title: Rationale and design of a proof-of-concept trial investigating the effect of uninterrupted perioperative (par)enteral nutrition on amino acid profile, cardiomyocytes structure, and cardiac perfusion and metabolism of patients undergoing coronary artery bypass grafting.
abstract: BACKGROUND
  Malnutrition is very common in patients undergoing cardiac surgery. Malnutrition can change myocardial substrate utilization which can induce adverse effects on myocardial metabolism and function. We aim to investigate the hypothesis that there is a disturbed amino acids profile in the cardiac surgical patient which can be normalized by (par)enteral nutrition before, during and after surgery, subsequently improving cardiomyocyte structure, cardiac perfusion and glucose metabolism.
  
  
  METHODS
  This randomized controlled intervention study investigates the effect of uninterrupted perioperative (par)enteral nutrition on cardiac function in 48 patients undergoing coronary artery bypass grafting. Patients are given enteral nutrition (n = 16) or parenteral nutrition (n = 16), at least two days before, during, and two days after coronary artery bypass grafting, or are treated according to the standard guidelines (control) (n = 16). We will illustrate the effect of (par)enteral nutrition on differences in concentrations of amino acids and asymmetric dimethylarginine and in activity of dimethylarginine dimethylaminohydrolase and arginase in cardiac tissue and blood plasma. In addition, cardiomyocyte structure by histological, immuno-histochemical and ultrastructural analysis will be compared between the (par)enteral and control group. Furthermore, differences in cardiac perfusion and global left ventricular function and glucose metabolism, and their changes after coronary artery bypass grafting are evaluated by electrocardiography-gated myocardial perfusion scintigraphy and ¹⁸F-fluorodeoxy-glucose positron emission tomography respectively. Finally, fat free mass is measured before and after intervention with bioelectrical impedance spectrometry in order to evaluate nutritional status.
  
  
  BACKGROUND
  Netherlands Trial Register (NTR): NTR2183.
authors: Department of Cardiothoracic Surgery, Academic Medical Center University of Amsterdam, Amsterdam, The Netherlands.
authors: Marlieke
authors: M
authors: Visser
authors: Mariska
authors: M
authors: Davids
authors: Hein J
authors: HJ
authors: Verberne
authors: Wouter E M
authors: WE
authors: Kok
authors: Hans W M
authors: HW
authors: Niessen
authors: Lenny M W
authors: LM
authors: van Venrooij
authors: Riccardo
authors: R
authors: Cocchieri
authors: Willem
authors: W
authors: Wisselink
authors: Bas A J M
authors: BA
authors: de Mol
authors: Paul A M
authors: PA
authors: van Leeuwen
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000596:Amino Acids / Q000378:metabolism*; D001026:Coronary Artery Bypass / Q000379:methods*; D003326:Coronary Circulation / Q000187:drug effects*; D004750:Enteral Nutrition / Q000379:methods*; D005502:Food; D006801:Humans; D008875:Middle Aged; D017202:Myocardial Ischemia / Q000378:metabolism / Q000473:pathology / Q000601:surgery*; D009206:Myocardium / Q000378:metabolism; D032383:Myocytes, Cardiac / Q000378:metabolism / Q000473:pathology*; D009426:Netherlands; D010288:Parenteral Nutrition / Q000379:methods*; D011300:Preoperative Care / Q000379:methods; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: D000596:Amino Acids