Doctor consults with cancer

patient and her father

Credit: Rhoda Baer

New research suggests a need to revisit cardiac screening guidelines for survivors of childhood cancers.

The study indicates that less frequent screening for early signs of impending congestive heart failure (CHF) may yield a similar clinical benefit as current screening recommendations.

Furthermore, some survivors might be better served by a different method of screening than the one currently used. And early treatment of patients at high risk of CHF may be beneficial.

The researchers reported these findings in the Annals of Internal Medicine.

Current CHF screening guidelines recommend that childhood cancer survivors treated with chemotherapeutic agents known to affect long-term heart health be screened as often as every year, with a schedule dependent on their level of CHF risk.

The Children’s Oncology Group (COG) recommends that survivors undergo screening by echocardiography for asymptomatic left ventricular dysfunction (ALVD). If left untreated, this clinically silent condition can progress to CHF, so clinicians typically prescribe beta blockers and ACE inhibitors to patients with signs of ALVD.

The COG recommends that patients at high risk of developing CHF be screened every year or 2 and those at low risk be screened every 2 or 5 years

“It is important to monitor survivors so we can reduce the late effects of treatment whenever possible, but we may be asking them to be tested too often, which burdens both individuals and the healthcare system,” said study author Lisa Diller, MD, of the Dana-Farber/Boston Children’s Cancer and Blood Disorders Center in Massachusetts. “We think it is worthwhile to review the current CHF screening guidelines.”

To estimate the clinical benefits and cost-effectiveness of the current heart screening guidelines, Dr Diller and her colleagues constructed a computer model of a virtual cohort of 15-year-olds who had survived cancer at least 5 years.

Using data from the Childhood Cancer Survivors Study and the Framingham Heart Study, the researchers modeled the cohort’s CHF risk and clinical progression over the course of survivors’ lifetimes. Results suggested that routine screening may prevent as many as 1 in 12 cases of CHF.

The team then used Medicare data to estimate the costs and value (expressed in cost per quality-adjusted life-year [QALY]) of different screening schedules—every 1, 2, 5, or 10 years—and methods—echocardiography vs cardiac magnetic resonance imaging (cMRI)—for the different CHF risk groups.

At a cost-effectiveness threshold of $100,000/QALY, the model’s results indicated that echocardiographic screening might not be the best value for resources invested to reduce lifetime CHF risk among survivors at low risk of developing the disease.

On the other hand, the data suggested that biennial echocardiography screening may be a high-value strategy for high-risk survivors.

The simulation’s data also suggested that cMRI may be preferable to echocardiography as a screening method, with cMRI’s greater cost per test balanced by its greater sensitivity. According to the model, cMRI-based screening of low-risk survivors every 10 years and high-risk survivors every 5 years was more cost-effective than any echocardiography-based schedule.

Lastly, the data suggested it may be most beneficial to treat high-risk survivors before signs of ALVD even appear. For instance, proactively treating all high-risk patients in the virtual cohort with ACE inhibitors and beta blockers reduced their lifetime CHF risk more than if they received an echocardiograph every 2 years.

The researchers relied on simulation modeling using the best available clinical and epidemiologic data because of the logistical obstacles to conducting a prospective, randomized, clinical trial.

They said enrolling the number of survivors needed for such a study would be challenging, given how rare childhood cancers are. Yet guidance on the health benefits associated with current recommendations is needed.

“Our findings suggest that there is a long-term benefit in screening survivors at elevated risk for CHF,” said study author Jennifer Yeh, PhD, of the Harvard School of Public Health in Boston.

“Yet less frequent screening than currently recommended may be reasonable when other factors are considered. We hope these results can help inform the ongoing discussion about screening childhood cancer survivors.”

CHF screening guidelines need another look, group says