title: Early diagnosis of perioperative myocardial infarction after coronary bypass grafting: a study using biomarkers and cardiac magnetic resonance imaging.
abstract: BACKGROUND
  Myocardial injury related to coronary artery bypass grafting (CABG) is poorly characterized, and understanding the characteristic release of biomarkers associated with revascularization injury might provide novel therapeutic opportunities. This study characterized early changes in biomarkers after revascularization injury during on-pump CABG.
  
  
  METHODS
  This prospective study comprised 28 patients undergoing on-pump CABG and late gadolinium enhancement (LGE) cardiac magnetic resonance imaging (CMRI) who underwent measurements of cardiac troponin I (cTnI), creatine kinase-MB, and inflammatory markers (C-reactive protein, serum amyloid A, myeloperoxidase, interleukin 6, tumor necrosis factor-α, matrix metalloproteinase 9a, monocyte chemotactic protein-1, plasminogen activator inhibitor-1a) at baseline, at 1, 6, 12, and 24 hours, and at 1 week (inflammatory markers only) post-CABG. Biomarker results at 1 hour were studied for a relationship to new myocardial infarction as defined by CMRI-LGE, and the diagnostic utility of combining positive biomarkers was assessed.
  
  
  RESULTS
  All patients had an uneventful recovery, but 9 showed a new myocardial infarction demonstrated by new areas of hyperenhancement on CMR. Peak cTnI at 24 hours (ρ = 0.66, p < 0.001) and CK-MB (ρ = 0.66, p < 0.001) correlated with the amount of new LGE. At 1 hour, 3 biomarkers--cTnI, interleukin 6, and tumor necrosis factor-α--were significantly elevated in patients with vs those without new LGE. Receiver operating curve analysis showed cTnI was the most accurate at detecting new LGE at 1 hour: a cutoff of cTnI exceeding 5 μg/L at 1 hour had 67% sensitivity and 79% specificity for detecting new LGE.
  
  
  CONCLUSIONS
  Unexpected CABG-related myocardial injury occurs in a significant proportion of patients. A cTnI test at 1 hour after CABG could potentially differentiate patients with significant revascularization injury.
authors.affiliation: Oxford Heart Centre, John Radcliffe Hospital, Oxford, United Kingdom.
authors.forename: Chris C S
authors.initials: CC
authors.lastname: Lim
authors.forename: Florim
authors.initials: F
authors.lastname: Cuculi
authors.forename: William J
authors.initials: WJ
authors.lastname: van Gaal
authors.forename: Luca
authors.initials: L
authors.lastname: Testa
authors.forename: Jayanth R
authors.initials: JR
authors.lastname: Arnold
authors.forename: Theodoros
authors.initials: T
authors.lastname: Karamitsos
authors.forename: Jane M
authors.initials: JM
authors.lastname: Francis
authors.forename: Janet E
authors.initials: JE
authors.lastname: Digby
authors.forename: Charalambos
authors.initials: C
authors.lastname: Antoniades
authors.forename: Rajesh K
authors.initials: RK
authors.lastname: Kharbanda
authors.forename: Stefan
authors.initials: S
authors.lastname: Neubauer
authors.forename: Stephen
authors.initials: S
authors.lastname: Westaby
authors.forename: Adrian P
authors.initials: AP
authors.lastname: Banning
mesh_terms: D000368:Aged; D015415:Biomarkers / Q000097:blood; D001026:Coronary Artery Bypass / Q000009:adverse effects*; D042241:Early Diagnosis; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000175:diagnosis*; D059035:Perioperative Period; D011446:Prospective Studies; D012372:ROC Curve
chemical_list: D015415:Biomarkers