Abstract Introduction Institutional aCute decompensAted HeaRt FailUre RegiStry (ICARUS) will provide information on clinical characteristics, medical practice, patterns of treatment, and outcomes of patients hospitalized with Acute Decompensated Heart Failure (ADHF) in a hospital in a middle-income country. Objective Describe the methodological aspects, sociodemographic, and clinical characteristics of patients hospitalized with ADHF and their short-term outcomes. Method Prospective cohort of patients with ADHF from the emergency service of a cardiovascular center. Descriptive statistics were used to synthesize sociodemographic characteristics, clinical characteristics during hospitalization, and outcomes. Results 1595 patients with ADHF. The median age was 68 years (Q1=58; Q3=76), and 69.28% were men. The median hospital stay was six days (Q1=4; Q3=11), with an accumulative incidence (AI) for rehospitalization at 30 days of 8.70 % (95% CI 7.18 to 10.40%), in-hospital mortality AI of 4.33% (95% CI 3.38 to 5.44%), and a median change in the quality-of-life score like Minnesota Living with Heart Failure Questionnaire (MLHFQ) at 30 days of -20 points (Q1=-37; Q3=-5). At discharge, all patients had a percentage greater than 70% of the use of quadruple neurohormonal blockade therapy. Conclusions ICARUS is one of the first registries in Latin America since the indication of the use of SGLT2 inhibitors, evaluating the clinical and sociodemographic characteristics, treatment patterns, and outcomes of a preliminary cohort of 1595 patients hospitalized for ADHF. The results indicate that, at discharge, up to 82.79% of patients were receiving quadruple neurohormonal blockade therapy, which is considerably challenging to achieve in Latin America. Considering the results of the Safety, tolerability and efficacy of up-titration of Guideline-Directed Medical therapies for acute heart failure (STRONG-HF study), our study reinforces the benefit of discharge with Guideline-Directed Medical Therapy (GDMT) for heart failure from hospitalization. The use of GDMT for heart failure may have influenced our positive outcomes in terms of in-hospital mortality, improvement in quality of life, and the percentage of short-term rehospitalizations compared to similar cohorts.Proportion of HF drug group