Discontinuation of Renin-Angiotensin-Aldosterone System Inhibitors Secondary to Hyperkalemia Translates into Higher Cardiorenal Outcomes

Abstract

<b><i>Introduction:</i></b> Discontinuation of renin-angiotensin-aldosterone system inhibitor (RAASi) is common after hyperkalemia. We evaluated the risk of kidney and mortality outcomes associated with RAASi discontinuation among patients with chronic kidney disease (CKD) and hyperkalemia. <b><i>Methods:</i></b> We identified adult patients with CKD (eGFR &lt;60 mL/min/1.73 m²) who experienced new-onset hyperkalemia (potassium ≥5.0 mEq/L) between 2016 and 2017 from Kaiser Permanente Southern California and followed them through 2019. We defined treatment discontinuation as having ≥90-day gap in refills of all RAASi within 3 months after hyperkalemia. We used multivariable Cox proportional hazards models to evaluate the association between RAASi discontinuation and the primary composite outcome of kidney (≥40% eGFR decline, dialysis, kidney transplant) or all-cause mortality. We evaluated cardiovascular events and recurrence of hyperkalemia as secondary outcomes. <b><i>Results:</i></b> Among 5,728 patients (mean age 76 years), 13.5% discontinued RAASi within 3 months after new-onset hyperkalemia. During the median 2 years of follow-up, 29.7% had the primary composite outcome (15.5% with ≥40% eGFR decline, 2.8% dialysis or kidney transplant, 18.4% all-cause mortality). Patients who discontinued RAASi had a higher all-cause mortality compared with those who continued RAASi (26.7% vs. 17.1%) but had no differences in kidney outcomes, cardiovascular events, and recurrence of hyperkalemia. RAASi discontinuation was associated with a higher risk of kidney or all-cause mortality composite outcome (adjusted hazard ratio [aHR] 1.21, 95% CI: 1.06, 1.37) mainly driven by all-cause mortality (aHR: 1.34, 95% CI: 1.14, 1.56). <b><i>Conclusion:</i></b> RAASi discontinuation after hyperkalemia was associated with worsened mortality, which may underscore the benefits of continuing RAASi among patients with CKD.