Cardio-oncology & otherCohort study

Inflammatory Cell Profiles in Early- and Late-Manifestation Immune Checkpoint Inhibitor Myocarditis

JACC CardioOncolPublished

  • Retrospective cohort study
  • national

Authors' conclusion

Late-manifestation ICI myocarditis may represent a temporally distinct or partially attenuated inflammatory phase. Despite a milder inflammatory profile, higher cancer-related mortality was observed

Study context

Population
Patients diagnosed with myocarditis after immune checkpoint inhibitor (ICI) initiation who underwent endomyocardial biopsy
Participants
35 patients
Exposure
Early- vs late-manifestation ICI myocarditis
  • Early-manifestationn = 26
  • Late-manifestationn = 9reference

Main finding

As reported in the abstract

Myocardial inflammatory cell infiltration on endomyocardial biopsy
GroupCD3+ T cellsCD8+ T cellsCD 68+ macrophages
Early-manifestation432 [173-1,381]289 [73-994]307 [116-841]
Late-manifestation121 [43-400]86 [21-168]57 [36-200]
  • Early-manifestation vs Late-manifestation: P = 0.036 — CD3+ T cells
  • Early-manifestation vs Late-manifestation: P = 0.019 — CD8+ T cells
  • Early-manifestation vs Late-manifestation: P = 0.008 — CD 68+ macrophages
  • Early-manifestation vs Late-manifestation: P = 0.054 — CD4+ T cells, higher in early, not significant

Observational data: associations, not effects.

Further findings

events

OutcomeEarly-manifestationLate-manifestation
Myocarditis mortality20
Cancer-related mortality23

Clinical features

Early-manifestation: higher cardiac biomarker levels and older age
LVEF similar between groups

ICI reinitiation

ICI therapy reinitiated in patients overall
2

Original publication

Inflammatory Cell Profiles in Early- and Late-Manifestation Immune Checkpoint Inhibitor Myocarditis. JACC CardioOncol. Published 30 July 2026. doi:10.1016/j.jaccao.2026.07.008

Summarised from the published abstract; every number is checked against it