Assessment of Myocardial Fibrosis Using Advanced Echocardiography in Patients With Systemic Lupus Erythematosus: a Pilot Study

Background: Systemic lupus erythematosus (SLE) is an autoimmune disease, which is characterized by a multi-organ involvement and increased mortality, mainly due to cardiovascular complications. Myocardial fibrosis (MF) is common in SLE, affecting up to 30% of these patients. Cardiac magnetic resonance imaging allows an accurate assessment of myocardial tissue in SLE patients, but it is costly, time consuming, and unfit for patients with coexisting chronic kidney disease. Recent advanced echocardiographic techniques allow an accurate assessment of MF. In particular, speckle tracking echocardiography (STE) is a reproducible technique that provides information about MF by detecting abnormalities in myocardial active deformation. Scar imaging echocardiography with ultrasound multi-pulse scheme (eSCAR) is another novel technique that has been validated for detecting ischemic myocardial scars in patients with prior acute myocardial infarction. Aim: To examine whether STE and eSCAR may detect the presence of subclinical myocardial involvement in patients with SLE. Methods: We consecutively recruited 29 patients (M/F=3/26; age 45±11 years) with established SLE, who had a disease duration of 15±10 years. Their median SLE Disease Activity Index (SLEDAI) score was 2 (0-6). Patients with current cardiac symptoms or prior history of any heart disease were excluded from the study. We also recruited a sample of 32 control individuals, who were comparable for age, sex and traditional cardiovascular risk factors to the cases. All participants underwent a complete echocardiography examination, using both STE and eSCAR. Results: Global longitudinal strain (GLS) was significantly impaired in most myocardial segments in SLE patients than in control subjects, except for the myocardial apical region that was comparable between the two groups. Higher SLEDAI was associated with an impaired GLS-4 chamber (r=0.470, p=0.01) and GLS infero-septal wall (r=0.464, p=0.01). A higher daily dosage of prednisone was also associated with an impaired GLS in the infero-septal myocardial segment (r=0.414, p=0.02). Myocardial scar by eSCAR was observed in 5 (17%) out of 29 SLE patients, mainly in the infero-septal myocardial segment. A significant association was found between the infero-septal GLS and the presence of scar by eSCAR technique (r=0.569, p<0.001). Conclusions: Advanced echocardiography techniques detected the presence of subclinical myocardial dysfunction in SLE patients with no history of cardiac disease compared to controls. An ‘apical sparing’ GLS pattern was also observed in SLE patients, with possible important diagnostic implications. In about one fifth of SLE patients a myocardial scar by eSCAR technique was identified, mainly in the infero-septal segments. Larger prospective studies are certainly needed to confirm these findings and to better elucidate the diagnostic and prognostic significance of advanced echocardiography techniques (including GLS and eSCAR) in patients with SLE.