ANZCTR - Registration

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Trial registered on ANZCTR

Registration number

ACTRN12624000868583

Ethics application status

Approved

Date submitted

11/07/2022

Date registered

16/07/2024

Date last updated

16/07/2024

Date data sharing statement initially provided

16/07/2024

Type of registration

Retrospectively registered

Titles & IDs

Public title

The effect of weight loss surgery on cardiovascular haemodynamics in adults with obesity

Scientific title

The effect of weight loss surgery on cardiovascular haemodynamics in adults with obesity

Secondary ID [1]

None

Universal Trial Number (UTN)

Trial acronym

Linked study record

Health condition

Health condition(s) or problem(s) studied:

Obesity

Condition category

Condition code

Diet and Nutrition

Obesity

Intervention/exposure

Study type

Observational

Patient registry

False

Target follow-up duration

Target follow-up type

Description of intervention(s) / exposure

We will assess the impact of bariatric surgery on adults with obesity. Participants will be followed up 12 months after their surgery.
Participants will be assessed before and 12 months after their bariatric surgery. Each face-to-face visit is estimated to take approximately three hours to complete. This will include a cardiac MRI (~1hr); echocardiogram and 6-minute walk test (~1hr); anthropometric measurements, quality of life questionnaires, and blood collection (~10 tubes for cholesterol, glucose, other biomarkers) to take the remaining time. The MRI and echocardiogram will be performed by trained imaging technicians supervised by a cardiologist. Blood samples will be taken by a qualified blood collector. Other assessments will be performed by trained research staff.

Intervention code [1]

Diagnosis / Prognosis

Comparator / control treatment

No control group

Control group

Uncontrolled

Outcomes

Primary outcome [1]

Change in cardiac output from MRI scan

Timepoint [1]

At baseline and 12 months post-surgery

Primary outcome [2]

Change in cardiac output from echocardiogram

Timepoint [2]

At baseline and 12 months post-surgery

Secondary outcome [1]

Change in epicardial fat volume from MRI scan

Timepoint [1]

At baseline and 12 months post-surgery

Secondary outcome [2]

Change in global longitudinal strain from echocardiogram

Timepoint [2]

At baseline and 12 months post-surgery

Secondary outcome [3]

Change in atrial strain from echocardiogram

Timepoint [3]

At baseline and 12 months post-surgery

Secondary outcome [4]

Change in T1 mapping from MRI scan

Timepoint [4]

At baseline and 12 months post-surgery

Secondary outcome [5]

Exercise capacity measured by the 6-minute walk test

Timepoint [5]

At baseline and 12 months post-surgery

Secondary outcome [6]

Quality of life questionnaire using the EQ-5D-5L

Timepoint [6]

At baseline and 12 months post-surgery

Secondary outcome [7]

Measures of cholesterol in the blood

Timepoint [7]

At baseline and 12 months post-surgery

Secondary outcome [8]

Sleep quality assessed using the Pittsburgh Sleep Questionnaire

Timepoint [8]

At baseline and 12 months post-surgery

Secondary outcome [9]

Measures of triglycerides in the blood

Timepoint [9]

At baseline and 12 months post-surgery

Secondary outcome [10]

Measures of glucose in the blood

Timepoint [10]

At baseline and 12 months post-surgery

Secondary outcome [11]

Measures of the glycated form of haemoglobin (HbA1c)

Timepoint [11]

At baseline and 12 months post-surgery

Secondary outcome [12]

Measures of the N-terminal prohormone of brain natriuretic peptide in the blood (NT-proBNP)

Timepoint [12]

At baseline and 12 months post-surgery

Eligibility

Key inclusion criteria

Individuals with a BMI >= 30
Weight <200kg
Individuals suitable for bariatric surgery

Minimum age

18 Years

Maximum age

65 Years

Sex

Both males and females

Can healthy volunteers participate?

No

Key exclusion criteria

Contraindication to MRI
Unable to provide a valid consent to participate in the study
Known cardiovascular disease
Claustrophobia
Pregnancy

Study design

Purpose

Natural history

Duration

Longitudinal

Selection

Convenience sample

Timing

Prospective

Statistical methods / analysis

The sample size has been calculated based on cardiac output. For a paired sample, assuming a 1.5L reduction in cardiac output with a standard deviation of 2.5L/min before and after surgery, set at a p-value of 0.05 and power of 95%, we will require 40 participants. Considering that attrition rates of 10-80% have been reported in obesity studies, we plan to recruit 80 participants. As our study includes a longer follow-up period (i.e. 12 months), we have accommodated for 50% loss to follow-up.

