title: Catalytic iron in acute myocardial infarction complicated by cardiogenic shock - A biomarker substudy of the IABP-SHOCK II-trial.
abstract: BACKGROUND
  Catalytic iron (CI) is unbound ferric iron with the potential to generate reactive oxygen species with further deleterious vascular effects. In acute coronary syndromes, high levels of CI are linked to all-cause mortality. The prognostic impact of CI and iron metabolism in cardiogenic shock (CS) is currently undetermined. Aims of this study were to investigate the prognostic impact of CI and to identify predictors of high CI levels in patients with CS complicating acute myocardial infarction.
  
  
  METHODS
  The Intraaortic Balloon Pump in Cardiogenic Shock II (IABP-SHOCK II) trial randomized 600 patients with CS to either therapy with intraaortic balloon pump or control. In 185 of these patients, blood samples were systematically collected at baseline and day 3. CI levels were measured using a modified bleomycin detectable iron assay. Furthermore, levels of free hemoglobin, total serum iron, transferrin, total iron binding capacity, ferritin, hepcidin, and transferrin saturation were assessed.
  
  
  RESULTS
  Patients with baseline CI levels in the highest quartile had a worse outcome in comparison to patients with lower CI (day 1: HR 1.91 [1.11-3.31], p=0.005; day 3: HR 2.15 [1.06-4.34], p=0.01). In multivariable Cox-regression analysis baseline CI remained an independent predictor of 30-day mortality (HR per 10LOG 2.08 [1.25-3.47], p=0.005). Predictors of CI levels on day 3 were baseline CI, bleeding events, and baseline troponin T.
  
  
  CONCLUSIONS
  CI levels were associated with increased short-term mortality in CS complicating acute myocardial infarction. High levels of CI at day 3 were associated with bleeding and high troponin levels.
authors.affiliation: Department of Internal Medicine II, Cardiology/Angiology/Intensive Care Medicine, University Heart Center Lübeck, Lübeck, Germany; German Center for Cardiovascular Research (DZHK), partner site Hamburg/Kiel/Lübeck, Lübeck, Germany; Department of Internal Medicine/Cardiology, University of Leipzig - Heart Center, Leipzig, Germany. Electronic address: georg.fuernau@uksh.de.
authors.forename: Georg
authors.initials: G
authors.lastname: Fuernau
authors.affiliation: Department of Internal Medicine/Cardiology, University of Leipzig - Heart Center, Leipzig, Germany.
authors.forename: Florian
authors.initials: F
authors.lastname: Traeder
authors.affiliation: Department of Cardiology, Bhailal Amin General Hospital, Baroda, Gujarat, India.
authors.forename: Suhas S
authors.initials: SS
authors.lastname: Lele
authors.affiliation: Department of Nephrology, Muljibhai Patel Society for Research in Nephro-Urology, Nadiad, India.
authors.forename: Mohan M
authors.initials: MM
authors.lastname: Rajapurkar
authors.affiliation: Department of Biochemistry, Muljibhai Patel Urological Hospital, Nadiad, India.
authors.forename: Banibrata
authors.initials: B
authors.lastname: Mukhopadhyay
authors.affiliation: Department of Internal Medicine II, Cardiology/Angiology/Intensive Care Medicine, University Heart Center Lübeck, Lübeck, Germany; German Center for Cardiovascular Research (DZHK), partner site Hamburg/Kiel/Lübeck, Lübeck, Germany.
authors.forename: Suzanne
authors.initials: S
authors.lastname: de Waha
authors.affiliation: Department of Internal Medicine II, Cardiology/Angiology/Intensive Care Medicine, University Heart Center Lübeck, Lübeck, Germany; German Center for Cardiovascular Research (DZHK), partner site Hamburg/Kiel/Lübeck, Lübeck, Germany.
authors.forename: Steffen
authors.initials: S
authors.lastname: Desch
authors.affiliation: Department of Internal Medicine II, Cardiology/Angiology/Intensive Care Medicine, University Heart Center Lübeck, Lübeck, Germany; German Center for Cardiovascular Research (DZHK), partner site Hamburg/Kiel/Lübeck, Lübeck, Germany.
authors.forename: Ingo
authors.initials: I
authors.lastname: Eitel
authors.affiliation: Department of Internal Medicine/Cardiology, University of Leipzig - Heart Center, Leipzig, Germany.
authors.forename: Gerhard
authors.initials: G
authors.lastname: Schuler
authors.affiliation: Department of Internal Medicine/Cardiology, University of Leipzig - Heart Center, Leipzig, Germany.
authors.forename: Volker
authors.initials: V
authors.lastname: Adams
authors.affiliation: Department of Internal Medicine II, Cardiology/Angiology/Intensive Care Medicine, University Heart Center Lübeck, Lübeck, Germany; German Center for Cardiovascular Research (DZHK), partner site Hamburg/Kiel/Lübeck, Lübeck, Germany.
authors.forename: Holger
authors.initials: H
authors.lastname: Thiele
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015415:Biomarkers / Q000097:blood; D002384:Catalysis; D007423:Intra-Aortic Balloon Pumping; D007501:Iron / Q000097:blood; D009203:Myocardial Infarction / Q000097:blood / Q000150:complications / Q000601:surgery; D012770:Shock, Cardiogenic / Q000097:blood / Q000150:complications / Q000601:surgery
chemical_list: D015415:Biomarkers; D007501:Iron
keywords: Acute myocardial infarction; Bleeding; Cardiogenic shock; Catalytic iron; Prognosis