# Angiotensin Dysregulation in Patients with Arterial Aneurysms

## TL;DR

This study shows that patients with arterial aneurysms have higher levels of angiotensin metabolites, suggesting a link between the RAS system and aneurysm development.

## Contribution

The study provides the first comprehensive characterization of RAS profiles in aneurysm patients using advanced biochemical profiling.

## Key findings

- Aneurysm patients had higher systemic levels of Ang I, Ang II, Ang 1–5, and Renin compared to controls.
- ACE inhibitor use in aneurysm patients was associated with lower ACE2 activity and higher Ang IV levels.
- Postoperative angiotensin metabolite dynamics varied depending on ACE inhibition status.

## Abstract

Besides playing a critical role in maintaining cardiovascular homeostasis, the renin–angiotensin–aldosterone system (RAS) has been strongly implicated in (aortic) aneurysm pathogenesis. This study aims to investigate systemic and local levels of angiotensin (Ang) and its metabolites in patients with arterial aneurysms, predominantly abdominal aortic aneurysms, using advanced biochemical profiling techniques to provide new insights into the involvement of RAS in aneurysm genesis. A prospective, single-center study was conducted between October 2023 and July 2024. Serum Ang metabolite levels were measured using RAS Fingerprint technology. Aortic tissue samples were analyzed for local RAS activity, including Ang levels and enzyme activity. Additionally, pre- and postoperative serum samples were obtained in a select group of patients. In total, 37 aneurysm patients and 56 controls were included. Aneurysm patients exhibited higher systemic levels of nearly all Ang metabolites compared to controls, with significant differences in Ang I (p = 0.002), Ang II (p = 0.047), Ang 1–5 (p = 0.004), and Renin (p = 0.014) in patients without pharmacological RAS interference. Aneurysm patients receiving ACE inhibitors showed lower serum concentrations in ACE2 activity (p = 0.042) and increased Ang IV levels (p = 0.049) compared to controls. Postoperative measurements indicated different dynamics regarding angiotensin metabolite changes in patients with or without ACE inhibition. This study provides the first comprehensive characterization of RAS profiles in aneurysm patients. These findings add to the body of evidence regarding associations between of RAS and the pathogenesis of arterial aneurysms.