Aim: To estimate the time course of changes in brachial artery (BA) functional parameters in patients with unstable angina (UA) treated with angiotensin-converting enzyme inhibitors.
Subjects and methods: After examination, 30 patients with Braunwald Classes IB and IIB UA were randomized to two groups to receive perindopril or enalapril as part of combination therapy (Group 1 and Group 2, respectively). The authors carried out BA duplex scanning with a reactive hyperemia test, calculated the values of its viscoelastic properties, and determined pulse wave velocity (PWV) at baseline and after 3 months.
Results: The patients of both groups did not differ in BA functional parameters at baseline. Following 3 months, Group 1 showed a reduction in Young's (p = 0.046) and Peterson's (p = 0.049) modules, an increase in compliance (p = 0.016) and distensibility (p = 0.02) coefficients, and a decrease in PWV (p = 0.23). Estimation of endothelium-dependent vasodilation of BA revealed a significant increase in its diameter increment both at testing minutes 1 (p = 0.047) and 2 (p = 0.049). In Group 2, only did the distensibility coefficient change significantly (p = 0.041). After the reactive hyperemia test, there was a significant rise in BA diameter increment at minute 1 (p = 0.047) and no change in this indicator at minute 2.
Conclusion: After 3-month treatment, the viscoelastic properties of BA improved in all indicators in the patients taking perindopril as part of combination therapy. The use of enalapril improved only an arterial distensibility index. The BA endothelial function estimated by its diameter increment also displayed better changes in the patients receiving perindopril.