Normality of data will be assessed using histograms and the Shapiro-Wilk test. Categorical variables will be compared using the Chi-Square test and reported as percentages. A paired sample T-test will be used to analyse parametric (normally distributed variables) which will be reported as mean and standard deviation (SD). A Wilcoxon test (non-parametric paired t-test) will be used to compare non-normally distributed variables which will be expressed as median and interquartile range (IQR). Univariate analyses will be performed. Associations between clinical and imaging variables will be assessed using multivariate linear or logistic regression analysis, where appropriate. Data comparisons between echocardiography and CMR will utilise Bland- Altman analysis for assessment of systematic and proportional bias.

Recruitment

Recruitment status

Recruiting

Date of first participant enrolment

Anticipated

Actual

26/04/2022

Date of last participant enrolment

Anticipated

Actual

Date of last data collection

Anticipated

Actual

Sample size

Target

80

Accrual to date

40

Final

Recruitment in Australia

Recruitment state(s)

NSW

Recruitment hospital [1]

Nepean Hospital - Kingswood

Recruitment postcode(s) [1]

2747 - Kingswood

Funding & Sponsors

Funding source category [1]

Government body

Name [1]

NSW Health

Address [1]

100 Christie Street, St Leonards NSW 2065

Country [1]

Australia

Primary sponsor type

Hospital

Name

Nepean Blue Mountains Local Health District

Address

Derby Street, Penrith NSW 2750

Country

Australia

Secondary sponsor category [1]

None

Name [1]

Address [1]

Country [1]

Ethics approval

Ethics application status

Approved

Ethics committee name [1]

Nepean Blue Mountains Local Health District HREC

Ethics committee address [1]

Nepean Hospital
Derby Street, Penrith NSW 2750

Ethics committee country [1]

Australia

Date submitted for ethics approval [1]

Approval date [1]

31/03/2021

Ethics approval number [1]

2020/ETH03050

Summary

Brief summary

Obesity continues to be a major public health concern in Australia and overseas. In particular, obesity contributes to changes in the heart’s blood flow in the form of increased circulating blood volume, cardiac output, systolic blood pressure and pulmonary pressures. Long-term, these lead to the development of heart failure, atrial fibrillation and ischaemia. Furthermore, fat deposited around the heart is associated with the development of a specific type of heart failure common in individuals with obesity. Hence, obesity is considered an important risk factor for cardiovascular disease.
However, there is growing evidence that effective management of obesity also improves cardiovascular outcomes for patients. Bariatric surgery, an established treatment for weight loss, has been shown to reduce the incidence of cardiovascular risk factors and heart attacks.
In this study, we seek to assess the impact of bariatric surgery on the heart’s structures and blood flow using cardiac magnetic resonance imaging (CMR). Although ultrasound technology or echocardiography is widely used for assessing such features, challenges remain when acquiring accurate images in those with obesity. CMR offers an opportunity to overcome some of these imaging challenges. CMR is less user dependent compared to echocardiography and has demonstrated excellent feasibility in this population. 
We hypothesize that bariatric surgery will lead to a decrease in cardiac output, and reductions in the degree of fibrosis of the heart muscle and the volume of fat around the heart as measured by pre- and post-surgery CMR, thus reducing cardiovascular disease risk. 
Eighty participants will be recruited for this study. Assessments will include cardiac imaging scans, measurement of exercise capacity, blood tests, and quality of life questionnaires. These will be performed before and 12 months after their bariatric surgery.

Trial website

Trial related presentations / publications

Public notes

Contacts

Principal investigator

Name

Dr Faraz Pathan

Address

Nepean HospitalDepartment of CardiologyDerby Street, Penrith NSW 2750

Country

Australia

Phone

+61 2 4734 1719

Fax

Email

faraz.pathan@sydney.edu.au

Contact person for public queries

Name

Faraz Pathan

Address

Nepean HospitalDepartment of CardiologyDerby Street, Penrith NSW 2750

Country

Australia

Phone

+61 2 4734 2000

Fax

Email

faraz.pathan@sydney.edu.au

Contact person for scientific queries

Name

Faraz Pathan

Address

Nepean HospitalDepartment of CardiologyDerby Street, Penrith NSW 2750

Country

Australia

Phone

+61 2 4734 2000

Fax

Email

faraz.pathan@sydney.edu.au

Data sharing statement

Will individual participant data (IPD) for this trial be available (including data dictionaries)?

No

No/undecided IPD sharing reason/comment

Participant consent has not been obtained to use the data for future studies.

What supporting documents are/will be available?

No Supporting Document Provided

Results publications and other study-related documents

Documents added manually

No documents have been uploaded by study researchers.

Documents added automatically

No additional documents have been identified.