This study is open to adults aged 18 years and older. People without liver problems and people who have mild or moderate liver problems can join the study.

The purpose of this study is to find out how a medicine called BI 1015550 is taken up in the blood of people with and without liver problems. Liver problems may change how a medicine is processed in the body.

Participants are in the study for about 2 weeks. During this time, they visit the study site 6 times. On the second visit, participants stay overnight at the study site for 4 nights. At the visits, doctors take blood samples to measure the levels of BI 1015550 in participants' blood. Then they compare the results between the groups of participants with and without liver problems. The doctors also check participants' health and take note of any unwanted effects.

Inclusion criteria applicable to all participants

• Male or female participants
• Age 18-79 years (inclusive)
• Body Mass Index (BMI) of 18.5 to 35 kilogram per square meter (kg/m2) (inclusive)
• Signed and dated written informed consent in accordance with Guideline for Guideline for Good Clinical Practice - Good Clinical Practice (ICH-GCP) and local legislation prior to admission to the trial
• Male participants are not required to use contraception
• Women of childbearing potential are allowed to participate provided they use a highly effective contraception from at least 30 days before the administration of trial medication until 7 days after trial completion. Of note, oral hormonal contraceptives are not considered as highly effective in this study due to the potential CYP3A induction by BI 1015550. Methods of contraception considered adequate for female participants of childbearing potential are listed in the protocol.

Inclusion criteria applying only to participants with impaired hepatic function

• Hepatic impairment classified as Child-Pugh A (score 5-6 points) or Child-Pugh B (score 7-9 points)
• further inclusion criteria apply

Inclusion criteria applying only to participants with normal hepatic function

• Individually matched to participants with hepatic impairment according to sex, age, and weight
• further inclusion criteria apply

Exclusion criteria applying to all participants

• Any evidence of a concomitant disease assessed as clinically relevant by the investigator
• Cholecystectomy or other surgery of the gastrointestinal tract that could interfere with the pharmacokinetic(s) (PK) of the trial medication (except appendectomy or simple hernia repair)
• Diseases of the central nervous system (CNS) (including but not limited to any kind of seizures or stroke), and other relevant neurological or psychiatric disorders (including but not limited to major depressive disorder)
• History of relevant orthostatic hypotension, fainting spells, or blackouts
• Relevant chronic or acute infections
• Any documented active or suspected malignancy or history of malignancy within 5 years prior to screening, except appropriately treated basal cell carcinoma of the skin or squamous cell carcinoma in situ of the skin or in situ carcinoma of uterine cervix
• further exclusion criteria apply

Exclusion criteria applying only to participants with hepatic impairment

• A marked prolongation of time from the start of the Q wave to the end of the T wave (QT)/ QT corrected for heart rate (QTc) interval (such as QT Corrected by the Fridericia Formula (QTcF) intervals that are repeatedly greater than 480 milliseconds (ms) in males or repeatedly greater than 500 ms in females) or any other relevant Electrocardiogram (ECG) finding at screening
• further exclusion criteria apply

Exclusion criteria applying only to participants with normal hepatic function

• Any finding in the medical examination (including blood pressure (BP), pulse rate (PR) or ECG) deviating from normal and assessed as clinically relevant by the investigator
• further exclusion criteria apply

Clinical studies sponsored by Boehringer Ingelheim, phases I to IV, interventional and non interventional, are in scope for sharing of the raw clinical study data and clinical study documents. Exceptions might apply, e.g. studies in products where Boehringer Ingelheim is not the license holder; studies regarding pharmaceutical formulations and associated analytical methods, and studies pertinent to pharmacokinetics using human biomaterials; studies conducted in a single center or targeting rare diseases (in case of low number of patients and therefore limitations with anonymization). For more details refer to: https://www.mystudywindow.com/msw/datatransparency

Treated set (TS) included all participants who were treated with 1 dose of trial drug.

From the administration of BI 1015550, until the end of the on-treatment period, up to 7 days. All-cause mortality was recorded from the administration of BI 1015550 until the end of trial, up to 2 weeks.

Treated set (TS) included all participants who were treated with 1 dose of trial drug.

Adverse events are reported by impairment group according to the Statistical Analysis Plan. The sum of matched controls to the renal impairment groups (16) does not match the number of total participants with normal hepatic function (12), because 4 controls were matched to 1 participant with mild hepatic impairment and to 1 participant with moderate hepatic impairment.