Endothelial Dysfunction in Unstable Angina of Good Prognosis

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Abstract

Background

Endothelial dysfunction may contribute to symptoms of instability in patients with acute coronary syndromes. High-resolution external ultrasound assessment of the brachial artery responses allows non-invasive determination of endothelial function. The aim of this study was to assess endothelial function in patients with unstable angina us-ing a non-invasive technique.

Material and methods

We studied 189 patients who were subdivided in 3 groups. Group I: 60 healthy subjects without cardiovascular risk factors or symptoms of coronary artery disease; Group II: 105 subjects with cardiovascular risk factors -arterial hypertension, hypercholesterolemia, cigarette smoking, diabetes and obesity, but no evidence of coronary artery disease; and Group III: 24 patients with unstable angina and chest pain at rest within the 24 hours previous to study entry. All patients underwent pre- and post-ischemic brachial artery test evaluation with measurements of internal arterial diameters and blood flow.

Results

Results are expressed as percentage changes from basal values. Subjects in Group I and II showed a diameter increase of 19.1% and 11.9%, respectively ,whereas patients in Group III showed a diameter change of 1.2% (p < 0.002 and < 0.0001, respectively). Calculated blood flow did not differ significantly in Group I and II (63.1% and 43.0%), but was markedly lower in Group III (0.2%, p < 0.0001 vs. GroupsI and II). In 9 patients of Group III the brachial studies were repeated 4 weeks after symptom stabilization and showed values comparable tothose in Group II.

Conclusions

Patients with unstable angina showed endothelial dysfunction, compared to control individuals. Interestingly, in patients whose symptoms were stabilized by medical therapy 4 weeks after hospital discharge, endothelial function was restored.