Frequency and Structure of Heart Damage in Systemic Lupus Erythematosus

Abstract

Study Objective: To identify the structure and prevalence of cardiac involvement in patients with systemic lupus erythematosus (SLE); evaluation of the relationship with the activity, disease duration and antirheumatic therapy. Study Design: Prospective cross-sectional study. Material and Methods. The study included 87 patients with SLE (90.8% women), with the median age of 32 [28; 41] years old and disease duration of 6 [1; 10] years; Systemic Lupus Erythematosus Disease Activity Index, modification 2К, was 9 [4; 16] points, Systemic Lupus International Collaborating Clinics Damage Index was 0 [0; 1] points. All patients were examined by a cardiologist, and traditional risk factors (TRF) of cardiovascular diseases were identified. Patients underwent transthoracic echocardiography (ECHO); if indicated, 24-hour ECG and blood pressure monitoring was performed. Serum NT-proBNP concentration was measured with electrochemiluminescence. Study Results. The most common cardiac complication was valvular insufficiency with various degree of regurgitation, which was diagnosed in 92% patients; endocarditis was recorded in 30%; mitral or tricuspid valve prolapse was observed in 33.3%. Pericardium pathologies were diagnosed in 44.8% patients, and adhesive pericarditis prevailed (61.5%). Myocarditis was observed in 4.6%, ischemic heart disease (IHD) — in 5.7%, cardiac failure (CF) — in 11.5%, rhythm and cardiac conduction disturbances — in 18.4% and 2.3%, respectively, myocardial infarction (MI) — in 2.3%. Dislipidemy and arterial hypertension (AH) were recorded in 50.6% and 46% patients. 31% demonstrated high NT-proBNP levels (> 125.0 pg/mL); median NT-proBNP concentration was 91.8 [27.1–331.2] pg/mL. Patients were divided into two groups: group 1 did not take any glucocorticoids (GC), immunosuppressants and genetically engineered biologic drugs; group 2 had various combinations of these products. Patients in both groups were of similar age and sex; they did not have any differences in the prevalence of valvular insufficiency (86.7% and 97.6%), endocarditis (26.2% and 33.3%), pericarditis (42.9% and 46.7%), rhythm disturbance (19% and 17,8%), and impaired cardiac conduction (2.4% and 2.2%), IHD (2.4% and 8.9%), CF (7% and 15.5%). MI and myocarditis were diagnosed only in group 1 (4.4% and 9.5%, respectively); however, these differences were not statistically significant. AH was observed more frequently in group 2 than in group 1 (62.2% and 28.6%, р < 0.01); other TRFs did not demonstrate any differences; however, total cholesterol concentration and body mass index in group 2 were higher than in group 1: 5.7 and 4.5 mmol/L (р < 0.05); 22.66 and 22.10 kg/m2 (р < 0.01). NT-proBNP concentration in untreated patients was higher than in group 2 (150.7 and 32.6 pg/mL, respectively, р < 0.01), exceeding the normal values. Conclusion. Despite the juvenile age of patients, the therapy (mostly GC) and longer disease duration are associated with higher incidence of TRF (AH, hypercholesterolemia, overweight), while myocarditis and high NT-proBNP concentration are typical of untreated patients with highly active SLE. SLE patients should be followed up by a cardiologist; symptom-free CF markers should be identified as this condition is life-threatening, especially in patients with extremely active disease; TRFs should be monitored; and minimal GC doses should be used during remission/low-activity disease. Keywords: systemic lupus erythematosus; cardiac involvement; pericarditis; myocarditis; endocarditis; NT-proBNP; ECHO.