Abstract Background: Brazil is a country with different biomes and social disparities. There are limited data available on regional differences and prognosis of heart failure (HF) in the country. Objective: The Rosa dos Ventos study aims to investigate regional differences and the current prognosis of HF outpatients with reduced or mildly reduced ejection fraction in Brazil. Methods: This is a prospective, multicenter, observational cohort study that will include outpatients older than 18 years with HF and an ejection fraction < [...]