Hyperkalemia may increase the risks for kidney disease progression, cardiovascular (CV) events, and death in patients with chronic kidney disease (CKD), a Japanese study finds.
Using a hospital claims registry from 2008 to 2018, investigators propensity score matched 5859 patients with hyperkalemia (serum potassium 5.1 mmol/L or greater) and 5859 control patients with normokalemia. Patients with hyperkalemia had a 4.4-fold higher risk for all-cause mortality, Toshitaka Yajima, MD, PhD, of AstraZeneca KK in Osaka, Japan, and colleagues reported in Mayo Clinic Proceedings: Innovations, Quality & Outcomes. They also had a 5.1-fold higher risk for heart failure and a 2.0-fold higher risk for hospitalization for cardiac events.
The cohort had an estimated glomerular filtration rate (eGFR) of less than 60 mL/min/1.73 m2 at baseline. At 3 years, eGFR had declined faster in the hyperkalemia than normokalemia group: −5.75 vs −1.79 mL/min/1.73 m2, respectively. Results showed the hyperkalemia group had a 7.5-fold higher risk for initiation of renal replacement therapy, Dr Yajima and his colleagues reported. All results were comparable in subgroup analyses of patients with and without heart failure.
At baseline, the hyperkalemia and normokalemia groups were matched by age, CKD stage, and eGFR. They had similar prevalence of acute kidney injury, heart failure, diabetes, hypertension, dyslipidemia, and other major comorbidities. Their use of drugs associated with hyperkalemia, diabetes medications, and CV drugs were comparable, except for inotrope and mineralocorticoid receptor antagonist.
Although the study could not prove that hyperkalemia directly causes these adverse outcomes, the investigators noted that hyperkalemia commonly interferes with a healthy diet, contributes to metabolic acidosis, and prompts discontinuation of renin-angiotensin-aldosterone system (RAAS) inhibitors.
“Our findings underscore the significance of hyperkalemic condition as a precursor of future adverse events,” Dr Yajima’s team stated. “Continuous [serum potassium] level management in high-risk patients with CKD with hyperkalemia would be important for better clinical outcomes.”
Kohsaka S, Okami S, Kanda E, Kashihara N, Yajima T. Cardiovascular and renal outcomes associated with hyperkalemia in chronic kidney disease: a hospital-based cohort study. Mayo Clin Proc Innov Qual Outcomes. 5(2):274-285. doi:10.1016/j.mayocpiqo.2020.10.001