Relation between Peripheral Vascular Endothelial Function and Coronary Flow Reserve in Patients with Chest Pain and Normal Coronary Angiogram

Park, Chul Soo; Youn, Ho Joong; Ihm, Sang Hyun; Cho, Eun Joo; Jung, Hae Ok; Jeon, Hui Kyung; Lee, Jong Min; Oh, Yong Seok; Chung, Wook Sung; Kim, Jae Hyung; Choi, Kyu Bo; Hong, Soon Jo

Abstract

BACKGROUND AND OBJECTIVES
Previous studies suggest the endothelium dependent coronary vasodilation is impaired in many patients with microvascular angina. However, the relationship between the peripheral vascular endothelial function and coronary flow reserve (CFR) in these patients remains elusive. The relationship between the peripheral vascular endothelial function and CFR was sought in patients with chest pain and a normal coronary angiogram.
SUBJECTS AND METHODS
In 32 subjects (mean age 58+/-9 yrs, M:F=9:23) with chest pain and a normal coronary angiogram, the flow mediated dilation (FMD) was assessed in the brachial artery by measuring the change in brachial artery diameter in response to hyperemic flow. In all subjects, the intimamedia thickness (IMT) of the carotid artery was also measured using a 15 MHz linear array transducer. Subjects were divided into 2 groups according to their CFR:> or =2.1 or<2.1, as measured with transthoracic echocardiography in the distal left anterior descending coronary artery.
RESULTS
The percentage FMD was 6.04+/-5.78% in those with a CFR<2.1 and 11.77+/-6.82% in those with a CFR> or =2.1 (p<0.05). The CFR was closely related to the peripheral FMD (r=0.361, p<0.05). The average IMT were 0.71+/-0.26 and 0.68+/-0.14 mm in those with CFR<2.1 and > or =2.1 (p=NS), respectively. The percentage FMD was not related to the IMT (p=NS).
CONCLUSION
Microvascular dysfunction is primarily related to endothelial dysfunction, rather than advanced atherosclerosis, and this endothelial dysfunction is a generalized process that involves whole arteries in patients with chest pain and a normal coronary angiogram.