Stiffness and impaired blood flow in lower-leg arteries are associated with severity of coronary artery calcification among asymptomatic type 2 diabetic patients

Abstract

Objective: To clarify whether stiffness and impaired blood flow in lower-leg arteries are associated with severity of coronary artery calcification among asymptomatic diabetic patients.

Research design and methods: We enrolled 102 asymptomatic type 2 diabetic patients with no history of cardiovascular complications consecutively admitted to our hospital. Agatston coronary artery calcium (CAC) score, as a marker of coronary artery calcification, was obtained using electron-beam computed tomography. Total flow volume and resistive index, as an index of vascular resistance, at the popliteal artery were evaluated using gated two-dimensional cine-mode phase-contrast magnetic resonance imaging. Brachial-ankle pulse-wave velocity (PWV), as an index of distensibility in the lower-extremity arteries, was also measured using an automatic device.

Results: When the patients were grouped according to CAC scores of 0-10 (n = 54), 11-100 (n = 25), and > 100 (n = 23), those with the highest scores, which is considered to show possible coronary artery disease, showed the highest brachial-ankle PWV (P < 0.001) and resistive index (P < 0.001) and the lowest total flow volume (P < 0.001) among the groups. Simple linear regression analyses showed that both brachial-ankle PWV (r = 0.508, P < 0.001) and resistive index (r = 0.500, P < 0.001) were positively correlated and total flow volume (r = -0.528, P < 0.001) was negatively correlated with the log-transformed CAC score. Receiver operator characteristic curve analyses indicated that 1,800 cm/s for brachial-ankle PWV, 1.03 for resistive index, and 70 ml/min for total flow volume were diagnostic values for identifying patients with the highest scores.

Conclusions: Quantitatively assessed stiffness and impaired blood flow in lower-leg arteries may help identify diabetic patients with possible coronary artery disease.