title: Unrecognized myocardial scars detected by delayed-enhanced MRI are associated with increased levels of NT-proBNP.
abstract: OBJECTIVE
  Patients with unrecognized myocardial infarction (UMI) scars detected by delayed-enhanced magnetic resonance imaging (DE-MRI) have a decreased left ventricular ejection fraction and an increased left ventricular mass. N-terminal pro-brain natriuretic peptide (NT-proBNP) is a marker of heart failure, and troponin I (TnI) is a marker of myocardial injury. The primary aim of this study was to investigate whether NT-proBNP plasma levels (in addition to ejection fraction) differed in patients with UMI scars compared with normal participants. The second aim was to compare whether the TnI levels differed in those two groups.
  
  
  METHODS
  Data from the Prospective Investigation of Vasculature in Uppsala Seniors study were used. The participants who had undergone cardiac MRI were included in this study (n=248). Patients were divided into three groups depending on the existence of a myocardial infarction (MI) scar in DE-MRI and their earlier history of MI. In all the patients, a peripheral blood sample was collected and the plasma levels of NT-proBNP and TnI were determined.
  
  
  RESULTS
  Patients with UMI had higher plasma levels of NT-proBNP (median 140.2 ng/l; 25th-75th percentiles: 79-225.5) than no-MI participants (median 94.9 ng/l; 25th-75th percentiles: 59.2-144.2; P=0.01) and lower levels than patients with recognized MI (median 310.4 ng/l; 25th-75th percentiles: 122.6-446.5; P=0.02). Plasma TnI values did not differ among the three groups.
  
  
  CONCLUSIONS
  Patients with UMI scars detected by DE-MRI have increased plasma levels of NT-proBNP that is known to correlate with an increased risk of future cardiovascular adverse events.
authors.affiliation: Department of ORKI, Section of Radiology, Uppsala University Hospital, Sweden. Raquel.Themudo@radiol.uu.se
authors.forename: Raquel Espregueira
authors.initials: RE
authors.lastname: Themudo
authors.forename: Bertil
authors.initials: B
authors.lastname: Lindahl
authors.forename: Lars
authors.initials: L
authors.lastname: Johansson
authors.forename: Per
authors.initials: P
authors.lastname: Venge
authors.forename: Håkan
authors.initials: H
authors.lastname: Ahlström
authors.forename: Charlotte
authors.initials: C
authors.lastname: Ebeling Barbier
authors.forename: Kai M
authors.initials: KM
authors.lastname: Eggers
authors.forename: Lars
authors.initials: L
authors.lastname: Lind
authors.forename: Tomas
authors.initials: T
authors.lastname: Bjerner
mesh_terms: D000368:Aged; D015415:Biomarkers / Q000097:blood*; D002921:Cicatrix / Q000097:blood / Q000175:diagnosis*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D009203:Myocardial Infarction / Q000097:blood* / Q000175:diagnosis*; D020097:Natriuretic Peptide, Brain / Q000097:blood*; D010446:Peptide Fragments / Q000097:blood*; D011446:Prospective Studies; D013318:Stroke Volume; D019210:Troponin I / Q000097:blood
chemical_list: D015415:Biomarkers; D010446:Peptide Fragments; D019210:Troponin I; C109794:pro-brain natriuretic peptide (1-76); D020097:Natriuretic Peptide, Brain