Abstract
Background and Aims
Acute kidney injury (AKI) occurring after diuretic treatment initiation for acute heart failure (AHF) is a common phenomenon, with an incidence estimated between 20 and 50% of AHF hospitalizations. Previous studies found that persistent AKI is associated with poor prognosis. Treatment-induced hemoconcentration is associated with improved prognosis, but several definitions previously used are not suited for clinical practice. Transient AKI, with or without hemoconcentration, is of unsettled prognosis. We aim to determine the independent prognostic value of transient AKI, persistent AKI and hemoconcentration in the context of AHF hospitalization, using practical definitions.
Method
Data were obtained from the Greater Paris University Hospitals (GPUH) Clinical Data Warehouse. Patients hospitalized for AHF in various GPUH units were included. AHF hospitalization was defined as hospitalization with at least one AHF ICD-10 code and at least one recorded furosemide administration. Bumetanide is rarely used in GPUH hospitals hence it was not considered. AKI in a period of 14 days following first furosemide administration was defined based on KDIGO guidelines. Hemoconcentration was defined as an increase in serum proteins ≥ 5 g/l during the same period. Multivariate logistic regression was performed to determine which characteristics were predictive of AKI. Cox regression of 100 days all-cause mortality using multiple confounders was performed to determine the prognostic value of transient AKI (< 14 days), persistent AKI (≥ 14 days) and hemoconcentration. Patients with AKI upon hospital entry were excluded from regression analyses. AKI and hemoconcentration were treated as time-dependent covariates to adjust for immortality bias.
Results
Five hundred seventy nine patients were included. Among them, 529 had no AKI upon hospital entry and 513 had at least one recorded serum proteins and creatinine value following furosemide initiation. Median follow-up was 114 days. AKI in a period of 14 days following furosemide initiation occurred in 234 patients (40.4%). At baseline, patients in the AKI group more frequently suffered from chronic kidney disease or presented with clinical and echocardiographic signs of right heart failure. Independent predictors of AKI were arterial hypertension upon furosemide initiation (adjusted OR 1.86 [1.08 – 3.22]), elevated serum creatinine upon furosemide initiation (adjusted OR 1.07 [1.01 – 1.14] per 10 µmol/l increase) and initial intravenous administration of furosemide (adjusted OR 2.42 [1.39 – 4.29]). Death during follow-up occurred in 35% of patients in the AKI group compared to 21% in the non-AKI group (p < 0.001). In multivariate analysis, persistent AKI was independently associated with increased mortality in a period of 100 days following furosemide initiation (adjusted HR 2.31 [1.07 – 4.99]). Transient AKI was not significantly associated with mortality (adjusted HR 0.64 [0.34 – 1.19]). Hemoconcentration was independently associated with decreased mortality (adjusted HR 0.46 [0.27 – 0.79]).
Conclusion
After furosemide initiation during hospitalization for AHF, persistent AKI (≥ 14 days) was independently associated with increased 100 days mortality. Hemoconcentration, using a definition suited for clinical practice (≥ 5 g/l increase in serum proteins), was independently associated with decreased 100 days mortality. No significant association was found between mortality and transient AKI (< 14 days). Those findings show that laboratory tests at a limited cost – serum proteins and creatinine – are helpful to evaluate treatment response and mortality risk during AHF. Prospective randomized controlled trials are needed to establish diuretic strategies based on both AKI and hemoconcentration.
Galactin-3: diagnostic and prognostic value in patients with chronic heart failure
