Heterogeneity of Echocardiographic Variables in Systemic Lupus Erythematosus among Clinical Subgroups according to Non-Cardiac Involvement

Background – Systemic lupus erythematosus (SLE) is a heterogeneous autoimmune disease. Cardiac involvement is important due to its impact on survival. Transthoracic echocardiography (TTE) is a sensitive technique to assess cardiac structure and function. The degree of cardiac involvement according to SLE subsets defined by non-echocardiographical manifestations remains unknown. The objective of this study was to identify differences in TTE parameters associated with different SLE clinical subgroups. Methods and Results – One hundred and eighty-one patients fulfilling the ACR/EULAR 2019 classification criteria for SLE and who had undergone systematic TTE at least once were included in this cross-sectional study. The earliest available TTE from the date of diagnosis was considered the baseline TTE. We defined four subsets of SLE which was based on the predominant clinical manifestations. A multivariate multinomial regression analysis was performed to determine whether TTE parameters differ between the phenotypical subsets. The first subset (n = 37) of patients showed clinical features of mixed connective tissue disease (MCTD); the second subset (n = 76) had primarily cutaneous involvement; the third subset (n = 18) exhibited serositis; the last subset (n = 50) had severe disease with significant organ involvement, including renal involvement. Forty TTE parameters were assessed in all patients. Using a multivariate multinomial regression analysis, 3 parameters differed according to groups: RV-E’(early diastolic tricuspid annular velocity, p<0.0001), RV-S’ (RV-pulse DTI systolic peak wave, p = 0.0031), and RV end-diastole diameter (p = 0.0419). Conclusion – SLE is an heterogeneous disease. Four distinct clinical subsets based on clinical manifestations differed in terms of TTE derived parameters of right heart dysfunction and diastolic dysfunction. This SLE heterogeneity in cardiac involvement could help to tailor the follow-up required for these patients.