Pilot study for CHAOS-Two (Cambridge Heart Anti-Oxidant study: trial with other vitamins)

ISRCTN	ISRCTN41864011
DOI	https://doi.org/10.1186/ISRCTN41864011
Secondary identifying numbers	Brown HSR/06/97

Submission date: 23/01/2004
Registration date: 23/01/2004
Last edited: 30/04/2018

Recruitment status: No longer recruiting
Overall study status: Completed
Condition category: Circulatory System

Prospectively registered

Protocol

Statistical analysis plan

Results

Individual participant data

Record updated in last year

Plain English summary of protocol

Not provided at time of registration

Contact information

Prof Morris Brown
Scientific

University of Cambridge
Clinical Pharmacology Unit
Level 6, ACCI
Hills Road
Addenbrooke's Hospital
Cambridge
CB2 2QQ
United Kingdom

Phone	+44 (0)1223 336743
Email	mjb14@medschl.cam.ac.uk

Study information

Study design	Randomised placebo controlled trial
Primary study design	Interventional
Secondary study design	Randomised controlled trial
Study setting(s)	Hospital
Study type	Prevention
Scientific title	Pilot study for CHAOS-Two (Cambridge Heart Anti-Oxidant study: trial with other vitamins)
Study acronym	CHAOS-Two
Study objectives	The overall aim of CHAOS-Two is to determine whether folic acid reduces the incidence of myocardial infarction. The principle current hypothesis on which to base expectation of benefit is a well documented effect of folic acid to reduce plasma levels of the amino acid, homocysteine, which has been found in several prospective and case-control studies to be a major risk factor for atherosclerotic diseases. CHAOS-Two should thus provide a test of the homocysteine hypothesis. However, an additional pathway through which folic acid may be beneficial is the so-called salvage pathway to synthesis of the co-factor, tetrahydrobiopterin, required for Nitric Oxide (NO) synthesis. The principle requirement of the pilot study is to permit calculation of numbers required for the main study, using the relative risk of homocysteine in the epidemiological studies, and the average difference after 1 year between homocysteine levels in the folate and placebo groups. The pilot will also establish whether folic acid had the additional action via NO.
Ethics approval(s)	Not provided at time of registration
Health condition(s) or problem(s) studied	Heart disease
Intervention	1. Folate 5 mg 2. Placebo
Intervention type	Other
Primary outcome measure	1. Main Study 1.1. Fatal or non-fatal myocardial infarction. 2. Pilot Study 2.1. Percentage of patients with B12 deficiency on entry despite normal Hb and MCV, and patients becoming B12 deficient at follow-ups. 2.2. Percentage change in plasma homocysteine and plasma tetrahydrobiopterin in response to folic acid, and variation in these over one year. 2.3. Compliance with treatment addeddes from rise in rbc folate in active group. 2.4. Estimate of number of eligible patients likely to be recruited annually.
Secondary outcome measures	Not provided at time of registration
Overall study start date	01/07/1997
Completion date	01/07/1999

Eligibility

Participant type(s)	Patient
Age group	Not Specified
Sex	Not Specified
Target number of participants	Not provided at time of registration
Key inclusion criteria	1. Patients admitted for coronary angiograph 2. Stable angina 3. Positive coronary angiogram
Key exclusion criteria	Patients with a macrocytic anaemia (Hb <10, mean cell volume [MCV] >100) will be excluded from the pilot unless their serum B12 is normal. To be revised if indicated by follow-up results of Hb and B12 pilot.
Date of first enrolment	01/07/1997
Date of final enrolment	01/07/1999

Locations

Countries of recruitment

England
United Kingdom

Study participating centre

University of Cambridge

Cambridge
CB2 2QQ
United Kingdom

Sponsor information

NHS R&D Regional Programme Register - Department of Health (UK)
Government

The Department of Health
Richmond House
79 Whitehall
London
SW1A 2NL
United Kingdom

Phone	+44 (0)20 7307 2622
Email	dhmail@doh.gsi.org.uk
Website	http://www.doh.gov.uk

Funders

Funder type

Government

NHS Executive Eastern (UK)

No information available

Results and Publications

Intention to publish date
Individual participant data (IPD) Intention to share	No
IPD sharing plan summary	Not provided at time of registration
Publication and dissemination plan	Not provided at time of registration
IPD sharing plan

Editorial Notes

30/04/2018: No publications found, verifying study status with principal investigator.
04/03/2016: No publications found, verifying study status with principal investigator.