Central BP variability, aortic stiffness and AAA growth rates
Research type
Research Study
Full title
Investigation into the effects of central blood pressure variability, aortic stiffness and antihypertensive adherence on the size and growth rate of abdominal aortic aneurysms
IRAS ID
307961
Contact name
Colin Bicknell
Contact email
Sponsor organisation
Imperial College London
Duration of Study in the UK
2 years, 0 months, 2 days
Research summary
Abdominal Aortic Aneurysms (AAAs) are a significant health risk in the older population with ~4000 deaths each year in England and Wales attributed to rupture. There is good evidence that central blood pressure (BP) is more closely associated with adverse cardiovascular events than peripheral (brachial) BP. Variability in brachial BP predicts stroke, coronary heart disease, cardiovascular and all-cause mortality independent of mean systolic brachial BP. Measures of arterial stiffness predict cardiovascular risk in multiple large studies. There is limited evidence that aortic growth may be influenced by these indices of aortic haemodynamics.
The AARDVARK (Aortic Aneurysmal Regression of Dilation: Value of ACE-Inhibition on RisK) trial was designed to investigate the hypothesis that an ACE-inhibitor (perindopril) would reduce growth rate of small AAAs in a three-arm randomised placebo-controlled trial. While this didn’t show a significant effect, results from an in-trial sub-study (CAVE study) demonstrated a relationship between central BP variability and aneurysm growth rates. This requires confirmation, in a dedicated prospective longitudinal cohort study.
Patients will be recruited into a prospective longitudinal cohort study where their baseline peripheral and central BP, aortic stiffness values (acquired by non-invasive methods) and AAA size will be measured (AAA size by ultrasound [USS]), alongside questionnaires on medication adherence and beliefs about adherence. Participants will undergo repeat measurements every 4 months over a period of up to 2 years. Clinical data will be used to ascertain AAA growth rates according to central BP variability, aortic health and medication adherence. All patients will also undergo ambulatory BP monitoring using a validated device.
If a clinically relevant relationship is found, then modification of central BP variability may lead to a reduction in aneurysm growth rates. If aneurysms don’t grow to 5.5cm then patients almost always avoid a high-risk repair and the risk of rupture will be reduced.
REC name
South West - Cornwall & Plymouth Research Ethics Committee
REC reference
22/SW/0039
Date of REC Opinion
3 May 2022
REC opinion
Further Information Favourable Opinion