Immune checkpoint inhibitor-associated myocarditis: a novel risk score

Area of Science:

• Cardiology
• Oncology
• Immunology

Background:

• Immune checkpoint inhibitors (ICI) can cause life-threatening myocarditis, with milder forms increasingly recognized.
• The autoimmune process in ICI myocarditis may also cause myositis, myasthenia-like syndrome, and respiratory failure.
• Prognostic factors for ICI-associated cardiomyotoxicity are currently lacking.

Purpose of the Study:

• To identify predictors of negative outcomes in patients hospitalized for ICI myocarditis.
• To develop and validate a prognostic risk score for ICI-induced cardiomyotoxicity.

Main Methods:

• Retrospective analysis of a multicenter registry (2014-2023) from 17 countries, including 748 patients.
• Multivariable Cox regression identified risk factors for a composite outcome (severe arrhythmia, heart failure, respiratory failure, death).
• A point-based risk score was derived using identified parameters and externally validated.

Main Results:

• The 30-day incidence of the composite outcome was 33%; cardiomyotoxicity-related death was 13%.
• Predictors of the composite outcome included active thymoma, cardiomuscular symptoms, low QRS voltage, LVEF < 50%, and troponin elevation.
• The derived risk score demonstrated good performance, with 30-day outcome incidence ranging from 4% to 81% based on score.

Conclusions:

• ICI-associated myocarditis presents significant morbidity and mortality.
• Myocarditis severity correlates with troponin levels, thymoma, low QRS voltage, reduced LVEF, and cardiomuscular symptoms.
• The developed risk score effectively predicts outcomes and can potentially guide management, as shown in prospective use.