P789TLR-4 expression predicts mortality in patients with acute heart failure
Abstract Background Inflammation is regarded as an important trigger for disease progression in heart failure (HF) and activation of the inflammatory system was implicated in the pathophysiology of acute heart failure (AHF). Toll-like receptors (TLRs) play an important role in acute inflammatory processes in critically ill patients by binding to pathogen associated molecular patterns (PAMP) and danger associated molecular patterns (DAMP). However, it is not known whether the expression patterns of TLRs on neutrophils and monocytes are associated with outcome in patients with severe AHF requiring intensive care unit (ICU) admission. The aim of this prospective, observational study was to analyze whether TLR-expression on monocytes or neutrophils is associated with 30-day survival in patients with severe AHF. Methods We included 84 patients with severe AHF admitted to a cardiac ICU. Blood was taken at admission and mean fluorescence activity (MFI) of TLR-2, TLR-4 and TLR-9 on monocytes and neutrophils was analyzed by flow cytometry. Results Median age was 64 (IQR 48–74) years and 76.2% of patients were male. Median NT-proBNP was 4941 (IQR 1298–12273) pg/mL and 30-day mortality was 33.3%. TLR-4 expression on monocytes in survivors (740 IQR 694–854) was significantly lower than in non-survivors (871 IQR 723–979; p<0.05). TLR-2 and TLR-9 expression on monocytes and TLR expression on neutrophils was not associated with survival. TLR-4 expression on monocytes was significantly associated with survival independent of age, sex, creatinine and NT-proBNP levels. Conclusion Monocyte TLR-4 expression predicts mortality in patients admitted to a cardiac ICU for severe acute heart failure. This suggests that activation of the innate immune system by TLR-binding of DAMPS may play a significant role in critically ill acute heart failure patients.