The present invention relates in part to diagnosing the occurrence of heart failure, particularly in subjects who exhibit a normal body fluid level of a natriuretic peptide. The present invention further relates in part to assigning an outcome risk (e.g., worsening cardiac function or a mortality risk, a risk of rehospitalization) to a subject. The methods comprise performing one or more assays that detect one or more biomarkers selected from the group consisting of WAP4C, ESAM, LTBR, Mesothelin, and Syndecan-1 performed on a body fluid sample obtained from a subject, and assigning diagnosis or risk based, at least in part, on the result(s) obtained thereby.