Condition category
Circulatory System
Date applied
23/01/2004
Date assigned
23/01/2004
Last edited
04/03/2016
Prospective/Retrospective
Retrospectively registered
Overall trial status
Completed
Recruitment status
No longer recruiting

Plain English Summary

Not provided at time of registration

Trial website

Contact information

Type

Scientific

Primary contact

Prof Morris Brown

ORCID ID

Contact details

University of Cambridge
Clinical Pharmacology Unit
Level 6
ACCI
Hills Road
Addenbrooke's Hospital
Cambridge
CB2 2QQ
United Kingdom
+44 (0)1223 336743
mjb14@medschl.cam.ac.uk

Additional identifiers

EudraCT number

ClinicalTrials.gov number

Protocol/serial number

Brown HSR/06/97

Study information

Scientific title

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

Acronym

CHAOS-Two

Study hypothesis

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

Not provided at time of registration

Study design

Randomised placebo controlled trial

Primary study design

Interventional

Secondary study design

Randomised controlled trial

Trial setting

Hospitals

Trial type

Prevention

Patient information sheet

Condition

Heart disease

Intervention

1. Folate 5 mg
2. Placebo

Intervention type

Other

Phase

Not Specified

Drug names

Primary outcome measures

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 trial start date

01/07/1997

Overall trial end date

01/07/1999

Reason abandoned

Eligibility

Participant inclusion criteria

1. Patients admitted for coronary angiograph
2. Stable angina
3. Positive coronary angiogram

Participant type

Patient

Age group

Not Specified

Gender

Not Specified

Target number of participants

Not provided at time of registration

Participant 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.

Recruitment start date

01/07/1997

Recruitment end date

01/07/1999

Locations

Countries of recruitment

United Kingdom

Trial participating centre

University of Cambridge
Cambridge
CB2 2QQ
United Kingdom

Sponsor information

Organisation

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

Sponsor details

The Department of Health
Richmond House
79 Whitehall
London
SW1A 2NL
United Kingdom
+44 (0)20 7307 2622
dhmail@doh.gsi.org.uk

Sponsor type

Government

Website

http://www.doh.gov.uk

Funders

Funder type

Government

Funder name

NHS Executive Eastern (UK)

Alternative name(s)

Funding Body Type

Funding Body Subtype

Location

Results and Publications

Publication and dissemination plan

Not provided at time of registration

Intention to publish date

Participant level data

Not provided at time of registration

Results - basic reporting

Publication summary

Publication citations

Additional files

Editorial Notes

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