title: The low triiodothyronine syndrome: a strong predictor of low cardiac output and death in patients undergoing coronary artery bypass grafting.
abstract: BACKGROUND
  There is strong clinical and experimental evidence that altered thyroid homeostasis negatively affects survival in cardiac patients, but a negative effect of the low triiodothyronine (T3) syndrome on the outcome of coronary artery bypass grafting (CABG) has not been demonstrated. This study was designed to evaluate the prognostic significance of low T3 syndrome in patients undergoing CABG.
  
  
  METHODS
  The thyroid profile was evaluated at hospital admission in 806 consecutive CABG patients. Known thyroid disease, severe systemic illness, and use of drugs interfering with thyroid metabolism were considered exclusion criteria. The effect of the baseline free T3 (fT3) concentration and of preoperative low T3 syndrome (fT3 <2.23 pmol/L) on the risk of low cardiac output (CO) and death was analyzed in a logistic regression model.
  
  
  RESULTS
  There were 19 (2.3%) deaths, and 64 (7.8%) patients experienced major complications. After univariate analysis, fT3, low T3, New York Heart Association class greater than II, low left ventricular ejection fraction (LVEF), and emergency were associated with low CO and hospital death. History of atrial fibrillation, cardiopulmonary bypass time, and peripheral vascular disease were associated only with low CO. At multivariate analysis, only fT3, low T3, emergency, and LVEF were associated with low CO, and fT3 (odds ratio, 0.172, 95% confidence interval, 0.078 to 0.379; p < 0.0001) and LVEF (odds ratio, 0.934, 95% confidence interval, 0.894 to 0.987; p = 0.03) were the only independent predictors of death.
  
  
  CONCLUSIONS
  Our study demonstrates that low T3 is a strong predictor of death and low CO in CABG patients. For this reason, the thyroid profile should be evaluated before CABG, and patients with low T3 should be considered at higher risk and treated accordingly.
authors.affiliation: Operative Unit of Cardiac Surgery, "G. Pasquinucci" Hospital, "G. Monasterio" Foundation, Massa, Italy. Electronic address: acerillo@yahoo.com.
authors.forename: Alfredo Giuseppe
authors.initials: AG
authors.lastname: Cerillo
authors.affiliation: Clinical Chemistry Laboratory, "G. Pasquinucci" Hospital, "G. Monasterio" Foundation, Massa, Italy.
authors.forename: Simona
authors.initials: S
authors.lastname: Storti
authors.affiliation: Operative Unit of Cardiac Surgery, "G. Pasquinucci" Hospital, "G. Monasterio" Foundation, Massa, Italy.
authors.forename: Enkel
authors.initials: E
authors.lastname: Kallushi
authors.affiliation: Anesthesia and Intensive Care, "G. Pasquinucci" Hospital, "G. Monasterio" Foundation, Massa, Italy.
authors.forename: Dorela
authors.initials: D
authors.lastname: Haxhiademi
authors.affiliation: Operative Unit of Cardiac Surgery, "G. Pasquinucci" Hospital, "G. Monasterio" Foundation, Massa, Italy.
authors.forename: Antonio
authors.initials: A
authors.lastname: Miceli
authors.affiliation: Operative Unit of Cardiac Surgery, "G. Pasquinucci" Hospital, "G. Monasterio" Foundation, Massa, Italy.
authors.forename: Michele
authors.initials: M
authors.lastname: Murzi
authors.affiliation: Cardiology, "G. Pasquinucci" Hospital, "G. Monasterio" Foundation, Massa, Italy.
authors.forename: Sergio
authors.initials: S
authors.lastname: Berti
authors.affiliation: Operative Unit of Cardiac Surgery, "G. Pasquinucci" Hospital, "G. Monasterio" Foundation, Massa, Italy.
authors.forename: Mattia
authors.initials: M
authors.lastname: Glauber
authors.affiliation: Clinical Chemistry Laboratory, "G. Pasquinucci" Hospital, "G. Monasterio" Foundation, Massa, Italy.
authors.forename: Aldo
authors.initials: A
authors.lastname: Clerico
authors.affiliation: Operative Unit of Cardiovascular Endocrinology and Metabolism, "G. Monasterio" Foundation, Istituto di Fisiologia Clinica del Consiglio Nazionale delle Ricerche, Pisa, Italy.
authors.forename: Giorgio
authors.initials: G
authors.lastname: Iervasi
mesh_terms: D000368:Aged; D002303:Cardiac Output, Low / Q000097:blood / Q000209:etiology*; D001026:Coronary Artery Bypass / Q000009:adverse effects / Q000401:mortality*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D013577:Syndrome; D014284:Triiodothyronine / Q000097:blood*
chemical_list: D014284:Triiodothyronine