Key Findings: Prevalence of Congenital Heart Defects, Metro-Atlanta

The journal Birth Defects Research (Part A) has published a new study: “Patterns in the Prevalence of Congenital Heart Defects, Metropolitan Atlanta, 1978–2005.” You can read the article’s abstract here. Read more below for a summary of the findings from this article.

Main Findings from This Study:

From 1978-2005, the prevalence of more common (and less severe) congenital heart defects (CHDs) increased, while the prevalence of many severe CHDs remained stable. There are some differences in prevalence estimates between different racial/ethnic groups. Prevalence means the total number of babies who have a certain condition, in this case, heart defects, in relation to the number of live births in the study area. More research is needed to look into the possible reasons for these racial/ethnic differences, including access to care and differences in risk factors for heart defects between racial/ethnic groups.

About This Study:

• What are congenital heart defects?
  Congenital heart defects (CHDs) are conditions that are present at birth and can affect the structure of a baby’s heart and the way it works. As medical care and treatment have advanced, infants with CHDs are living longer and healthier lives. Many now are living into adulthood.
• How common are congenital heart defects?
  CHDs are the most common type of birth defect in the United States, affecting nearly 1% of―or about 40,000―births per year^1,2. CHDs are also a leading cause of birth defect-associated infant illness and death³.
• What are the study results?
  The study used data from the Metropolitan Atlanta Congenital Defects Program (MACDP). The researchers split the period of 1978-2005 into five separate time periods to calculate prevalence of heart defects by racial/ethnic groups. They also looked at trends over time.
  • Overall, the prevalence of CHDs increased over time in metropolitan Atlanta. This upward trend was driven by an increase in the more common, milder defects, such as ventricular septal defects (VSD) and atrial septal defects (ASD).
  • The prevalence of many severe CHDs remained about the same throughout the 27-year study period.
  • Racial/ethnic differences in prevalence were seen for some CHDs, but reasons for why these differences occurred were not examined in this study. For example, Blacks had a lower prevalence of aortic stenosis and muscular type of VSD than Whites. During later years, Hispanics had a lower prevalence of atrioventricular septal defects than non-Hispanic Whites.
  • The study has some limitations. For example, we don’t know if there are true differences between groups or whether some other factors played a role, like differences in identification between the groups. Some of the increase is likely due to improved technology which identifies milder cases of heart defects.
• Why is this study important?
  The MACDP is a population-based birth defects surveillance system where clinicians review and categorize the cases of CHDs. Population-based means that the researchers look at all babies with birth defects that live in a defined study area, which is important to get a complete picture of what is happening within the population. This study examined 23 different types of CHDs over 27 years and included data on whites, blacks and Hispanics.  It used new methods to examine trends over time.  This study highlights the increase in the prevalence of specific types of CHDs over time. Future studies should look into reasons for the differences in prevalence estimates across racial/ethnic groups, such as access to care or different risk factors for heart defects.

Heart Defects: CDC’s Activities

Centers for Disease Control and Prevention (CDC) works to identify causes of congenital heart defects and ways to prevent them. We do this through:

• Surveillance or disease tracking:
  • State programs: CDC funds and coordinates the Metropolitan Atlanta Congenital Defects Program (MACDP).  CDC also funds 14 population-based state tracking programs. Birth defects tracking systems are vital to help us find out where and when birth defects occur and who they affect.
  • Newborn screening: As more states start screening newborns for critical congenital heart defects (CCHDs), CDC will help track babies with a CCHD found through newborn screening.
  • Adolescents and adults: CDC recently launched 3 pilot sites to track congenital heart defects among adolescents and adults in order to learn about their health issues and needs across the lifespan.
• Research: CDC funds a large study of birth defects called the National Birth Defects Prevention Study. This study is working to identify risk factors for birth defects, including heart defects.
• Collaboration:
  • CDC provides technical assistance to the Congenital Heart Public Health Consortium, a unique collaboration that brings together families, experts, and organizations to address congenital heart defects.
  • CDC works with states to evaluate new screening for critical congenital heart defects activities. CDC is assessing states’ needs for help with CCHD screening. CDC worked with New Jersey and is working with Georgia to assess tracking of CCHD screening. CDC is also helping states and hospitals to understand the costs associated with these new screening activities.

More Information

To learn more about congenital heart defects, please visit https://www.cdc.gov/ncbddd/heartdefects/.

References

1. Hoffman JL, Kaplan S. The incidence of congenital heart disease. J Am Coll Cardiol. 2002;39(12):1890-1900.
2. Reller MD, Strickland MJ, Riehle-Colarusso T, Mahle WT, Correa A. Prevalence of congenital heart defects in Atlanta, 1998-2005. J Pediatrics 2008;153:807-813.
3. Yang, Q., Chen, H., Correa, A., Devine, O., Mathews, T.J. and Honein, M. A, Racial differences in infant mortality attributable to birth defects in the United States, 1989–2002. Birth Defects Research Part A: Clinical and Molecular Teratology. 2006; 76: 706–713.
4. Grech V. Epidemiology and diagnosis of ventricular septal defect in Malta. Cardiol Young. 1998; 8(3):329-336.
5. Martin GR, Perry LW, Ferencz C. Increased prevalence of ventricular septal defect: epidemic or improved diagnosis. Pediatrics. 1989; 83(2):200-203.

Paper Reference

Bjornard K, Riehle-Colarusso T, Gilboa SM, Correa A. Patterns in the prevalence of congenital heart defects, metropolitan Atlanta, 1978-2005. Birth Defects Research Part A. 2013. [epub ahead of print]