(P163) HYPERKALEMIA-RELATED HEART FAILURE THERAPY DISCONTINUATION AND ITS ASSOCIATION WITH ADVERSE OUTCOMES IN PATIENTS WITH HEART FAILURE: A POPULATION-BASED STUDY

Background: Renin–angiotensin–aldosterone system (RAAS) inhibitors are evidence-based therapies in patients with heart failure (HF), but their use is often limited by episodes of hyperkalemia.

METHODS AND RESULTS: A population-based cohort study in patients who were hospitalized or presented to the emergency department in Alberta with HF and experienced RAASi-induced hyperkalemia between April 2012 and March 2020. Episodes of hyperkalemia were identified from all potassium (K>5.0 mmol/L) measurements available. Patients were followed for 30 days following the hyperkalemia episode to determine whether their RAAS was dose-changed, discontinued, or maintained. Overall, 7,527 patients (median age of 79 years, 54.7% men) with heart failure had RAASi-associated hyperkalemia over 123,038 RAASi-treatment years (17 events per 100 RAASi-treatment years) and 73.4% had serum K < 5.5 mEq/L. The development of hyperkalemia led to the discontinuation of RAASi in 35.2% of episodes, down-titration in 8.4%, and continuation in 56.4%. Discontinuation or down-titration of RAASi was more common when serum potassium exceeded 6.0 mEq/L (49.4%) than when serum K was 5.5-6.0 mEq/L (37.2%) or 5.0-5.4 (33.8%). Over a median follow-up of 1.4 years, discontinuation or down-titration of RAASi was associated with increased risk of all-cause mortality (aHR 1.80), hospitalizations for cardiovascular disease (aHR 1.09), and ED visits for heart failure (aHR 1.17) as compared to the continuation of RAASi therapy.

Conclusion: In patients with heart failure, RAASi discontinuation or down-titration was associated with higher mortality and cardiovascular events compared to continuation of RAASi therapy, even after inverse probability weighting. Developing strategies to maintain RAASi treatment after hyperkalemia events may improve clinical outcomes in heart failure patients.