Abstract 16651: Diuretic Responsiveness and Its Prognostic Importance in Children With Heart Failure

Introduction: Fluid overload and congestion are common features of acute decompensated heart failure (ADHF) in children. However, response to diuretics is variable and, in adults, may predict outcome. We sought to identify risk factors for and prognostic relevance of decreased diuretic responsiveness (DR) in children hospitalized with ADHF. Hypothesis: We hypothesized that diminished diuretic responsiveness is associated with worse clinical outcomes. Methods: We performed a single center, retrospective cohort study, examining the medical records of 197 consecutive children <21 years of age who were hospitalized with ADHF. Patients receiving thiazide diuretics were excluded. DR was defined as net fluid (mL) output per 1mg of furosemide equivalents during the first 72 hours of treatment with a loop diuretic. Greater and lesser DR was determined by DR values above and below the median, respectively. Multivariable analysis was performed to determine association of DR with the composite end-point of inpatient death or need for mechanical circulatory support (MCS). Results: A total of 119 patients (51% female) met study criteria. Median age at admission was 6.7 years (IQR 1.6 to 14.2 years). Etiologies of ADHF included dilated cardiomyopathy (n=73), congenital heart disease (n=16), acute heart transplant rejection (n=10), myocarditis (n=9), restrictive cardiomyopathy (n=7), hypertrophic cardiomyopathy (n=1), and ischemic cardiomyopathy (n=1). Median ejection fraction was 26% (IQR 18-38%). Median DR was 5.8 ml/mg (IQR -3.6 to 15.3 ml/mg). Thirty-four percent of patients remained in a positive fluid balance after 72 hours of treatment with a loop diuretic. Factors associated with lesser DR included: younger age, the absence of peripheral edema, female sex and the use of inotropes. The composite end-point of death or MCS occurred in 31 (26%) patients. Lesser DR was associated with worse outcomes, even after adjusting for age and total urine output per weight (OR 6.9, p<0.01). Patients with lesser DR also experienced longer length of hospital stay than patients with greater DR (median, 55 vs 27 days, p<0.01). Conclusions: In children hospitalized with ADHF, early diminished DR during decongestion therapy is common and portends a poor prognosis.