Endothelial dysfunction in systemic lupus erythematosus: evaluation with 13N-ammonia PET

Area of Science:

• Cardiovascular research
• Rheumatology
• Medical imaging

Background:

• Systemic lupus erythematosus (SLE) is a multisystem autoimmune disease with significant cardiovascular implications.
• Cardiovascular complications, including coronary artery disease (CAD), are a major cause of morbidity and mortality in SLE patients.
• Endothelial dysfunction is an early marker of cardiovascular disease and may be prevalent in SLE.

Purpose of the Study:

• To evaluate endothelial function in asymptomatic SLE patients using (13)N-ammonia PET.
• To assess myocardial blood flow (MBF) and myocardial flow reserve (MFR) in SLE patients compared to healthy controls.

Main Methods:

• 16 women with SLE and 16 age-matched healthy women were enrolled.
• (13)N-ammonia PET/CT was used to quantify MBF at rest and during cold pressor test (CPT) and stress.
• Endothelium-dependent vasodilation index and MFR were calculated to assess endothelial function.

Main Results:

• SLE patients exhibited significantly lower mean endothelium-dependent vasodilation index (1.18 ± 0.55 vs. 1.63 ± 0.65, P=0.04) and %ΔMBF (18 ± 55 vs. 63 ± 65, P=0.04) compared to controls.
• MFR was also reduced in SLE patients (2.41 ± 0.59 vs. 2.73 ± 0.77, P=0.20), though not statistically significant.
• These findings indicate impaired coronary flow and endothelial dysfunction in asymptomatic SLE patients.

Conclusions:

• Asymptomatic SLE patients, even without active disease, demonstrate abnormal coronary flow and endothelial dysfunction.
• These results highlight the need for intensified treatment strategies targeting CAD in SLE patients.
• Early detection and management of cardiovascular risk factors are essential in SLE care.