Impact of Pharmacotherapy on Interstage Outcomes in Single Ventricle Infants

Abstract

To characterize the pharmacotherapeutic regimens used in infants with single ventricle heart disease and determine the influence of outpatient medications on interstage weight gain. Retrospective review. Tertiary care pediatric hospital. All patients discharged from our institution with single ventricle heart disease that underwent neonatal first stage surgical palliation between 2002 and 2009 were included. Patients who died prior to second stage palliation or underwent orthotopic heart transplantation were excluded. Outpatient medication regimens during the interstage period were reviewed. Medication regimens were compared between surgical eras and between patient groups experiencing different outcomes. A logistic regression model was developed to determine independent factors for an interstage increase in weight-for-age z-score (WAZ) and a linear regression model to determine medications significant for an increase in weight gain per day. The study cohort consisted of 161 patients (58% male). Most patients in this cohort had either hypoplastic left heart syndrome (51%) or unbalanced complete atrioventricular canal (29%). Patients were placed on a median of four medications (range 1-9) at discharge from first surgical palliation, with aspirin (79%), furosemide (79%), and angiotensin converting enzyme inhibitors (ACE-I) (73%) most commonly prescribed. A median of six medication doses per day (range 2-18) were prescribed at discharge. Most patients (71%) had a decrease in WAZ during the interstage period. Use of digoxin (P < 0.01) and high-dose furosemide (P = .02) were associated with a decrease in WAZ score during the interstage period. Additionally, the use of ACE-I, ranitidine, proton-pump inhibitors, or promotility agents was not associated with improved somatic growth during the interstage period. Infants with single ventricle heart disease have a high-medication burden during the interstage period. Despite the focused and intensified use of medications to improve feeding tolerance and somatic growth, current pharmacotherapeutic regimens appear to have little effect on interstage weight gain.