The following keywords or corresponding Medical Subject Headings (MeSH) were used for the search of relevant articles: “heart failure with reduced ejection fraction,” “angiotensin receptor-neprilysin inhibitor,” “Angiotensin receptor blockers,” and “clinical outcomes.” Outcomes assessed in the present meta-analysis included changes in ejection fraction (EF) from baseline in percentage. The gene discussed is MME; the disease is heart failure.