Serum Potassium Levels and Short-Term Outcomes in Patients With ST-Segment Elevation Myocardial Infarction

Angiology. 2016 Sep;67(8):729-36. doi: 10.1177/0003319715617074. Epub 2015 Dec 1.

Abstract

Current guidelines recommend maintaining serum potassium levels between 4.0 and 5.0 mEq/L (1 mEq/L = mmol/L) in patients with acute myocardial infarction. However, these guidelines are based on studies conducted before the β blocker and reperfusion era. We retrospectively analyzed 6613 patients diagnosed with ST-segment elevation myocardial infarction (STEMI) who presented without renal insufficiency. Patients were categorized into 5 groups according to mean serum potassium levels: <3.5, 3.5 to <4.0, 4.0 to <4.5, 4.5 to <5.0, and ≥5.0 mEq/L. Patients with potassium levels of 4.0 to <4.5 mEq/L had the lowest predefined event rates, which were 6.4% for 7-day malignant arrhythmia, 3.7% for 7-day mortality, and 5.3% for 30-day mortality. Compared with the reference group (4.0 to <4.5 mEq/L), multivariate regression analysis revealed significantly higher 30-day mortality risk in patients with potassium level of 4.5 to <5.0 (hazard ratio [HR]: 1.52, 95% confidence interval [CI]: 1.17-1.98; P = .002) and even higher risk in patients with potassium level of ≥5.0 mEq/L (HR: 1.80, 95% CI: 1.22-2.66; P = .002). The lowest 30-day mortality was observed in patients with STEMI having potassium levels between 4.0 and 4.5 mEq/L, and a level >4.5 mEq/L significantly increased mortality risk.

Keywords: acute myocardial infarction; malignant arrhythmia; mortality; serum potassium.

Publication types

  • Observational Study

MeSH terms

  • Aged
  • Arrhythmias, Cardiac / blood*
  • Arrhythmias, Cardiac / diagnosis
  • Arrhythmias, Cardiac / mortality
  • Arrhythmias, Cardiac / therapy
  • Biomarkers / blood
  • Chi-Square Distribution
  • China / epidemiology
  • Female
  • Humans
  • Hyperkalemia / blood*
  • Hyperkalemia / diagnosis
  • Hyperkalemia / mortality
  • Hyperkalemia / therapy
  • Hypokalemia / blood*
  • Hypokalemia / diagnosis
  • Hypokalemia / mortality
  • Hypokalemia / therapy
  • Incidence
  • Kaplan-Meier Estimate
  • Male
  • Middle Aged
  • Multivariate Analysis
  • Potassium / blood*
  • Prognosis
  • Proportional Hazards Models
  • Retrospective Studies
  • Risk Assessment
  • Risk Factors
  • ST Elevation Myocardial Infarction / blood*
  • ST Elevation Myocardial Infarction / diagnosis
  • ST Elevation Myocardial Infarction / mortality
  • ST Elevation Myocardial Infarction / therapy
  • Time Factors

Substances

  • Biomarkers
  • Potassium