title: Serum potassium levels on admission and infarct size in patients with acute myocardial infarction.
abstract: BACKGROUND
  Little data exist on the relationship between potassium level and infarct size after ST-segment elevation acute myocardial infarction (STEMI). We investigated the influence of potassium levels on infarct size measured with single photon emission computed tomography (SPECT) in patients with STEMI after mechanical reperfusion.
  
  
  METHODS
  The study included 598 patients. Potassium measurements at baseline and 2 SPECT examinations, at baseline and 7-14 days after intervention, were performed. Infarct size in the 7-14 days SPECT and salvage index were the primary outcome analyses.
  
  
  RESULTS
  Tertiles of baseline potassium were: <4.05 mEq/L (1st tertile), 4.05-4.37 mEq/L (2nd tertile) and >4.37 mEq/L (3rd tertile). In potassium 1st, 2nd and 3rd tertiles, the infarct size in the 7-14 days SPECT (median [25th-75th percentiles]) was 9.0% [2.0%-21.8%], 10.0% [3.5%-22.0%] and 12.0% [5.0%-25.5%] of left ventricle (p=0.026); salvage index was 0.50 [0.26-0.84], 0.56 [0.26-0.81] and 0.40 [0.23-0.75] (p=0.09). Patients with anterior infarction in upper potassium tertile had greater infarct size compared with patients in lower potassium tertile (p=0.049). After adjustment in multivariable analysis, potassium was an independent correlate of infarct size in the 7-14 days SPECT (p=0.05).
  
  
  CONCLUSIONS
  In patients with STEMI, higher baseline potassium levels are associated with a larger scintigraphic infarct size.
authors.affiliation: Department of Nephrology, Klinikum rechts der Isar, Technische Universität München, Munich, Germany. marcel.roos@lrz.tum.de
authors.forename: Marcel
authors.initials: M
authors.lastname: Roos
authors.forename: Gjin
authors.initials: G
authors.lastname: Ndrepepa
authors.forename: Marcus
authors.initials: M
authors.lastname: Baumann
authors.forename: Cheng Rui
authors.initials: CR
authors.lastname: Pan
authors.forename: Uwe
authors.initials: U
authors.lastname: Heemann
authors.forename: Jens
authors.initials: J
authors.lastname: Lutz
authors.forename: Dritan
authors.initials: D
authors.lastname: Keta
authors.forename: Stefanie
authors.initials: S
authors.lastname: Schulz
authors.forename: Robert A
authors.initials: RA
authors.lastname: Byrne
authors.forename: Julinda
authors.initials: J
authors.lastname: Mehilli
authors.forename: Albert
authors.initials: A
authors.lastname: Schömig
authors.forename: Adnan
authors.initials: A
authors.lastname: Kastrati
mesh_terms: D005260:Female; D006801:Humans; D008875:Middle Aged; D015999:Multivariate Analysis; D009203:Myocardial Infarction / Q000097:blood* / Q000000981:diagnostic imaging / Q000473:pathology* / Q000628:therapy; D010343:Patient Admission; D011188:Potassium / Q000097:blood*; D012189:Retrospective Studies; D015899:Tomography, Emission-Computed, Single-Photon
chemical_list: D011188:Potassium