The present meta-analysis was conducted to compare the safety and efficacy of angiontensin receptor neprilysin inhibitor (ARNI) with angiotensin receptor blockers (ARBs) and angiotensin-converting-enzyme inhibitors (ACEi) in patients with heart failure with reduced ejection fraction (HFrEF). This meta-analysis was conducted and reported in accordance with the guidelines of the Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) statement. Two authors carried out a scientific literature search on online databases, including EMBASE, PubMed, and the Cochrane Library. The gene discussed is ACE; the disease is heart failure.