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AARDVARK (Aortic Aneurysmal Regression of Dilation: Value of ACE-Inhibition on RisK) (AARDVARK)

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details.
ClinicalTrials.gov Identifier: NCT01118520
Recruitment Status : Completed
First Posted : May 6, 2010
Results First Posted : January 26, 2021
Last Update Posted : January 26, 2021
National Institute for Health Research, United Kingdom
Information provided by (Responsible Party):
Imperial College London

Brief Summary:

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
Abdominal Aortic Aneurysm Drug: perindopril arginine Drug: amlodipine 5mgs Drug: placebo Phase 2

Detailed Description:

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.

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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
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
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
Drug: placebo
one daily

Primary Outcome Measures :
  1. 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).

Secondary Outcome Measures :
  1. Number of Participants With Aneurysm Related Death [ Time Frame: 24 months ]

Information from the National Library of Medicine

Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the contacts provided below. For general information, Learn About Clinical Studies.

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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.

Information from the National Library of Medicine

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

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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
Sponsors and Collaborators
Imperial College London
National Institute for Health Research, United Kingdom
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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
  Study Documents (Full-Text)

Documents provided by Imperial College London:
Study Protocol  [PDF] July 29, 2010

Additional Information:
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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

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Studies a U.S. FDA-regulated Drug Product: No
Studies a U.S. FDA-regulated Device Product: No
Keywords provided by Imperial College London:
abdominal aortic aneurysm
ACE Inhibition
Additional relevant MeSH terms:
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Aortic Aneurysm
Aortic Aneurysm, Abdominal
Vascular Diseases
Cardiovascular Diseases
Aortic Diseases
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