Abdominal aortic aneurysm (AAA) is a common vascular disease and associated with risk of rupture, but also with a high cardiovascular (CV) event rate. A key difficulty in AAA is predicting these life-threatening complications, which are strongly linked to vascular health. In 2013, the SMART risk score was developed to calculate the risk of the patients for recurrent vascular events based on clinical characteristics. Recently, a novel, easy to perform, non-invasive test of endothelial function (the carotid artery reactivity (CAR) test), reflecting target organ damage, has been introduced. The CAR is a simple, quick (5-min), non-invasive test that uses ultrasound to examine the carotid artery in response to sympathetic stimulation by placing one hand in cold water. This test shows strong agreement with both coronary and aortic responses to sympathetic stimulation and predicted CV-events in patients with peripheral arterial disease.

The aim of this prospective 2-year follow-up study is to investigate the predictive capacity of the CAR-test for development of CV-events after elective AAA repair in comparison to the SMART risk score. Secondary objectives are to investigate the predictive capacity of arterial stiffness measurements and the post-operative CAR-test for development of CV-events and to evaluate health status scores to provide insight if these scores can support clinical decision making.

The investigators will include 194 patients with an AAA who will be scheduled for repair. Participants will be recruited from all collaborating hospitals (currently Radboudumc, Rijnstate, CWZ) after providing written informed consent.

In this observational, prospective study, a total of 194 patients who are going to be treated for their AAA will be included. Baseline patient characteristics will be registered, including traditional risk factors and CV-history. In addition to regular care of measuring AAA diameter progression (in mm/year), we will perform the CAR-test (10-min) and non-invasive arterial stiffness measures (PWA and PWV) with the SphygmoCor device (10-min).

Furthermore, the investigators will ask patients to complete a questionnaire about the quality of their life. A second questionnaire tries to clarify the disease experience of the patients. Both questionnaires will be asked to be completed at the start, 6-8 weeks after repair, after one year and after two years of repair. Subsequently, the investigators will record major adverse cardiovascular events (MACE) according to the International Classification of Disease-10. Registration of MACE will be performed using hospital-records and following international guidelines. Across a 2-year follow-up, by means of regular follow-up appointments, the investigators will examine the ability of the CAR parameter and arterial stiffness parameters to predict CV-events.

Inclusion Criteria:

• Male or female at least 18 years old;
• Informed consent form understood and signed and patient agrees to follow- up visits;
• Has an infrarenal or juxtarenal abdominal aortic aneurysm (AAA), scheduled for elective repair (i.e open repair, EVAR, FEVAR and CHEVAR) according to standard practice;

Exclusion Criteria:

• Life expectancy < 2 years;
• Psychiatric or other condition that may interfere with the study;
• Participating in another clinical study, interfering on outcomes;
• Increased risk for coronary spasms (score Rose-questionnaire ≥2;
• Presence of Raynaud's phenomenon, Marfan syndrome, chronic pain syndrome at upper extremity(s), presence of an AV fistula or shunt, open wounds to the upper extremity(s), and/or scleroderma associated with placing the hand in ice water;
• Recent (<3 months) presence of angina pectoris, myocardial infarction, cerebral infarction, and/or heart failure, or PAD treatment.

Patients with an AAA who will be scheduled for repair, will be included. AAA patients will be recruited from all collaborating hospitals (Radboudumc, Rijnstate, CWZ), who provide written informed consent. Additionally, also AAA-patients under surveillance of general practitioners are eligible (and will be contacted through the hospital-links), since the nature of the tests allow for performing all tests at the general practitioners' office.