Status and timing of angiotensin receptor-neprilysin inhibitor implementation in patients with heart failure and reduced ejection fraction: Data from the Swedish Heart Failure Registry

Aims: We explored timing, settings and predictors of angiotensin receptor-neprilysin inhibitor (ARNI) initiation in a large, nationwide cohort of patients with heart failure (HF) with reduced ejection fraction (HFrEF). Methods and results: Patients with HFrEF (ejection fraction <40%) registered in the Swedish HF Registry in 2017-2021 and naïve to ARNI were evaluated for timing and location of, and their characteristics at ARNI initiation. ARNI use increased from 8.3% in 2017 to 26.7% in 2021. Among 3892 hospitalized patients, 8% initiated ARNI in-hospital or ≤14 days after discharge, 4% between 15 and 90 days, and 88% >90 days after discharge or never initiated. Factors associated with earlier initiation included follow-up in specialized HF care, more severe HF, previous HF treatment use and higher income, whereas older age, higher comorbidity burden and living alone were associated with later/no initiation. Of 16 486 HFrEF patients, 8.1% inpatients and 5.9% outpatients initiated an ARNI at the index date. Factors associated with initiation in outpatients were overall consistent with those linked with an in-hospital/earlier ARNI initiation; 4.9% of 10 209 with HF duration <6 months and 9.1% of 5877 with HF duration ≥6 months initiated ARNI. Predictors of ARNI initiation in HF duration <6 months were inpatient status, lower ejection fraction, hypertension, whereas previous angiotensin-converting enzyme inhibitor/angiotensin receptor blocker use was associated with less likely initiation. Discontinuation at 1 year ranged between 13% and 20% across the above-reported analyses. Conclusions: In-hospital and early initiation of ARNI are limited in real-world care but still slightly more likely than in outpatients. ARNI were more likely initiated in patients with more severe HF, which might suggest its use as a second-line treatment and only following worsening of clinical status. One-year discontinuation rates were consistent regardless of the timing/setting of ARNI initiation.