PERIPHERAL VASCULAR ENDOTHELIAL DYSFUNCTION IN PATIENTS WITH ANGINA-PECTORIS AND NORMAL CORONARY ARTERIOGRAMS

Objectives. We sought to determine endothelium dependent vasodilator f unction in the brachial artery of patients with micro vascular angina pectoris. Background. Previous studies suggest the presence of endothe lial dysfunction of the coronary microcirculation in patients with mic rovascular angina pectoris. It is not known whether endothelial dysfun ction in these patients is a generalized process or whether it is conf ined to the coronary microcirculation only. Methods. In 11 women (mean [+/-SD] age 60.1 +/- 7.8 years) with microvascular angina (anginal pa in, normal epicardial coronary arteries, positive exercise stress test ), endothelium-dependent vasodilation was assessed in the brachial art ery by measuring the change in brachial artery diameter in response to hyperemic flow. Results were compared with 11 age and gender-matched patients with known three-vessel coronary artery disease and 11 age- a nd gender-matched healthy control subjects. In all subjects, the intim a-media thickness (IMT) of the common carotid artery was also measured . Results. Flow-mediated dilation (FMD) was comparable in patients wit h microvascular angina and coronary artery disease (1.9 +/- 2.5% vs. 3 .3 +/- 3.3%, p = NS) but was significantly lower in patients with micr ovascular angina than in healthy control subjects (1.9 +/- 2.5% vs. 7. 9 +/- 3%, p < 0.05). IMT was significantly lower in patients with micr ovascular angina than in those with coronary artery disease (0.64 +/- 0.08 vs. 1.0 +/- 0.28 mm, p < 0.05) and was comparable between patient s with microvascular angina pectoris and healthy control subjects (0.6 4 a 0.08 vs. 0.56 +/- 0.14 mm, p = NS). IMT greater than or equal to 0 .8 mm was observed in 1 of 11 patients with microvascular angina, 1 of 11 control subjects and 10 of 11 patients with coronary artery diseas e. Conclusions. These findings suggest that endothelial dysfunction in microvascular angina is a generalized process that also involves the peripheral conduit arteries and is similar to that observed in atheros clerotic disease. IMT could be helpful in discriminating patients with microvascular angina and atherosclerotic coronary artery disease. (C) 1998 by the American College of Cardiology.