Worsening renal function in children hospitalized with decompensated heart failure: evidence for a pediatric cardiorenal syndrome?

OBJECTIVES: The purpose of this study was to determine the incidence of renal insufficiency in children hospitalized with acute decompensated heart failure and whether worsening renal function is associated with adverse cardiovascular outcome.

DESIGN: Prospective observational cohort study.

SETTING: Single-center children's hospital.

PATIENTS: All pediatric patients from birth to age 21 yrs admitted to our institution with acute decompensated heart failure from October 2003 to October 2005.

INTERVENTIONS: None.

MEASUREMENTS AND MAIN RESULTS: Acute decompensated heart failure was defined as new-onset or acute exacerbation of heart failure signs or symptoms requiring hospitalization and inpatient treatment. We required that heart failure be attributable to ventricular dysfunction only. Worsening renal function was defined as an increase in serum creatinine by > or = 0.3 mg/dL during hospitalization. Sixty-three patients (35 male, 28 female) comprised 73 patient hospitalizations. Median age at admission was 10 yrs (range 0.1-20.3 yrs). Median serum creatinine at admission was 0.6 mg/dL (range 0.2-3.5 mg/dL), and median creatinine clearance was 103 mL/min/1.73 m2 (range 22-431 mL/min/1.73 m2). Serum creatinine increased during 60 of 73 (82%) patient hospitalizations (median increase 0.2 mg/dL, range 0.1-2.7 mg/dL), and worsening renal function occurred in 35 of 73 (48%) patient hospitalizations. Clinical variables associated with worsening renal function included admission serum creatinine (p = .009) and blood urea nitrogen (p = .04) and, during hospitalization, continuous infusions of dopamine (p = .028) or nesiritide (p = .007). Worsening renal function was independently associated with the combined end point of in-hospital death or need for mechanical circulatory support (adjusted odds ratio 10.2; 95% confidence interval 1.7-61.2, p = .011). Worsening renal function was also associated with longer observed length of stay (33 +/- 30 days vs. 18 +/- 25 days, p < .03).

CONCLUSIONS: These data suggest that an important cardiorenal interaction occurs in children hospitalized for acute decompensated heart failure. Renal function commonly worsens in such patients and is associated with prolonged hospitalization and in-hospital death or the need for mechanical circulatory assistance.