Haemodynamic Effects of Sacubitril/Valsartan Initiation in Outpatients with Chronic Heart Failure

BACKGROUND: Sacubitril/valsartan (S/V) improves outcomes in patients with heart failure with reduced ejection fraction (HFrEF). Data about the immediate, short-, and intermediate-term hemodynamic effects of S/V are limited. METHODS: In this prospective observational study, 37 outpatients with chronic HFrEF were treated with S/V according to current guideline recommendations. Next to clinical, laboratory and echocardiographic parameters, haemodynamic variables were assessed non-invasively by use of inert gas rebreathing and bioimpedance cardiography at baseline and at 2-week, 3-month and 6-month follow-up. The course of variables throughout the study and the relationship between variables were analysed using fractional polynomials. RESULTS: S/V treatment resulted in short- and intermediate-term improvements in NYHA functional class (2.3 ± 0.6 at baseline vs. 1.9 ± 0.5 at 6-month follow-up, p = 0.14), 6-min walk test (453 ± 110 vs. 528 ± 98 m, p = 0.02), ejection fraction (31 ± 9 vs. 36 ± 12%, p = 0.13), pulmonary artery pressure (39 ± 10 vs. 31 ± 10 mmHg, p = 0.02), and NT-proBNP values (1702 (782-2897 vs. 1004 (599-1627) ng/L, p = 0.03). In addition, S/V caused immediate decreases in systemic vascular resistance index (SVRI) and systolic blood pressure (SBP), which were associated with a simultaneous drop in stroke volume (SV) and cardiac index (CI). However, while SVRI and SBP remained at low levels during further treatment, SV and CI restored rapidly and increased to slightly higher levels thereafter. CONCLUSION: The vasodilative effects of S/V result in immediate reductions in SVRI, SBP, SV and CI. However, S/V induces reverse cardiac remodelling, which is apparent shortly after treatment initiation and leads to improvements of clinical, functional, echocardiographic, laboratory and haemodynamic variables.