Real-world cardiovascular toxicity of immune checkpoint inhibitors in cancer patients: a retrospective controlled cohort study

Over the past decade, immune checkpoint inhibitors (ICI) have dramatically improved the prognosis of many cancer patients, but many immune-related adverse cardiovascular events (ACEs) have been observed. We aimed to investigate the occurrence of ACEs in the real world after receiving ICI and provide clinical reference for how to evaluate it. The study retrospectively included 204 patients who received ICI from October 2019 to November 2020 and 205 patients who only received traditional chemotherapy. The mean duration of follow-up for ICI group was 4.88 months, and the control group was 4.79 months. Patients in the control group did not develop myocarditis, only 2 cases of new-onset pericardial effusion occurred. In contrast, among ICI group, there were 3 cases of ICI-associated myocarditis, accounting for 1.47% (3/204), 6 cases of pericardial effusion. The incidence of new-onset ECG abnormalities in the ICI group was significantly higher than that of the control group (38/180 VS 16/178, HR 2.71, 95% CI: 1.449-5.067, P=0.001). In the ICI group, after receiving ICI treatment, cardiac biomarkers including average cardiac troponin T and N terminal pro B type natriuretic peptide increased significantly, peak in about 1 month, and then gradually decreasing. After the third or fourth month, the cardiac biomarkers gradually increased again. In conclusion, ICI may lead to various ACEs, and its incidence is higher than that of patients who only receive traditional chemotherapy. The changing trend of cardiac biomarkers reflects that ICI may cause acute and chronic myocardial damage. Regularly performing ECG, echocardiogram and cardiac biomarker examinations are helpful for early detection of ACEs caused by ICI and providing timely treatment.