Bariatric Surgery and Epicardial Adipose Tissue: a MRI Study
Condition: Obesity
Study type: Observational

Summary: 
      The aim of this study is to measure the volume of the epicardial adispose tissue (EAT) and
      other morphological and functional cardiovascular parameters in subjects with severe obesity,
      using an open magnetic resonance unit capable of holding up to 220 kg of weight. These
      measurements will be repeated a year after bariatric surgery to assess the effect of the
      weight loss on EAT. The possible difference among different types of bariatric surgery will
      be considered.
    

Detailed description: 
      In this prospective observational study, 28 obese male and female subjects underwent
      bariatric surgery will be studied: 14 subjects candidates for SG and 14 at RYGB. These
      patients will enrolled in this type of intervention at the INCO bariatric surgery unit
      (National Institute for Obesity). All patients are first evaluated by a multidisciplinary
      team to establish adherence to the criteria suggested by the guidelines for bariatric
      surgery.

      All enrolled subjects will be subjected to the following protocol within one month prior to
      surgery and one year (±1 month) after surgery:

        1. CMR without contrast medium with 1-T (Panorama, Philips) open device for the measurement
           of EAT volume in systoles and diastoles for the evaluation of the main morpho-functional
           parameters (left ventricular size and mass , Right ventricular size, atrial size, left
           and right ventricular systolic function, diastolic left and right ventricular function)
           and for evaluating the elasticity of the thoracic aortic wall, evaluated as compliance
           and stiffness (duration of examination About 30 minutes).

        2. performing axial MRI scans without contrast medium at the IV lumbar vertebra for
           quantification of abdominal and subcutaneous adipose tissue;

        3. direct detection of anthropometric indexes (weight, height, abdominal circumference, hip
           circumference);

        4. measurement of systolic and diastolic blood pressure with sphygmomanometer;

        5. assessment of body composition by bioimpedenzometry with estimate of fat and lean mass
           expressed in kg and in percentage.

      The examinations will be carried out following the normal procedures provided by clinical
      practice and all scans performed by Magnetic Resonance will be performed at the Italian
      Diagnostic Center (CDI), Via Saint Bon, 20 - 20147 Milan (which has MRI equipment open).
      Other investigations will be carried out at the Istituto Nazionale per la cura del dono
      (INCO) of the Sant'Ambrogio Clinical Institute.

      The sample size was calculated assuming that an average thickness of 12.3±1.8 mm (Iacobellis
      G. at al, 2008) is expected to reduce the thickness by approximately 30% to 4 ± 0.8 mm (from
      An average epicardial fat content of 137 ± 37 ml is expected to be about 30% reduction of 39
      ± 12 ml). With a 90% power and alpha error of 5% (two-tailed) we have obtained a minimum
      number of 22 subjects. Assuming a 20% loss to follow-up, approximately 28 subjects should be
      recruited.
    

Intervention name(s): Bariatic surgery
Intervention type(s): Procedure
Intervention description(s): One of two different types of surgery: sleeve gastrectomy and Roux-en-Y gastric by-pass.
Observational model: Case-Only
Time perspective: Prospective
Sampling method: Probability Sample
Study population: 
        Obese patients