Inflammatory markers in Eisenmenger syndrome and their association with clinical outcomes. A cross-sectional comparative study

Background: Inflammation may be an important factor contributing to the progression of Eisenmenger syndrome (ES). The purpose of the current study was to: characterize the inflammatory profile in ES patients and compare measures to reference values for congenital heart disease and pulmonary arterial hypertension (CHD-PAH); and investigate whether inflammatory markers are associated with other clinical markers in ES.

Methods: Twenty-seven ES patients were prospectively selected and screened for systemic inflammatory markers, including interleukin (IL)-1β, tumor necrosis factor-alpha (TNF-α) and IL-10. Clinical data and echocardiographic parameters were obtained, with concomitant analysis of ventricular function. Functional capacity was assessed using the 6-min walk test (6MWT). Renal function and blood homeostasis were evaluated by the level of blood urea nitrogen (BUN), creatinine, and plasma electrolytes.

Results: Patients with ES expressed higher IL-10, IL-1β and TNF-α compared to reference values of patients with CHD-PAH. IL-10 was negatively associated with BUN (r = -0.39,p = 0.07), creatinine (r = -0.35, p = 0.002), sodium (r = -0.45, p = 0.03), and potassium (r = -0.68, p = 0.003). IL-10 was positively associated with bicarbonate (r = 0.45, p = 0.02) and trended toward a positive association with right ventricular fractional area change (RV_FAC) (r = 0.35, p = 0.059). IL-1β was negatively associated with potassium (r = -0.5, p = 0.01). TNF-α demonstrated positive association with creatinine (r = 0.4,p = 0.006), BUN (r = 0.63,p = 0.003), sodium (r = 0.44, p = 0.04), potassium (r = 0.41, p = 0.04), and was negatively associated with RV_FAC (r = -0.38,p = 0.03) and 6MWT distance (r = -0.54, p = 0.004).

Conclusion: ES patients exhibit a more severe inflammatory profile compared to reference values for CHD-PAH. Furthermore, inflammatory markers are related to renal dysfunction, right ventricular impairment and poorer functional capacity.