Early assessment of subclinical myocardial injury in systemic lupus erythematosus by two-dimensional longitudinal layer speckle tracking imaging

Background: To investigate the feasibility of quantitatively assessing left ventricular function and synchronization and diagnose subclinical myocardial injury in patients with systemic lupus erythematosus (SLE) using two-dimensional (2D) longitudinal layer speckle tracking imaging (STI). Methods: This was a single-center prospective study. A total of 69 patients with SLE were included in the case group and further divided into 2 subgroups, a nonactive and an active group, according to the Systemic Lupus Erythematosus Disease Activity Index (SLEDAI) 2000 scoring standard. We selected 30 healthy volunteers as the control group. The global longitudinal strain (GLSglobal), global endocardial longitudinal strain (GLSendo), global epicardial longitudinal strain (GLSepi), and peak strain dispersion (PSD) were obtained. The transmural gradient of longitudinal strain (TGLS) was calculated for the difference in strains between the inner and outer membranes. Results: (I) Compared with the control group, decreased speckle strain parameters and elevated PSD were observed in patients with SLE (GLSglobal: -18.80%+/- 2.41% vs. -21.19%+/- 2.16%, GLSendo: -21.15%+/- 2.47% vs. -24.09 +/- 2.49%; GLSepi: -16.58%+/- 2.39% vs. -18.50 +/- 1.77%; TGLS: -4.56%+/- 1.24% vs. -5.59%+/- 1.39%; and PSD: 36.61 +/- 10.85 vs. 30.00 +/- 8.54 ms). More severely impaired layer strains were observed in active-stage patients. Compared with the nonactive group, GLSendo, GLSglobal, GLSepi, TGLS, complement C3, and complement C4 were decreased in the active group, while SLEDAI, erythrocyte sedimentation rate (ESR), and high-sensitivity C-reactive protein (Hs-CRP) were elevated. (II) Receiver operating characteristic (ROC) analysis demonstrated that subendocardial myocardial longitudinal strain was the most powerful tool for detecting myocardial insufficiency early in patients with SLE [area under the curve (AUC) =0.809], especially in patients in the active stage (AUC =0.734), and the optimal cut-off point was -21.35%, with a sensitivity of 71.9% and a specificity of 62.2%. (III) Correlation analysis revealed that GLSendo was moderately correlated with PSD, SLEDAI, ERS, Hs-CRP, and complement C3 (correlation coefficients: 0.535, 0.428, 0.659, 0.559, and -0.440, respectively). Conclusions: Subclinical myocardial injury in patients with SLE can be assessed early using 2D longitudinal STI, and the injury is more obvious in active-stage patients. Endocardial longitudinal strain is a more sensitive index than epicardial longitudinal strain for the early detection of subclinical myocardial injury in patients with SLE, which is a potentially valuable clinical tool to assist in the early detection of myocardial damage.