Clinical characteristics and prognostic impact of immune checkpoint inhibitor-associated myocarditis in advanced non-small cell lung cancer

Background: Myocarditis is a rare immune-related adverse events (irAEs) with high mortality rates, with few reports on its clinical characteristics and prognostic impact. This study designed to explore the associations between cardiac parameters and outcomes of myocarditis in advanced non-small cell lung cancer (NSCLC) who treated with immune checkpoint inhibitor (ICI). Methods: : Fourteen patients diagnosed with ICI-associated myocarditis by clinicians were admitted to the study analysis. By Cox univariate and multivariate survival analyses, potential risk factors for the development of severe myocarditis were identified. Survival analysis was also performed to explore the prognosis of patients with myocarditis. Results: : Among patients with myocarditis, higher B-type natriuretic peptide (BNP) levels ( P =0.04) and conduction block ( P =0.03) were associated with progression to severe myocarditis.In addition, high lactate dehydrogenase (LHD)levels ( P =0.04) and myocarditis onset within 2 months ( P =0.02) were prognostic factors of severe myocarditis. The median progression-free survival (PFS) time and median overall survival (OS) time for all patients were 5.9 months and 18.5 months, respectively. However, there were no statistical differences between mild and severe cohorts in terms of PFS and OS (PFS: 4.5 vs. 8.5 months, P =0.17; OS: 21.3 vs. 18.5months, P =0.36). And we found that the earlier occurrence of myocarditis, worse PFS prognosis (4.5 months vs. 10.5 months, P =0.008), while no difference in OS (18.5 months vs. 21.3 months, P =0.35). Conclusion: Compared to mild myocarditis, severe myocarditis presented with higher BNP levels and cardiac conduction abnormalities. In addition, patients with mild and early myocarditis tended to have better survival rates.