Abdominal aortic aneurysm, arterial stiffening and the role of the intraluminal thrombus

Background: Measures of arterial stiffness could be affected by the presence of abdominal aortic aneurysm (AAA) and especially an intraluminal thrombus (ILT). We, therefore, sought to study this possible connection by measuring pulse wave velocity (PWV) and pulse wave analysis (PWA) including augmentation index adjusted to heart rate 75(Aix75) in patients with AAA +/- ILT. Patients and methods: PWV and PWA were measured in male patients with AAA from an ongoing Danish AAA screening trial. Information on blood pressure, medications, BMI and smoking status was obtained at inclusion. Results: In total, 157 patients were included. Mean age was 73 years. Mean AAA size was 42.2 mm. Fifty-six of the patients had an intraluminal thrombus, and patients with AAA and ILT had a significantly higher Aix75 than patients with AAA but without ILT (Mean = 28.3 ± 1.4 SEM vs. 24.9 ± 0.81, p=0.027), a difference that was also significant when adjusting for AAA size, blood pressure and age. There was no difference in PWV between the groups. Conclusions: Haemodynamic properties of the aorta are affected by the presence of ILT in patients with AAA that is not explained by aortic size. Alternatively, these findings could be explained by associations between ILT and properties of the left ventricle.