Clinical Characteristics and Outcomes in Immune Checkpoint Inhibitor Therapy-Associated Myocarditis

Immune checkpoint inhibitor (ICI) therapy has played an important role in the treatment of several groups of cancers. Although a life prolonging treatment, many side effects have been shown with ICI therapy. This study looked at individual level clinical characteristics and outcomes with ICI therapy in patients who developed ICI-related myocarditis. A comprehensive review of the National Library of Medicine PubMed database was performed. Inclusion criteria were all studies that were composed of case reports and case series of individual patients undergoing ICI therapy that developed myocarditis. To appreciate individual patient level data, observational studies, clinical trials, systematic reviews, and meta-analyses were excluded. Our search yielded 333 results with 71 cases reviewed of ICI therapy-related myocarditis. The findings included an average age of 68 years, higher incidence in men, and pretreatment cardiac history of hypertension. Melanoma was the most prevalent malignancy with nivolumab being the most used ICI therapy. Heart failure was the most prevalent adverse event that was co-prevalent with myocarditis. Corticosteroid therapy alone was the most utilized therapy to treat ICI-related myocarditis. Mortality was seen in nearly half of the patient population. Our study reviewed the preexisting literature of prior reported myocarditis secondary to ICI therapy. Periodic surveillance should be performed by the cardio-oncologist and internist. Due to the expanding role of ICI therapy in treating a variety of cancer patients, appreciation of its impact on the development of myocarditis is needed.