title: Performance of angiographic, electrocardiographic and MRI methods to assess the area at risk in acute myocardial infarction.
abstract: Objective Validation of methods to assess the area at risk (AAR) in patients with ST elevation myocardial infarction is limited. A study was undertaken to test different AAR methods using established physiological concepts to provide a reference standard.  Main outcome measured In 78 reperfused patients with first ST elevation myocardial infarction, AAR was measured by electrocardiographic (Aldrich), angiographic (Bypass Angioplasty Revascularization Investigation (BARI), APPROACH) and cardiovascular magnetic resonance methods (T2-weighted hyperintensity and delayed enhanced endocardial surface area (ESA)). The following established physiological concepts were used to evaluate the AAR  METHODS:  (1) AAR size is always ≥ infarct size (IS); (2) in transmural infarcts AAR size=IS; (3) correlation between AAR size and IS increases as infarct transmurality increases; and (4) myocardial salvage ((AAR-IS)/AAR×100) is inversely related to infarct transmurality.  Results Overall, 65%, 87%, 76%, 87% and 97% of patients using the Aldrich, BARI, APPROACH, T2-weighted hyperintensity and ESA methods obeyed the concept that AAR size is ≥IS. In patients with transmural infarcts (n=22), Bland-Altman analysis showed poor agreement (wide 95% limits of agreement) between AAR size and IS for the BARI, Aldrich and APPROACH methods (95% CI -22.9 to 29.6, 95% CI -28.3 to 21.3 and 95% CI -16.9 to 20.0, respectively) and better agreement for T2-weighted hyperintensity and ESA (95% CI -6.9 to 16.6 and 95% CI -4.3 to 18.0, respectively). Increasing correlation between AAR size and IS with increasing infarct transmurality was observed for the APPROACH, T2-weighted hyperintensity and ESA methods, with ESA having the highest correlation (r=0.93, p<0.001). The percentage of patients within a narrow margin (±30%) of the inverse line of identity between salvage extent and infarct transmurality was 56%, 76%, 65%, 77% and 92% for the Aldrich, BARI, APPROACH, T2-weighted hyperintensity and ESA methods, respectively, where higher percentages represent better concordance with the concept that the extent of salvage should be inversely related to infarct transmurality.  Conclusions For measuring AAR, cardiovascular magnetic resonance methods are better than angiographic methods, which are better than electrocardiographic methods. Overall, ESA performed best for measuring AAR in vivo.
authors.affiliation: Department of Cardiology, Maastricht University Medical Center, P. Debyelaan 25, Maastricht, The Netherlands.
authors.forename: Mathijs O
authors.initials: MO
authors.lastname: Versteylen
authors.forename: Sebastiaan C A M
authors.initials: SC
authors.lastname: Bekkers
authors.forename: Martijn W
authors.initials: MW
authors.lastname: Smulders
authors.forename: Bjorn
authors.initials: B
authors.lastname: Winkens
authors.forename: Casper
authors.initials: C
authors.lastname: Mihl
authors.forename: Mark H M
authors.initials: MH
authors.lastname: Winkens
authors.forename: Tim
authors.initials: T
authors.lastname: Leiner
authors.forename: Johannes L
authors.initials: JL
authors.lastname: Waltenberger
authors.forename: Raymond J
authors.initials: RJ
authors.lastname: Kim
authors.forename: Anton P M
authors.initials: AP
authors.lastname: Gorgels
mesh_terms: D000368:Aged; D000792:Angiography; D004562:Electrocardiography; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000175:diagnosis* / Q000453:epidemiology*; D015588:Observer Variation; D018570:Risk Assessment; D012307:Risk Factors