This was comparable to the 8506 patients with an index registration in SwedeHF during 2023 with 52% HFrEF and 20% HFpEF, age 75 years, 36% females and NT-proBNP 1560 [629-3617] pg/mL.<h4>Conclusions</h4>We are building a high-quality detailed biobank linked to SwedeHF, the world's largest continuous HF registry, consisting of plasma, serum, whole blood and urine samples. Here, NPPB is linked to hydrops fetalis.