Neutrophil extracellular traps (NETs) are DNA–protein structures released by neutrophils in response to various stimuli, including oxidized, low-density lipoprotein (oxLDL). Accumulating evidence suggests a role for NETs in the pathogenesis of abdominal aortic aneurysm (AAA). In this study, we investigated the potential association of lipoprotein particles and NETs in AAA in comparison to non-AAA control groups. The concentrations of neutrophil myeloperoxidase (MPO), the NET parameters citrullinated histone H3 (citH3) and circulating cell-free DNA (cfDNA), as well as of blood lipids were determined in plasma or serum of patients with AAA (n = 40), peripheral artery occlusive disease (PAD; n = 40) and healthy donors (n = 29). A sandwich ELISA detecting oxidized phosphatidylcholine in association with apolipoprotein B-100 (oxPL/apoB) was applied to measure oxidized phospholipids in circulation. The effect of lipoparticles on NET formation was tested using a DNA release assay with isolated human neutrophils. Plasma MPO, citH3 and cfDNA levels were significantly increased in AAA patients in comparison to healthy donors and PAD patients. Plasma concentrations of citH3 positively correlated with serum oxPL/apoB in AAA patients. In functional in vitro assays, the addition of oxLDL induced NET formation in pre-stimulated neutrophils. In conclusion, our data suggest a promoting role of oxLDL on NET formation in AAA patients.

Abdominal aortic aneurysm (AAA) and peripheral artery disease (PAD) share pathophysiological mechanisms including the activation of the fibrinolytic and innate immune system, which explains the analysis of D-dimer and myeloperoxidase (MPO) in both conditions. This study evaluates the diagnostic marker potential of both variables separately and as a combined MPO/D-dimer score for identifying patients with AAA versus healthy individuals or patients with PAD. Plasma levels of MPO and D-dimer were increased in PAD and AAA compared to healthy controls (median for MPO: 13.63 ng/mL [AAA] vs. 11.74 ng/mL [PAD] vs. 9.16 ng/mL [healthy], D-dimer: 1.27 μg/mL [AAA] vs. 0.58 μg/mL [PAD] vs. 0.38 μg/mL [healthy]). The combined MPO/D-dimer score (median 1.26 [AAA] vs. −0.19 [PAD] vs. −0.93 [healthy]) showed an improved performance in distinguishing AAA from PAD when analysed using the receiver operating characteristic curve (area under the curve) for AAA against the pooled data of healthy controls + PAD: 0.728 [MPO], 0.749 [D-dimer], 0.801 [score]. Diagnostic sensitivity and specificity ranged at 82.9% and 70.2% (for score cut-off = 0). These findings were confirmed for a separate collective of AAA patients with 35% simultaneous PAD. Thus, evaluating MPO together with D-dimer in a simple score may be useful for diagnostic detection and the distinction of AAA from athero-occlusive diseases like PAD.

Background: Abdominal aortic aneurysm (AAA) is a multifactorial vascular disease with limited therapeutic options, as no pharmacological treatments currently exist to mitigate the progression of small AAAs. Quality of life (QoL) has emerged as a valuable supplementary metric for assessing the efficacy of pharmacological interventions. This study evaluated QoL scores of MetAAA trial patients on metformin therapy compared to those with placebo intake. Methods: Overall, 54 patients with AAA were included in the MetAAA trial (ClinicalTrials.gov-Identifier:NCT03507413) and randomized to either metformin or placebo treatment. All participants were asked to complete three established and validated (in total 659 longitudinally collected) QoL questionnaires: (1) the 36-Item Short Form Health Survey (SF-36), (2) the Aneurysm Symptom Rating Questionnaire (ASRQ), and (3) the Aneurysm-Dependent Quality of Life questionnaire (ADQoL). Results: A superior health-related QoL was found in metformin-treated AAA patients compared to enrolled AAA patients receiving a placebo. In detail, AAA patients undergoing metformin treatment showed a superior overall current QoL score (p = 0.038), general health perception (p = 0.013), improved physical functioning (p = 0.004), and increased energy/lower fatigue scores (p = 0.008). Furthermore, fewer limitations due to cognitive distress (p = 0.001) and lower limb function (p = 0.021) were detected. Other QoL subscales did not show statistical significance. Inflammatory blood parameters suggest that while systemic inflammation may have some impact on perceived QoL, the relationship is largely limited. Conclusions: In patients with small AAA, metformin led to a limited improvement in health-related QoL compared to a placebo.

Background: Abdominal aortic aneurysm (AAA) is a multifactorial vascular disease associated with high morbidity and mortality. Currently, surgical intervention is the only treatment option, and there is no drug therapy available for AAA. Hence, surveillance of AAA until indication for surgery may impact patient quality of life (QoL). There is a paucity of high-quality observational data on health status and QoL, particularly among AAA patients participating in randomized controlled trials. The objective of this study was to compare the QoL scores of AAA patients on surveillance to those of AAA patients enrolled in the MetAAA trial. Material and methods: Overall, 54 MetAAA trial patients and 23 AAA patients under regular surveillance for small AAA (part of a longitudinal monitoring study) were asked to complete three established and validated (in total 561 longitudinally collected) QoL questionnaires: the 36-Item Short Form Health Survey (SF-36), the Aneurysm Symptom Rating Questionnaire (ASRQ), and the Aneurysm-Dependent Quality of Life questionnaire (ADQoL). Results: A superior health status and QoL was found in AAA patients participating in the MetAAA trial compared to AAA patients under regular surveillance. In detail, MetAAA trial patients showed superior general health perception (P=0.012), higher energy level (P=0.036) as well as enhanced emotional well-being (P=0.044) and fewer limitations due to general malaise (P=0.021), which was subsequently reflected in an overall superior current QoL score (P=0.039) compared to AAA patients under regular surveillance. Conclusion: AAA patients enrolled in the MetAAA trial showed superior health status and QoL compared to AAA patients under regular surveillance.

Background: The infrarenal neck is a crucial anatomical segment for the repair of abdominal aortic aneurysm (AAA), requiring special attention when hostile neck features are present. The aim of the study was to perform a detailed morphological analysis of neck anatomy, hostility, progression and a prediction of neck length in the presence of AAA. Methods: In total, 625 computed tomography angiographies (CTAs) of 114 patients, diagnosed with infrarenal AAA, were included. CTA-scanning was performed in 6-month intervals. Neck characteristics were assessed by determining length, diameter, angulation, shape, calcification and thrombus, and depending on these six parameters necks were classified in non-hostile, single-hostile, or multiple-hostile. Moreover, a prediction model for neck length decline was established. Results: AAAs showed neck deterioration over time, with a 0.6 mm decrease in neck length for 1.0 mm increase in AAA diameter. Multiple-hostile neck characteristics were more common when the maximum AAA diameter exceeded 45 mm ( P = 0.003) or when the AAA volume increased to above 100 ml ( P = 0.029). At baseline, 39% of patients exhibited multiple-hostile neck anatomy compared to 52% at the last available measurement ( P ≤ 0.001), underlining the continuous progression of neck hostility. Single signs of hostile neck features in patients with AAAs <45 mm predicted for future neck hostility progression in one-third of patients. Conclusion: The neck deteriorates over time as AAA progresses in size, with development of neck hostility even before the maximum aortic diameter reaches the current threshold for repair of 50 mm/55 mm (women/men). The progressive nature of neck anatomy should be carefully considered when surveilling AAA patients and selecting them for future endovascular or open repair.