We conducted a systematic review of randomized controlled trials (RCTs), which used at least one angiotensin-converting enzyme inhibitor (ACEI), angiotensin receptor blocker (ARB), or beta-blocker (BB) to prevent cardiotoxicity of antineoplastic agents for breast cancer, in 4 databases (PubMed, Cochrane Library, EMBASE, Web of Science) from inception to 11 May 2022, without language restrictions. The gene discussed is ACE; the disease is breast cancer.