Clinical Research in Congenital Heart Disease

Projects in this area relate to outcomes of cardiovascular surgery and interventional cardiology procedures. Projects underway include studies of innovations in surgical technique for palliation of hypoplastic left heart syndrome and for assessment of outcomes of heart defects corrected at very young ages. Dr. Pizarro is an active member of the Congenital Heart Surgeons’ Society (CHSS). The Nemours Cardiac Center continues to actively enroll patients in the inception cohorts of left ventricular outflow tract obstruction, pulmonary conduits, and tricuspid atresia. In addition, Drs. Pizarro and Baffa are involved in the design and implementation of a new study on unbalanced complete common AV canal. The Center has completed enrollment of patients in two multicenter trials that are closed: 1) the Clarinet trial, which is a prospective randomized multicenter double blinded trial evaluating the effect of Clopidrogel on the outcome of patients with a single ventricle who receive a systemic-pulmonary artery shunt as part of the initial surgical palliation, and 2) the single ventricle reconstruction trial, which is sponsored by NHLBI. The initial results abstract (Dr. Pizarro co-authored) was presented and won the Taussig award at the American Heart Association annual meeting. The initial results manuscript has been submitted for publication in the New England Journal of Medicine. Further writing committees for this trial include Cardiac Center staff, Drs. Christopher Derby, Christian Pizarro, Ellen Spurrier, and Majeed Bhat. In addition, a follow-up phase of this study (SVR II) aimed at collecting data on outcomes at 6 years will be launched in the next few months. Dr. Pizarro has joined the Society for Thoracic Surgeons (STS) Task Force on Outcomes Following Congenital Heart Surgery, currently charged with the development of a morbidity index as a means to assess performance and utilization of resources.

Dr. Julie Simons, a clinical psychologist, works in collaboration with the Division of Behavioral Health to assess the neurodevelopmental and psychosocial outcome of patients who underwent repair of congenital heart defects in infancy. She is currently involved in a study assessing the neurodevelopmental outcome of patients undergoing cardiac repair with current perfusion techniques. She is also working on a project aimed at evaluating coping mechanisms among parents of children undergoing cardiac repair early in life.

Dr. McCulloch is involved in several collaborative projects in CHSS. One is to describe natural history of patients with anomalous aortic origins of a coronary artery. He is also the primary investigator in another study that describes the growth of the ascending aorta in postoperative children with congenital heart disease in which the pulmonary valve is in the systemic position.

Dr. Radtke is participating in the Congenital Cardiovascular Interventional Study Consortium (CCISC), with a current project comparing surgery versus balloon angioplasty and stent placement for aortic coarctation. Dr. Radtke also participates in the Midatlantic Group Interventional Cardiology Consortium (MAGIC), a registry designed as a comprehensive framework for quality assurance and short and long-term outcome analysis of catheter interventions. Dr. Radtke is the principal investigator at duPont Hospital for two new multicenter FDA device trials: 1) the post-market approval study of the Amplatzer Muscular VSD Occluder that is used for non-surgical or “minimally invasive” closure of muscular ventricular septal defects, and 2) the pivotal approval study of the new Amplatzer Duct Occluder II that is used for non-surgical closure of small to moderate patent ductus arteriosus.

Dr. Spurrier, as the principal investigator, has enrolled 13 of a projected 30 subjects in a clinical research project designed to evaluate the efficacy of pre-emptive postoperative administration of inhaled nitric oxide in decreasing pleural effusions and shortening hospital length of stay following the Fontan operation. Dr. Robinson is developing normal values for graded exercise testing of children.

Reports of clinical experience are the primary way that national recognition is achieved in congenital heart disease management. Publications of new procedures and their outcomes influence care nationally. Participation in national research organizations is the current standard for congenital heart disease research. Since there are several disease management approaches for which Nemours is in the vanguard, these efforts will be critical to enhancing the organization’s reputation. These new projects will place Nemours on the cutting-edge of investigation in these areas.