes from baseline to post Ach or CPT. Subjects are stratified by their responses to Ach as either normal endothelial response (e.g. increase in diameter, 1A, left panel) or abnormal endothelial response (e.g. no change or decrease in diameter, 1B, right). Note that although correlations among both strata are statistically significant the correlation among those with normal endothelial function is strong (r = 0.628, P<0.001) but only moderate among those with abnormal endothelial function (r = 0.353, P = 0.002), supporting the suggestion that other factors contribute to this association.