title: Unrecognized myocardial infarctions detected by cardiac magnetic resonance imaging are associated with cardiac troponin I levels.
abstract: BACKGROUND
  Both unrecognized myocardial infarction (UMI) and elevated levels of biomarkers are common in patients with stable coronary artery disease (CAD). The objective of this study was to determine the association between levels of cardiac biomarkers, UMI and extent of CAD in patients with stable CAD.
  
  
  METHODS
  A total of 235 patients (median age: 65years; 34% women) with stable CAD without previously known myocardial infarction were examined with late gadolinium enhancement cardiovascular magnetic resonance imaging and coronary angiography. Blood samples were drawn at enrolment and high sensitivity cardiac troponin I (cTnI), NT-proBNP and Galectin-3 were analyzed.
  
  
  RESULTS
  UMI was detected in 58 patients (25%). The median levels of cTnI, NT-proBNP and Galectin-3 were significantly higher in patients with UMI compared to those without, (p<0.001, p=0.006 and p=0.033, respectively). After adjustment for cardiovascular risk factors, left ventricular ejection fraction and renal function, cTnI remained independently associated with the presence of UMI (p=0.031) and the extent of CAD (p=0.047). Neither NT-proBNP, nor Galectin-3, was independently associated with UMI or extent of CAD.
  
  
  CONCLUSIONS
  The independent association between levels of cTnI and UMI indicates a common pathophysiological pathway for the cTnI elevation and development of UMI.
  
  
  BACKGROUND
  ClinicalTrials.gov (NCT01257282).
authors.affiliation: Department of Cardiology, Faculty of Health, Örebro University, Örebro, Sweden. Electronic address: anna.nordenskjold@regionorebrolan.se.
authors.forename: Anna M
authors.initials: AM
authors.lastname: Nordenskjöld
authors.affiliation: Department of Radiology, Västerås Hospital, Västerås, Sweden; Department of Radiology, Oncology and Radiation Science, Uppsala University, Uppsala, Sweden.
authors.forename: Per
authors.initials: P
authors.lastname: Hammar
authors.affiliation: Department of Radiology, Oncology and Radiation Science, Uppsala University, Uppsala, Sweden.
authors.forename: Håkan
authors.initials: H
authors.lastname: Ahlström
authors.affiliation: Department of Radiology, Oncology and Radiation Science, Uppsala University, Uppsala, Sweden.
authors.forename: Tomas
authors.initials: T
authors.lastname: Bjerner
authors.affiliation: Department of Radiology, Oncology and Radiation Science, Uppsala University, Uppsala, Sweden.
authors.forename: Olov
authors.initials: O
authors.lastname: Duvernoy
authors.affiliation: Department of Medical Sciences, Cardiology, Uppsala University, Uppsala, Sweden; Uppsala Clinical Research Centre, Uppsala, Sweden.
authors.forename: Kai M
authors.initials: KM
authors.lastname: Eggers
authors.affiliation: Department of Cardiology, Faculty of Health, Örebro University, Örebro, Sweden.
authors.forename: Ole
authors.initials: O
authors.lastname: Fröbert
authors.affiliation: Uppsala Clinical Research Centre, Uppsala, Sweden.
authors.forename: Nermin
authors.initials: N
authors.lastname: Hadziosmanovic
authors.affiliation: Department of Medical Sciences, Cardiology, Uppsala University, Uppsala, Sweden; Uppsala Clinical Research Centre, Uppsala, Sweden.
authors.forename: Bertil
authors.initials: B
authors.lastname: Lindahl
mesh_terms: D000368:Aged; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000175:diagnosis* / Q000378:metabolism; D009206:Myocardium / Q000378:metabolism*; D019210:Troponin I / Q000378:metabolism*
chemical_list: D019210:Troponin I
keywords: Cardiac magnetic resonance imaging; Cardiac troponin; Coronary artery disease; NT-proBNP; Unrecognized myocardial infarction