title: Oral potassium supplement use and outcomes in chronic heart failure: a propensity-matched study.
abstract: BACKGROUND
  Hypokalemia is common in heart failure (HF) and is associated with increased mortality. Potassium supplements are commonly used to treat hypokalemia and maintain normokalemia. However, their long-term effects on outcomes in chronic HF are unknown. We used a public-use copy of the Digitalis Investigation Group (DIG) trial dataset to determine the associations of potassium supplement use with outcomes using a propensity-matched design.
  
  
  METHODS
  Of the 7788 DIG participants with chronic HF, 2199 were using oral potassium supplements at baseline. We estimated propensity scores for potassium supplement use for each patient and used them to match 2131 pairs of patients receiving and not receiving potassium supplements. Matched Cox regression models were used to estimate associations of potassium supplement use with mortality and hospitalization during 40 months of median follow-up.
  
  
  RESULTS
  All-cause mortality occurred in 818 (rate, 1327/10,000 person-years) and 802 (rate, 1313/10,000 person-years) patients respectively receiving and not receiving potassium supplements (hazard ratio {HR} when potassium supplement use was compared with nonuse, 1.05; 95% confidence interval {CI}, 0.94-1.18; P=0.390). All-cause hospitalizations occurred in 1516 (rate, 4777/10,000 person-years) and 1445 (rate, 4120/10,000 person-years) patients respectively receiving and not receiving potassium supplements (HR, 1.15; 95% CI, 1.05-1.26; P=0.004). HRs (95% CI) for hospitalizations due to cardiovascular causes and worsening HF were respectively 1.19 (95% CI, 1.08-1.32; P=0.001) and 1.27 (1.12-1.43; P<0.0001).
  
  
  CONCLUSIONS
  The use of potassium supplements in chronic HF was not associated with mortality. However, their use was associated with increased hospitalization due to cardiovascular causes and progressive HF.
authors.affiliation: University of Alabama at Birmingham, Birmingham, AL 35294-2041, USA.
authors.forename: O James
authors.initials: OJ
authors.lastname: Ekundayo
authors.forename: Chris
authors.initials: C
authors.lastname: Adamopoulos
authors.forename: Mustafa I
authors.initials: MI
authors.lastname: Ahmed
authors.forename: Bertram
authors.initials: B
authors.lastname: Pitt
authors.forename: James B
authors.initials: JB
authors.lastname: Young
authors.forename: Jerome L
authors.initials: JL
authors.lastname: Fleg
authors.forename: Thomas E
authors.initials: TE
authors.lastname: Love
authors.forename: Xuemei
authors.initials: X
authors.lastname: Sui
authors.forename: Gilbert J
authors.initials: GJ
authors.lastname: Perry
authors.forename: David S
authors.initials: DS
authors.lastname: Siscovick
authors.forename: George
authors.initials: G
authors.lastname: Bakris
authors.forename: Ali
authors.initials: A
authors.lastname: Ahmed
mesh_terms: D000284:Administration, Oral; D019587:Dietary Supplements; D018450:Disease Progression; D005260:Female; D005500:Follow-Up Studies; D006333:Heart Failure / Q000401:mortality*; D006760:Hospitalization / Q000706:statistics & numerical data; D006801:Humans; D007008:Hypokalemia / Q000401:mortality / Q000628:therapy*; D008297:Male; D016555:Matched-Pair Analysis; D008875:Middle Aged; D011188:Potassium / Q000627:therapeutic use*; D057216:Propensity Score
chemical_list: D011188:Potassium