A Systematic Review of Myocarditis Induced by Immune Checkpoint Inhibitors: How Concerning Is the Most Common Cardiotoxicity of Immune Checkpoint Inhibitors?

Novel cancer therapies have revolutionized the management of various cancers. An immune checkpoint inhibitor (ICI) is one of these antitumor medications. ICIs, which are immune therapies, enhance the immune system's capacity to fight cancer cells. Based on the receptors that they inhibit, such as PD-1, PD-L1, and CTLA-4, ICIs are subdivided. Although this class of drugs is extremely beneficial for cancer patients, their adverse effects can be fatal. Multiple organs, such as the cardiovascular system, may be impacted by immune-related adverse effects (irAEs). These cardiotoxic irAEs can occur at a rate of up to 1% and can be fatal. Myocarditis is the most prevalent of all cardiotoxicities. The purpose of this systematic review is to assess the seriousness of myocarditis, the most prevalent cardiotoxicity of ICIs, and the importance of screening. We chose studies based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020 criteria. Therefore, from 2018 to 2023, we gathered articles from databases such as PubMed, ScienceDirect, Web of Science, the Cochrane Library, and Google Scholar. Of the 665 studies identified based on various screening methods and quality assessment tools, 13 were selected for inclusion in the study. This study shows that although the risk of myocarditis in ICI therapy is low and the majority of cases are asymptomatic or mild, some cases can be deadly and disastrous, and physicians should be aware that if myocarditis is suspected based on clinical symptoms, troponin, electrocardiogram, and echocardiogram, treatment should be initiated accordingly.