Can lowering potassium alone improve the use of guideline-directed therapy in heart failure (HF)? Findings from the CARE-HK in HF (Cardiovascular and Renal Treatment in HF Patients with HK or at High Risk of HK) registry, published in the Journal of Cardiac Failure, address this gap in routine care. 

This prospective registry (NCT04864795) included patients with chronic HF at increased risk of hyperkalemia (HK), defined by prior or current HK or an estimated glomerular filtration rate (eGFR) <45 mL/min/1.73 m². Serum potassium (sK+), HK episodes, and renin-angiotensin system inhibitor (RASi) optimization were assessed using both prospective and retrospective data.

Among 2,558 patients, patiromer was prescribed in 234 (9.1%) for a median of 12.0 months (interquartile range 6.0-19.4 months). Propensity score matching yielded 211 patiromer-treated patients and 361 matched patients not receiving potassium binders. The cohort reflected a high-risk population, with a median age of 73 years (interquartile range 64–79 years), 79.4% men, 50.2% with diabetes, and 44.9% with eGFR <45 mL/min/1.73 m².

At treatment initiation, median sK+ was 5.5 mEq/L (interquartile range 5.4–5.7 mEq/L). Patiromer use was associated with a reduction in sK+ of 0.21 mEq/L (95% CI –0.30 to –0.12; P < .0001). However, optimization of RASi or mineralocorticoid receptor antagonists (MRA), defined as achieving ≥50% target doses, remained ≤40% over 2 years and did not increase with patiromer.

Patiromer improved potassium levels in routine clinical practice, but RASi and MRA dose optimization remained limited in patients with HF at risk of HK.