Survival data and predictors of functional outcome an average of 15 years after the Fontan procedure: the pediatric heart network Fontan cohort.

OBJECTIVE: Multicenter longitudinal outcome data for Fontan patients surviving into adulthood are lacking. The aim of this study was to better understand contemporary outcomes in Fontan survivors by collecting follow-up data in a previously well-characterized cohort. DESIGN: Baseline data from the Fontan Cross-Sectional Study (Fontan 1) were previously obtained in 546 Fontan survivors aged 11.9 ± 3.4 years. We assessed current transplant-free survival status in all subjects 6.8 ± 0.4 years after the Fontan 1 study. Anatomic, clinical, and surgical data were collected along with socioeconomic status and access to health care. RESULTS: Thirty subjects (5%) died or underwent transplantation since Fontan 1. Subjects with both an elevated (>21 pg/mL) brain natriuretic peptide and a low Child Health Questionnaire physical summary score (<44) measured at Fontan 1 were significantly more likely to die or undergo transplant than the remainder, with a hazard ratio of 6.2 (2.9-13.5). Among 516 Fontan survivors, 427 (83%) enrolled in this follow-up study (Fontan 2) at 18.4 ± 3.4 years of age. Although mean scores on functional health status questionnaires were lower than the general population, individual scores were within the normal range in 78% and 88% of subjects for the Child Health Questionnaire physical and psychosocial summary score, and 97% and 91% for the SF-36 physical and mental aggregate score, respectively. Since Fontan surgery, 119 (28%) had additional cardiac surgery; 55% of these (n = 66) in the interim between Fontan 1 and Fontan 2. A catheter intervention occurred in 242 (57%); 32% of these (n = 78) after Fontan 1. Arrhythmia requiring treatment developed in 118 (28%) after Fontan surgery; 58% of these (n = 68) since Fontan 1. CONCLUSIONS: We found 95% interim transplant-free survival for Fontan survivors over an average of 7 years of follow-up. Continued longitudinal investigation into adulthood is necessary to better understand the determinants of long-term outcomes and to improve functional health status.

A predictive model for neurodevelopmental outcome after the Norwood procedure.

Neurodevelopmental outcomes after the Norwood procedure for single right ventricular lesions are worse than those in the normal population. It would be valuable to identify which patients at the time of Norwood discharge are at greatest risk for neurodevelopmental impairment later in childhood. As such, this study sought to construct and validate a model to predict poor neurodevelopmental outcome using variables readily available to the clinician. Using data from the 14 month neurodevelopmental outcome of the Single-Ventricle Reconstruction (SVR) trial, a classification and regression tree (CART) analysis model was developed to predict severe neurodevelopmental impairment, defined as a Psychomotor Development Index (PDI) score lower than 70 on the Bayley Scales of Infant Development-II. The model then was validated using data from subjects enrolled in the Infant Single Ventricle (ISV) trial. The PDI scores were lower than 70 for 138 (44 %) of 313 subjects. Predictors of a PDI lower than 70 were post-Norwood intensive care unit (ICU) stay longer than 46 days, genetic syndrome or other anomalies, birth weight less than 2.7 kg, additional cardiac surgical procedures, and use of five or more medications at hospital discharge. Using these risk factors, the CART model correctly identified 75 % of SVR subjects with a PDI lower than 70. When the CART model was applied to 70 subjects from the ISV trial, the correct classification rate was 67 %. This model of variables from the Norwood hospitalization can help to identify infants at risk for neurodevelopmental impairment. However, given the overall high prevalence of neurodevelopmental impairment and the fact that nearly one third of severely affected children would not have been identified by these risk factors, close surveillance and assessment for early intervention services are warranted for all infants after the Norwood procedure.

Impact of sildenafil on echocardiographic indices of myocardial performance after the Fontan operation.

The objective of this study was describe the impact of sildenafil on echocardiographic measures of myocardial performance in children and young adults with a functional single-ventricle physiology late after Fontan surgery. A double-blind, placebo-controlled, crossover trial was conducted in children and young adults after the Fontan operation at a single pediatric center. Subjects were randomized to receive placebo or sildenafil (20 mg tid) for 6 weeks. After a 6-week washout period, subjects were crossed for an additional 6 weeks. Each subject underwent an echocardiogram at the start and finish of each phase. A total of 27 subjects completed study testing at a mean age of 14.9 years and a mean time from Fontan surgery of 11.3 years. After sildenafil, subjects demonstrated improvement in their myocardial performance index (MPI; -0.051; 95% CI -0.095, -0.0077; p 0.02) and in the product of the velocity time integral (VTI) of the dominant outflow tract and the heart rate (HR; 110 cm × bpm; 95% CI 7.5, 220; p = 0.04). Measures of diastolic performance, including inflow velocities, myocardial velocities, and the ratio of blood pool velocity to myocardial velocity during passive inflow, did not change. In this cohort, there were significant improvements in both the MPI and the product of the VTI × HR after 6 weeks of treatment with sildenafil. These findings suggest that sildenafil may be a useful therapy to improve or maintain ventricular performance in select patients after the Fontan operation.

Impact of oral sildenafil on exercise performance in children and young adults after the fontan operation: a randomized, double-blind, placebo-controlled, crossover trial.

BACKGROUND: Children and young adults with single-ventricle physiology have abnormal exercise capacity after the Fontan operation. A medication capable of decreasing pulmonary vascular resistance should allow improved cardiac filling and improved exercise capacity. METHODS AND RESULTS: This study was a double-blind, placebo-controlled, crossover trial conducted in children and young adults after Fontan. Subjects were randomized to receive placebo or sildenafil (20 mg three times daily) for 6 weeks. After a 6-week washout, subjects crossed over for an additional 6 weeks. Each subject underwent an exercise stress test at the start and finish of each phase. After taking sildenafil, subjects had a significantly decreased respiratory rate and decreased minute ventilation at peak exercise. At the anaerobic threshold, subjects had significantly decreased ventilatory equivalents of carbon dioxide. There was no change in oxygen consumption during peak exercise, although there was a suggestion of improved oxygen consumption at the anaerobic threshold. Improvement at the anaerobic threshold was limited to the subgroup with single left or mixed ventricular morphology and to the subgroup with baseline serum brain natriuretic peptide levels ≥100 pg/mL. CONCLUSIONS: In this cohort, sildenafil significantly improved ventilatory efficiency during peak and submaximal exercise. There was also a suggestion of improved oxygen consumption at the anaerobic threshold in 2 subgroups. These findings suggest that sildenafil may be an important agent for improving exercise performance in children and young adults with single-ventricle physiology after the Fontan operation. Clinical Trial Registration- URL: http://clinicaltrials.gov. Unique identifier: NCT00507819.