<p>Hyponatremia is a common finding in adults hospitalized with heart failure (HF) and is associated with longer hospital stays and increased mortality. The significance of hyponatremia in children with HF is not known. We sought to determine the incidence of hyponatremia and association with clinical outcome in children hospitalized with HF. Admission and inpatient serum sodium concentrations were analyzed in 141 consecutive children hospitalized with acute decompensated HF. Inclusion criteria include patients (age, birth to 21&nbsp;years) with biventricular hearts who were hospitalized for HF from January 2007 to December 2012. The primary composite end point was death, cardiac transplantation, or the use of mechanical circulatory support (MCS) during hospitalization. Data for 141 patients were included in the analysis. The cohort included 48 patients (34%) with preexisting HF. Mean serum sodium at admission was 136 ± 4&nbsp;mmol/L (range 124 to 150&nbsp;mmol/L). Hyponatremia (serum sodium &lt;135&nbsp;mmol/L) was present in 45 patients (32%) at admission. Seventy-one patients (75%) with normal serum sodium concentrations at admission subsequently developed acquired hyponatremia during their hospitalization. Hyponatremia persisted at discharge in 17 of 66 patients (26%). Fifty-eight patients (41%) reached the composite end point during hospitalization (death, n&nbsp;= 15; cardiac transplantation, n&nbsp;= 27; MCS, n&nbsp;= 46). Hyponatremia at admission was independently associated with death, cardiac transplantation, or the use of MCS during hospitalization (odds ratio 3.1, p&nbsp;= 0.02). In conclusion, hyponatremia occurs commonly in children hospitalized with acute decompensated HF and is associated with increased risk of in-hospital mortality, cardiac transplantation, and need for MCS.</p>

<p><strong>OBJECTIVE: </strong>To assess the frequency of inpatient 30-day readmission for heart failure in children with cardiomyopathy discharged after an admission for heart failure and the impact of discharge pharmacotherapy on readmissions.</p>

<p><strong>STUDY DESIGN: </strong>The Pediatric Health Information System Database was queried for patients ≤18&nbsp;years of age with an International Classification of Diseases, Ninth Revision code for heart failure (428.xx) or cardiomyopathy (425.xx) discharged from 2004 to 2013. Patients were excluded if they had congenital heart disease, expired on the initial admission, or underwent cardiac surgery. Patient admission characteristics were documented and discharge medications were captured. Frequency of 30-day readmission for heart failure was identified, and mixed effects multivariable logistic regression analysis was performed to determine factors significant for readmission.</p>

<p><strong>RESULTS: </strong>A total of 2386 patients met study criteria (52.1% male, median age 8.1&nbsp;years [IQR 1.2-14.6&nbsp;years]). Vasoactive medications were used in 70.3% of patients on initial admission, the most common of which was milrinone (62.8%). Angiotensin converting enzyme inhibitors and beta-blockers were given at discharge to 67.4% and 35.9%, respectively. Frequency of 30-day readmission for heart failure was 12.9%. Duration of milrinone or beta-blocker use at discharge and institutional heart failure patient volume were associated with a greater odds of 30-day readmission, whereas mechanical ventilation on initial admission was associated with decreased odds of readmission.</p>

<p><strong>CONCLUSIONS: </strong>Pediatric patients with cardiomyopathy and heart failure have a high frequency of heart failure-related 30-day readmission. Outpatient pharmacotherapy at discharge does not appear to influence readmission.</p>