Collect data on Mexican patients diagnosed with Heart Failure with reduced ejection fraction, their treatments, and their progress in a real-world environment. Additional objectives will be analyzed, such as mortality, the use of resources associated with the follow-up of this group of patients and the barriers, if any, to receiving the indicated treatment.

• Identify the main epidemiological and clinical characteristics of patients with Heart Failure with reduced ejection fraction, as well as the medical treatment models used.
• Determine the prescription rate of a cardiovascular pharmacological treatment and the prescription and implant rate of a cardiac medical device in patients with Heart Failure with reduced ejection fraction.
• Determine the mortality rate and its classification in patients with Heart Failure with reduced ejection fraction.
• Identify the barriers, if any, to prescribing and implanting a cardiac medical device in those patients with a Class I recommendation according to the ACC/AHA/HRS 2017 guidelines.
• Determine the population with a profile of 1.5 primary prevention of sudden cardiac death (patients with Heart Failure in primary prevention who have one or more of the following risk factors: syncope or pre-syncope; left ventricular ejection fraction less than 25%; presence of non-sustained ventricular tachycardia; more than 10 ventricular extrasystoles per hour observed in a 24-hour Holter).
• Collect data on the use of resources associated with the follow-up of patients diagnosed with Heart Failure with reduced ejection fraction during a period of 12 months to perform a secondary economic analysis.

Inclusion Criteria

• Men and women ≥18 years
• Patients with Heart Failure with LVEF ≤ 45% will be included
• Patients must be willing to comply with the study requirements and complete the Informed Consent Form (defined as the legally valid and documented confirmation of a patient's voluntary agreement to participate in the clinical study)

Exclusion Criteria

• Patients without Heart Failure or with Heart Failure with LVEF > 45%
• Patients unable of comply with the Clinical Investigation Plan
• Patients who are already enrolled or plan to participate in a concurrent clinical study of any medication and/or device at any time during the course of this clinical study without prior documented approval of the Medtronic Study Manager

Mexican patients diagnosed with Heart Failure with reduced ejection fraction, regardless of the time of disease progression.