This is an observational study in which only data are collected from participants receiving their usual treatment. The study is done in people with chronic heart failure with reduced ejection fraction (HFrEF). HFrEF is a long-term condition in which the heart does not pump blood as well as it should. Blood and fluid may collect in the lungs, blood vessels, and tissues causing shortness of breath or tiredness. Over time, heart failure can lead to other serious medical conditions that may result in hospital stays and death.

The study treatment vericiguat works by increasing the activity of an enzyme called soluble guanylate cyclase (sGC). sGC helps to regulate the heart and blood circulation. Vericiguat has already been studied in previous clinical studies and is available for doctors to prescribe to people with heart failure. This study will collect important data from real-world setting in Korea. The participants of this study are people with HFrEF who will receive vericiguat as prescribed by their doctors according to the approved product information

The main purpose of this study is to learn more about how safe vericiguat is in the participants. To do this, researchers will collect data on all medical problems (also called adverse events) that the participants have during the study. Doctors keep track of all adverse events, even if they do not think they might be related to the study treatment.

Further, researchers will collect data on how well vericiguat works and treatment patterns in the participants. For this, the following information will be collected:

• occurrence of death due to heart and circulatory events
• hospital stays due to heart conditions (failure)
• dose levels of vericiguat and duration of treatment

The data for this study will come from medical records and visits that take place in routine practice. Participants will be treated with vericiguat and observed up to 12 months or until death or they leave the study, whatever comes first.

Inclusion Criteria:

• Adult aged 19 years or older
• Chronic HF (NYHA functional class II, III, or IV) Reduced left ventricular ejection fraction (< 45%) within 12 months before enrollment
• Worsening of heart failure (hospitalized within 6 months before enrollment or intravenous diuretic therapy without hospitalization within 3 months)
• Participants who have been prescribed Verquvo (Vericiguat) as per locally approved label and didn't receive Verquvo (Vericiguat) therapy previously.
• Written informed consent from subject or legal representative; assent from subject when appropriate

Exclusion Criteria:

• Contraindication according to the local authorized label (including known hypersensitivity to the drug substance or any of its components, pregnancy)
• Participants participating in an investigational program with interventions outside of routine clinical practice

Female and male participants with a diagnosis of heart failure with reduced ejection fraction (HFrEF) will be enrolled after the decision for treatment with Verquvo (Vericiguat) has been made by the investigator´s discretion.

Availability of this study's data will later be determined according to Bayer's commitment to the EFPIA/PhRMA "Principles for responsible clinical trial data sharing". This pertains to scope, timepoint and process of data access. As such, Bayer commits to sharing upon request from qualified researchers patient-level clinical trial data, study-level clinical trial data, and protocols from clinical trials in patients for medicines and indications approved in the US and EU as necessary for conducting legitimate research. This applies to data on new medicines and indications that have been approved by the EU and US regulatory agencies on or after January 01, 2014.

Interested researchers can use www.vivli.org to request access to anonymized patient-level data and supporting documents from clinical studies to conduct research. Information on the Bayer criteria for listing studies and other relevant information is provided in the member section of the portal.