Increased days in hospital after RAASi reduction

Renin–angiotensin–aldosterone system inhibitors (RAASis) are a cornerstone of treatment for chronic kidney disease (CKD) and heart failure (HF), but also predispose to hyperkalaemia. Following an episode of hyperkalaemia, RAASi treatment is often down-titrated or discontinued, preventing patients with CKD or HF from receiving the maximum cardiorenal benefits associated with this class of drug.

The present study investigated patient-level changes in RAASi treatment following an episode of hyperkalaemia. It also aimed to describe the association between hyperkalaemia-related RAASi treatment reduction and healthcare resource utilisation in patients with CKD and/or HF, in two geographically diverse populations with different healthcare systems.

This observational cohort study used data collected retrospectively from health registers and hospital medical records in Sweden and Japan. Patients with CKD and/or HF who had been taking a RAASi for at least 90 days were eligible for enrolment if they had a coded episode of hyperkalaemia or lab potassium of >5.0 mmol/L. After this index episode, they were identified and categorised as having maintained or reduced RAASi treatment. Using baseline criteria including demographics, co-morbidities, co-medications and previous hospitalisations, propensity-score matching (1:1) was applied to provide two balanced groups.

In total, 42% of participants from Sweden (n=20,824) and 38% from Japan (n=7789) had their RAASi treatment reduced after an episode of hyperkalaemia. 

Prior to the index episode, the rates of all-cause hospitalised days per person-year were very similar in both Sweden (15.5 days [95% CI, 14.9–16.1] reduced RAASis vs 15.2 days [14.6–15.8] maintained RAASis) and Japan (28.3 days [27.9–28.6] reduced RAASis vs 28.3 days [28.0-28.6] maintained RAASis). During the following 6 months, those whose RAASi treatment was reduced spent more time in hospital for all causes (mean increase 18.2 [95% CI, 17.0–19.2] days per person-year in Sweden and 17.9 [17.4–18.5] days per person-year in Japan) than those patients whose treatment was maintained (mean increase 9.4 [8.6–10.4] days per person-year in Sweden and 8.5 [8.0–9.0] days per person-year in Japan). Similar patterns were observed for CKD- and HR-related hospitalised days.

Similarly, those in the reduced treatment group spent fewer days alive and out of hospital (mean 121.5 [SD, 75.0] days in Sweden and 141.7 [54.5] days in Japan) than those in the group whose RAASi treatment was maintained (mean 154.0 [51.3] days in Sweden and 157.5 [31.6] days in Japan).

Regression analyses on control frailty outcomes were negative. 

Despite the different study periods and data types available in the two countries studied, the trends in increased hospitalisation and reduced days alive out of hospital were consistent. Current guidelines recommend novel oral potassium binder treatments to manage hyperkalaemia and to facilitate the continuation of RAASi treatment: these were available during the duration of this study. The authors conclude that a better understanding of how adherence to guidelines can be improved is needed, so that patients with CKD or HF on a RAASi are not precluded from attaining their maximal cardiorenal benefit .

The full article can be read here.