Quantitative assessment of left ventricular systolic function in patients with systemic lupus erythematosus: a non-invasive pressure-strain loop technique

Abstract

Background: Systemic lupus erythematosus (SLE) is associated with a variety of cardiovascular diseases, even in the early stage of disease development. The purpose of this study was to quantitatively evaluate left ventricular (LV) systolic function in patients with SLE using a novel non-invasive pressure-strain loop (PSL) technique.

Methods: This prospective case-control study included 132 patients with SLE and 99 normal controls, all of whom underwent traditional transthoracic echocardiography. The LV myocardial work was evaluated with the PSL technique based on speckle tracking and brachial artery blood pressure. The differences among groups were compared, and the correlations between myocardial work, laboratory data, and disease activity were analyzed in the SLE group.

Results: Compared with the normal group, SLE patients had significantly higher global wasted work {GWW; SLE: 109 [82-150] mmHg%; controls: 66 [45-109] mmHg%; P<0.001} and impaired global work efficiency [GWE; SLE: 95% (94-97%); controls: 97% (96-98%); P<0.001]. Global work index (GWI) and global constructive work (GCW) did not show significant differences (P>0.05). Further subdivision analysis found that the increase of GWW and the damage of GWE were more obvious in SLE patients with high disease activity or severe diastolic dysfunction. Multivariate analysis revealed that increased erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), anti-phospholipid antibodies, peak strain dispersion, and SLE Disease Activity Index (SLEDAI) were independently associated with increased GWW (β=0.189, 0.230, 0.444, 0.111, and 0.180, respectively; all P<0.05) and damaged GWE (β=-0.184, -0.130, -0.468, -0.149, and -0.191, respectively; all P<0.05).

Conclusions: The non-invasive PSL can quantitatively evaluate the LV systolic function in SLE patients. This technique may provide a new method for monitoring cardiac function in chronic diseases.

Keywords: Systemic lupus erythematosus (SLE); myocardial work; pressure-strain loop (PSL).

Figure 1

LV myocardial work of control and SLE. (A,C) Control. (B,D) SLE. For (A) and (B), the left side shows the PSLs and their area represents the work index (red ring refers to global; green refers to a segment); the right side is the bullseye plot of 17 segments, which shows the global work efficiency (GWE). For (C) and (D), the left side represents the constructive work (GCW, green column) and wasted work (GWW, blue column) of the mid-septal and the global, respectively; the right side shows the specific values of the parameters. Note the LV myocardium was damaged in SLE. LVP, left ventricular pressure; ANT, anterior; SEPT, septal; INF, inferior; LAT, lateral; POST, posterior; BP, blood pressure; LV, left ventricular; SLE, systemic lupus erythematosus; PSL, pressure-strain loop; GLS, global longitudinal strain; GWI, global work index; GWE, global work efficiency; GCW, global constructive work; GWW, global wasted work.

Figure 2

Patient screening flow diagram. SLE, systemic lupus erythematosus; ACR/SLICC, American College of Rheumatology/Systemic Lupus International Collaborating Clinics; LVEF, left ventricular ejection fraction.

Figure 3

Grouping analysis was performed according to SLEDAI score (A) and LV diastolic function (B). The Y axis on the left corresponds to GWE, while the right corresponds to GWI, GCW, and GWW. SLEDAI, systemic lupus erythematosus Disease Activity Index; LV, left ventricular; GWE, global work efficiency; GWI, global work index; GCW, global constructive work; GWW, global wasted work.

Figure 4

Correlation between myocardial work parameters and GLS. (A) Correlation between GWE and GLS. (B) Correlation between GWW and GLS. GLS, global longitudinal strain; GWE, global work efficiency; GWW, global wasted work.