Athero- and Aneurysm-Express Biobank Studies

The Athero-Express Biobank Study (AE) and the Abdominal Aortic Aneurysm-Express Biobank Study (AAA) are two ongoing, prospective biobank studies initiated in 2002 and 2003, respectively. Together, they comprise detailed histological and clinical data from over 4,500 patients who underwent arterial surgery at two Dutch tertiary referral centers.

The AE Biobank includes over 3,500 patients who underwent endarterectomy to remove atherosclerotic plaques, predominantly from the carotid and femoral arteries. The AAA Biobank includes over 1,000 patients who underwent open surgical repair of arterial aneurysms, primarily abdominal aortic aneurysms.

For both studies, blood and vascular tissue (plaque or aneurysm wall) were collected during surgery and stored at −80℃. Tissue material is routinely processed for standardised (immuno)histochemical analysis, with histological observations performed by the same dedicated technician, ensuring consistency; interobserver analyses have been previously reported.

In AE, the following plaque characteristics were quantified or scored: • Macrophages (CD68) and smooth muscle cells (α-actin) as the percentage of field area using computerised analysis. • Intraplaque vessel density (CD34) as the average count per 3 hotspots. • Intraplaque haemorrhage (IPH) was scored as absent/present using hematoxylin and eosin (HE). • Intraplaque fat was defined as < or ≥40% of total plaque area (HE). • Calcification (HE) and collagen content (picrosirius red) were scored as no/minor vs. moderate/heavy staining. • Overall plaque vulnerability was assessed following the method by Verhoeven et al.

In AAA, tissue sections were stained using: • HE, EVG (elastin), picrosirius red (collagen), SMA (smooth muscle cells), CD68 (macrophages), CD3 (T cells), CD20 (B cells), CD138 (plasma cells), and von Willebrand factor (vasa vasorum). • Each marker was semiquantitatively scored from 0 to 3 (0: none, 1: minor, 2: moderate, 3: heavy), separately for the intima, media, and adventitia, across both structural components and immune cell types.

For both cohorts, clinical data is obtained through standardised questionnaires, and supplemented with electronic health records where necessary.

Ethical approval for this study (TME/C-01.18) was provided by the Medical Research Ethics Committee of University Medical Center Utrecht, Utrecht, The Netherlands on 10 April 2002, and all research was conducted according to the principles of the Declaration of Helsinki (59th amendment, Seoul 2008) and in accordance with the Dutch Medical Research Involving Human Subjects Act (WMO).

The Athero-Express Biobank Study (AE) is a longitudinal cross-sectional biobank study collecting blood and atherosclerotic plaque samples from patients undergoing endarterectomy. Clinical data is collected through standardised questionnaires and supplemented by querying electronic health records when needed. Patients are followed up to 3 years after surgery.

1. http://publications.europa.eu/resource/authority/data-theme/HEAL

1. http://data.europa.eu/eli/reg/2022/868/oj