e285 Pharmacological Treatment for Stage C HF With Reduced Ejection Fraction: Recommendations e285 Renin-Angiotensin System Inhibition With Angiotensin-Converting Enzyme Inhibitor or Angiotensin Receptor Blocker or ARNI: Recommendations . . e285 Ivabradine: Recommendation . . . . . . . e287 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . e288 Appendix 1. Author Relationships With Industry and Other Entities (Relevant) . . . . . . . . . . . e289 Appendix 2. Reviewer Relationships With Industry and Other Entities (Comprehensive) . . . . . . e291 Preamble Incorporation of new study results, medications, or de- vices that merit modification of existing clinical practice guideline recommendations, or the addition of new rec- ommendations, is critical to ensuring that guidelines re- flect current knowledge, available treatment options, and optimum medical care. To keep pace with evolving evi- dence, the American College of Cardiology (ACC)/Ameri- can Heart Association (AHA) Task Force on Clinical Prac- tice Guidelines ( Task Force ) has issued this focused update to reassess guideline recommendations on the basis of recently published study data. This update has been subject to rigorous, multilevel review and approval, similar to the full guidelines. For specific focused update criteria and additional methodological details, please see the ACC/AHA guideline methodology manual.1 Modernization Processes have evolved over time in response to pub- lished reports from the Institute of Medicine2,3 and ACC/ leading to adoption of a knowledge byte format. This process entails delineation of a rec- ommendation addressing a specific clinical question, followed by concise text (ideally <250 words) and hy- perlinked to supportive evidence. 