Sensitive detection of atherosclerotic coronary artery disease by a novel index of pressure-area relationship of the brachial artery.

Abstract

Cross-sectional area (eA) and volumetric elastic modulus (V_E) of the brachial artery estimated by an oscillometric device have been introduced to evaluate the degree of severity of atherosclerosis. However, there were concerns over the clinical efficacy of eA and V_E. In this study, we searched for a novel device-based index that effectively evaluates atherosclerosis, and compared its efficacy in detecting coronary artery disease (CAD) with conventional indexes comprising eA, V_E, carotid maximum intima-media thickness (IMT), cardio-ankle vascular index (CAVI), and flow-mediated dilation (FMD). The Health Chronos TM-2772 device approximates the arterial pressure-area relation to a logarithmic function. We hypothesized that the asymptotic pressure (P_a) of the logarithmic function that reflects the shift of the relation on the pressure axis may be effective in evaluating atherosclerosis. The diagnostic abilities of eA, V_E, P_a, IMT, CAVI, and FMD to detect CAD were analyzed in 60 patients who were classified into CAD (n = 30) and non-CAD (n = 30) groups based on coronary angiographic findings. In CAD group, P_a and FMD were significantly lower, and max-IMT was significantly higher than the respective indices in non-CAD group. eA, V_E, and CAVI showed no significant differences between the two groups. Receiver operating curve (ROC) analysis of the indices for diagnosing the presence of CAD indicated that only P_a [area under the ROC curve (AUC) = 0.706, p < 0.01] and max-IMT (AUC = 0.752, p < 0.01) had acceptable diagnostic ability. The optimal cutoff values were 15.3 mmHg for P_a (sensitivity 77%, specificity 67%) and 1.6 mm for max-IMT (sensitivity 71%, specificity 71%). In conclusion, P_a may be a sensitive and effective index for evaluating the severity of atherosclerosis. Verification of the efficacy and usefulness of P_a is warranted in further prospective multicenter studies and registries.