Objectives. To explore the relationship between IL-6 levels and echocardiographic abnormalities, and N-terminal probrain natriuretic peptide (NT-proBNP) levels in SSc patients and to correlate tested parameters with European Scleroderma Activity (EUSTAR) score.
Methods. This case–control study included 31 SSc patients with preserved left ventricular ejection fraction (LVEF) and 32 matched healthy controls. Serum IL-6 and NT-proBNP levels were measured and subjects were evaluated by conventional and pulsed-wave tissue Doppler echocardiography.
Results. The level of IL-6 was significantly increased in patients with SSc (3.2 vs 2.2 pg/ml, P < 0.001). SSc patients had significantly lower values of LV systolic (7.7 vs 9.25 cm/s, P < 0.001) and early diastolic (8.7 vs 10.3 cm/s, P = 0.014) myocardial velocities and higher E/e′ (9.04 vs 7.37, P = 0.001) ratio, although there was no between-group difference according to LVEF (68% vs 65%, P = 0.248). On evaluating the right ventricle there was no significant between-group difference in systolic tricuspid annular velocity (13 vs 13.9 cm/s, P = 0.105), but the peak early diastolic velocity was significantly lower (11.7 vs 13.6, P = 0.044) and E/e′ was significantly higher (4.3 vs 3.38, P = 0.008) in SSc patients. IL-6 level showed correlation with LV mean e′ (r = −0.57, P = 0.001), E/e′ (r = 0.55, P = 0.001) and NT-proBNP (r = 0.52, P = 0.003). EUSTAR score correlated with LV E/e′ (r = 0.48, P = 0.006), mean e′ (r = −0.67, P < 0.001), mean s′ (r = −0.51, P = 0.004), NT-proBNP (r = 0.60, P < 0.001) and IL-6 (r = 0.79, P < 0.001).
Conclusion. IL-6 level is increased in patients with SSc and significantly correlates with LV diastolic dysfunction, NT-proBNP and EUSTAR score. These results support the role of IL-6 in the development of cardiac disease in SSc patients.