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Trial registered on ANZCTR

Registration number
Ethics application status
Date submitted
Date registered
Date last updated
Type of registration
Retrospectively registered

Titles & IDs
Public title
Dietary fish oil and post surgical atrial fibrillation
Scientific title
Use of n-3 polyunsaturated fatty acids to reduce post surgical atrial fibrillation: A prospective randomised study
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Atrial fibrillation post cardiac surgery 1102 0
Condition category
Condition code
Cardiovascular 1181 1181 0 0
Other surgery

Study type
Description of intervention(s) / exposure
Dietary fish oil or high monounsaturated sunflower oil commencing 3 weeks prior to surgery. If surgery is postponed after commencing the intervention, then treatment will continue until surgery. There is no maximum period of the intervention. the dose is 15 ml/day and is supplied as bulk liquid in 500 ml bottles. subjects are instructed to take the oil on juice
Intervention code [1] 983 0
Comparator / control treatment
high monounsaturated sunflower oil
Control group

Primary outcome [1] 1594 0
Incidence of atrial fibrillation
Timepoint [1] 1594 0
first 6 post-operative days
Secondary outcome [1] 2886 0
• AF/AFL characteristics (incl. number of episodes, time to onset of first episode, mean and median duration of each episode, duration of longest episode, mean ventricular response rate during each episode of AF)
• AF burden (total time in AF)
• Mean heart rate
• Atrial premature beat frequency
Timepoint [1] 2886 0
Effect of n-3 fatty acids during the first 6 post-operative days.
Secondary outcome [2] 2887 0
• Post-operative complications including mortality
• Length of stay (ICU and total)
• Proportion of patients discharged within 6 post-operative days.
Timepoint [2] 2887 0
Effect of n-3 fatty acids throughout admission period.
Secondary outcome [3] 2888 0
• Association between hsCRP and atrial fibrillation.
Timepoint [3] 2888 0
Effect of n-3 fatty acids on hsCRP levels both prior to surgery and on post-operative day 1.
Secondary outcome [4] 2889 0
• Association between HRV and post-surgical AF/AFL
Timepoint [4] 2889 0
Effect of n-3 fatty acids onheart rate variability both prior to surgery and on day 4 post surgery.
Secondary outcome [5] 2890 0
Effect of n-3 fatty acids on measures of cardiac repolarisation and conduction
Timepoint [5] 2890 0
Both prior to surgery and on post-operative day 5.
Secondary outcome [6] 2891 0
Effect of n-3 fatty acids on adverse cardiac outcomes
Timepoint [6] 2891 0
At 6 months

Key inclusion criteria
Elective coronary bypass surgery (CABG and/or valve repair/replacement surgery)• Informed consent
Minimum age
18 Years
Maximum age
Not stated
Both males and females
Can healthy volunteers participate?
Key exclusion criteria
• Prior documented AF/AFL• Current anti-arrhythmic drug therapy or amiodarone use within the previous 3 months• NYHA class IV heart failure• MI < 2 weeks• Any condition which may affect the ability to ingest or absorb dietary fat (e.g. known active oesophagitis, gastric or duodenal ulceration, inflammatory bowel disease, coeliac disease, chronic pancreatitis, chronic liver disease, recent abdominal radiation therapy)• use of dietary supplements rich in n-6 or n-3 oils, e.g. fish oil, flaxseed oil, evening primrose oil• habitually consume > one fish meal / week.

Study design
Purpose of the study
Allocation to intervention
Randomised controlled trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
sealed envelope
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
random sequence generator
Masking / blinding
Blinded (masking used)
Who is / are masked / blinded?

Intervention assignment
Other design features
subjects, physicians, nurses, assessor and data analyst are blinded to treatment allocation. To enhance masking of the different oils, citrus flavouring has been added to both oils, although subjects allocated to fish oil may be able to tell. The bulk oil on juice method of consumption minimises the occurrence of "fishy" burps usually encountered with capsules.
Phase 2 / Phase 3
Type of endpoint(s)
Statistical methods / analysis

Recruitment status
Active, not recruiting
Date of first participant enrolment
Date of last participant enrolment
Date of last data collection
Sample size
Accrual to date
Recruitment in Australia
Recruitment state(s)
Recruitment postcode(s) [1] 202 0

Funding & Sponsors
Funding source category [1] 1292 0
Government body
Name [1] 1292 0
Address [1] 1292 0
GPO Box 1421, Canberra ACT 2601
Country [1] 1292 0
Primary sponsor type
Royal Adelaide Hospital
North Tce, Adelaide, SA 5000
Secondary sponsor category [1] 1142 0
Name [1] 1142 0
Address [1] 1142 0
Country [1] 1142 0

Ethics approval
Ethics application status
Ethics committee name [1] 2623 0
Royal Adelaide Hospital
Ethics committee address [1] 2623 0
North Tce, Adelaide, SA 5000
Ethics committee country [1] 2623 0
Date submitted for ethics approval [1] 2623 0
Approval date [1] 2623 0
Ethics approval number [1] 2623 0

Brief summary
Patients undergoing cardiac surgery for coronary artery bypass or valve repair/replacement are at risk of a number of complications. One of the most common complications is atrial fibrillation (AF), or abnormal contraction of the upper chamber of the heart, which occurs in about 30% to 55% of patients, depending on the type of surgery. While AF itself is not particularly dangerous, it does lead to increased length of stay in hospital, with associated costs, and also increases the risk of stroke. Patients suffering from post-surgical AF are generally prescribed additional medications, some of which can have unpleasant side effects. The purpose of this study is to determine whether fish oil given prior to surgery reduces the risk of developing AF after surgery. We also plan to investigate a number of mechanisms by which fish oil may exert its cardio-protective properties
Trial website
Trial related presentations / publications
Public notes

Principal investigator
Name 36250 0
Address 36250 0
Country 36250 0
Phone 36250 0
Fax 36250 0
Email 36250 0
Contact person for public queries
Name 10172 0
Dr Robert Metcalf
Address 10172 0
Cardiovascular Research Centre,
Royal Adelaide Hospital,
North Tce,
Adelaide SA 5000
Country 10172 0
Phone 10172 0
+61 8 82225581
Fax 10172 0
+61 8 82225895
Email 10172 0
Contact person for scientific queries
Name 1100 0
Dr Robert Metcalf
Address 1100 0
Cardiovascular Research Centre,
Royal Adelaide Hospital,
North Tce,
Adelaide SA 5000
Country 1100 0
Phone 1100 0
+61 8 82225581
Fax 1100 0
+61 8 82225895
Email 1100 0

No information has been provided regarding IPD availability
Summary results
Have study results been published in a peer-reviewed journal?
Other publications
Have study results been made publicly available in another format?
Results – basic reporting
Results – plain English summary