title: A mismatch index based on the difference between measured left ventricular ejection fraction and that estimated by infarct size at three months following reperfused acute myocardial infarction.
abstract: OBJECTIVE
  The reduction of left ventricular ejection fraction (LVEF) following ST-segment elevation myocardial infarction (STEMI) is a result of infarcted myocardium and may involve dysfunctional but viable myocardium. An index that may quantitatively determine whether LVEF is reduced beyond the expected value when considering only infarct size (IS) has previously been presented based on cardiac magnetic resonance (CMR). The purpose of this study was to introduce the index based on the electrocardiogram (ECG) and compare indices based on ECG and CMR.
  
  
  RESULTS
  In 55 patients ECG and CMR were obtained 3 months after STEMI treated with primary percutaneous coronary intervention. Significant, however moderate inverse relationships were found between measured LVEF and IS. Based on IS and LVEF an IS estimated LVEF was derived and an MI-LVEF mismatch index was calculated as the difference between measured LVEF and IS estimated LVEF. In 41 (74.5%) of the patients there was agreement between the ECG and CMR indices in regards to categorizing indices as >10 or ≤ 10 and generally no significant difference was detected, mean difference of 1.26 percentage points (p = 0.53).
  
  
  CONCLUSIONS
  The study found an overall good agreement between MI-LVEF mismatch indices based on ECG and CMR. The MI-LVEF mismatch index may serve as a tool to identify patients with potentially reversible dysfunctional but viable myocardium, but future studies including both ECG and CMR are needed.
authors.affiliation: Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark. Electronic address: e_a_carlsen@hotmail.com.
authors.forename: Esben A
authors.initials: EA
authors.lastname: Carlsen
authors.affiliation: Department of Cardiology, The Heart Center, Copenhagen University Hospital, Copenhagen, Denmark.
authors.forename: Lia E
authors.initials: LE
authors.lastname: Bang
authors.affiliation: Department of Cardiology, The Heart Center, Copenhagen University Hospital, Copenhagen, Denmark.
authors.forename: Jacob
authors.initials: J
authors.lastname: Lønborg
authors.affiliation: Department of Cardiology, The Heart Center, Copenhagen University Hospital, Copenhagen, Denmark.
authors.forename: Kiril A
authors.initials: KA
authors.lastname: Ahtarovski
authors.affiliation: Department of Cardiology, The Heart Center, Copenhagen University Hospital, Copenhagen, Denmark.
authors.forename: Lars
authors.initials: L
authors.lastname: Køber
authors.affiliation: Department of Cardiology, The Heart Center, Copenhagen University Hospital, Copenhagen, Denmark.
authors.forename: Henning
authors.initials: H
authors.lastname: Kelbæk
authors.affiliation: Department of Cardiology, The Heart Center, Copenhagen University Hospital, Copenhagen, Denmark.
authors.forename: Niels
authors.initials: N
authors.lastname: Vejlstrup
authors.affiliation: Department of Cardiology, The Heart Center, Copenhagen University Hospital, Copenhagen, Denmark.
authors.forename: Erik
authors.initials: E
authors.lastname: Jørgensen
authors.affiliation: Department of Cardiology, The Heart Center, Copenhagen University Hospital, Copenhagen, Denmark.
authors.forename: Steffen
authors.initials: S
authors.lastname: Helqvist
authors.affiliation: Department of Cardiology, The Heart Center, Copenhagen University Hospital, Copenhagen, Denmark.
authors.forename: Kari
authors.initials: K
authors.lastname: Saunamäki
authors.affiliation: Department of Cardiology, The Heart Center, Copenhagen University Hospital, Copenhagen, Denmark.
authors.forename: Peter
authors.initials: P
authors.lastname: Clemmensen
authors.affiliation: Department of Cardiology, The Heart Center, Copenhagen University Hospital, Copenhagen, Denmark.
authors.forename: Lene
authors.initials: L
authors.lastname: Holmvang
authors.affiliation: Department of Medicine, Duke University Medical Center, Durham, NC, USA.
authors.forename: Galen S
authors.initials: GS
authors.lastname: Wagner
authors.affiliation: Department of Cardiology, The Heart Center, Copenhagen University Hospital, Copenhagen, Denmark.
authors.forename: Thomas
authors.initials: T
authors.lastname: Engstrøm
mesh_terms: D004562:Electrocardiography / Q000379:methods*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000150:complications / Q000473:pathology / Q000503:physiopathology* / Q000628:therapy; D062645:Percutaneous Coronary Intervention; D012189:Retrospective Studies; D013997:Time Factors; D018487:Ventricular Dysfunction, Left / Q000209:etiology / Q000503:physiopathology*
keywords: Cardiac Magnetic Resonance; Electrocardiography; Infarct size; Infarct size estimated left ventricular ejection fraction; Left ventricular ejection fraction; MI–LVEF mismatch index; Selvester QRS score