Hyperkalemia and RAAS Inhibition in Patients with CKD

Kidney Week 2020

Patients with chronic kidney disease (CKD) commonly experience hyperkalemia. Hyperkalemia is also associated with therapeutic agents related to the renin-angiotensin-aldosterone system (RAAS). Luis Falcao Goncalves, MD, PhD, and Mario Rui Raimundo, MD, of Hospital Beatriz Angelo, Loures, Lisboa, Portugal, conducted a retrospective analysis to examine the incidence, prevalence, and clinical outcomes of at least one episode of hyperkalemia in a CKD population outpatient setting. The researchers also sought to assess the association of hyperkalemia with changes in RAAS inhibition and risk of mortality.

Results of the analysis were reported during a virtual poster session at the American Society of Nephrology Kidney Week 2020. The poster was titled Hyperkalemia, CKD, and RAAS Inhibition: A Triad with a Fine Balance to Prevent Mortality.

The cohort included all adult patients referred to a nephrology clinic over a period of 6 years. Inclusion criteria were CKD stage 3 with a minimum of 24 months of follow-up and three or more measurements of serum potassium level. The analysis examined the prevalence of hyperkalemia at baseline (first consultation) and the incidence during follow-up. Patients were categorized into two groups: those without any episodes of hyperkalemia (group A)  and those with at least one episode of hyperkalemia (Group B).

A total of 3008 patients were referred to the clinic during the study period; of those, 19.1% (n=575) met inclusion criteria. Mean age of the cohort was 70.4 years, 63.7% were male, and 94.0% were White. Mean follow-up was 4.1 years.

At baseline, the prevalence of hyperkalemia was 8.7%; the incidence at follow-up was 21.7%. There were 164 patients in group B (28.5% of the total cohort). A total of 101 patients died (17.6% of the total cohort).

During follow-up, 200 patients (34.8%) discontinued or did not initiate therapy with RAAS inhibition drugs, and 165 patients (28.7%) initiated diuretic therapy. Hyperkalemia was associated with diabetes, heart failure, macroalbuminuria, progression of CKD, higher frequency of initiation of diuretic therapy, and higher mortality.

Independent predictors of mortality were at least one episode of hyperkalemia (odds ratio [OR], 1.82; 95% confidence interval [CI], 1.08-3.04); heart failure (OR, 1.97; 95% CI, 1.16-3.35); older age (OR per 1 year increase, 1.04; 95% CI, 1.02-1.07); progression of CKD (OR, 4.18; 05% CI, 2.43-7.19). ORs among patients who maintained RAAS inhibition during follow-up and those who initiated RAAS inhibition during follow-up were 0.50 (95% CI, 0.26-0.96) and 0.38 (95% CI, 0.16-0.88), respectively.

In summary, the researchers said, “Our study confirms that RAAS inhibition had a protective and independent impact on mortality when prescribed in CKD early stages. Patients with at least one episode of hyperkalemia had a higher risk of mortality. All efforts should be made to maintain these therapeutic agents, looking for other ways to control hyperkalemia rather than stop [RAAS inhibition].”

Source: Goncalves LF, Raimundo MR. Hyperkalemia, CKD, and RAAS inhibition: A triad with a fine balance to prevent mortality. Abstract of a poster presented at the American Society of Nephrology virtual Kidney Week 2020 (Abstract PO0481), October 22, 2020.