Hypertonic Saline Therapy in Ambulatory Heart Failure Unit.

Inclusion Criteria: * Previous heart failure diagnosis (according to current European Guidelines) * Stable treatment in the previous 4 weeks (except diuretic). * Home oral treatment of ≥80 mg of furosemide/day or equivalent (40 mg furosemide = 20 mg of torasemide). * Transthoracic echocardiogram performed in the last year. * Congestive signs.The presence of two of the following congestion criteria will be required: jugular pressure\> 10 cm, lower limb edema, ascites, or pleural effusion * Elevation of natriuretic peptides (NTproBNP\> 1000 pg / mL or B-type natriuretic peptide\> 250 pg / ml) performed in a previous period of no more than 24 hours. * Need for intravenous diuretic therapy to relieve congestion according to the responsible physician. Exclusion Criteria: * Hospital admission criteria in the opinion of the responsible physician. * Systolic blood pressure \<90 mmHg or\> 180 mmHg. * Heart rate\> 150 bpm or \< 40 bpm * Basal oxygen saturation less than 90%. * Cardiogenic shock. * Acute Pulmonary Edema. * Clinically significant arrhythmia. * Acute myocardial ischemia. * Patients in hemodialysis or peritoneal dialysis program. * Serum sodium \<125 milliequivalent / L or\> 145 milliequivalent / L. * Serum potassium \< 3.5 milliequivalent/ L. * Hemoglobin \< 9 g / dL * Acute coronary syndrome or cardiological procedure in the previous 2 weeks. * Severe uncorrected valve disease except tricuspid regurgitation. * Moderate or severe dementia, active delirium or psychiatric problems. * Patients in whom cardiac surgery or device implantation is planned in the following 30 days. * Pregnancy or breastfeeding. * Inability to give informed consent in the absence of a legal officer. * Patients on tolvaptan. * Inability to collect the urine.