The CARE-HK in HF is a registry study based on the hypothesis that adherence to guidelines is associated with improved real-world outcomes for heart failure (HF) patients. For the purpose of this study, adherence to guidelines is defined as adherence to RAASi treatment recommendations, according to the AHA/ACC and ESC guidelines. Objectives relating to patiromer effectiveness will only be evaluated if a sufficient number of patients are available.

The study aims to evaluate in patients at high risk of hyperkalaemia; patients treated with ACEi/ARB/ARNi, and either treated with or candidates for treatment with MRA.

The study will have an enrolment period of approximately 24 months, and each patient will be followed prospectively for at least 6 months. Each patient is expected to contribute to the study data collection until study end or until premature discontinuation, whichever occurs first (i.e., due to death, withdrawal of consent, or lost to follow-up).

At enrolment (informed consent signed by patient), relevant patient data will be retrospectively extracted from medical records for the 24 months prior to enrolment or since the time of HF diagnosis.

There are no visits or procedures associated with the study, patients will follow routine clinical care, which may include in-person and/or virtual visits. The study protocol does not recommend the use of any specific treatments and no study medication is provided as part of participation. The nature and heterogeneity of HF means patients will be treated with different treatments over the course of the study, and at the discretion of their treating physician.

Patient data will be collected from patient records and/or during a routine clinical visit and will be entered into the electronic Case Report Form (eCRF) via an electronic data capture (EDC) system. This will include treatments prescribed, routine assessments and measurements (e.g., laboratory parameters) collected at routine clinical visits, as well as hospitalisations and other relevant patient data. Protocol version 3.0, 19-Jul-2023

Inclusion Criteria:

1. Adult aged ≥18 years at enrolment.

2. Patient diagnosed with chronic HF ≥3 months prior to signature of informed consent.

3. Patient has at least 1 record of LVEF documented in patient medical record in the 24 months prior to signature of informed consent. NOTE: If the proportion of patients with HFpEF exceeds 20% of the target sample size, enrolment of patients with an LVEF ≥50% may be capped.

4. Patient treated with ACEi/ARB/ARNi at enrolment.

5. Patient treated with or a candidate for treatment with MRA per a relevant treatment guideline (e.g., HF, CKD, resistant hypertension) at enrolment.

6. Patient at increased risk of hyperkalaemia due to one or more of the following:

   1. Current hyperkalaemia (sK+ >5.0 mEq/l) at enrolment
   2. Record of documented hyperkalaemia (sK+ >5.0 mEq/l) in the 24 months prior to signature of informed consent
   3. eGFR <45 ml/min/1.73 m2, or CKD Stage ≥3b.

7. Patient judged by the Investigator to have sufficient cognitive ability to participate.

8. Signed informed consent provided

Exclusion Criteria:

1. Patient on renal replacement therapy or mechanical circulatory support.
2. Disease other than HF with expected survival <1 year.
3. Patient is participating in, or being screened for, an interventional trial, with the exception of interventional trials relating to SARS-CoV-2.
4. Patient already found to be intolerant to MRA for reasons other than hyperkalaemia or renal impairment.

To the extent possible, representative sites (e.g., cardiologists and nephrologists) reflective of the treatment patterns within each country will be recruited. All patients treated for chronic HF during the enrolment period will be assessed for eligibility, and all eligible patients will be consecutively proposed to enrol in the study as they present for a routine clinical visit (in-person or virtual visits) in order to avoid potential selection bias.

Anonymized individual patient level data will be provided in a secure access environment upon approval of a research proposal and a signed data sharing agreement.

Data can be requested 6 months after the primary publication for the entire prospective observation period.

Data will be available 5 years for requesting.

A research proposal must be approved by an independent review panel and the study sponsor and researchers must sign a data sharing agreement.