Background: Systemic lupus erythematosus (SLE) is a multisystem, autoimmune disease with potential cardiovascular involvement. Layer-specific strain (LSS) analysis is a new method that allows early detection of subtle LV systolic dysfunction. The aim of this study was to evaluate left ventricular (LV) systolic function in patients with SLE using conventional echocardiographic measurements and longitudinal strain (LS) and circumferential strain (CS) by LSS. Furthermore, the association between echocardiographic parameters and the occurrence of cardiovascular events was assessed.
Methods: A total of 162 patients with SLE (the SLE group) who underwent a dedicated multidisciplinary assessment, including echocardiography, were analyzed at the time of their first visits. The control group consisted of 68 age- and sex-matched healthy subjects. LS and CS on endocardial, mid-myocardial, and epicardial layers at 17 cardiac segments were measured. Transmural strain gradient was calculated as the differences in systolic strain between the endocardial and epicardial layers.
Results: Compared with control subjects, patients with SLE had significantly lower LV ejection fraction, LS, and CS values in all layers (P<0.05); LV LS and CS gradient were all lower than control subjects(P<0.05). During a median follow-up period of 83 months (interquartile range: 64-95 months), 59 patients (36.4%) developed cardiovascular events. Using multivariate Cox regression analysis, we found that LV endocardial LS (hazard ratio, 1.022;95% CI,0.992-1.046; P=0.037) and CS (hazard ratio, 1.052;95% CI, 1.028-1.046; P<0.001) demonstrated independent associations with cardiovascular events; whereas LV ejection fraction was not significantly associated with cardiovascular events. The Kaplan-Meier survival curves showed that patients with SLE with lower LV endocardial LS and CS (based on the cutoff values of -21.5% and -29.0%, respectively) experienced higher cumulative rates of cardiovascular events compared with those with higher LV endocardial LS and CS.
Conclusions: In patients with SLE, LV systolic function measured by LV endocardial LS and CS were significantly lower than that of the control group and were associated with cardiovascular events, potentially representing a new technology to improve risk stratification in these patients.