AARDVARK (Aortic Aneurysmal Regression of Dilation: Value of ACE-Inhibition on RisK) (AARDVARK)
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ClinicalTrials.gov Identifier: NCT01118520 |
Recruitment Status :
Completed
First Posted : May 6, 2010
Results First Posted : January 26, 2021
Last Update Posted : January 26, 2021
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Abdominal aortic aneurysms (AAA) are balloon-like swellings of the body's main blood vessel (aorta) as it courses through the abdomen. As a result of the National Aneurysm Screening programme many more of these will be detected. Small AAAs grow slowly and remain a benign condition until the diameter exceeds 2-3 times the diameter of the normal aorta (about 5.5cm in size), when operative repair of the aneurysm is recommended avoiding the potentially fatal event of bursting and bleeding (aneurysm rupture). It is therefore important to identify a strategy to prevent aneurysm growth.
There is a suggestion that the use of a specific drug class, angiotensin converting enzyme (ACE) inhibitors, may reduce the risk of rupture of the larger aneurysms. This trial will assess whether an ACE inhibitor (perindopril) has aneurysm-related benefits, in patients with small AAAs at screening centres in the London area.
The effects of perindopril versus a placebo(dummy) on AAA growth rates will be compared. In addition by comparing the effects of perindopril with the effects of equivalent blood pressure lowering with another non-ACE inhibitor class of drug (amlodipine) on aneurysm growth rate, we can see whether any benefits of perindopril are simply the result of lowering blood pressure. 225 Patients will be assigned to one of these 3 treatments by chance (randomisation).In addition to analysis of the effect of perindopril and blood pressure lowering,the effect of the treatments on quality of life will be assessed. Patients will return at 3-monthly intervals for an ultrasound scan and blood pressure measurements, with questionnaires regarding quality of life at the start and end of the 2-year research period.
An ultrasound scan is a painless test that uses sound waves to create images of organs and structures inside your body.
Condition or disease | Intervention/treatment | Phase |
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Abdominal Aortic Aneurysm | Drug: perindopril arginine Drug: amlodipine 5mgs Drug: placebo | Phase 2 |
This trial will investigate the idea that an ACE-inhibitor reduces abdominal aortic aneurysm (AAA) growth rate, in a pilot 3-arm randomised controlled trial (i.e. the study treatment is chosen by random for each patient). The three interventions are ACE-inhibition with perindopril; equivalent blood pressure reduction with amlodipine (a calcium channel blocker) and a placebo tablet. By comparing the effects in the perindopril and amlodipine arms, this design will permit an evaluation of any blood pressure independent effects of perindopril.
Pending results of this pilot trial, we plan to work with the local and National Aneurysm Screening programme to conduct a larger, definitive trial, to investigate the hypothesis that blood pressure reduction with an ACE-inhibitor slows the rate of small AAA growth preferentially compared with other antihypertensive agents.
Secondary research questions in this trial are the effects of perindopril therapy on aneurysm-related death rates, other diseases possibly caused by an AAA and quality of life compared to similar blood pressure lowering effects with amlodipine and placebo.
Study Type : | Interventional (Clinical Trial) |
Actual Enrollment : | 224 participants |
Allocation: | Randomized |
Intervention Model: | Parallel Assignment |
Masking: | Triple (Participant, Care Provider, Investigator) |
Primary Purpose: | Treatment |
Official Title: | An Evaluation of the Effect of an Angiotensin-converting Enzyme (ACE) Inhibitor on the Growth Rate of Small Abdominal Aortic Aneurysms. |
Actual Study Start Date : | September 2011 |
Actual Primary Completion Date : | April 2015 |
Actual Study Completion Date : | April 2015 |

Arm | Intervention/treatment |
---|---|
Active Comparator: perindopril
ACE inhibitor blood pressure lowering agent
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Drug: perindopril arginine
10mgs orally daily for the duration of the trial
Other Name: coversyl arginine |
Active Comparator: amlodipine
calcium channel blocker blood pressure lowering agent
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Drug: amlodipine 5mgs
5 mgs taken orally daily for the duration of the trial |
Placebo Comparator: placebo
inactive substance identical in appearance to the othe two comparators
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Drug: placebo
one daily |
- Change in the Growth Rate of Abdominal Aortic Aneurysm [ Time Frame: Annual rate over the entire period of 24 month ]Aneurysm growth rate over 2 years, estimated from the sequential AAA diameter measurements (external diameter measured in the longitudinal plane).
- Number of Participants With Aneurysm Related Death [ Time Frame: 24 months ]

