The National Heart, Lung, and Blood Institute convened a Working Group of investigators on September 10-11, 2004, in Bethesda, Maryland to advise NHLBI and the Office of Rare Diseases on research needed to improve the care of the growing number of adults with congenital heart disease.
The Working Group reviewed data provided by each member on current American Heart Association (AHA) and American College of Cardiology (ACC) activities; the epidemiology of congenital heart disease; long-term outcomes of selected conditions; diagnosis and assessment of function; intervention in adult congenital heart disease; management of related conditions such as endocarditis, thrombosis, pulmonary hypertension, arrhythmia, sudden death, and pregnancy; quality of life; and informatics as applied to adult congenital heart disease.
Adults with congenital heart disease are an important emerging patient group. The modern era of surgery for congenital heart disease began 60 years ago, with the first "blue baby" operation. Since then, medical and surgical strategies have been devised and refined for even the most complex cardiac malformation, so the number of affected newborns surviving infancy, childhood and adolescence has increased steadily. Today, estimates of the number of adults with clinically significant, structural heart disease vary from one to two million. Part of the difficulty in determining the number of adults with congenital heart disease is that some were felt to be "cured" in the previous era, some have no access to medical care, and some have neglected follow-up care because of denial or lack of knowledge. Most importantly, however, there has been no systematic national collection of data for them.
Congenital heart disease in adulthood is heterogeneous, as it is in childhood. Diagnoses can range from uncomplicated atrial or ventricular septal defects that never required surgery or medication, to complex single ventricular defects that have required several surgical procedures and multiple medications. Even within diagnostic categories, patients can have a wide range of symptoms, ranging from none to severe congestive heart failure and pacemaker dependence. The question naturally arises: who should provide care for these patients? Pediatric cardiologists are trained to take care of patients with complex congenital heart disease, but pediatric offices and children's hospitals may not be suitable for the care of adult patients. Adult cardiologists are trained to take care of adult heart disease, but lack expertise in treating cardiovascular malformations. Both the AHA and the ACC have ongoing efforts to determine the optimal training for new specialists to care for adults with congenital heart disease.
Improvements in non-invasive imaging in the past ten years are helping to provide better data on cardiac structure and function for adults with congenital heart disease. Many of these adults have either a single right ventricle pumping to the systemic circulation, or two-ventricle physiology with an abnormal right ventricle. Magnetic resonance imaging (MRI) has been of particular benefit in measuring size and function in the right ventricle, where the standard geometric assumptions used to make echocardiographic assessments of left ventricular function may not apply so well. With survival into adulthood have come co-morbidities. Many adults with congenital heart disease have residual defects, arrhythmias, or progression to heart failure. Advances in both surgery and catheter-based interventions have helped to address some of these associated problems. As of the date of the working group meeting, there were no published data on the superimposition of adult cardiovascular disease on congenital heart disease.
The profound gaps in the knowledge base reviewed by the Working Group led to three recommendations:
The Working Group is planning to publish a formal report, which will include an overview of the field and review of the literature, as well as the Group's recommendations. The report will be posted on the NHLBI public web site with a link to the journal or journals where the report is published. Anticipated publication date is summer, 2005.
Gail D. Pearson, M.D., Sc.D., NHLBI, NIH