title: Serum potassium levels inversely correlate with D-dimer in patients with acute-onset atrial fibrillation.
abstract: BACKGROUND
  D-dimer values are frequently increased in patients with atrial fibrillation (AF) compared to subjects in sinus rhythm. Hypokalemia plays a role in several cardiovascular diseases, but little is known about the association with AF.
  
  
  OBJECTIVE
  D-dimer values are frequently increased in patients with atrial fibrillation (AF) compared with subjects in sinus rhythm. Hypokalemia plays a role in several cardiovascular diseases, but little is known about the association with AF. The aim of this study was to investigate correlations between D-dimer and serum potassium in acute-onset AF (AAF).
  
  
  METHODS
  To investigate the potential correlation between the values of serum potassium and D-dimer in patients with AAF, we retrospectively reviewed clinical and laboratory data of all emergency department visits for AAF in 2013.
  
  
  RESULTS
  Among 271 consecutive AAF patients with D-dimer assessments, those with hypokalemia (n = 98) had significantly higher D-dimer values than normokalemic patients (139 versus 114 ng/mL, p = 0.004). The rate of patients with D-dimer values exceeding the diagnostic cut-off was higher in the group of patients with hypokalemia than in those with normal serum potassium (26.5% versus 16.2%; p = 0.029). An inverse and highly significant correlation was found between serum potassium and D-dimer (r = -0.21; p < 0.001), even after adjustments for age and sex (beta coefficient -94.8; p = 0.001). The relative risk for a positive D-dimer value attributed to hypokalemia was 1.64 (95% CI, 1.02 to 2.63; p = 0.040). The correlation remained statistically significant in patients free from antihypertensive drugs (r = -0.25; p = 0.018), but not in those taking angiotensin-receptor blockers, angiotensin-converting enzyme inhibitors, or diuretics.
  
  
  CONCLUSIONS
  The inverse correlation between values of potassium and D-dimer in patients with AAF provides important and complementary information about the thromboembolic risk of these patients.
authors.affiliation: Academic Hospital of Parma, Italy.
authors.forename: Gianfranco
authors.initials: G
authors.lastname: Cervellin
authors.affiliation: Academic Hospital of Parma, Italy.
authors.forename: Laura
authors.initials: L
authors.lastname: Bonfanti
authors.affiliation: Academic Hospital of Parma, Italy.
authors.forename: Alessandra
authors.initials: A
authors.lastname: Picanza
authors.affiliation: Academic Hospital of Parma, Italy.
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Lippi
mesh_terms: D000208:Acute Disease; D000368:Aged; D001281:Atrial Fibrillation / Q000097:blood*; D002318:Cardiovascular Diseases / Q000209:etiology; D005260:Female; D005338:Fibrin Fibrinogen Degradation Products / Q000032:analysis*; D006801:Humans; D007008:Hypokalemia / Q000097:blood*; D008297:Male; D008875:Middle Aged; D011188:Potassium / Q000097:blood*; D012016:Reference Values; D012189:Retrospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D018709:Statistics, Nonparametric; D054556:Venous Thromboembolism / Q000209:etiology
chemical_list: D005338:Fibrin Fibrinogen Degradation Products; C036309:fibrin fragment D; D011188:Potassium