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Ages Eligible for Study: | 55 Years and older (Adult, Older Adult) |
Sexes Eligible for Study: | All |
Accepts Healthy Volunteers: | No |
Inclusion criteria:
Willing and able to give written informed consent
Men or women, aged at least 55 years
With AAA 3 to 5.4 cm in diameter by internal or external measurement according to ultrasound
A systolic BP <150mmHg (unless they require and are already receiving an ACE-inhibitor or amlodipine 10mg daily).
Exclusion criteria:
Patients who are already required to take either an ACE-inhibitor or a calcium channel blocker or Angiotensin II blocker (ARB) who cannot be converted to diuretic therapy and/ora 5mg dose of amlodipine for control (ie SBP < 150mmHg) of their BP.
Those with known renal artery stenosis (>50%), or with a serum creatinine of >180µmol/L
Those unable to give informed consent
Those too frail to travel for 3-monthly surveillance will be excluded
Any clinically significant medical condition which, in the opinion of the investigator, may interfere with the study results and or reduce life expectancy to < 2 years
Participation in another trial of an investigational product or device within the previous 30 days
Known allergy or sensitivity to perindopril or amlodipine
Unable or unwilling to comply with the requirements of the study, in the opinion of the investigator.

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.
Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT01118520
United Kingdom | |
The Royal Bournemouth and Christchurch Hospitals NHS Foundation Trust | |
Bournemouth, United Kingdom, BH7 7DW | |
Colchester Hospital | |
Colchester, United Kingdom, CO4 5JL | |
University Hospital Coventry and Warwickshire | |
Coventry, United Kingdom, CV2 2DX | |
Hull Royal Infirmary | |
Hull, United Kingdom, HU3 2JZ | |
Royal Free Hospital | |
London, United Kingdom, NW3 2QG | |
St Thomas' Hospital | |
London, United Kingdom, SE1 7EH | |
St Mary's Hospital, Imperial College Healthcare NHS Trust | |
London, United Kingdom, W21PG | |
Charing Cross Hospital, Imperial College NHS Trust | |
London, United Kingdom, W6 8RF | |
Freeman Hospital | |
Newcastle, United Kingdom, NE7 7DN |
Study Director: | Janet Powell, MD | Imperial College London | |
Study Director: | Colin Bicknell, FRCS | Imperial College London | |
Study Director: | Deborah Ashby, PhD | Imperial College London | |
Principal Investigator: | Meryl E Davis, FRCS | Royal Free Hospital NHS Trust | |
Principal Investigator: | Mathew Waltham, FRCS | Guys Hospital NHS trust | |
Study Director: | Neil Poulter, FRCP | Imperial College London | |
Principal Investigator: | Christopher Imray, FRCS | University Hospitals Coventry & Warwickshire | |
Principal Investigator: | Dynesh Rittoo, FRCS | The Royal Bournemouth and Christchurch Hospitals NHS Foundation Trust | |
Principal Investigator: | Ian Chetter, FRCS | Hull University Teaching Hospitals NHS Trust | |
Principal Investigator: | Sohail Choksy, FRCS | East Suffolk and North Essex NHS Foundation Trust | |
Principal Investigator: | Tim Lees, FRCS | The Newcastle Hospitals NHS Foundation Trust | |
Principal Investigator: | Andrew Thompson, FRCS | York Teaching Hospital NHS Foundation Trust | |
Principal Investigator: | Vince Smyth, FRCS | Manchester University NHS Foundation Trust | |
Principal Investigator: | Shah Nawaz, FRCS | Sheffield Teaching Hospitals NHS Foundation Trust | |
Principal Investigator: | Andrew Brown, FRCS | City Hospitals Sunderland NHS Foundation Trust | |
Principal Investigator: | Felicity Meyer, FRCS | Norfolk and Norwich University Hospitals NHS Foundation Trust |
Responsible Party: | Imperial College London |
ClinicalTrials.gov Identifier: | NCT01118520 |
Other Study ID Numbers: |
CRO1644 2010-020226-17 ( EudraCT Number ) 08/109/02 ( Other Grant/Funding Number: NIHR ) |
First Posted: | May 6, 2010 Key Record Dates |
Results First Posted: | January 26, 2021 |
Last Update Posted: | January 26, 2021 |
Last Verified: | January 2021 |
Individual Participant Data (IPD) Sharing Statement: | |
Plan to Share IPD: | No |
Studies a U.S. FDA-regulated Drug Product: | No |
Studies a U.S. FDA-regulated Device Product: | No |
abdominal aortic aneurysm ACE Inhibition |
Aneurysm Aortic Aneurysm Aortic Aneurysm, Abdominal Vascular Diseases Cardiovascular Diseases Aortic Diseases Amlodipine Perindopril Antihypertensive Agents |
Calcium Channel Blockers Membrane Transport Modulators Molecular Mechanisms of Pharmacological Action Calcium-Regulating Hormones and Agents Physiological Effects of Drugs Vasodilator Agents Angiotensin-Converting Enzyme Inhibitors Protease Inhibitors Enzyme Inhibitors |