PLASMA Mexico (PLASMA Mexico)

* 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.