Assessment of Hyperkalemia's Illness and Treatment Burden in Chronic Kidney Disease and Heart Failure Patients: HK Registry Pilot Study

Inclusion Criteria

• •Outpatients aged ≥20 years
• •Hyperkalemia patients defined as meeting either of the following criteria:
• •1. Having a history of S-K ≥5.1 mmol/L ≥2 times within 6 months before enrolment
• •2. Having a history of S-K ≥5.5 mmol/L once within 6 months before enrolment
• •3. Currently treated by potassium binders for the treatment of hyperkalemia at enrolment
• •Having been diagnosed as CKD (≥stage 3b) or HFrEF by investigators as defined below:
• •CKD is diagnosed based on the guidelines of CKD issued by the Japanese Society of Nephrology (JSN, 2018) as being either or both of condition 1 and 2 for ≥3 months
• •1. Clear sign of kidney impairment based on urinalysis, imaging, blood test, or biopsy. Especially, existence of ≥0.15 g/gCr of proteinuria (≥30 mg/gCr of albuminuria) is important.
• •2. GFR \<45 mL/min/1.73m2 Within the routine clinical practice, GFR is estimated by serum creatinine, gender, and age using following the formulation.
• •eGFR creat (mL/min/1.73m2) = 194 x serum creatinine (mg/dL)-1.094 x age (years)-0.287 (for female patients, x 0.739)
• •≥Stage 3b CKD is diagnosed based on the following eGFR categories:
• •Stage 3b: 30 mL/min/1.73m2 ≤ eGFR \<45 mL/min/1.73m2
• •Stage 4: 15 mL/min/1.73m2 ≤ eGFR \<30 mL/min/1.73m2
• •Stage 5: eGFR \<15 mL/min/1.73m2
• •Patients with HFrEF is enrolled if patients meet following criteria within 6 months:
• •1. EF ≤40%
• •2. NYHA class II-IV
• •* Provision of signed, written, and detailed informed consent
• •* Signed written informed consent by themselves