Your participation in this study begins either after completing the previous FIORE study (21466) or as a newly enrolled infant under 6 months of age.

If you are newly enrolled, your heart function will be assessed through an echocardiography (an ultrasound of the heart) to measure your left ventricular ejection fraction (a measurement showing how well the left side of your heart pumps blood).

Blood tests will be performed to measure NT-pro BNP levels (a substance in the blood that indicates heart stress) and serum potassium levels (the amount of potassium in your blood).

Your systolic blood pressure (the pressure in your arteries when your heart beats) will be measured.

Your kidney function will be assessed by measuring estimated glomerular filtration rate (a calculation that shows how well your kidneys are filtering waste from your blood).

If you are a newly enrolled newborn or infant under 6 months of age, your body weight must be at least 3 kilograms.

You must have been receiving standard treatment for heart failure on a stable regimen for 30 days before this baseline visit.

You will receive finerenone in addition to your standard heart failure treatment.

The medication is available in different forms: film-coated tablets or granules for oral suspension (granules that can be mixed with liquid for swallowing).

The medication is taken by mouth (oral use).

The specific dosage, frequency, and exact duration of treatment will be determined based on your individual condition.

You will continue taking finerenone for an extended period as part of this long-term safety study.

Throughout the treatment period, you will attend regular visits for monitoring.

You will have scheduled visits throughout the study to monitor your safety and response to treatment.

At each visit, your healthcare team will check for any adverse events (unwanted or harmful effects that may occur during treatment).

Blood samples will be taken regularly to monitor your serum potassium levels and kidney function.

Your blood pressure will be measured at each visit.

Heart function assessments using echocardiography will be performed to evaluate changes in how your heart pumps blood.

Blood tests will measure NT-proBNP levels to assess heart stress.

At some visits, blood samples will be collected to measure the concentration of finerenone in your blood to understand how your body processes the medication.

If you receive the pediatric formulation (granules for oral suspension), you may be asked to complete a questionnaire about the taste and texture of the medication.

The end of treatment visit will occur on Day 270, with a window of 7 days before or after (Visit 6).

At this visit, comprehensive assessments will be performed including blood tests for potassium levels and kidney function.

Your blood pressure will be measured.

An echocardiography will be performed to evaluate your heart function.

Blood tests will measure NT-proBNP levels.

Any adverse events that occurred during the study will be documented.

Changes in your condition from the beginning of the study to this final visit will be assessed.