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Tackling heart disease: the Scottish aspirin trial
DOI 10.1186/ISRCTN66587262
ClinicalTrials.gov identifier
EudraCT number
Public title Tackling heart disease: the Scottish aspirin trial
Scientific title Randomised controlled trial of low dose Aspirin in the prevention of cardiovascular events and death in subjects with Asymptomatic Atherosclerosis
Acronym AAA Trial
Serial number at source RG/97006; 057762
Study hypothesis Primary prevention strategies aimed at modifying cardiovascular risk factors in otherwise healthy individuals have proved of only limited benefit in the primary prevention of cardiovascular disease. It is possible to identify in the general population large numbers of subjects with asymptomatic preclinical atherosclerosis who are at high risk of subsequent cardiovascular events using a simple blood pressure measurement - the Ankle Brachial Pressure Index (ABPI). We are currently conducting the first prevention trial on such high-risk subjects to determine whether low dose aspirin can reduce the incidence of cardiovascular events and death. 3,350 subjects aged over 50 years with an ABPI of at least 0.95 but no history of cardiovascular disease have been randomised into this double-blind placebo-controlled trial.

The principal hypothesis is that treatment of subjects with asymptomatic atherosclerosis, using low-dose aspirin, prevents subsequent cardiovascular disease indicated by incidence of major cardiovascular and cerebrovascular events.

An additional endpoint was added to this trial shortly after funding was obtained for the original AAA trial. As this additional endpoint has little to do with cardiovascular disease, funding was sought, and gained, from the Wellcome Trust. This end point was known as the ‘Randomised controlled trial of aspirin in the reduction of age associated cognitive decline’, and any information relating only to this endpoint will be headed with the title: ‘Cognitive decline endpoint’

The aim of this endpoint is to determine whether low dose aspirin treatment over a five-year period reduces cognitive decline in subjects at high risk of cardiovascular disease.
Lay summary Not provided at time of registration
Ethics approval AAA Trial:
1. Lanarkshire Research Ethics Committee: date of approval 22/04/1997 (ref: ER/4/97/8)
2. Greater Glasgow Community/Primary Care Local Research Ethics Committee: date of approval 14/06/1999 (ref: 45A/99)
3. Lothian Research Ethics Committee: date of approval 31/05/1999 (ref: 1702/99/3/23)

Cognitive Study:
1. Lanarkshire Research Ethics Committee: date of approval 26/10/1999 (ref: ER/49/10/99)
2. Greater Glasgow Community/Primary Care Local Research Ethics Committee: details as for AAA Trial (see above)
3. Lothian Research Ethics Committee: amendment to AAA Trial made and approved on 11/10/1999
Study design Randomised, placebo-controlled trial
Countries of recruitment United Kingdom
Disease/condition/study domain Cardiovascular disease, cognitive decline
Participants - inclusion criteria 1. Men and women aged between 50 and 80 years
2. Ankle brachial pressure index 0.95 or less in at least one limb
3. Living in central Scotland (Lothian, Greater Glasgow and Lanarkshire)
4. No history of clinical cardiovascular disease
Participants - exclusion criteria 1. Receiving aspirin and/or other anticoagulants
2. Contraindication to aspirin therapy
Anticipated start date 01/04/1998
Anticipated end date 31/12/2009
Status of trial Completed
Patient information material Not available in web format, please use the contact details below to request a patient information sheet
Target number of participants 3350 (recruitment ended as of 1st February 2002)
Interventions 100 mg enteric-coated aspirin daily for five years or placebo daily for five years

The trials were initially designed to end simultaneously, but follow-up in the AAA Trial has been extended (with corresponding supplementary funding from BHF and CSO) to obtain the required number of major cardiovascular endpoints. Similar power considerations were not necessary for the cognitive decline endpoint; therefore the end date for the cognitive decline endpoint is 31st April 2006.

Public contact for the cognitive decline endpoint:
Dr Jackie Price
Community Health Sciences
University of Edinburgh Medical School
Teviot Place
United Kingdom
Tel: +44 (0)131 650 3240
Fax: +44 (0)131 650 6904
Email: Jackie.Price@ed.ac.uk
Primary outcome measure(s) Myocardial infarction and stroke (fatal and non-fatal) or revascularisation

Cognitive decline endpoint:
A detailed battery of tests was administered to assess a broad range of the participants’ cognitive functions. The test battery was administered in a quiet room either in the clinic or at the patient’s home by a trained researcher. The order of tests in the battery was predetermined. The Mini Mental State Examination (MMSE) was included as a general mental assessment and as a ‘screen’ for dementia. Executive function was assessed with use of the Verbal Fluency Test, which requires participants to generate as many words as possible with a specified initial letter (C, F and L).

As a measure of non-verbal reasoning, participants were asked to work through all five sets (A to E) of the Raven’s Progressive Matrices, and were scored according to the number of items they completed correctly within 20 minutes. Immediate and delayed memory was assessed using a participant’s total score on the first five trials (I through V) of the Auditory Verbal Learning Test.

As a measure of mental flexibility, the Trail Making Test was administered and the time taken to complete part B was used in the subsequent analysis. In the Digit Symbol Test, used as a measure of speed of information processing, the number of symbols matched correctly to their corresponding numbers in 90 seconds was recorded.

The Hospital Anxiety and Depression Scale (HAD A and HAD D) was also used for the assessment of mood states, as these can affect performance on the tests, and the National Adult Reading Test (NART) was used to estimate Intelligence Quotient (IQ).
Secondary outcome measure(s) 1. Total cardiovascular mortality
2. All cause mortality
3. Angina
4. Intermittent claudication
5. Transient ischaemic attack
6. Side effects/adverse events
Sources of funding 1. British Heart Foundation (UK) (ref: RG/97006)
2. Chief Scientist Office (CSO) (UK) (ref: K/OPR/2/2/D320)

Cognitive decline endpoint:
The Wellcome Trust (UK) (grant ref: 057762)
Trial website
Publications 1. 2008 results in http://www.ncbi.nlm.nih.gov/pubmed/18762476
2. 2010 results in http://www.ncbi.nlm.nih.gov/pubmed/20197530
3. 2011 results in http://www.ncbi.nlm.nih.gov/pubmed/21223551
Contact name Prof  FGR  Fowkes
  Address Wolfson Unit for Prevention of Peripheral Vascular Diseases
University of Edinburgh
Teviot Place
  City/town Edinburgh
  Zip/Postcode EH8 9AG
  Country United Kingdom
  Tel +44 (0)131 650 3219
  Fax +44 (0)131 650 6909
  Email Gerry.Fowkes@ed.ac.uk
Sponsor University of Edinburgh (UK)
  Address ACCORD Office
The Queen's Medical Research Institute
47 Little France Crescent
  City/town Edinburgh
  Zip/Postcode EH16 4TJ
  Country United Kingdom
  Sponsor website: http://www.ed.ac.uk/
Date applied 31/01/2002
Last edited 26/11/2012
Date ISRCTN assigned 31/01/2002
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