Amino Acid-Derived Metabolic Signature Across Stages of Systolic Dysfunction: Derivation and Internal Evaluation of the HASI (Heart Failure Amino Acid-Derived Systolic Index)—40 Index. - Krasińska, Beata; Spasenenko, Ievgen; Pietkiewicz, Dagmara; Plewa, Szymon; Filipiak, Krzysztof J.; Pawlaczyk-Gabriel, Katarzyna; Bartkowski, Jarosław; Tykarski, Andrzej; Krasiński, Zbigniew; Matysiak, Jan; Urbanowicz, Tomasz (International Journal of Molecular Sciences, 2026)