title: Short-term mortality risk of serum potassium levels in acute heart failure following myocardial infarction.
abstract: OBJECTIVE
  Diuretic treatment is often needed in acute heart failure following myocardial infarction (MI) and carries a risk of abnormal potassium levels. We examined the relation between different levels of potassium and mortality.
  
  
  RESULTS
  From Danish national registries we identified 2596 patients treated with loop diuretics after their first MI episode where potassium measurement was available within 3 months. All-cause mortality was examined according to seven predefined potassium levels: hypokalaemia <3.5 mmol/L, low normal potassium 3.5-3.8 mmol/L, normal potassium 3.9-4.2 mmol/L, normal potassium 4.3-4.5 mmol/L, high normal potassium 4.6-5.0 mmol/L, mild hyperkalaemia 5.1-5.5 mmol/L, and severe hyperkalaemia: >5.5 mmol/L. Follow-up was 90 days and using normal potassium 3.9-4.2 mmol/L as a reference, we estimated the risk of death with a multivariable-adjusted Cox proportional hazard model. After 90 days, the mortality rates in the seven potassium intervals were 15.7, 13.6, 7.3, 8.1, 10.6, 15.5, and 38.3%, respectively. Multivariable-adjusted risk for death was statistically significant for patients with hypokalaemia [hazard ratio (HR): 1.91, confidence interval (95%CI): 1.14-3.19], and mild and severe hyperkalaemia (HR: 2, CI: 1.25-3.18 and HR: 5.6, CI: 3.38-9.29, respectively). Low and high normal potassium were also associated with increased mortality (HR: 1.84, CI: 1.23-2.76 and HR: 1.55, CI: 1.09-2.22, respectively).
  
  
  CONCLUSIONS
  Potassium levels outside the interval 3.9-4.5 mmol/L were associated with a substantial risk of death in patients requiring diuretic treatment after an MI.
authors.affiliation: Aalborg University Hospital , Aalborg , Denmark.
authors.forename: Maria Lukács
authors.initials: ML
authors.lastname: Krogager
authors.affiliation: Aalborg University Hospital , Aalborg , Denmark.
authors.forename: Lotti
authors.initials: L
authors.lastname: Eggers-Kaas
authors.affiliation: Department of Cardiology , Aalborg University Hospital , Aalborg , Denmark.
authors.forename: Kristian
authors.initials: K
authors.lastname: Aasbjerg
authors.affiliation: Department of Clinical Epidemiology , Aalborg University Hospital , Aalborg , Denmark.
authors.forename: Rikke Nørmark
authors.initials: RN
authors.lastname: Mortensen
authors.affiliation: Department of Cardiology, The Heart Center , Rigshospitalet , Copenhagen , Denmark.
authors.forename: Lars
authors.initials: L
authors.lastname: Køber
authors.affiliation: Department of Cardiology, Copenhagen University Hospital Gentofte, Hellerup, Denmark; National Institute of Public Health, University of Southern Denmark, Copenhagen, Denmark.
authors.forename: Gunnar
authors.initials: G
authors.lastname: Gislason
authors.affiliation: Department of Clinical Epidemiology , Aalborg University Hospital , Aalborg , Denmark.
authors.forename: Christian
authors.initials: C
authors.lastname: Torp-Pedersen
authors.affiliation: Department of Cardiology and Clinical Institute , Aalborg University Hospital , Aalborg , Denmark.
authors.forename: Peter
authors.initials: P
authors.lastname: Søgaard
keywords: Heart failure after myocardial infarction; Mortality; Serum potassium