Relationship Between Systemic Lupus Erythematosus Disease Activity Index Scores and Subclinical Cardiac Problems

Background: Systemic lupus erythematosus (SLE) is an autoimmune connective-tissue disease involving multiple organs and systems. Some evidence has demonstrated that disease activity could be associated with increased risk of organ damage.

Objectives: The aim of this study was to determine the association between systemic lupus erythematosus Disease Activity Index (SLEDAI) scores and subclinical cardiac involvement.

Methods: This cross-sectional study was conducted on 45 SLE patients (88% female; mean age: 31.2 ± 8.2 years) from 2011 to 2013 in Mashhad, Iran. The patients had no clinical signs and symptoms of cardiac problems or risk factors for cardiovascular disease and were selected consecutively. All patients underwent complete echocardiographic examinations (using two dimensional (2D) tissue Doppler and 2D speckle tracking). Disease activity was evaluated by using the SLEDAI.

Results: Patients with higher SLEDAI scores had higher pulmonary artery pressure rates (r = 0.34; P = 0.024; 95% CI (0.086 to 0.595)) and SLE durations (r = 0.43; P = 0.004; 95% CI (0.165 to 0.664). The correlation between disease duration and left ventricular mass was also significant (r = 0.43; P = 0.009; 95% CI (0.172 to 0.681)), even after adjusting for age (r = 0.405; P = 0.016). There was no correlation between SLEDAI scores or disease duration and the left/right ventricle systolic function parameters. This was true while assessing the right ventricle's diastolic function. A statistically significant correlation was found between mitral E/E' as an index of left ventricle diastolic impairment and the SLEDAI scores (r = 0.33; P = 0.037; 95% CI (0.074 to 0.574)) along with disease duration (r = 0.45; P = 0.004; 95% CI (0.130 to 0.662); adjusted for age: r = 0.478; P = 0.002).

Conclusions: Echocardiography is a useful noninvasive technique for screening subclinical heart problems in SLE patients. Although disease activity in general should suggest a closer follow-up, regular scanning would enable earlier detection of cardiovascular involvement and should not be confined to cases with higher SLEDAI indices or longer disease durations.