The prevalence of congenital heart disease (CHD) has increased strikingly in adults and children, according to a new population study by MUHC researchers and reported in Circulation: Journal of the American Heart Association.
Severe CHD has risen in adults by 85 percent and 22 percent in children during the 15-year study (1985-2000) of the Quebec population. Congenital heart defects are structural problems arising from abnormal formation of the heart or major blood vessels near the heart that occurs before birth. Most heart defects either obstruct blood flow in the heart or vessels near it, or cause blood to flow through the heart in an abnormal way.
"To our knowledge, this is the first study to measure the changing number of patients in a North American population during a period of major progress in the management of CHD," said Dr. Ariane J. Marelli, lead author of the study and director of the McGill Adult Unit for Congenital Heart Disease Excellence (MAUDE) of the McGill University Health Centre.
The study measured prevalence, age and proportion of adults relative to children at four time points: 1985, 1990, 1995 and 2000, and analyzed the Quebec administrative databases recorded for the general population, identifying 46,000 adults and children with CHD in Quebec. "This is one of the largest population studies of CHD to have been performed in North America," Marelli said.
Extrapolating from these numbers, Marelli estimated that 181,000 Canadians and 1.8 million Americans had CHD in 2000 and that this number is increasing and will have implications for women, pregnancy and genetics. She estimated about 951,000 adults and 944,000 children had CHD in North America.
In 2000, the study indicated that one in every 85 children had CHD and one in 250 adults. "For comparison purposes, cystic fibrosis occurs in one of 4,500 live births, so there are 45 times more children with CHD than children with cystic fibrosis and most of these children are now becoming adults," Marelli said.
"Between 1985 and 2000, the group of patients that increased the most rapidly were adults with severe CHD, so, as of 2000, there was a nearly equal number of children and adults with severe CHD," Marelli said. "This is a testimony to the progress of pediatric cardiac medicine and surgery over the last 30 years," she added.
The data in the study reflects advances in the diagnosis and surgical treatment of CHD. "Since the mid-1980s, the advent of cardiac ultrasound has improved the diagnosis of CHD," Marelli said. "This technique can be used to detect CHD beyond the first year of life. Advances in corrective pediatric cardiac surgery have made an impact, enabling children with CHD to live longer."
The median age of those with severe CHD increased markedly from 1985 to 2000. The median age in 1985 was 11 years, compared to 17 years in 2000.
"The increasing numbers of patients with CHD means children will live longer and may acquire other forms of heart disease," Marelli said. "We need to increase public awareness about CHD in order to be able to better care for the increasing number of young people with heart disease.
"CHD has been thought of as a disease of childhood, but with the increased numbers, it has become an important disease of adulthood as well," she added. "It is an important public health problem in North America that is largely under-recognized."
Co-authors of the study are Andrew S. Mackie, MD, SM; Raluca Ionescu-Ittu, MSc; Elham Rahme, PhD; and Louise Pilote, MD, MPH, PhD, all of the MUHC.
The Heart and Stroke Foundation of Canada and the FRSQ provided funding for this study. The researchers are funded by the FRSQ, the Arthritis Society and the CIHR.
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