Myocarditis in systemic lupus erythematosus diagnosed by ¹⁸F-fluorodeoxyglucose positron emission tomography

Area of Science:

• Cardiology
• Rheumatology
• Nuclear Medicine

Background:

• Cardiovascular disease and heart failure are leading causes of mortality in systemic lupus erythematosus (SLE).
• Myocardial inflammation and lupus myocarditis (LM) are implicated in increased cardiac dysfunction in SLE.
• The diagnostic utility of advanced imaging for LM requires further investigation.

Purpose of the Study:

• To evaluate the role of 18F-fluorodeoxyglucose-positron emission tomography/computed tomography (18F-FDG-PET/CT) in diagnosing lupus myocarditis (LM).
• To describe the clinical characteristics and cardiac findings in patients with presumed LM.

Main Methods:

• Case series of eight patients with suspected LM, including those with active symptoms and a pilot study cohort.
• Comprehensive evaluation included clinical assessment, laboratory tests, ECG, echocardiography, and 18F-FDG-PET/CT imaging.
• Analysis focused on correlating imaging findings with clinical presentation and cardiac function.

Main Results:

• Patients presented with diverse symptoms including chest pain, dyspnea, or were asymptomatic.
• Laboratory findings showed elevated troponin in some patients, with non-specific ECG abnormalities.
• Echocardiography revealed decreased ejection fraction in 50% of patients, while all demonstrated diffuse myocardial 18F-FDG uptake on PET/CT, indicating inflammation.

Conclusions:

• This is the first case series to report the use of 18F-FDG-PET/CT for diagnosing LM.
• Cardiac 18F-FDG-PET/CT imaging shows promise in identifying myocardial inflammation in SLE patients.
• The findings support the utility of cardiac 18F-FDG-PET/CT in the diagnostic workup of LM.