Hyperkalemia in acute heart failure: Short term outcomes from the EAHFE registry

Both hyperkalemia (HK) and Acute Heart Failure (AHF) are associated with increased short-term mortality, and the management of either may exacerbate the other. As the relationship between HK and AHF is poorly described, our purpose was to determine the relationship between HK and short-term outcomes in Emergency Department (ED) AHF.

The EAHFE Registry enrolls all ED AHF patients from 45 Spanish ED and records in-hospital and post-discharge outcomes. Our primary outcome was all-cause in-hospital death, with secondary outcomes of prolonged hospitalization (>7 days) and 7-day post-discharge adverse events (ED revisit, hospitalization, or death). Associations between serum potassium (sK) and outcomes were explored using logistic regression by restricted cubic spline (RCS) curves, with sK =4.0 mEq/L as the reference, adjusting by age, sex, comorbidities, patient baseline status and chronic treatments. Interaction analyses were performed for the primary outcome.

Of 13,606 ED AHF patients, the median (IQR) age was 83 (76-88) years, 54% were women, and the median (IQR) sK was 4.5 mEq/L (4.3-4.9) with a range of 4.0-9.9 mEq/L. In-hospital mortality was 7.7%, with prolonged hospitalization in 35.9%, and a 7-day post-discharge adverse event rate of 8.7%. Adjusted in-hospital mortality increased steadily from sK ≥4.8 (OR = 1.35, 95% CI = 1.01-1.80) to sK = 9.9 (8.41, 3.60-19.6). Non-diabetics with elevated sK had higher odds of death, while chronic treatment with mineralocorticoid-receptor antagonists exhibited a mixed effect. Neither prolonged hospitalization nor post-discharge adverse events was associated with sK.

In ED AHF, initial sK >4.8 mEq/L was independently associated with in-hospital mortality, suggesting that this cohort may benefit from aggressive HK treatment.