Abstract Aims To compare baseline characteristics of patients with heart failure with reduced ejection fraction (HFrEF) initiated on sacubitril/valsartan compared with patients continued on conventional heart failure (HF)-treatment in a European out-patient setting. Methods and results Between July 2016 and July 2019, ARIADNE enrolled 8787 outpatients aged ≥18 years with HFrEF from 17 European countries. Choice of therapy was solely at the investigators’ discretion. In total, 4173 patients were on conventional HF-treatment (non-S/V group), while 4614 patients were on sacubitril/valsartan either at enrolment or started sacubitril/valsartan within 1 month of enrolment (S/V group). Of these, 2108 patients started sacubitril/valsartan treatment ±1 month around enrolment [restricted S/V (rS/V) group]. The average age of the patients was 68 years. Patients on S/V were more likely to have New York Heart Association (NYHA) class III or IV symptoms (50.3%, 44.6%, 32.1% in rS/V, S/V, and non-S/V, respectively) and had lower left ventricular ejection fraction (LVEF; 32.3%, 32.7%, and 35.4% in rS/V, S/V, and non-S/V, respectively; P < 0.0001). The most frequently received HF treatments were angiotensin-converting enzyme inhibitor/angiotensin receptor blocker (ACEI/ARB; ∼84% in non-S/V), followed by β-blockers (∼80%) and mineralocorticoid receptor antagonists (MRAs; 53%). The use of triple HF therapy (ACEI/ARB/angiotensin receptor neprilysin inhibitor with β-blockers and MRA) was higher in the S/V groups than non-S/V group (48.2%, 48.2%, and 40.2% in rS/V, S/V, and non-S/V, respectively). Conclusion In this large multinational HFrEF registry, patients receiving sacubitril/valsartan tended to be younger with lower LVEF and higher NYHA class. Fewer than half of the patients received triple HF therapy.