Side Effect: Inflammation of the Heart (Myocarditis)

What is Inflammation of the Heart (Myocarditis)?

Myocarditis is a condition characterized by inflammation of the heart muscle, or myocardium. Inflammation of the heart muscle can be a life-threatening condition that can lead to complications such as heart attack (myocardial infarction) or chronic heart failure if not properly treated.

What does Inflammation of the Heart (Myocarditis) look like?

Symptoms of myocarditis include fatigue, decreased exercise tolerance, palpitations, chest pain and fainting.

If your doctor is concerned that you have myocarditis, you may have heart tests such as an electrocardiogram (ECG or EKG) to look at the electrical activity of the heart, and an echocardiogram (ECHO) to check the structures and function of the heart. Cardiac magnetic resonance imaging (MRI) may also be done to look at a more detailed picture of the blood vessels, blood flow, heart structures and inflammation of the heart. Additionally, blood tests may be done to check for damage to the heart (troponin) or increased blood volume (B-type natriuretic peptide or BNP). In some cases, more invasive tests such as cardiac catheterization or myocardial biopsy may be performed.

Who gets Inflammation of the Heart (Myocarditis)?

Inflammation of the lungs can occur as an immune-related adverse event (irAE) in patients with cancer who are receiving immune checkpoint inhibitor (ICI) therapy such as:

PD-1 inhibitors:

PD-L1 inhibitors:

CTLA-4 inhibitors:

PD-1 inhibitor + LAG-3 inhibitor:

ICIs activate the immune system against cancer cells, but they can also trigger an immune response against healthy tissues, including the myocardium, leading to myocarditis. ICIs can cause myocarditis when used alone, but the incidence can be higher when two ICI therapies are combined such as a PD-1 inhibitor and CTLA-4 inhibitor.

How to prevent Inflammation of the Heart (Myocarditis)

Preventing myocarditis in patients with cancer can be challenging. Patients should be carefully screened before starting treatment to identify any preexisting conditions that could increase the risk of developing myocarditis. During treatment, patients should be monitoring closely for any signs or symptoms of myocarditis. Patients should be educated about the signs and symptoms of myocarditis and advised to seek medical attention promptly if they experience any of these symptoms.

How to treat Inflammation of the Heart (Myocarditis)

Treatment of myocarditis typically requires hospitalization for treatment, stopping the therapy that is causing the inflammation, and using medications to control symptoms and reduce inflammation. Medications to reduce inflammation may include

References

1) Cooper LT Jr. Myocarditis. N Engl J Med 2009;360(15):1526-1538

2) Schneider BJ, Naidoo J, Santomasso BD, et al. Management of immune-related adverse events in patients treated with immune checkpoint inhibitor therapy: ASCO guideline update. J Clin Oncol 2021;39:4073-4126

3) National Comprehensive Cancer Network. Management of Immunotherapy-Related Toxicities (Version 1.2024). https://www.nccn.org/professionals/physician_gls/pdf/immunotherapy.pdf. Accessed May 10, 2024.

Created: May 24, 2024 Updated: July 16, 2024