141 Hyperkalaemia and outcomes in hospitalised adults with and without heart failure on raasi: a prospective single centre study

Background Inhibitors of the Renin-angiotensin-aldosterone-system (RAASi) offer prognostic advantages in heart failure with reduced ejection fraction (HFrEF), after myocardial infarction (MI) and for those with chronic kidney disease (CKD). Nevertheless, when patients develop hyperkalaemia RAASi dosage might be lowered or discontinued, potentially leading to unfavourable outcomes. Purpose A prospective observational study at a single center analysed real-world data of patient's post-hospitalisation with a hyperkalaemia episode. The study focused on (i) the subsequent prescription patterns of renin-angiotensin-aldosterone system inhibitors (RAASi), particularly in HFrEF, (ii) the timing of follow-up blood tests after discharge, and (iii) one-year outcomes. Methods Patients hospitalized in a major district hospital (Portsmouth Hospitals University NHS Trust, UK), who were on RAAS inhibitors (RAASi) with a potassium level of ≥5.5 mmol/l, capable of providing consent, were selected for inclusion. Exclusion criteria encompassed patients undergoing dialysis. Data regarding demographics, existing health conditions, medication history, RAASi prescriptions, scheduling of blood tests, and patient outcomes during the initial hospital stay and at follow-up intervals of 3 and 12 months were gathered and analysed. Results Between July 2022 - November 2023, 100 patients with at least one episode of hyperkalaemia on RAASi were included. 55% of patients had history of hyperkalaemia in the preceding year. Mean age 75-years (SD +/-11), 26% women. Comorbidities were common (Fig 1A), 31% had 4 or more. HFrEF was the most common prognostic indication for RAASi (n=45), for these patients mean age was 76 years, 29% female. Contributory causes of hyperkalaemia are shown in figure 1B, the most common of which was acute kidney injury (AKI). Leading cause for AKI was infection (n=16), and dehydration (n=11). Survival to 1-year and re-hospitalisations for are shown in the figure 1C and 1D respectively. Of the 45 patients with HFrEF, 10 died by 3 months and 11 by 1 year. Renal function within 2 weeks post discharge was checked in 55% (51/92) of all patients, 48% (22/45) of HFrEF. This increased to 71% and 68% by 4 weeks, respectively. All patients had RAASi stopped during hospitalisation. All patients with HFrEF (n=41) who survived the index admission had at least one RAASi restarted, however, only 17 were receiving 2 RAASi at discharge. 63% (22/35) of those alive at 3 months, with HFrEF were on at least one RAASi, 67% (23/34) at 1 year. Conclusion Hospitalized patients experiencing an episode of hyperkalaemia exhibit suboptimal one-year outcomes. Despite the complication of acute kidney injury (AKI) in numerous cases, consistent post-discharge renal function assessment is lacking. Additionally, renin-angiotensin-aldosterone system inhibitors (RAASi) are under prescribed during follow-up, even for patients with compelling indications like heart failure with reduced ejection fraction (HFrEF) and post MI. Enhancing patient care for this vulnerable group may require focused educational initiatives and the strategic use of potassium binders. Conflict of Interest No conflict of interest.