Myocarditis not uncommon in cancer patients on immune checkpoint inhibitors

The incidence of myocarditis and myocardial damage is higher than expected in cancer patients receiving immune checkpoint inhibitor (ICI) treatment, reports a recent real-world study.

Researchers conducted prospective analysis of 126 patients (mean age 64 years, 69 percent men) on ICIs, who were assessed for clinical outcomes between April 2017 and May 2020. Endpoints included vital signs, biomarker profiles, electrocardiograms, echocardiographs, and chest radiographs. Assessments were conducted before ICI initiation and at follow-up of 7, 14, 21, and 60 days after.

At baseline, 30.2 percent of participants had a history of prior cardiovascular disease, while 28.6 percent had received chest radiotherapy in the past. Anthracycline medication was ongoing in 3.2 percent of patients.

Overall, 46 patients had abnormalities in at least one of the cardiovascular tests, yielding a rate of 36.5 percent. Abnormalities arose a median of 21 days after ICI administration. The most common abnormality was elevated troponin I level, which was observed in 14.3 percent of patients, followed by heightened creatinine kinase and brain natriuretic peptide. Conduction disturbances were also common.

Clinically suspected myocarditis, assessed in accordance with the European Society of Cardiology guidelines, was detected in 13 patients (10.3 percent), of whom eight were symptomatic. Four of these patients had mild symptoms, while the other four showed moderate or severe manifestations.

Regardless of severity, clinically suspected myocarditis appeared soon after ICI treatment, a median of 44 days after initiation.