Estimated Number Needed to Treat to Avoid a First Hospitalization by Maintaining Instead of Reducing Renin-Angiotensin-Aldosterone System Inhibitor (RAASi) Therapy after Hyperkalemia.

Key Points: Renin-angiotensin-aldosterone system inhibitor (RAASi) therapy is frequently downtitrated or discontinued after a hyperkalemia episode. Reducing RAASi therapy after a hyperkalemia episode is associated with increased risk of hospitalization compared with maintaining RAASi. Our data suggest that a hospitalization within 6 months could be avoided if 25 patients maintained instead of reduced their RAASi therapy.

Background: Renin-angiotensin-aldosterone system inhibitor (RAASi) therapy provides cardiorenal protection but is often downtitrated or discontinued after a hyperkalemia episode. This observational study describes the extent of hyperkalemia-related RAASi reduction in patients with CKD and/or heart failure (HF) and estimates the number needed to treat (NNT) to avoid a first hospitalization if RAASi had been maintained at the prior dose.

Methods: Health care registers and claims data from Germany, Spain, Sweden, and the United Kingdom were used to identify nondialysis patients with CKD and/or HF who had a hyperkalemia episode while on RAASi. Patients whose RAASi therapy was reduced (downtitrated/discontinued) after the hyperkalemia episode were propensity score matched to those with maintained RAASi, and their risks of a hospitalization within 6 months were estimated using the Kaplan–Meier method. On the basis of the absolute difference in this 6-month risk, the NNT framework was applied to estimate the number of patients who needed to have maintained instead of reduced their RAASi to avoid a first hospitalization during this period.

Results: Overall, 40,059 patients from Germany, Spain, Sweden, and the United Kingdom were included. Presence of CKD at baseline was similar across countries (72%–92%), while HF was less common in Spain (18%) versus other countries (32%–71%). After the hyperkalemia episode, RAASi was reduced in 25%–57% of patients. After propensity score matching, the 6-month risk of hospitalization was consistently higher in those with reduced versus maintained RAASi; the absolute risk difference ranged from 2.7% to 7.3%. Applying the NNT framework, these data suggest that a first hospitalization within 6 months could potentially have been avoided if 25 patients had maintained instead of reduced their RAASi.

Conclusions: Our findings suggest a potential for avoiding a first hospitalization, even within a short time frame, by increasing adherence to guidelines to maintain instead of reduce RAASi after a hyperkalemia episode.