title: Strain echocardiography and wall motion score index predicts final infarct size in patients with non-ST-segment-elevation myocardial infarction.
abstract: BACKGROUND
  Infarct size is a strong predictor of mortality and major adverse cardiovascular events after myocardial infarction. Acute reperfusion therapy limits infarct size and improves survival, but its use has been confined to patients with ST-segment-elevation myocardial infarction. The purpose of this study was to assess the relationship between echocardiographic parameters of left ventricular (LV) systolic function obtained before revascularization and final infarct size in patients with non-ST-segment-elevation myocardial infarction, as well as the ability of these parameters to identify patients with substantial infarction.
  
  
  RESULTS
  Sixty-one patients with non-ST-segment-elevation myocardial infarction were examined by echocardiography immediately before revascularization, 2.1+/-0.6 days after hospitalization. LV systolic function was assessed by ejection fraction, wall motion score index, and circumferential, longitudinal, and radial strain in a 16-segment LV model. Global strain represents average segmental strain values. Infarct size was assessed after 9+/-3 months by late-enhancement MRI, as a percentage of total LV myocardial volume. A good correlation was found between infarct size and wall motion score index (r=0.74, P<0.001) and global longitudinal strain (r=0.68, P<0.001). Global longitudinal strain >-13.8% and wall motion score index >1.30 accurately identified patients with substantial infarction (> or =12% of myocardium, n=13; area under the receiver operator curve, 0.95 and 0.92, respectively).
  
  
  CONCLUSIONS
  Echocardiographic parameters of LV systolic function correlate to infarct size in patients with non-ST-segment-elevation myocardial infarction. Global longitudinal strain and wall motion score index are both excellent parameters to identify patients with substantial myocardial infarction, who may benefit from urgent reperfusion therapy.
authors.affiliation: Department of Cardiology, Rikshospitalet, Oslo University Hospital, Oslo, Norway.
authors.forename: Christian
authors.initials: C
authors.lastname: Eek
authors.forename: Bjørnar
authors.initials: B
authors.lastname: Grenne
authors.forename: Harald
authors.initials: H
authors.lastname: Brunvand
authors.forename: Svend
authors.initials: S
authors.lastname: Aakhus
authors.forename: Knut
authors.initials: K
authors.lastname: Endresen
authors.forename: Per K
authors.initials: PK
authors.lastname: Hol
authors.forename: Hans-Jørgen
authors.initials: HJ
authors.lastname: Smith
authors.forename: Otto A
authors.initials: OA
authors.lastname: Smiseth
authors.forename: Thor
authors.initials: T
authors.lastname: Edvardsen
authors.forename: Helge
authors.initials: H
authors.lastname: Skulstad
mesh_terms: D016009:Chi-Square Distribution; D017023:Coronary Angiography; D025401:Echocardiography, Stress / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000000981:diagnostic imaging* / Q000188:drug therapy / Q000503:physiopathology*; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012372:ROC Curve; D012044:Regression Analysis; D015203:Reproducibility of Results; D012307:Risk Factors; D013599:Systole