Hyperkalemia and Treatment With RAAS Inhibitors During Acute Heart Failure Hospitalizations and Their Association With Mortality

Objectives: This study investigated associations between incident hyperkalemia during acute heart failure (HF) hospitalizations and changes in renin-angiotensin-aldosterone system (RAAS) inhibitors.

Background: Hyperkalemia is a potential complication of RAAS inhibitors. For patients with HF, fear of hyperkalemia may lead to failure to deliver guideline-recommended doses of RAAS inhibitors.

Methods: Serum potassium concentrations were measured daily from baseline (<24 h after admission) until discharge or day 7 in 1,589 patients enrolled in the PROTECT (Placebo-Controlled Randomized Study of the Selective A1 Adenosine Receptor Antagonist Rolofylline for Patients Hospitalized with Acute Decompensated Heart Failure and Volume Overload to Assess Treatment Effect on Congestion and Renal Function) trial. Incident hyperkalemia was defined as at least 1 episode of potassium >5.0 mEq/l. The primary outcome was all-cause mortality at 180 days.

Results: Overall, serum potassium concentrations increased from 4.3 ± 0.6 mEq/l at baseline to 4.5 ± 0.6 mEq/l at discharge or day 7 (p < 0.001). Patients developing incident hyperkalemia (n = 564; 35%) were more often taking mineralocorticoid antagonists (MRAs) therapy prior to hospitalization and were more likely to have them down-titrated during hospitalization, independent of confounders. Incident hyperkalemia was not associated with adverse outcomes. Yet, down-titration of MRAs during hospitalization was independently associated with 180-day mortality (hazard ratio [HR]: 1.73; 95% confidence interval [CI]: 1.15 to 2.60), regardless of incident hyperkalemia (p_interaction >0.10). Patients with incident hyperkalemia who were discharged with the same or increased dose of MRAs (HR: 0.52; 95% CI: 0.32 to 0.85) or angiotensin-converting enzyme (ACE) inhibitors/angiotensin receptor blockers (ARBs) (HR: 0.47; 95% CI: 0.29 to 0.77) had a lower 180-day mortality.

Conclusions: Incident hyperkalemia is common in patients hospitalized for acute HF and is not associated with adverse outcomes. Incident hyperkalemia is associated with down-titration of MRAs, but patients who maintained or increased their dose of MRAs and/or ACE inhibitors/ARB during acute HF hospitalization had better 180-day survival.