The 2017 HF focused update writing group included representa- tives from the ACC, AHA, and HFSA, as well as the American Academy of Family Physicians, American College of Chest Physicians, American College of Phy- sicians, and International Society for Heart and Lung Transplantation. 1.3. Document Review and Approval The focused update was reviewed by 2 official reviewers each nominated by the ACC, AHA, and HFSA; 1 reviewer each from the American Academy of Family Physicians, American College of Chest Physicians, and International Society for Heart and Lung Transplantation; and 19 in- dividual content reviewers. Reviewers RWI information is published in this document (Appendix 2). This document was approved for publication by the governing bodies of the ACC, AHA, and HFSA. 6. INITIAL AND SERIAL EVALUATION OF THE HF PATIENT Assays for BNP (B-type natriuretic peptide) and NT- proBNP (N-terminal pro-B-type natriuretic peptide), which are both natriuretic peptide biomarkers, have been used increasingly to establish the presence and severity of HF. In general, both natriuretic peptide bio- marker values track similarly, and either can be used in patient care settings as long as their respective ab- solute values and cutpoints are not used interchange- ably. Notably, BNP, but not NT-proBNP, is a substrate for neprilysin. Therefore, ARNI increases BNP levels12 but not NT-proBNP levels.13 Note that the type of natri- uretic peptide assay that has been performed must be considered during interpretation of natriuretic peptide biomarker levels in patients on ARNI. 