Immune Checkpoint Inhibitor Associated Myopathy with Concurrent Myocardial Injury: A Retrospective Cohort Study

Area of Science:

• Immunology
• Neurology
• Cardiology

Background:

• Immune checkpoint inhibitors (ICIs) are vital cancer immunotherapies.
• Immune-mediated myopathy is a known side effect of ICIs.
• Cardiac involvement in ICI myopathy requires further characterization.

Purpose of the Study:

• To characterize immune checkpoint inhibitor (ICI) myopathy complicated by myocardial injury.
• To identify clinical, laboratory, and electrophysiological features of ICI-induced myopathy with cardiac involvement.

Main Methods:

• Retrospective analysis of 16 patients with ICI myopathy and myocardial injury.
• Review of clinical manifestations, laboratory findings (CK, CK-MB, hs-TnT), antibody status, and electrophysiological tests.
• Observation of treatment response and unique biochemical phenomena.

Main Results:

• All 16 patients showed cardiac involvement, with common symptoms including ptosis and muscle weakness.
• Elevated creatine kinase (CK), CK-MB, and high-sensitivity troponin T (hs-TnT) were universal.
• A novel discordant phenomenon of rising CK-MB with falling CK was observed in 50% of patients during hormone therapy.

Conclusions:

• ICI myopathy is a distinct immune-mediated disorder affecting skeletal and cardiac muscle.
• Cardiac involvement is common and requires careful monitoring for arrhythmias, even with mild symptoms.
• Early diagnosis, prompt intervention, and vigilant monitoring are essential for improved outcomes in ICI myopathy.