There is an increased risk of atherosclerosis in hereditary angioedema.

Background: Hereditary angioedema is associated either with a deficiency in the amount or in the function of the C1 inhibitor (C1 INH).

Objective: In this study the endothelial function of HAE patients was investigated to evaluate the impact of hereditary C1-INH deficiency on atherosclerosis, which has not yet been established before.

Methods: A total of 26 patients (14 female, 12 male. Mean age: 38±13) diagnosed with HAE and 30 healthy controls were enrolled in the study. Measurement of coronary flow reserve (CFR) in the left anterior descending coronary artery was performed using transthoracic doppler harmonic echocardiography at baseline and following dipyridamol infusion. The intima-media thickness (IMT) in the carotid artery was measured using an echocardiographic system equipped with 10 MHz linear transducer (Vingmed System Five).

Results: The mean CFR value for the HAE patient group was significantly lower than that of the control group (p<0.001). The mean IMT was not found to be significantly different between the two groups, although it was slightly higher in the HAE patient group. No correlation was found between the CFR and the disease severity scores, nor was it shown between the CFR values and the duration of danazol treatment.

Conclusion: Our results indicate that there is a microvascular endothelial dysfunction in HAE patients. Although carotid intima media thickness of these patients was not significantly increased, the presence of microvascular endothelial dysfunction might be regarded as an early indicator of a premature atherosclerosis.