Exercise Screening Reveals Silent Cardiovascular Risks Common in Childhood Cancer Survivors

Cardiopulmonary exercise testing (CPET) can detect key early signs of cardiovascular problems in asymptomatic children with cancer that cannot be detected by other screening tests, according to a study by Nemours Children’s Health published in the journal. Pediatric cardiology. The findings are important for the hundreds of thousands of people in the US who have had childhood cancer but face an increased risk of major cardiovascular events in middle age.

“Historically, we’ve aimed to cure children of cancer so they can live into adulthood, which is rightly seen as a big win,” said lead author Takeshi Tsuda, MD, a pediatric cardiologist at Nemours Children’s Health, Delaware. “But with these advances, we must shift our focus to helping more survivors achieve normal longevity.”

Remarkable progress in the fight against childhood cancer has meant that almost 80% of patients now survive into adulthood without cancer. However, in middle age, many experience serious cardiovascular complications that limit their life expectancy by 20-30 years compared to people who have never had the disease childhood cancer.

“This may be just one example of the premature aging process that we observe in the cardiovascular and other organ systems of children with cancer,” Tsuda noted. “This is an important new area of ​​pediatric care and research aimed at helping children with cancer lead fulfilling and healthy adulthood.”

This retrospective single-center study found that a novel exercise testing approach combining peak and submaximal patient exercise parameters was able to identify multiple factors underlying low exercise in pediatric cancer survivors. This method has been shown to be an effective noninvasive way to detect asymptomatic cardiovascular disorders in this population.

“Our results suggest that this simple, novel method of exercise testing may be an important tool for assessing cardiovascular risk in childhood cancer survivors,” Tsuda said. “It should be used more regularly to monitor these patients before any symptoms appear, given its ability to find subtle warning signs missed by standard testing.”

The researchers describe their two-dimensional CPET analysis, which evaluates exercise data through a combination of peak and submaximal parameters simultaneously. They analyzed the records of 53 children with cancer who received anthracyclines for chemotherapy and had normal echocardiograms (US) compared with a healthy control group of 60 matched survived age, gender and weight group. The group of survivors was diverse in terms of primary cancer diagnosis, treatment (cumulative anthracycline dose, radiation and/or bone marrow transplantation), age at diagnosis, years since remission, and baseline level of physical activity.

Maximal exercise values ​​were significantly lower in cancer survivors than in controls. Survivors also had significantly higher peak respiratory exchange rates (CO₂ compared to oxygen consumed) and lower stroke volume reserves (the amount of blood pumped from left ventricle at peak exercise intensity compared to rest) suggesting a fundamental problem with oxygen utilization.

Traditionally, peak exercise test parameters have been considered the gold standard for assessing cardiac reserve, but their value may be limited if patients are unable to achieve maximal exercise status. However, submaximal CPET data representing dynamic responses to light and moderate exercise may help fill the gap, the researchers say.

The authors note that reduced peak oxygen delivery/consumption is likely to be a major factor among pediatric cancer survivors, regardless of identified ventricular dysfunction, emphasizing the critical importance of CPET for risk-stratified asymptomatic survivors.

“We believe that CPET is an excellent surveillance method for screening those people who are at risk for cardiovascular disease. However, most current published clinical guidelines do not recognize the importance of CPET as a screening tool,” Tsuda said. “Moving forward, we must advocate for the use of CPET in the clinical setting, challenging the current paradigm.”

The authors note that further research is needed to confirm whether CPET abnormalities detected in childhood or adolescence can predict major cardiovascular complications in adulthood decades after completion cancer treatment.