NPPB and heart failure: Within a National Institutes of Health (NIH) funded parent study about Long COVID, we embedded the My ILLInet RECOVER Return of Results study to explore clinician-level considerations (e.g., validity, actionability, recommendations for follow-up) about returning a clinically used biomarker for heart failure (N-terminal pro-B-type natriuretic peptide, (NT-proBNP) collected as part of the NIH RECOVER study protocol.