Impact of worsening renal function during hospital admission on resource utilization in patients with heart failure

Renal impairment frequently accompanies heart failure (HF) and is a recognized independent risk factor for morbidity and mortality. Few data are available assessing the impact of worsening renal function (WRF) during hospitalization on health care resource use in patients with HF. Health Insurance Portability and Accountability Act-compliant, de-identified, clinical, laboratory, and economic data for patients admitted to a tertiary care medical center with a primary diagnosis of HF were extracted by MedMining and reviewed retrospectively by the authors. Patients were excluded if they had no previous HF or were admitted for acute coronary syndrome or coronary artery bypass grafting within 30 days of index hospitalization. WRF was defined as ≥ 0.3 mg/dl increase in serum creatinine from baseline at any time during hospitalization. Of 5,803 hospitalized patients with primary HF diagnosis, 827 patients (14%) fulfilled all prespecified inclusion and exclusion criteria (74 ± 14 years of age, 43% men, 98% white, admission serum creatinine 1.4 ± 0.9 mg/dl, estimated glomerular filtration rate < 90 ml/min/1.73 m(2) at admission in 83%). During index hospitalization, WRF was identified in nearly 33%. Compared to patients without WRF, those with WRF had greater prevalence of diabetes (54% vs 43%), lower estimated glomerular filtration rate (44 ± 30 vs 62 ± 35 ml/min/1.73 m(2)), higher serum potassium (4.3 ± 0.7 vs 4.2 ± 0.7 mEq/L), and higher B-type natriuretic peptide (845 ± 821 vs 795 ± 947 pg/ml) at baseline (all p values < 0.05). Patients developing WRF incurred higher total inpatient costs ($10,977, range 671 to 212,819, vs $7,820, range 697 to 269,797, p < 0.001) and longer hospital stay (8.2 ± 6.8 vs 5.7 ± 5.5 days, p < 0.001). In conclusion, occurrence of WRF during HF-related hospitalization is associated with higher hospitalization costs and longer hospital stay.