Retrospective analysis of immune checkpoint inhibitor-associated myocarditis from 12 cancer centers in China.

e15130 Background: Immune checkpoint inhibitor(ICI) -associated myocarditis is rare, but it could account for a very high mortality rate. This study reviewed the occurrence of ICI-associated myocarditis in Chinese cancer patients. Methods: A retrospective analysis was made on the occurrence of ICI-associated myocarditis in cancer centers of 12 3A-grade hospitals in China from January 1, 2018 to December 31, 2019. More than 100 patients were treated with ICIs in each center. Results: A total of 2373 patients were treated with ICI alone or in combination. The incidence of ICI-associated myocarditis was 1.05% (25/2373). Of all the data elicited from 16 patients in this study, the tumor types were listed, including: melanoma, lung cancer, renal cancer, urothelial cancer, liver cancer, gastric cancer, colorectal cancer, etc. The 16 patients included 8 male and 8 female with a median age of 65 (36-80). 3 of them had coronary heart disease. The ICI drugs included nivolumab, pembrolizumab and toripalimab, camrelizumab, sintilimab, tislelizumab, atezolizumab. Among them, there were 10 cases of PD-1 inhibitor, 1 case of PD-L1 inhibitor, 5 cases of PD-1 inhibitor combined with chemotherapy or molecular targeted drug. ICI-associated myocarditis occurred in a median of 38 days (2-420) after treatment during which 81.2% (13/16) of them received ICI 1-2 infusions. The common clinical symptoms were palpitation, chest distress and dyspnea, in addition to 8 cases with asthenia, 4 cases with respiratory failure, 2 cases without symptoms. ECG abnormality accounted for 87.5% (14/16). The common abnormalities included: 6 cases of atrial premature contraction, 4 cases of ventricular premature contraction, 3 cases of sinus tachycardia, 1 case of Grade 3 atrioventricular, 1 case of complete right bundle block, and 1 case of acute myocardial infarction. 15 cases of abnormal troponin I or T were observed, followed by CK, CK-MB, MYO and BNP increased. 14 patients were treated with glucocorticoid. 6 patients died with the mortality rate 37.5%(6/16) and 66.7% (4/6) were over 70 years old. Conclusions: The incidence of ICI-associated myocarditis in Chinese patients is low, but the mortality rate is high. Regular monitoring of cardiac biomarkers and ECG is helpful for early diagnosis.