Hypokalemia and Outcomes in Patients With Chronic Heart Failure and Chronic Kidney Disease

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 2 . Of these, 527 had hypokalemia (serum potassium P P P 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 2 , all-cause mortality occurred in 57% and 47% of patients with hypokalemia (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.