title: Magnetic resonance imaging delineates the ischemic area at risk and myocardial salvage in patients with acute myocardial infarction.
abstract: BACKGROUND
  The area at risk (AAR) is a key determinant of myocardial infarction (MI) size. We investigated whether magnetic resonance imaging (MRI) measurement of AAR would be correlated with an angiographic AAR risk score in patients with acute MI.
  
  
  RESULTS
  Bright-blood, T2-prepared, steady-state, free-precession MRI was used to depict the AAR in 50 consecutive acute MI patients, whereas infarct size was measured on gadolinium late-contrast-enhancement images. AAR was also estimated by the APPROACH and DUKE angiographic jeopardy scores and ST-segment elevation score. Myocardial salvage was calculated as AAR minus infarct size. Results are mean ± SD unless specified otherwise. Patients were 61 ± 12 years of age, 76% had an ST-segment elevation MI, and 20% had a prior MI. All underwent MRI 4 ± 2 days after initial presentation. The relation between MRI and the APPROACH angiographic estimates of AAR was similar (overall size relative to left ventricular mass was 32 ± 12% vs 30 ± 12%, respectively, P=0.33), correlated well (r = 0.78, P < 0.0001), and had a 2.5% bias on Bland-Altman analysis. The DUKE jeopardy score underestimated AAR relative to infarct size and was correlated less well with MRI (r = 0.39, P = 0.0055). ST-segment elevation score underestimated infarct size in 19 subjects (50%) and was not correlated with MRI (r = 0.27, P = 0.06). Myocardial salvage varied according to Thrombolysis in Myocardial Infarction flow grade at the end of angiography/percutaneous coronary intervention (P = 0.04), and Thrombolysis in Myocardial Infarction flow grade was a univariable predictor of myocardial salvage (P = 0.011). In multivariable analyses, infarct size was predicted by T2-prepared, steady-state, free-precession MRI (P < 0.0001).
  
  
  CONCLUSIONS
  T2-prepared, steady-state, free-precession MRI delineates the AAR and enables estimation of myocardial salvage when coupled with a measurement of infarct size.
authors.affiliation: Department of Health and Human Services, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD 20892-1061, USA.
authors.forename: Colin
authors.initials: C
authors.lastname: Berry
authors.forename: Peter
authors.initials: P
authors.lastname: Kellman
authors.forename: Christine
authors.initials: C
authors.lastname: Mancini
authors.forename: Marcus Y
authors.initials: MY
authors.lastname: Chen
authors.forename: W Patricia
authors.initials: WP
authors.lastname: Bandettini
authors.forename: Tracy
authors.initials: T
authors.lastname: Lowrey
authors.forename: Li-Yueh
authors.initials: LY
authors.lastname: Hsu
authors.forename: Anthony H
authors.initials: AH
authors.lastname: Aletras
authors.forename: Andrew E
authors.initials: AE
authors.lastname: Arai
mesh_terms: D000368:Aged; D015906:Angioplasty, Balloon, Coronary; D003287:Contrast Media; D017023:Coronary Angiography; D003326:Coronary Circulation; D004489:Edema, Cardiac / Q000473:pathology / Q000503:physiopathology; D019786:Gadolinium DTPA; D006801:Humans; D019028:Magnetic Resonance Imaging, Cine; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000175:diagnosis* / Q000473:pathology / Q000503:physiopathology / Q000628:therapy; D009206:Myocardium / Q000473:pathology*; D011237:Predictive Value of Tests; D012044:Regression Analysis; D018570:Risk Assessment; D012307:Risk Factors; D012720:Severity of Illness Index; D016896:Treatment Outcome
chemical_list: D003287:Contrast Media; D019786:Gadolinium DTPA