Imaging-based Diagnosis of Diffuse Coronary Artery Disease and Quantification of Cardiac Remodeling in Obesity
Condition: Obesity
MeSH terms: Coronary Artery Disease; Myocardial Ischemia; Coronary Disease; Obesity
Study type: Observational

Summary: 
      The study aims to:

        1. Characterize coronary artery disease (CAD) using CT Angiography (CTA) and scaling power
           law in 100 patients with obesity

        2. Characterize cardiac remodeling using curvedness-based MRI in 100 patients with obesity

        3. Compare the differences of cardiac and vascular remodeling in patients with metabolic
           syndrome and those without
    

Detailed description: 
      Background and Objectives:

      Obesity is a common [affecting about 33% in the general adult population in US] metabolic
      disorder and it is increasing in prevalence in Singapore (about 10% of general adult
      population). As obesity is associated with cardiovascular disease (i.e., diffused coronary
      artery disease, DCAD) and leads to heart remodeling and heart failure, timely and accurate
      diagnosis of diffused coronary artery disease and its related cardiac remodeling in obesity
      is clinically urgently needed and this study aims to:

        1. Characterize coronary artery disease (CAD) using CTA and scaling power law in 100
           patients with obesity

        2. Characterize cardiac remodeling using curvedness-based MRI in 100 patients with obesity

        3. Compare the differences of cardiac and vascular remodeling in patients with metabolic
           syndrome and those without

      Methodologies: 100 patients with obesity will be recruited for this study. All recruited
      patients will undergo fasting blood test for diagnosing metabolic syndrome. After that, they
      will undergo CTA and MRI within 1-2 weeks in-between. Patients' CTA images will be segmented
      and transformed to build 3D coronary artery models. The application of novel scaling power
      laws on these models will be used to diagnose diffuse CAD. Based on patients MRI images, the
      cardiac remodeling will be assessed with a novel curvedness-based imaging analysis method.
      The differences of cardiac and vascular remodeling in patients with metabolic syndrome and
      those without will be compared and analyzed.

      In addition, subjects shall undergo ultrasound examination of the heart (echocardiogram),
      carotids and forearm arteries. Doppler and tissue-Doppler echocardiography constitutes the
      gold standard for cardiac diastolic function assessment. The findings shall be correlated
      with diastolic cine MRI findings. Carotid and forearm artery ultrasound allows investigation
      of vessel distensibility, carotid intimal thickness, pulse wave velocity, central arterial
      blood pressure estimation as well as endothelial function (via flow-mediated dilation).
      Perturbations of these parameters may be correlated with functional abnormalities on cardiac
      MRI and coronary disease on CT.

      Subjects shall undergo fasting blood tests for metabolic profiling. The tests include blood
      levels of creatinine, electrolytes, insulin, glycated haemoglobin, fasting lipids, fasting
      sugar and postprandial sugar (75 g standard oral glucose load). Additionally blood samples
      shall be stored for potential future studies.

      Clinical Significance: If success, this study in obesity should advance understanding of
      obesity-related CAD and cardiac and vessel remodeling, and further translate into improved
      diagnosis and treatment in obese patients.

      Clinical Significance: If success, this study in obesity should advance understanding of
      obesity-related CAD and cardiac remodeling, and further translate into improved diagnosis and
      treatment in obese patients.
    

Observational model: Case-Only
Time perspective: Prospective
Sampling method: Non-Probability Sample
Study population: 
        Total recruitment number: 100 Participants' age limit of 21 to 80.
      
Biospecimen description: 
      blood specimen for future research