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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] 307390 0
None
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Obesity 326705 0
Condition category
Condition code
Diet and Nutrition 323948 323948 0 0
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] 323823 0
Diagnosis / Prognosis
Comparator / control treatment
No control group
Control group
Uncontrolled

Outcomes
Primary outcome [1] 331745 0
Change in cardiac output from MRI scan
Timepoint [1] 331745 0
At baseline and 12 months post-surgery
Primary outcome [2] 335356 0
Change in cardiac output from echocardiogram
Timepoint [2] 335356 0
At baseline and 12 months post-surgery
Secondary outcome [1] 410986 0
Change in epicardial fat volume from MRI scan
Timepoint [1] 410986 0
At baseline and 12 months post-surgery
Secondary outcome [2] 411776 0
Change in global longitudinal strain from echocardiogram
Timepoint [2] 411776 0
At baseline and 12 months post-surgery
Secondary outcome [3] 411777 0
Change in atrial strain from echocardiogram
Timepoint [3] 411777 0
At baseline and 12 months post-surgery
Secondary outcome [4] 411778 0
Change in T1 mapping from MRI scan
Timepoint [4] 411778 0
At baseline and 12 months post-surgery
Secondary outcome [5] 424047 0
Exercise capacity measured by the 6-minute walk test
Timepoint [5] 424047 0
At baseline and 12 months post-surgery
Secondary outcome [6] 424048 0
Quality of life questionnaire using the EQ-5D-5L
Timepoint [6] 424048 0
At baseline and 12 months post-surgery
Secondary outcome [7] 424050 0
Measures of cholesterol in the blood
Timepoint [7] 424050 0
At baseline and 12 months post-surgery
Secondary outcome [8] 437355 0
Sleep quality assessed using the Pittsburgh Sleep Questionnaire
Timepoint [8] 437355 0
At baseline and 12 months post-surgery
Secondary outcome [9] 437356 0
Measures of triglycerides in the blood
Timepoint [9] 437356 0
At baseline and 12 months post-surgery
Secondary outcome [10] 437357 0
Measures of glucose in the blood
Timepoint [10] 437357 0
At baseline and 12 months post-surgery
Secondary outcome [11] 437358 0
Measures of the glycated form of haemoglobin (HbA1c)
Timepoint [11] 437358 0
At baseline and 12 months post-surgery
Secondary outcome [12] 437359 0
Measures of the N-terminal prohormone of brain natriuretic peptide in the blood (NT-proBNP)
Timepoint [12] 437359 0
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] 22588 0
Nepean Hospital - Kingswood
Recruitment postcode(s) [1] 37842 0
2747 - Kingswood

Funding & Sponsors
Funding source category [1] 311667 0
Government body
Name [1] 311667 0
NSW Health
Country [1] 311667 0
Australia
Primary sponsor type
Hospital
Name
Nepean Blue Mountains Local Health District
Address
Derby Street, Penrith NSW 2750
Country
Australia
Secondary sponsor category [1] 313120 0
None
Name [1] 313120 0
Address [1] 313120 0
Country [1] 313120 0

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 311123 0
Nepean Blue Mountains Local Health District HREC
Ethics committee address [1] 311123 0
Nepean Hospital
Derby Street, Penrith NSW 2750
Ethics committee country [1] 311123 0
Australia
Date submitted for ethics approval [1] 311123 0
Approval date [1] 311123 0
31/03/2021
Ethics approval number [1] 311123 0
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 120018 0
Dr Faraz Pathan
Address 120018 0
Nepean HospitalDepartment of CardiologyDerby Street, Penrith NSW 2750
Country 120018 0
Australia
Phone 120018 0
+61 2 4734 1719
Fax 120018 0
Email 120018 0
[email protected]
Contact person for public queries
Name 120019 0
Faraz Pathan
Address 120019 0
Nepean HospitalDepartment of CardiologyDerby Street, Penrith NSW 2750
Country 120019 0
Australia
Phone 120019 0
+61 2 4734 2000
Fax 120019 0
Email 120019 0
[email protected]
Contact person for scientific queries
Name 120020 0
Faraz Pathan
Address 120020 0
Nepean HospitalDepartment of CardiologyDerby Street, Penrith NSW 2750
Country 120020 0
Australia
Phone 120020 0
+61 2 4734 2000
Fax 120020 0
Email 120020 0
[email protected]

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.