Cardiovascular and Renal Treatment in Heart Failure Patients With Hyperkalemia or High Risk of Hyperkalemia: Rationale and Design of the CARE-HK in HF Registry

Background: Despite guideline recommendations, many patients with heart failure (HF) do not receive target dosages of renin-angiotensin-aldosterone system inhibitors (RAASis) in clinical practice due, in part, to concerns about hyperkalemia (HK). Methods and Results: This noninterventional, multinational, multicenter registry (NCT04864795; 111 sites in Europe and the USA) enrolled 2558 eligible adults with chronic HF (mostly with reduced ejection fraction [HFrEF]). Eligibility criteria included use of angiotensin-converting-enzyme inhibitor/angiotensin-II receptor blocker/angiotensin-receptor-neprilysin inhibitor, being a candidate for or treatment with a mineralocorticoid receptor antagonist, and increased risk of HK (eg, current serum potassium > 5.0 mmol/L), history of HK in the previous 24 months, or estimated glomerular filtration rate < 45 mL/min/1.73 m²). Information on RAASi and other guideline-recommended therapies was collected retrospectively and prospectively (≥ 6 months). Patients were followed according to local clinical practice, without study-specific visits or interventions. The main objectives were to characterize RAASi treatment patterns compared with guideline recommendations, describe RAASi modifications following episodes of HK, and describe RAASi treatment in patients treated with patiromer. Baseline characteristics for the first 1000 patients are presented. Conclusions: CARE-HK is a multinational prospective HF registry designed to report on the management and outcomes of patients with HF at high risk for HK in routine clinical practice.