In a nutshell
The study evaluated occurrence, risk-factor, and exercise response of cardiac autonomic dysfunction (CAD) in adult survivors of childhood acute lymphoblastic leukemia (ALL). The authors found that over one-third of survivors developed CAD. It was related to lower exercise capacity.
Survivors of childhood ALL have reduced exercise ability and higher risks of heart disease. CAD occurs when nerves lose control over the heart. A small study showed that children developed CAD soon after finishing ALL therapy. This could be a side effect of receiving toxic drugs. However, risk factors of CAD are unknown. How CAD affects exercise ability among adult survivors of ALL is also unclear.
Methods & findings
The study included 338 adult survivors of childhood ALL. They were treated for childhood ALL between 1980 and 2003. 325 people of similar age, race, and sex without a history of ALL were included as a control group. Abnormalities in heart rate were considered as CAD symptoms. Participants received radiation and several drugs for ALL treatment. The drugs included vincristine (Oncovin), methotrexate (Otrexup), corticosteroids, anthracyclines, and alkylating agents.
CAD was significantly more common in ALL survivors (33.7%) than in controls (27.6%). Heart rate recovery (HRR) refers to the heart’s capacity to recover from exercise. On average, survivors had a lower HRR compared with that of controls. Good exercise capacity was presented by higher oxygen uptake and Duke Treadmill Score. Both factors were lower in survivors compared to controls. Exercise capacity was better in survivors and controls without CAD, compared to both groups with CAD.
Some survivors received alkylating agents such as cyclophosphamide (Cytoxan) with high doses of vincristine and/or corticosteroids like prednisone (Deltasone). They had 56% higher risks of CAD compared to patients who never received this intense treatment. Among survivors, obese patients had 78% higher risks of CAD compared to others.
The bottom line
The study concluded that CAD occurred in a third of adult survivors of childhood ALL. Cyclophosphamide with high doses of vincristine and/or corticosteroids caused increased CAD risks.
The fine print
ALL therapy guidelines have changed since 2003. This study should be carefully reviewed while applying to patients treated after 2003.
If you have concerns about the heart side effects of childhood ALL, please discuss this with your doctor.
Published By :
Pediatric blood & cancer
May 08, 2020