Angiotensin-Converting Enzyme Inhibitor Washout Period Prior to Angiotensin Receptor/Neprilysin Inhibitor Initiation in the Inpatient Setting.

Background: The 2022 AHA-ACC HFSA Guideline for Management of Heart Failure recommend initiating an angiotensin receptor/neprilysin inhibitor (ARNI) in patients with heart failure with reduced ejection fraction (HFrEF) who can tolerate an angiotensin-converting enzyme inhibitor (ACEi). The manufacturer recommends initiating a 36-hour washout period when switching from ACEi to ARNI due to an increased risk of adverse effects, including angioedema. This study investigated the adherence to the washout period when transitioning from ACEi to ARNI at a community hospital.

Objectives: The primary objective was to assess the rate of adherence to the 36-hour washout when transitioning patients from ACEi to ARNI. Secondary outcomes included heart failure exacerbation readmission rates within 90 days and the rate of adverse effects (angioedema, hypotension, acute kidney injury, and hyperkalemia).

Methods: This was a retrospective cohort study including patients with HFrEF who were transitioned from ACEi to ARNI during their hospital stay between March 1, 2016 and December 31, 2022. Patients were excluded if they did not receive an ACEi or ARNI during their admission or if they had an ejection fraction >40%. Pearson chi-square was used to analyze categorical data.

Results: Of 33 patients included in this study, 67% received the full 36-hour washout period when transitioning from ACEi to ARNI. There were no significant differences between the rates of hospital readmissions or adverse effects between the groups. No patients experienced hyperkalemia or angioedema.

Conclusion and relevance: This is the first study to our knowledge to describe real-world prescribing practices when transitioning patients from ACEi to ARNI for the treatment of HFrEF. Larger, multicenter studies are needed to provide more data on prescribing practices outside this single center. Future research should also include pharmacist's role in adhering to the recommended washout.