Effects of Sacubitril/Valsartan on Biomarkers of Extracellular Matrix Regulation in Patients With HFrEF

BACKGROUND Myocardial fibrosis is an important pathophysiological mechanism underlying the development of heart failure (HF). Given the biochemical targets of sacubitril/valsartan, we hypothesized that circulating biomarkers reflecting the mechanisms that determine extracellular matrix (ECM) homeostasis, including collagen synthesis, processing, and degradation, are altered by sacubitril/valsartan in comparison to enalapril. OBJECTIVES The purpose of this study was to examine the effects of sacubitril/valsartan on biomarkers of ECM homeostasis and the association between the rate of primary composite outcome (cardiovascular death or HF hospitalization) and these biomarkers. METHODS Biomarkers at baseline (n = 2,067) and both baseline and 8 months after randomization (n = 1,776) included aldosterone, soluble ST2 (sST2), tissue inhibitor of matrix metalloproteinase (TIMP)-1, matrix metalloproteinase (MMP)-2, MMP-9, Galectin-3 (Gal-3), N-terminal propeptide of collagen I (PINP), and N-terminal propeptide of collagen III (PIIINP). The effects of sacubitril/valsartan on biomarkers were compared with enalapril. Baseline biomarker values and changes from baseline to 8 months were related to primary outcome. RESULTS At baseline, the profibrotic biomarkers aldosterone, sST2, TIMP-1, Gal-3, PINP, and PIIINP were higher, and biomarkers associated with collagen degradation, MMP-2 and -9, were lower than published referent control values. Eight months after randomization, aldosterone, sST2, TIMP-1, MMP-9, PINP, and PIIINP had decreased more in the sacubitril/valsartan than enalapril group. At baseline, higher values of sST-2, TIMP-1, and PIIINP were associated with higher primary outcome rates. Changes from baseline to 8 months in sST-2 and TIMP-1 were associated with change in outcomes. CONCLUSIONS Biomarkers associated with profibrotic signaling are altered in HF with reduced ejection fraction, sacubitril/valsartan significantly decreased many of these biomarkers, and these biomarkers have important prognostic value. These findings suggest that sacubitril/valsartan may reduce profibrotic signaling, which may contribute to the improved outcomes. (This Study Will Evaluate the Efficacy and Safety of LCZ696 Compared to Enalapril on Morbidity and Mortality of Patients With Chronic Heart Failure PARADIGM-HF; NCT01035255).