Relationship Between Endothelial Dependent Vasodilation and Size of Abdominal Aortic Aneurysms

Background

Flow-mediated dilation of the brachial artery (FMDB) indirectly reflects the action of nitric oxide liberated by the endothelium. In patients with abdominal aortic aneurysms (AAA), the changes in nitric oxide metabolism in close association with inflammation, appear to play a leading role in the aetiopathology of this disease, although it is still not clear. The objective was to study the correlation and behavior of FMDB relative to the aneurysm diameter (AD). To evaluate the relationship between C-reactive protein (CRP) and the FMDB in these patients. To study the correlation and behavior of FMDB relative to the aneurysm diameter (AD). To evaluate the relationship between C-reactive protein (CRP) and the FMDB in these patients.

Methods

The FMDB value and the CRP were determined in a total of 30 patients with an AAA ≥30 mm, confirmed by computed tomography. The cardiovascular and treatment history was recorded, together with the lipid and renal profile and leucocyte count.

Results

The median AD in the sample was 43 mm (25 percentile: 37 mm; 75 percentile: 60 mm). The primary variables of the study, FMDB and CRP, were the only ones that differed statistically when we stratified the sample according to AD quartiles (p < 0.001). There was a negative correlation between the FMDB and the AD (R = −0.78 [p < 0.001]) and a positive one for CRP (0.74 [p < 0.001]). The CRP/FMDB gave an R value of −0.56 (p = 0.001).

Conclusion

Endothelium dependent vasodilation has a linear and negative correlation with the AD. The positive correlation between the FMDB and CRP supports the hypothesis that inflammation and endothelial dysfunction are processes associated with the physiopathology of AAA and vary with their growth.