NPPB and heart failure: A representative search structure in PubMed was: ((“Heart Failure”[Mesh] OR “heart failure” OR “cardiac failure” OR “congestive heart failure” OR HFrEF OR HFpEF) AND (“Metabolomics”[Mesh] OR metabolom* OR “metabolic profiling” OR “metabolite profiling” OR “metabolic signature*” OR “metabolic fingerprint*”) AND (biomarker* OR “risk stratification” OR prognos* OR outcome* OR “NT-proBNP” OR “B-type natriuretic peptide” OR acylcarnitine* OR “branched-chain amino acid*” OR BCAA* OR phenylalanine OR “ketone bod*” OR “trimethylamine N-oxide” OR TMAO)).