The prognostic impact of vascular calcification on abdominal aortic aneurysm progression

Christoph Neumayer,Johannes Klopf,Rüdiger Schernthaner,Christoph M Domenig,Wolf Eilenberg,Christine Brostjan,Bernd Gollackner,Lukas Fuchs

doi:10.1016/j.jvs.2021.11.062

Abstract

ObjectiveThe maximal aortic diameter is currently the only clinically applied predictor of abdominal aortic aneurysm (AAA) progression. It is known that the risk of rupture is associated with aneurysm size; hence, accurate monitoring of AAA expansion is crucial. Aneurysmal vessel wall calcification and its implication on AAA expansion are insufficiently explored. We evaluated the vascular calcification using longitudinal computed tomography angiographies (CTA) of patients with an AAA and its association with AAA growth. MethodsWe conducted a retrospective study of 102 patients with an AAA with a total of 389 abdominal CTAs at 6-month intervals, treated and followed at the Division of Vascular Surgery, Department of General Surgery, Medical University of Vienna. Digitally stored CTAs were reviewed for vascular calcification (volume and score) of the infrarenal aorta and common iliac arteries as well as for morphometric AAA analysis. In the prognostic setting, slow versus fast AAA progression was defined as a less than 2 mm or a 2-mm or greater increase in AAA diameter over 6 months. In addition, to analyze the association of vascular calcification and the AAA growth rate with longitudinal monitoring data, a specifically tailored log-linear mixed model was used. ResultsAn inverse relation of increased abdominal vessel wall calcification and short-term AAA progression was detected. Compared with fast progressing AAA, the median calcification volume of the infrarenal aorta (1225.3 mm³ vs 519.8 mm³; P = .003), the median total calcification volume (2014.1 mm³ vs 1434.9 mm³; P = .008), and the median abdominal total customized Agatston calcium (cAC) score (1663.5 vs 718.4; P = .003) were significantly increased in slow progressing AAA. Importantly, a log-linear mixed model efficiently predicted AAA expansion based on current diameter and abdominal total cAC score (P = .042). ConclusionsWe assessed the prognostic value of CTA-measured vascular calcification for AAA progression. Increased vascular calcification stabilizes the aortic aneurysmal wall and likely protects against progressive AAA expansion, resulting in a significant decrease of aneurysm growth over time. As a consequence, this may have implications for rupture risk, mortality, morbidity, and cost.

Highlights

An abdominal aortic aneurysm (AAA) is diagnosed if the maximal aortic diameter exceeds 30 mm.[1]
The maximal aortic diameter is solely used as clinically applied predictor of AAA progression and indication of surgery, while other parameters such as vascular calcification are still debated.[3]
The main objective of this study was to determine the prognostic impact of vascular calcification on AAA progression

Summary

Introduction

An abdominal aortic aneurysm (AAA) is diagnosed if the maximal aortic diameter exceeds 30 mm.[1] If left undiagnosed or untreated, the AAA will continue to grow indefinitely and eventually rupture, with a 50 - 80% mortality rate.[2] To date, the maximal aortic diameter is solely used as clinically applied predictor of AAA progression and indication of surgery, while other parameters such as vascular calcification are still debated.[3] the importance of other parameters for AAA risk stratification is undeniable. The individual risk assessment is often not well reflected in AAA diameter alone, large studies such as the Aneurysm Detection and Management Trial and the United Kingdom Small Aneurysm Trial show that the maximal. AAA diameter is predictive of aneurysm rupture.[4, 5] To improve the effectiveness of individual

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