Understanding the benefits of renin-angiotensin-aldosterone system inhibitors and influence of hyperkalaemia on their prescription: a UK survey of healthcare professionals' views and practice

Abstract Background Renin–angiotensin–aldosterone system inhibitors (RAASi) improve outcomes in heart failure with reduced ejection fraction (HFrEF) and they should be increased to the maximally tolerated dose. However, their use is often hindered by hyperkalaemia leading to discontinuation or down titration. Purpose Assess perceptions of primary and secondary healthcare professionals regarding benefits of RAASi according to indication and, in the context of developing hyperkalaemia, to identify barriers to optimal utilisation, and to explore options for improving management protocols, specifically in HFrEF. Methods An electronic survey was distributed in primary and secondary care setting in Hampshire, UK, to evaluate knowledge about benefits of RAASi, clinical response to varying level of potassium (K+), and decision-making using several clinical scenarios. Hyperkalaemia was graded into mild (serum K+ 5.5 – 5.9 mmol/L), moderate (serum K+ 6.0 – 6.4 mmol/L) or severe (serum K+ ≥ 6.5 mmol/L). Results Between November 2021 and January 2023, 300 questionnaires were completed by 274 (91%) physicians (varying grades of seniority), 22 (7%) non-medical prescribers, and 4 (1%) pharmacists. 80% were working in secondary care across different specialities (31 working in cardiology and 15 in nephrology). The majority were aware of prognostic benefit of angiotensin converting enzyme inhibitors (ACEi) in patients with HFrEF although this was lower for mineralocorticoid receptor antagonists (MRA) (Fig 1). Fewer than 2/3 of respondents were aware of impact of ACEi on symptoms. In the presence of mild hyperkalaemia, 75% and 88% of healthcare professionals would stop or reduce ACEi and MRA, respectively. In moderate or severe hyperkalaemia, this increased to 96% and 97%, respectively (Fig 2A-B). When considering the scenario of a patient with HFrEF who had ACEi stopped due to K+ 5.9 mmol/L, the potassium at which the responder would consider re-starting the ACEi ranged from 77% when potassium level < 5.5 mmol/L to 1% in moderate or severe hyperkalaemia (Fig 2C). 74% of healthcare professionals were familiar with local hyperkalaemia management protocol and 93% supported dedicated training on RAASi dose adjustment and hyperkalaemia management. Conclusion This survey, across a broad range of healthcare professionals, shows uncertainties around knowledge of benefits of RAASi in patients with HFrEF and there is sizeable variation in the prescribing response to degrees of hyperkalaemia. Given the voluntary nature of the survey, it is plausible that these data are biased towards individuals with greater understanding. Regardless, there is a need for continued education with a goal of improving patient-centred care.