Myocarditis in systemic lupus erythematosus diagnosed by¹⁸F-fluorodeoxyglucose positron emission tomography

Abstract

ObjectivesCardiovascular diseaseand heart failure (CHF) are leading causes of death in systemic lupus erythematosus (SLE). The underlying mechanisms for increased CHF in SLE are unclear but myocardial inflammation and lupus myocarditis (LM) may play a role. We propose that 18F-fluorodeoxyglucose–positron emission tomography (18F-FDG–PET)/CT can help diagnose LM.MethodsThis report describes eight patients with presumed LM; five patients were evaluated due to active cardiorespiratory symptoms and three patients were participating in a pilot study to determine the prevalence of subclinical myocarditis in SLE. Clinical characteristics, laboratory and cardiac testing including electrocardiography (ECG), transthoracic echocardiogram (TTE), coronary artery evaluation as well as 18F-FDG–PET/CT imaging are discussed.ResultsFour patients were African American and the others were Hispanic. Half presented with chest pain; 37% had dyspnoea and 25% were asymptomatic. The median SLE Disease Activity Index (SLEDAI-2K) was 5 (2–18) and SLICC Damage Index (SDI) 0.5 (0–5). The median troponin level was 0.08 ng/mL (0–0.9). The most common ECG findings were non-specific ST-T wave abnormalities (n=5). Fifty per cent of the patients had a decreased ejection fraction on TTE and all patients had diffuse myocardial FDG uptake on 18F-FDG–PET/CT consistent with myocardial inflammation.ConclusionThis case series is the first to describe the use of 18F-FDG–PET/CT in the diagnosis of LM and discuss the clinical characteristics and cardiac findings of eight patients with LM supporting the role for cardiac 18F-FDG–PET/CT in its diagnosis.

Management of Acute Myocarditis and Chronic Inflammatory Cardiomyopathy

“…Although positron emission tomography (PET) is not usually used in the setting of AM or chronic infl-CMP, it can be considered as an alternative noninvasive diagnostic tool in stable patients with contraindication to CMRI or in patients with suspected systemic autoimmune disease where other organs could be involved by the inflammatory process. 56 PET is especially useful for the diagnosis and monitoring of CS. 57 , 58 T cells, macrophages, or granulocytes that infiltrate the myocardium, either as a nonspecific response to cell injury or as primary lesion in CS, are characterized by an enhanced glucose metabolism that can be detected by the focal uptake of the glucose analogue 18F-fluorodeoxyglucose.…”

Endomyocardial biopsies in the diagnosis of myocardial involvement in systemic lupus erythematosus

“…4 However, EMBs are rarely performed in clinical practice due to the invasive nature of the procedure and potential risks, which limit the biopsy site to the right ventricle, resulting in a lower yield, as it is the LV that is predominantly affected in FDG-PET studies of lupus myocarditis. 8 In this series of EMBs in suspected SLE myocarditis patients, only 27% had evidence of an inflammatory myocardial infiltrate, and these were considered to be nonspecific for myocarditis. These findings suggest that EMBs have limited value in the diagnosis of lupus myocarditis and are instead more useful to rule out alternative diagnoses.…”

Myocarditis as a lupus challenge: two case reports

“…Transthoracic echocardiography showed an EF of 57% (range, 50–60%) with normal wall motion in another four patients within 6–8 months. The last patient was lost to follow-up [8]. It seems to be a reasonable choice to consider MMF as a suitable induction therapy for lupus myocarditis.…”