Peripheral Vascular Endothelial Dysfunction in Patients With Angin Pectoris and Normal Coronary Arteriograms

Objectives. We sought to determine endothelium-dependent vasodilator function in the brachial artery of patients with microvascular angin pectoris. Background. Previous studies suggest the presence of endothelial dysfunction of the coronary microcirculation in patients with microvascular angin pectoris. It is not known whether endothelial dysfunction in these patients is generalized process or whether it is confined to the coronary microcirculation only. Methods. In 11 women (mean [±SD] age 60.1 ± 7.8 years) with microvascular angin (anginal pain, normal epicardial coronary arteries, positive exercise stress test), endothelium-dependent vasodilation was assessed in the brachial artery 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- and gender-matched healthy control subjects. In all subjects, the intima–medi thickness (IMT) of the common carotid artery was also measured. Results. Flow-mediated dilation (FMD) was comparable in patients with microvascular angin and coronary artery disease (1.9 ± 2.5% vs. 3.3 ± 3.3%, p = NS) but was significantly lower in patients with microvascular angin than in healthy control subjects (1.9 ± 2.5% vs. 7.9 ± 3%, p < 0.05). IMT was significantly lower in patients with microvascular angin than in those with coronary artery disease (0.64 ± 0.08 vs. 1.0 ± 0.28 mm, p < 0.05) and was comparable between patients with microvascular angin pectoris and healthy control subjects (0.64 ± 0.08 vs. 0.56 ± 0.14 mm, p = NS). IMT ≥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 disease. Conclusions. These findings suggest that endothelial dysfunction in microvascular angin is generalized process that also involves the peripheral conduit arteries and is similar to that observed in atherosclerotic disease. IMT could be helpful in discriminating patients with microvascular angin and atherosclerotic coronary artery disease.