Immune checkpoint inhibitor-induced myocarditis and outcomes after re-exposure

Immune checkpoint inhibitors (ICI) can cause myocarditis, leaving physicians uncertain regarding the safety of restarting ICIs after recovery. This study aims to measure real-world incidence of ICI-induced myocarditis and whether re-exposure to ICI after myocarditis impacts all-cause mortality.

Adult patients with cancer treated with ICIs were identified from TriNetX network, and outcomes were compared between patients re-exposed to ICI and those who were not.

Among 195,578 patients receiving ICIs, 0.6% (n=1,214) developed myocarditis. Myocarditis was associated with increased all-cause mortality (hazard ratio [HR], 1.44; 95% confidence interval [CI], 1.25-1.66). Among those with myocarditis, 13.8% (n=168) were re-exposed to ICIs; re-exposure was associated with lower all-cause mortality (HR, 0.50; 95% CI, 0.35-0.73).

ICI-induced myocarditis increases mortality, while re-exposure may improve survival in selected patients.