Study identifies link between congenital heart disease prevalence and high-altitude environments

The global prevalence of congenital heart disease is higher among women who live at high altitudes, according to a new study presented at ACC Latin America 2024 in Punta Cana, Dominican Republic. However, congenital heart disease in these regions is underestimated and underdiagnosed because of poor access to health care and health systems that lack essential tools.

It is crucial to implement cardiovascular public health policies to ensure these communities receive effective care, maternal detection, early intervention and improved survival rates related to congenital heart disease.

“There is an underdiagnosed prevalence of congenital heart disease because not all high-altitude regions have the health resources for its evaluation, management and follow-up,” said lead author Jean Pierre Eduardo Zila-Velasque, MD, a medical doctor at the Red Latinoamericana de Medicina en la Altitud e Investigación (REDLAMAI).

Congenital heart disease refers to an issue with the heart’s structure that’s present at birth and prevents the blood from flowing normally. Recent reports have shown that in Latin America and the Caribbean, congenital heart disease is 60% more prevalent than cancer and occurs in eight to 13 cases per every 1,000 births in these nations.

Hypoxia is a condition where there is insufficient oxygen in the tissues to sustain bodily functions, which can also impact the development of an embryo or the process of forming organs during the embryonic period of human development, including the heart.

As altitude increases, barometric pressure decreases, and the risk of hypoxia is heightened. This study sought to evaluate the impact of high-altitude environments on the prevalence of congenital heart disease.

The authors conducted a systematic analysis of cross-sectional studies on the prevalence of congenital heart disease in people living in regions that are greater than 1,500 meters above sea level.

The analysis included 1,180,544 participants from eight countries: Bolivia, China, Turkey, Colombia, Ecuador, Ethiopia, the United States and Mexico. The participants were 52.4% male and 47.6% female, and ages ranged from birth to 20 years old. The study was conducted over the span of seven months.

“In relation to the sociodemographic variables, we were able to carry out analysis by place of residence (urban or rural area), type of resident (native or immigrant) and the altitude level in which they reside,” Zila-Velasque said.

“Sociodemographic information had a greater impact on the prevalence, unlike gender, where it was evident that the majority of patients with some type of CHD were female.”

Across all high-altitude populations, the prevalence of congenital heart disease was 8.97% overall and more prevalent in women. Broken down by altitude levels, congenital heart disease was prevalent in 6.8% of people living at an altitude of 1,500–2,500 meters, 14.47% in 2,500–3,500 meters, 7.26% in 3,500–4,500 meters and 1.52% in 4,500 meters.

The most common type of heart defect was atrial septal defect, which occurred in 29.9% of the participants. Congenital heart disease was more prevalent in rural environments, native people and American countries. By comparison, according to the U.S. Centers for Disease Control and Prevention, congenital heart defects affect 1% of births in the United States each year.

“In high-altitude environments, cardiovascular public health policies need to address the unique challenges posed by lower oxygen levels and increased physical strain,” Zila-Velasque said.

“This can be achieved through enhanced screening and monitoring. Implementing regular cardiovascular health screenings for residents and workers in high-altitude areas could help us identify and manage hypertension, arrhythmias and other cardiovascular conditions early.”

Public health policies should also focus on access to medical care and the development of new educational programs, Velasque noted. These communities often lack access to specialized medical care, such as cardiologists who are trained in high-altitude medicine, and improving access could help ensure that local facilities are equipped to address altitude-related cardiovascular emergencies.

Educational campaigns that highlight the cardiovascular risks associated with high-altitude environments can promote awareness about symptoms and preventive measures.

“Further research is needed on cardiovascular health in high-altitude environments to better understand the specific risks and effective interventions,” Zila-Velasque said.