Impaired Left Ventricular Systolic Synchrony in Patients with Lupus Nephritis: A Speckle Tracking Echocardiography Study

Objectives We aimed to explore the value of two-dimensional speckle tracking echocardiography measurements of the global longitudinal strain (GLS) and left ventricular mechanical dispersion (LVMD) in the assessment of early stage left ventricular systolic dysfunction and heterogeneity of myocardial contraction in patients with lupus nephritis (LN). Methods Patients with LN and extra-renal systemic lupus erythematosus (SLE) and healthy participants in the control group underwent echocardiography for the traditional measurement of the left ventricular systolic and diastolic function and speckle tracking measurements of the GLS and LVMD. GLS was defined as the average value of the peak strain during systole of the left ventricular 17 segments, and LVMD was defined as the standard deviation. The demographic characteristics including age, sex, and body mass index (BMI) of all the participants were collected. The clinical and laboratory characteristics of the patients with LN were collected. Results We included 41 healthy control, 37 patients with extra-renal SLE, and 73 patients with LN. There were statistically significant differences in the GLS and LVMD between the extra-renal SLE and LN groups (GLS -19.36% vs. -17.61%, p < 0.001; LVMD 35.62 ms vs 42.96 ms, p<0.001). There was a statistically significant difference in the LVMD between the extral-renal SLE and control groups (35.62ms vs 25.51ms, p<0.001), but not in GLS (-19.36% vs -19.52%, p > 0.05). Multiple regression analyses were conducted in a subset of patients, and 24-hour proteinuria was independently associated with LVMD (beta [SE], 0.793 [0.302], p < .05). Conclusions Patients with LN have more severe myocardial involvement than patients with extra-renal SLE. The asynchrony in myocardial contraction represented by the LVMD can be recognized earlier than that of the overall contractile functional impairment represented by GLS. In patients with LN, the 24-hour proteinuria was associated with LVMD. This indicates that the heterogeneity in the contractile function may be associated with the severity of renal damage.