title: Low preoperative selenium is associated with post-operative atrial fibrillation in patients having intermediate-risk coronary artery surgery.
abstract: Post-operative atrial fibrillation (POAF) is a frequent complication of cardiac surgery. Oxidative stress and reduced antioxidant function have major roles in its development. Selenium is a key to normal antioxidant function, and levels are often low before cardiac surgery. This study investigated whether low preoperative selenium levels were associated with POAF in cardiac surgical patients.
  
  
  
  Using the Society of Thoracic Surgeons (STS) Mortality risk score, 50 patients having primary coronary artery bypass grafts (CABG) surgery were divided into two groups: (i) low-risk group (STS ⩽0.5%; n=26) and (ii) intermediate-risk group (STS ⩾2.0%; n=24). Plasma levels of selenium, glutathione peroxidase (GPx) and malondialdehyde (MDA) were measured in all patients at anaesthetic induction, after aortic cross-clamp removal, 3 h post cardiopulmonary bypass and on post-operative days 1 and 5. Multiple logistic regression was used to assess whether selenium levels were associated with POAF development.
  
  
  
  Seventeen patients developed POAF (14 patients in the intermediate-risk group and 3 patients in the low-risk group). Preoperative selenium was lower in patients who developed POAF compared with those with normal sinus rhythm (0.73±0.16 vs 0.89±0.13 μmol/l, P=0.005), and this was independently associated with POAF (PR 0.32; 95% confidence credible interval (95%cI) 0.06-0.85, P=0.016). Regardless of POAF, preoperative selenium was lower in the intermediate-risk patients than in the low-risk patients (0.77±0.15 vs 0.89±0.14 μmol/l; P=0.004).
  
  
  
  Intermediate-risk patients with low preoperative selenium levels may be at a greater risk of developing POAF following CABG. This raises the question of whether selenium supplementation in select cardiac surgical patients may reduce their POAF risk.
authors.affiliation: Anaesthesia and Perfusion Services, The Prince Charles Hospital, Chermside, Queensland, Australia.|Critical Care Research Group, The Prince Charles Hospital, The University of Queensland, Brisbane, Queensland, Australia.
authors.forename: C
authors.initials: C
authors.lastname: McDonald
authors.affiliation: Critical Care Research Group, The Prince Charles Hospital, The University of Queensland, Brisbane, Queensland, Australia.|Adult Intensive Care Services, The Prince Charles Hospital, Chermside, Queensland, Australia.
authors.forename: J
authors.initials: J
authors.lastname: Fraser
authors.affiliation: Critical Care Research Group, The Prince Charles Hospital, The University of Queensland, Brisbane, Queensland, Australia.|Adult Intensive Care Services, The Prince Charles Hospital, Chermside, Queensland, Australia.
authors.forename: K
authors.initials: K
authors.lastname: Shekar
authors.affiliation: Department of Cardiac Surgery, The Prince Charles Hospital, Chermside, Queensland, Australia.
authors.forename: A
authors.initials: A
authors.lastname: Clarke
authors.affiliation: School of Human Movement and Nutrition Sciences, University of Queensland, St Lucia, Queensland, Australia.
authors.forename: J
authors.initials: J
authors.lastname: Coombes
authors.affiliation: Critical Care Research Group, The Prince Charles Hospital, The University of Queensland, Brisbane, Queensland, Australia.|Queensland University of Technology, Kelvin Grove, Queensland, Australia.
authors.forename: A
authors.initials: A
authors.lastname: Barnett
authors.affiliation: Anaesthesia and Perfusion Services, The Prince Charles Hospital, Chermside, Queensland, Australia.|Adult Intensive Care Services, The Prince Charles Hospital, Chermside, Queensland, Australia.|Department of Cardiac Surgery, The Prince Charles Hospital, Chermside, Queensland, Australia.
authors.forename: B
authors.initials: B
authors.lastname: Pearse
authors.affiliation: Critical Care Research Group, The Prince Charles Hospital, The University of Queensland, Brisbane, Queensland, Australia.|School of Health and Sports Science, University of the Sunshine Coast, Sippy Downs, Queensland, Australia.
authors.forename: L
authors.initials: L
authors.lastname: Fung
mesh_terms: D000368:Aged; D001281:Atrial Fibrillation / Q000097:blood / Q000401:mortality*; D001026:Coronary Artery Bypass; D003324:Coronary Artery Disease / Q000097:blood / Q000473:pathology / Q000601:surgery*; D005260:Female; D006801:Humans; D016015:Logistic Models; D008297:Male; D011183:Postoperative Complications / Q000097:blood / Q000401:mortality; D011300:Preoperative Care; D011446:Prospective Studies; D011793:Queensland; D012643:Selenium / Q000097:blood*; D012720:Severity of Illness Index
chemical_list: D012643:Selenium