title: Pre-hospital evaluation of electrocardiographic grade 3 ischemia predicts infarct progression and final infarct size in ST elevation myocardial infarction patients treated with primary percutaneous coronary intervention.
abstract: BACKGROUND
  In STEMI, grade-3 ischemia (G3) on admission ECG predicts larger infarct size (IS) than grade-2 (G2). We evaluated whether pre-hospital G3 and its temporal behavior are associated with IS and salvage after pPCI.
  
  
  METHODS
  In 401 STEMI patients, pre-hospital and pre-PCI ECGs were classified as G3 or G2. IS was assessed by single-photon emission computed tomography (SPECT) at 30days. In 245 patients, pre-PCI SPECT was available to determine myocardium at risk (MaR).
  
  
  RESULTS
  G3 criteria were met by 88, and G2 by 313 patients. G3 was independently associated with IS (p=0.006). With ST resolution (STR) group as a reference, G2->G2, G2->G3 and G3->G3 were associated with larger IS (B=4.4, p=0.004; B=5.4, p=0.01; B=10.2, p<0.001, respectively), whereas G3->G2 was not. Salvage was similar between G3 and G2 on pre-hospital ECG if treated early, however lower for G3 when treated later (>2.5h); 48% (35-78) vs 62% (40-87); p=0.04.
  
  
  CONCLUSIONS
  Development or persistence of G3 is associated with larger IS and less salvage, but decreasing grade G3->G2 was not.
authors.affiliation: Department of Cardiology, Clinical Sciences, Lund University, Lund, Sweden; Center for Integrative Electrocardiology at Lund University (CIEL), Lund, Sweden; Thoracic Center, Blekingesjukhuset, Karlskrona, Sweden. Electronic address: michaelringborn@yahoo.com.
authors.forename: Michael
authors.initials: M
authors.lastname: Ringborn
authors.affiliation: Department of Medicine, Section of Cardiology, Baylor College of Medicine, Houston, TX, USA.
authors.forename: Yochai
authors.initials: Y
authors.lastname: Birnbaum
authors.affiliation: Department of Nuclear Medicine, Hospital of South-Western Jutland, Esbjerg, Denmark.
authors.forename: Søren Steen
authors.initials: SS
authors.lastname: Nielsen
authors.affiliation: Department of Cardiology, Aarhus University Hospital in Skejby, Denmark.
authors.forename: Anne Kjer
authors.initials: AK
authors.lastname: Kaltoft
authors.affiliation: Department of Cardiology, Aarhus University Hospital in Skejby, Denmark.
authors.forename: Hans Erik
authors.initials: HE
authors.lastname: Bøtker
authors.affiliation: Center for Integrative Electrocardiology at Lund University (CIEL), Lund, Sweden; Department of Clinical Physiology, Lund University, Lund, Sweden.
authors.forename: Olle
authors.initials: O
authors.lastname: Pahlm
authors.affiliation: Duke University Medical Center, Durham, NC, USA.
authors.forename: Galen S
authors.initials: GS
authors.lastname: Wagner
authors.affiliation: Department of Cardiology, Clinical Sciences, Lund University, Lund, Sweden; Center for Integrative Electrocardiology at Lund University (CIEL), Lund, Sweden.
authors.forename: Pyotr G
authors.initials: PG
authors.lastname: Platonov
authors.affiliation: Department of Cardiology, Aarhus University Hospital in Skejby, Denmark.
authors.forename: Christian Juhl
authors.initials: CJ
authors.lastname: Terkelsen
mesh_terms: D000368:Aged; D003324:Coronary Artery Disease / Q000150:complications / Q000175:diagnosis* / Q000601:surgery*; D004562:Electrocardiography / Q000379:methods*; D004632:Emergency Medical Services / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000175:diagnosis* / Q000209:etiology / Q000601:surgery*; D062645:Percutaneous Coronary Intervention; D011320:Primary Health Care; D011379:Prognosis; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D016896:Treatment Outcome
keywords: Electrocardiography; Ischemia grading; ST elevation myocardial infarction; Single-photon emission computed tomography; Terminal QRS distortion