Longitudinal pilot study among heart failure patients from six Spanish hospitals to evaluate the feasibility of establishing and maintaining for one year the set of standards for measuring results in patients with heart failure proposed by ICHOM (International Consortium for Health Outcomes Measurement), as well as identifying factors that hinder the use and applicability of this group of standards in real life, where appropriate, defined as the variables not filled in and the reason for the absence of such information.

1. MAIN GOAL To evaluate through a pilot study the viability of establishing and maintaining for one year in selected Spanish centers the set of standards for measuring results in patients with heart failure proposed by ICHOM (International Consortium for Health Outcomes Measurement). (International Consortium for Health Outcomes Measurement).
2. SPECIFIC GOALS To identify factors that hinder the use and applicability of this group of standards in real life, where appropriate, defined as the variables not filled in and the reason for the absence of such information To estimate the workload necessary to implement this set of variables within everyday clinical practice.
3. STUDY DESIGN Observational pilot study with prospective follow-up with data collection at 30 days, 6 months and 1 year.

Due to the defined objective, the methods used are, to a large extent, those proposed by ICHOM, except in those sections that may be slightly modified to adapt to the local situation.

3.1. Selection of centers and patients Six centers with experience and adequate organization (heart failure unit) and with a sufficient size have been selected to guarantee the recruitment of patients in a short period of time (around three weeks). The main justification was to seek, within the usual clinical practice, centers where, due to the organization and interest in heart failure, the chances of success of this initiative were greater.

100 consecutive patients with a diagnosis of heart failure who meet inclusion criteria and with no exclusion criteria will be selected in each center.

3.2. Sample size considerations For the main outcome, success is considered if the proportion of patients followed is ≥ 70%. A random sample of 588 individuals is sufficient to estimate, with 95% confidence and a precision of +/- 3.5 percentage units, a population percentage that is expected to be around 75%. Six Spanish centers will participate and a recruitment target of 100 consecutive patients is set, for a total of 600 patients in the study. In addition, these sizes in each center offer, accepting an alpha risk of 0.05, a power greater than 80% to detect statistically significant differences between two centers, assuming that a follow-up of 75% of patients is achieved in one and 55% in the other.

3.3. Follow-up From the baseline or inclusion visit and afterwards, in newly diagnosed patients or in those recruited in an acute situation, follow-up visits at 30 days, 6 months and 1 year [Hospitalized patients (1. A recent diagnosis, that is, they did not previously have the diagnosis of HF and 2.Patients with a previous diagnosis of HF and who are admitted for an episode of decompensation of HF) and Outpatients (1. A recent diagnosis that is in the process of titration and/or compensation and 2.A previous diagnosis, that they have suffered a decompensation, either defined because they have had to go to the emergency room or have been seen in the outpatient clinic for that reason)].

In patients who were included in a stable situation, the 30-day visit will not be carried out (Outpatients: "Stable" patients attending a follow-up visit. A simple follow-up) since doing so would unjustifiably complicate the follow-up, giving more work and discomfort to patients and health professionals. The outcomes reported by the patient (PROMs) in the visits every six months may be collected by telephone contact if the doctor, due to the stable situation of the patient, does not consider the face-to-face visit necessary. Information will be collected at in the case of hospital admissions during follow-up, these admissions also set the "counter to zero" with regard to time for the following visits (30 days, six months…).

4. DATA COLLECTION AND MANAGEMENT A data entry application will be enabled that will include filters to detect inconsistencies and anomalous data and alarms for patient monitoring. The data will be anonymized for all the people involved in the study except for the person in charge in each center, who will be able to identify their patients to enable follow-up.

5. PLAN FOR DATA ANALYSIS Two data analyses are planned, one that includes the information from the baseline visit and the 30-day visit (in patients for whom it is indicated in the protocol) and the final one with all the information collected. In both cases, a global analysis and a comparison between centers (benchmarking) will be carried out.

In line with the main objective of this pilot study, the main variables are the proportion of patients who remain in follow-up, the proportion of patients in whom follow-up is carried out, in terms of time, as planned, and the proportion of missing data in each one of the defined outcomes.

The pilot's success criteria will be a follow-up> 70%, a proportion of missing data in the outcomes <10%.

Inclusion Criteria:

• Patients aged 18 years or older.
• Diagnosed with heart failure: Clinical identification of signs and symptoms of heart failure and objective evidence of heart dysfunction.
• Acute presentation (first presentation or decompensation of already known HF, whether or not it causes hospital admission) or chronic (stable outpatients) of any etiology
• Any value of the ejection fraction.
• Give writed informed consent to participate in the study.

Exclusion Criteria:

• Patients whose first manifestation of heart failure is cardiogenic shock, in that first episode. Those patients who survived an initial episode of shock and remain in heart failure can be included once stabilized.
• Heart transplant patients
• Patients with long-lasting ventricular assist devices
• Patients with isolated right heart failure.
• Patients with onset of heart failure and whose cause can be corrected immediately (eg, acute ischemia).

Based on the situation at the time of inclusion,5 types of patients are defined that reflect different clinical situations and influence the necessary follow-up plan.

A.Hospitalized patients:

1. A recent diagnosis (at that admission), that is, they did not previously have the diagnosis of HF
2. Patients with a previous diagnosis of HF and who are admitted for an episode of decompensation of HF.

B.Outpatients:

1. A recent diagnosis that is in the process of titling and/or compensation
2. A previous diagnosis, that they have suffered a decompensation, well defined because they have had to go to the emergency room (and the diuretic treatment has been increased) or have been seen in the outpatient clinic for that reason
3. "Stable" patients attending a follow-up visit.A simple follow-up