Myocardial performance index in active and inactive paediatric systemic lupus erythematosus

Objective To evaluate cardiac structure and function in paediatric SLE patients without clinical evidence of cardiovascular disease in active and inactive diseases. Methods Patients aged = 20 years who fulfilled the diagnostic criteria of active SLE underwent transthoracic echocardiography to evaluate cardiac structure and function, and were then followed up echocardiographically every 3-4 months until SLE disease was inactive. Patients with heart failure, myocarditis, pericarditis, endocarditis, coronary artery disease, or abnormal structural heart disease were excluded. Results Twenty-six active SLE patients, mean age 13.2 ± 3.3 years, of whom 20 were female (77%), were enrolled. Most patients had cardiac abnormalities especially LV global dysfunction assessed by left ventricular myocardial performance index (LV MPI). LV MPI by conventional method, by tissue Doppler imaging (TDI) at medial and lateral mitral valve annulus were significantly decreased when compared to LV MPI in patients with inactive disease (0.44 ± 0.14 vs. 0.30 ± 0.05, 0.52 ± 0.09 vs. 0.36±0.04, and 0.51±0.09 vs. 0.35±0.05, p < 0.001). Using receiver operating characteristic, LV MPI cut-off at 0.37, 0.40, and 0.40 by conventional, medial TDI, lateral TDI had sensitivity and specificity of 90% and 84%, 90% and 96%, 90% and100%, respectively. Conclusion Left ventricular global dysfunction was found to be common in paediatric patients with active SLE. LV MPI by TDI might be useful to diagnose active SLE in paediatric patients.