Abstract 3395: Potassium Supplement Use May Increase Hospitalization without Affecting Mortality in Chronic Heart Failure: Implications for Use of Aldosterone Antagonists to Maintain Potassium Balance in Chronic Heart Failure
Background: Hypokalemia is common in heart failure (HF). Aldosterone antagonists can raise serum potassium (K) and also improve survival. Yet, K-supplements are often used to correct hypokalemia; although little is known about the effects of K-supplements in HF.
Methods: Of the 7788 ambulatory chronic HF patients in the Digitalis Investigation Group trial, 2199 (28%) were receiving K-supplements. Propensity scores for K-supplement use was calculated for each patient and were used to match 2131 patients receiving K-supplements with 2131 no-K-supplements patients (absolute standardized differences <10% for all measured covariates). Matched Cox regression models were used to estimate effects of K-supplements on outcomes during 40 months of median follow-up.
Results: Compared with 68% (rate, 4120/10000 person-years) of no-K-supplement patients, 71% (rate, 4777/10000 person-years) of patients receiving K-supplements were hospitalized from all causes (hazard ratio, 1.15; 95% CI, 1.05–1.26; P=0.004). Compared with 38% (rate, 1313/10000 person-years) of no-K-supplement patients, 38% (rate, 1327/10000 person-years) of patients receiving K-supplements died from all causes (hazard ratio, 1.05; 95% CI, 0.94–1.18; P=0.390).
Conclusion: K-supplement use was associated with no mortality reduction but increased hospitalization. This first report on the effect of K-supplement in HF raises question about the wisdom of K-supplement use to correct hypokalemia and maintain normokalemia in HF. Given the proven mortality benefits of aldosterone antagonists and their ability to raise serum K, spironolactone may be preferable to maintain normokalemia in chronic HF.