Atrial fibrillation (AF) represents a problem of great implications to patients with heart failure (HF). Therefore, the risk of having AF increases up to 4,5 -5,9 times with the presence of HF. Both conditions share risk factors and the presence of the one worsens the progress of the other. Therefore, the AF is not only relevant in terms of thromboembolic events. Timing of AF progression seems to be associated with an increase in all causes of mortality. Although, it is estimated that between 30%-40% of the patients with HF develop AF, given that in many cases it occurs with no apparent symptoms for the patients, is considered that the number of affected patients is greater. Since silent AF poses a problem of great impact in patients with HF, monitoring through continuous electrocardiographic registry could be useful in those patients with a higher risk of thromboembolic events. The purpose of this study is to understand the mechanism and biological and clinical relevance of the AF from a holistic approach. Trying to distinguish the symptomatic AF from the silent one using the implementation of insertable cardiac devices. The purpose of this study is 1. To determine in which percentage of patients with HF, episodes of AF both symptomatic and asymptomatic occur, as well as if the presence of AF represents an irrelevant fact in the progression of the insufficiency or in the contrary, it is the cause of the HF patients clinical decline. 2. To examine the presence of triggers of AF in patients with HF and to identify the presence of clinical markers, image markers of the atrium and left ventricle, as well as biomarkers which allow the risk of stratification and could mean future therapeutic targets.

Multicenter prospective study formed by units with experience in the management of patients with HF (Hospital Clínico Universitario de Santiago de Compostela, Santiago de Compostela, Spain; Hospital Clínico Universitario de Salamanca, Salamanca, Spain and Hospital Universitario Virgen de la Arrixaca, Murcia, Spain).

Based on an AF development estimate of 30%, it has been estimated a minimum follow-up of 18 months and a maximum of 36 months for obtaining robust conclusions. On the basis of previously reported data, it has been estimated that the annual rate of AF in patients 65 years of age or older who have CHA2DS2VASc ≥ 2 and who have received an ICM is 6%. The enrolment of 300 patients had been estimated. The study would have 95% power to detect an episode of rapid atrial rate.

Those patients with a CHA2DS2VASc ≥2 seen in the HF unit will be prospectively included. In these patients, the previous diagnosis of AF will be assessed by means of clinical history and medical records. Patients with previous AF will be excluded.

Patients with preserved or intermediate LVEF will be defined according to current guidelines.

• Patients with signs and symptoms of HF.

• LVEF between 40 and 49 for "mid-range" and greater than or equal to 50 for those with LVEF preserved and at least one of these two criteria:

  • High natriuretic peptides (BNP> 35 pg / ml and / or NT-proBNP> 125 pg / mL)
  • Relevant structural disease (left ventricular hypertrophy or dilatation left earphone).
  • Diastolic dysfunction.

The data will be collected individually by each recruiting center and introduced in the online registration form that will be enabled (see next point). The definition of variables will be agreed upon among all recruiting centers. The information collected will be dumped into a database created specifically for this purpose and will be coordinated from the Hospital Clínico de Santiago de Compostela.

Remote monitoring The CareLink remote monitoring system allows remote monitoring of patients, without the need to go to the hospital center. This system establishes a connection between the patient and the medical center, through the patient monitor that reads the information from the implanted device and transmits it to a secure server. This communication allows the transmission of clinically significant events or, in the case of wireless devices, the sending of alerts. In this way, the healthcare professional has information of the event and allows him to anticipate the evaluation and treatment with the consequent benefit for the patient.

Biological characterization

Human plasma samples: Total venous blood samples (10 ml) will be collected in EDTA tubes as anticoagulants and separated by centrifugation at 1500xg during 15 minutes plasma and cellular fractions. The supernatant and the cell pellet are transferred to tubes and stored at -80°C. The serological samples will be stored in each center of origin. Several determinations will be performed:

Inclusion Criteria:

• Patients with the previous diagnosis of HF with both preserved and depressed LVEF. Patients with preserved or intermediate LVEF will be defined according to current guidelines.

  1. Patients with signs and symptoms of HFor b) LVEF between 40 and 49 for "mid range" and greater than or equal to 50 for those with LVEF preserved, high natriuretic peptides (BNP> 35 pg / ml and / or NT-proBNP> 125 pg / mL)and at least one of these two criteria: Relevant structural disease (left ventricular hypertrophy or dilatation left earphone).

Diastolic dysfunction.

Exclusion Criteria:

• Previous history of atrial fibrillation.
• CHA2DS2VASc < 2.
• Patients requiring ventricular pacing > 40 patients
• Patients under cardiac resynchronization therapy pacemaker/devices.
• Patients with severe valvulopathy.
• Patients with reverseble

On the basis of previously reported data, we estimated that the annual rate of AF in patients 65 years of age or older who have CHA2DS2VASc ≥ 2 and who have received an ICM or a pacemaker would be approximately 6%. We then estimated that with enrolment of 300 patients, the study would have 95% power to detect an episode of rapid atrial rate

The data will be collected individually by each recruiting center and introduced in the online registration form that will be enabled.

Information collection will be dumped into a database created specifically for this purpose and will be coordinated from the Hospital Clínico de Santiago de Compostela.