Hypokalemia and outcomes in patients with chronic heart failure and chronic kidney disease: findings from propensity-matched studies.

Pubmed ID: 20103777

Pubmed Central ID: PMC2909749

Journal: Circulation. Heart failure

Publication Date: March 1, 2010

Affiliation: Section of Geriatrics, VA Medical Center, Birmingham, Ala, USA.

MeSH Terms: Humans, Male, Female, Aged, United States, Proportional Hazards Models, Chronic Disease, Heart Failure, Hospitalization, Cause of Death, Chi-Square Distribution, Statistics, Nonparametric, Kidney Failure, Chronic, Hypokalemia, Glomerular Filtration Rate, Canada

Grants: R01 HL085561, R01-HL085561, K23 DK064649, R01 HL085561-04, R01 HL097047, R01 HL097047-01, R01-HL097047, K23 DK064649-05, P30 DK079337, R01 DK046199, P30DK079337

Authors: Ahmed MI, Love TE, Aronow WS, Ahmed A, Mujib M, Campbell RC, Aban IB, Pitt B, Allman RM, Sanders PW, Bakris GL, Bowling CB

Cite As: Bowling CB, Pitt B, Ahmed MI, Aban IB, Sanders PW, Mujib M, Campbell RC, Love TE, Aronow WS, Allman RM, Bakris GL, Ahmed A. Hypokalemia and outcomes in patients with chronic heart failure and chronic kidney disease: findings from propensity-matched studies. Circ Heart Fail 2010 Mar;3(2):253-60. Epub 2010 Jan 26.

Studies:

Abstract

BACKGROUND: Little is known about the effects of hypokalemia on outcomes in patients with chronic heart failure (HF) and chronic kidney disease. METHODS AND RESULTS: Of the 7788 patients with chronic HF in the Digitalis Investigation Group trial, 2793 had chronic kidney disease, defined as estimated glomerular filtration rate <60 mL/min per 1.73 m(2). Of these, 527 had hypokalemia (serum potassium <4 mEq/L; mild) and 2266 had normokalemia (4 to 4.9 mEq/L). Propensity scores for hypokalemia were used to assemble a balanced cohort of 522 pairs of patients with hypokalemia and normokalemia. All-cause mortality occurred in 48% and 36% of patients with hypokalemia and normokalemia, respectively, during 57 months of follow-up (matched hazard ratio when hypokalemia was compared with normokalemia, 1.56; 95% CI, 1.25 to 1.95; P<0.0001). Matched hazard ratios (95% CIs) for cardiovascular and HF mortalities and all-cause, cardiovascular, and HF hospitalizations were 1.65 (1.29 to 2.11; P<0.0001), 1.82 (1.28 to 2.57; P<0.0001), 1.16 (1.00 to 1.35; P=0.036), 1.27 (1.08 to 1.50; P=0.004), and 1.29 (1.05 to 1.58; P=0.014), respectively. Among 453 pairs of balanced patients with HF and chronic kidney disease, all-cause mortality occurred in 47% and 38% of patients with mild hypokalemia (3.5 to 3.9 mEq/L) and normokalemia, respectively (matched hazard ratio, 1.31; 95% CI, 1.03 to 1.66; P=0.027). Among 169 pairs of balanced patients with estimated glomerular filtration rate <45 mL/min per 1.73 m(2), all-cause mortality occurred in 57% and 47% of patients with hypokalemia (<4 mEq/L; mild) and normokalemia, respectively (matched hazard ratio, 1.53; 95% CI, 1.07 to 2.19; P=0.020). CONCLUSIONS: In patients with HF and chronic kidney disease, hypokalemia (serum potassium <4 mEq/L) is common and associated with increased mortality and hospitalization.