Characterization of Epicardial and Pericardial Adipose Tissue in Coronary Artery Disease

Study Overview
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Brief Summary
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Human epicardial fat is the true visceral fat depot of the heart, and its regional distribution and physiology is of growing scientific and clinical interest. This study aims to characterize the expression profile and function of the epicardial and pericardial adipose tissue compartments of the heart (EAT and PAT). EAT and PAT adipose biopsies will be obtained from patients undergoing coronary artery bypass graft surgery (CABG) or valve replacement surgery.

Detailed Description
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The epicardial adipose tissue (EAT) stretches from the myocardium to the visceral layer of the pericardium. Adipose located on the outside of the visceral pericardium to the external site of the pericardium is called the pericardial adipose tissue (PAT), and is of a separate origin than EAT. Therefore, this study aims to investigate the global expression profile of the EAT and PAT compartments, in addition to characterizing the function, structure, metabolic and inflammatory profile. Furthermore, this study will determine whether CABG and valve replacement patients display different EAT and PAT characteristics

Official Title
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Characterization of Epicardial and Pericardial Adipose Tissue in Coronary Artery Disease

Conditions
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Coronary Artery Disease

Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Age <80 years Patients undergoing elective heart surgery either for coronary bypass grafting or for other purposes Exclusion Criteria: Inability of the patient to provide informed consent Severe kidney failure, GFR<30 Previous cardio-thoracic surgery There are no other specific exclusion criteria, as long as the patient is considered eligible for surgery by the clinicians

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 80 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| open elective cardiac surgery patients<br>Including coronary artery bypass graft and valve replacement surgery patients | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Characterization of cardiac adipose tissue | Cardiac adipose tissue biopsies will be compared and characterized as brown, beige or white adipose according to gene expression of adipocyte markers | Time of collection during surgery is approximately 3 hours | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Characterization of cardiac adipose tissue gene expression in coronary artery bypass graft (CABG) and valve replacement surgery patients | Gene expression will be measured and compared within cardiac adipose tissue biopsies from patients undergoing CABG or valve replacement surgery. | Time of collection during surgery is approximately 3 hours | 
| Characterization of cardiac adipose tissue protein expression in coronary artery bypass graft (CABG) and valve replacement surgery patients | Protein expression will be measured and compared within cardiac adipose tissue biopsies from patients undergoing CABG or valve replacement surgery. | Time of collection during surgery is approximately 3 hours | 
| Cardiac adipose tissue volume | Cardiac fat volume will be measured by cardiac MRI scan prior to undergoing CABG or valve replacement surgery to assess whether cardiac fat volume correlates with the cardiac adipose profile. | Prior to surgery | 
| Functional characterization of cardiac adipose biopsy cell culture | Primary cell culture will be derived from the cardiac adipose biopsies to perform functional assays in vitro. Gene expression will be measured. | Time of collection during surgery is approximately 3 hours | 
| Functional characterization of cardiac adipose biopsy cell culture | Primary cell culture will be derived from the cardiac adipose biopsies to perform functional assays in vitro. Protein expression will be measured. | Time of collection during surgery is approximately 3 hours | 
| Cardiac muscle biopsies | Gene expression in cardiac muscle biopsies and progenitor cells will be compared to that of the adipose biopsies. | Time of collection during surgery is approximately 3 hours |