OBJECTIVES : Hyperkalemia is a potentially electrolyte abnormality which threatens patients with kidney or cardiovascular disfunction. This study aims to estimate the clinical outcomes among patients who experienced hyperkalemia in China.

METHODS : Data were obtained from the Tianjin Urban Employee Basic Medical Insurance database (2011-2017). Adult patients who experienced ≥1 hyperkalemia episodes (ICD-10 codes E87.5) identified through inpatient or outpatient claims between January 1, 2012 and December 31, 2016 were included, with dates of their first hyperkalemia episode defined as index dates. Subgroups based on the presence of chronic kidney disease (CKD) and heart failure (HF) during the 12 months pre-index (baseline) period were further identified, which included patients with CKD, HF, and both CKD and HF (CKD-HF). The recurrence of hyperkalemia and incidence of all-cause mortality and major adverse cardiovascular events (MACEs) including arrhythmias, myocardial infarction, and stroke were also investigated and compared.

RESULTS : 2,470 patients (mean age 67.6 ± 14.1 years, 41.6% female, mean follow-up 1.8 years) were included, with 1,025, 179, and 352 patients in CKD, HF, and CKD-HF subgroups, respectively. 18.66% of patients experienced a recurrent event after index with mean interval of 10.5 months. The cumulative mortality rate was 59.60%, with 47.76% died within 3 months after index. 23.40% of patients experienced MACEs, and the incidence rate was 28.17 per 100 patient-year. Compared with the CKD subgroup, the mortality rate was higher in HF (75.98% vs. 52.39%, P<0.001) and CKD-HF (78.69% vs. 52.39%, P<0.001) subgroups, while no significant difference was found across CKD, HF, and CKD-HF subgroups in regards to incidence of MACEs (25.07%, 18.99%, 22.44%, respectively, P=0.169).

CONCLUSIONS : The observed health conditions of patients with hyperkalemia were unfavorable with the high rates of recurrence, mortality and MACEs, which indicates the importance of prevention and management for hyperkalemia, especially for patients with CKD or HF.