Evaluation Of The Left Ventricular Systolic Function In Patients With Systemic Lupus Erythematosus By Two Dimensional Speckle Tracking Imaging

Background:Systemic lupus erythematosus (SLE) is a multisystem connective tissue disease characterized by the presence of numerous autoantibodies, circulating immune complexes, and wide spread of immunologically determined tissue damage. Premature cardiovascular disease is an increasing cause of death in SLE patients. Cardiac manifestations are common in SLE patients. Pericarditis is common but often asymptomatic. Other cardiac manifestations are myocarditis, endocarditis and coronary artery disease. Coronary artery disease is occasionally caused by vasculitis, but more often results from premature atherosclerosis. Myocardial involvement occurs in10%～14%of patients, and all cardiac structures may be involved. However, the detection of myocardial involvement in patients with SLE is difficult since clinical signs and symptoms are nonspecific. The majority of SLE cardiomyopathy goes undiagnosed for the reasons that it usually begins in a stealth mode with no symptoms or warning signs, the laboratory test is insensitive and nonspecific, and heart biopsy may not be used for routine screening. Looking for a noninvasive method for early detecting SLE cardiomyopathy is urgently needed.Previous studies have proven the potentials of cardiac magnetic resonance (CMR), tissue Doppler imaging (TDI), strain rate imaging (SRI) in detecting myocardial damage of SLE patients in a subclinical stage. However, CMR is time consuming and expensive, thus the application is subjected to certain restrictions. DTI and SRI are less reproducible for nonbasal segments of myocardium, moreover, it is angle dependent and vulnerable to surrounding tissue force. Two dimensional speckle tracking imaging (2D-STI) detection speckle patterns of myocardial tissue on ultrasound images frame-by-frame, irrespective of angle dependency. The use of2D-STI in the studies of hypertension, coronary heart disease, cardiomyopathy, etc. has displayed the good sensitivity and clinical value. The objective of this study was to analysis of the left ventricular myocardial systolic deformation in patients with SLE using2D-STI, to search parameters of strain for predict disease activity.Objective:To explore the left ventricular systolic function in patients with SLE using the2D-STI.Methods:Forty-three patients with SLE (SLE group) and thirty-three age and gender-matched healthy controls (control group) were collected and underwent transthoracic echocardiography. Global longitudinal strain (GLS), global cirumferential strain (GCS), left ventricular twist (LVTW) were calculated via Qlab9.0analysis software offline. Disease activity was evaluated for all SLE patients by Systemic Lupus Erythematosus Disease Activity Index2000(SLEDAI2000, SLEDAI-2K), disease activity is classified into3categories:mildly active(score<10), moderately active(score10-14), severely active (score≥15). All of the above parameters were compared between groups. Pearson correlation analysis was used to examine the correlation between two variables, We conducted multiple linear regression analysis to determine the independent predictors of SLEDAI. Draw ROC curve of GLS to predict severely active.20cases of the research object were drawed randomly and measured by the same observer and another experienced observer again after two weeks. P<0.05was considered statistically significant.Results:1. Population:The2groups did not show significant differences regarding age, gender, height, weight, heart rates or diastolic blood pressure. Systolic blood pressure, although in the normal range, was significantly higher in SLE patients compared with controls.2.2D Echocardiographic analysis:Interventricular septum diastolic thickness (IVST), left ventricle diastolic dimension(LVDD), left ventricular diastolic posterior wall thickness (PWT), left ventricular fractional shorting (FS), the maximum velocity of left ventricular outflow tract(Vlvot) and left ventricular ejection fraction(LVEF) had no statistically signifiancant difference between SLE group and control group. Compared with controls, Tei index measured by PW was significantly higher in SLE group(P<0.01).3.2D-STI comparison in the two groups:Compared with controls, GLS,GCS were significantly reduced in the SLE group (all P<0.01), LVWT was significantly increased in SLE group (P<0.05). 4. Strain values of SLE patients grouped by disease activity:GLS, GCS, and LVTW were significantly decreased in patients with severely active SLE compared with those in patients with moderately active (all P<0.05). GCS and LVTW tended to be higher in patients with moderately active SLE than in patients with mildly active, but the difference was significant(P>0.05).5. Linear correlation analyses:Good correlation were noted between GLS and LVEF(r=-0.608, P<0.01); There was noteable correlation between SLEDAI and the values of GLS (r=0,598, P<0.01), GCS(r=0.331, P<0.05), except LVWT (P>0.05). In a multivariate reression analysis with GLS, GCS, and LVWT included, only GLS was independently with correlated with SLEDAI score (P<0.05). The regression model was as follws:Y=67.71+0.68GLS.6. Optimal cut-off value of GLS to predict severely active was-18.60%(sensitivity71.5%, specificity75.6%and areas under the ROC curve0.756).7. Bland-Altman analysis showed GLS, GCS were good agreements in both patients with SLE and control subjects.Conclusions:This study using2D-STI technology for evaluating of the left ventricular systolic function in patients with systemic lupus erythematosus, the conclusion is as follows:1. Multidirectional dysfunction of myocardial movment was observed in SLE patients using2D-STI, whose LV systolic function was normal measured by standard echocardiography.2. Compared with controls, GLS, GCS were significantly reduced in the SLE group(all P<0.01), LVWT was significantly increased in SLE group(P<0.05).3. GLS, GCS, and LVTW were significantly decreased in patients with severely active SLE compared with those in patients with moderately active(all P<0.05). GCS and LVTW tended to be higher in patients with moderately active SLE than in patients with mildly active,but the difference was significant(P>0.05).4. GLS was independently with correlated with SLEDAI score(P<0.05).5. GLS of LV is independently correlated with SLE disease activity, may be severed as a complementary index for assessing disease status of SLE.6. Optimal cut-off value of GLS to predict severely active was-18.60%(sensitivity71.5%, specificity75.6%and AUC0.756).7. There have good consistency in relevant measurements.8. The operation of this technology is convenient, and the image is intuitive, can be combined with disease activity in patients with SLE, it will have broad clinical application prospect in detection and diagnosis of dysfunction of myocardial movement.