Influence of Daily Salt Intake on Blood Pressure and Atrial Natriuretic Peptide Levels in Patients Treated with Sacubitril/Valsartan.

Objective Sacubitril/valsartan combines the effects of angiotensin receptor blockers (ARBs) with increased atrial natriuretic peptide (ANP) levels through neprilysin inhibition. ANP has vasodilatory and natriuretic effects. ARB efficacy is diminished by high daily salt intake (HDSI) in hypertension; however, it is unclear whether HDSI similarly affects the efficacy of sacubitril/valsartan. We aimed to assess the effect of ANP on blood pressure (BP) in patients with hypertension and HDSI treated with sacubitril/valsartan. Methods Fifty consecutive patients with hypertension previously on ARBs were enrolled and switched to sacubitril/valsartan (200 mg). BP and ANP levels were measured at baseline and two weeks after initiation. DSI was calculated from spot urine samples at these time points. Patients were divided into HDSI and low DSI (LDSI) groups based on the median baseline DSI. Results All patients had chronic kidney disease. The baseline average systolic/diastolic BP was 151±11/89±16 mmHg. At follow-up, both groups showed significant absolute and percentage BP reductions, with no significant differences between the groups. The DSI levels obtained by urine tests were significantly higher in the HDSI group than in the LDSI group. ANP levels increased in both groups at follow-up and more significantly in the HDSI group than in the LDSI group (573±585 vs. 84±78 pg/mL, p<0.001; 144±98% vs. 35±28%, p<0.001). Conclusions Sacubitril/valsartan was effective in lowering BP not only in patients with lower salt intake but also in patients with higher salt intake. The notable medication-induced increase in ANP levels may contribute to BP reduction through vasodilatory and natriuretic actions.