OBJECTIVES : Heart failure (HF) is a major epidemic in the US and a significant public health burden. Electrolyte imbalances, such as hypo- and hyperkalemia, are common among HF patients and increase the risk of fatal and non-fatal outcomes leading to higher health resource utilization (HRU) and costs. The objective of this study was to assess the differences in HRU and cost among HF patients with preserved ejection fraction (HFpEF) or reduced ejection fraction (HFrEF) who experience hypo- and hyperkalemia relative to normal potassium levels during care.

METHODS : United Optum administrative claims data were used to sample patients enrolled between January 1, 2007 and June 1, 2016. Continuous enrollment during 180-day baseline period and one-year follow-up was required to be included in the analyses. ICD-9/10 diagnosis codes were used to identify patients with diastolic heart failure (DHF) (n=112,093) and systolic heart failure (SHF) (n=93,181) to approximate HFpEF and HFrEF. Laboratory results and diagnosis codes were used to identify patients with hypo- and hyperkalemia. Risk-set sampling was used to create four comparative cohorts of patients: normal potassium vs hypokalemia in SHF (n=7,444) and in DHF (n= 11,034) and normal potassium vs hyperkalemia in SHF (n=6,736) and in DHF (n=8,514). Propensity-score matching was used to adjust for potential confounders.

RESULTS : Patients with hypo- and hyperkalemia had significantly higher unadjusted and adjusted HRU and cost in all categories compared to normal potassium-level patients. The additional costs were on average 26% in the SHF and 29% in the DHF cohort for hyperkalemia and 12% in the SHF and 7% in the DHF cohort for hypokalemia. The difference in cost was attributed to more hospitalization with longer duration of stay, more office visits, and procedures.

CONCLUSIONS : In a sample of HF patients from a US claims database, DHF patients with hyperkalemia accumulated more HRU and costs compared to SHF patients.