Sacubitril/valsartan that combines a neprilysin (NEP) inhibitor and an angiotensin receptor blocker (ARB) was shown superior to enalapril for the treatment of heart failure with reduced ejection fraction (HFrEF) (1). The inhibition of sNEP by Sacubitril on the processing of proBNP remains unclear.

The aim was to evaluate the evolution of cardiovascular biomarkers in patients who were switched from angiotensin converting enzyme inhibitor or ARB to sacubitril/valsartan and to evaluate the possible implication of the T71 proBNP glycosylation.

We included 90 consecutive HFrEF patients who were treated with sacubitril/valsartan according to the current ESC guidelines in two university hospital. Plasma samples were collected before the first intake of sacubitril/valsartan, at day 30 (D30) and at day 90 (D90) for 60 patients who were selected for further paired analysis.

sNEP activity decreased from D30 onward and being the lowest at D90. In contrast, there was no change in sNEP concentration. BNP and NT-proBNP plasma levels remained unchanged while high-sensitive troponin I decrease and GLP-1 increase from D90. We observed a gradual increase in T71 proBNP glycosylation. To assess the effect of T71 proBNP glycosylation on the processing of proBNP, we plotted the slope of the linear regression between BNP and NT-proBNP versus the median values of T71 proBNP glycosylation at each time points; the direct correlation observed (R²=0.99) strongly suggest that the independent evolution of BNP and NT-proBNP plasma levels in patients receiving sacubitril/valsartan results directly from the increase in T71 proBNP glycosylation.

The results showed that while sacubitril/valsartan decreased sNEP activity without no effect on the mNEP release. The increase in T71 proBNP glycosylation being responsible for the discrepancies between BNP and NT-proBNP plasma levels.