NPPB and hydrops fetalis: In this sense, we aimed to quantify underreporting of HF in individuals in Brazil and to estimate their mortality trends.<h4>Methods</h4>We identified potential HF patients using a guideline-based flowchart that combines ICD-10 codes (e.g. I21, I25, I42) and HF-related procedures (e.g. echocardiography, B-type Natriuretic Peptide (BNP) testing).