WILMINGTON, Delaware (October 19, 2022) – Cardiopulmonary exercise testing (CPET) can detect underlying early signs of cardiovascular problems in asymptomatic pediatric cancer survivors that other types of monitoring cannot, according to a study led by Nemours Children’s Health and published in the journal pediatric cardiology. The findings are critical to hundreds of thousands of people across the United States who survived childhood cancer but are at increased risk of serious cardiovascular disease in middle age.
“In the past we have attempted to cure children of cancer so that they could survive into adulthood, which is rightly considered a major victory,” said lead author Dr. Takeshi Tsuda, pediatric cardiologist at Nemours Children’s Health, Delaware. “But with these achievements, we must now focus on helping more of these survivors achieve typical longevity.”
Remarkable advances in the treatment of childhood cancer have meant that almost 80% of patients now survive cancer-free into adulthood. However, in middle age, many experience severe cardiovascular complications that shorten their life expectancy by 20 to 30 years compared to people who have never had cancer.
“This may be just one example of the premature aging we see in the cardiovascular and other organ systems of childhood cancer survivors,” Tsuda noted. “This is an important, emerging area of pediatric care and research aimed at helping pediatric cancer survivors lead full, healthy adult lives.”
This single-center retrospective study found that a new exercise testing approach that combined a patient’s maximal and submaximal exercise parameters was able to identify multiple factors of poor physical performance in pediatric cancer survivors. This method proved to be an effective, non-invasive way to detect asymptomatic cardiovascular abnormalities in this population.
“Our results suggest that this simple, new exercise testing method may be an important tool for measuring cardiovascular risk in patients surviving pediatric cancer,” said Tsuda. “It should be used more routinely in monitoring these patients before any symptoms appear because of its ability to find subtle warning signs that standard methods miss.”
Researchers describe their two-dimensional CPET analysis, which assesses training data through a combination of peak and submaximal parameters simultaneously. They analyzed the records of 53 pediatric cancer survivors who had received anthracycline chemotherapy and had normal echocardiograms (ultrasound) compared with a healthy control group of 60 people matched for age, sex and weight with the survivors’ group. The group of survivors was diverse with respect to their primary cancer diagnosis, treatment (cumulative dose of anthracycline, radiation, and/or bone marrow transplantation), age at diagnosis, years since remission, and baseline physical activity level.
Peak exercise power scores were significantly lower in cancer survivors than in controls. Survivors also had significantly higher peak respiratory exchange ratio (CO2 produced versus oxygen consumed) and lower stroke volume reserves (amount of blood pumped out of the left ventricle at peak exercise intensity versus at rest), suggesting a fundamental problem in oxygen utilization.
Traditionally, peak exercise test parameters have been considered the gold standard for assessing cardiac reserve, but their value may be limited when patients cannot reach peak exercise status. However, submaximal CPET data depicting dynamic responses to light-to-moderate exercise could help close the gap, the researchers said.
The authors state that reduced peak oxygen delivery/consumption is likely to be a key factor in pediatric cancer survivors independent of apparent ventricular dysfunction, underscoring the critical importance of CPET in risk stratifying asymptomatic survivors.
“We believe that CPET is an excellent surveillance method to screen people at risk for future cardiovascular disease. However, most of the currently published clinical guidelines do not recognize the importance of CPET as a screening tool,” said Tsuda. “Going forward, we must champion the use of CPET in a clinical setting and challenge the current paradigm.”
The authors note that further research is needed to confirm whether CPET-detected abnormalities in childhood or adolescence can predict major cardiovascular complications in adulthood, decades after the completion of cancer treatment.
About Nemour’s children’s health
Nemours Children’s Health is one of the nation’s largest multi-state pediatric health systems, comprising two standalone children’s hospitals and a network of more than 70 primary and specialty care practices. Nemours Children’s seeks to transform children’s health by adopting a holistic healthcare model that leverages innovative, safe, quality care while caring about whole child health beyond medicine. Nemours Children’s also operates the world’s most visited website for child and adolescent health information, Nemours KidsHealth.org.
Established through the legacy and philanthropy of Alfred I. duPont, the Nemours Foundation provides pediatric clinical care, research, education, advocacy, and prevention programs to the children, families, and communities it serves. Visit Nemours.org for more information.
Randomized controlled/clinical study
subject of research
Cardiopulmonary stress testing characterizes silent cardiovascular abnormalities in asymptomatic survivors of pediatric cancer
Article publication date
September 8, 2022
Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of the press releases published on EurekAlert! by contributing institutions or for the use of information about the EurekAlert system.