Abstract 10440: Exercise Stress Test Identifies Preclinical Cardiotoxicity in Pediatric Cancer Survivors With Normal Left Ventricular Function Shown By Echocardiogram

BackgroundLate-onset anthracycline-induced cardiotoxicity is responsible for major morbidity and mortality in adulthood for pediatric cancer survivors (PCS), but its progression is insidious and poorly recognized. Preclinical stage of cardiotoxicity should be identified before left ventricular (LV) function deteriorates.HypothesisExercise stress test (EST) can identify a preclinical stage of cardiotoxicity in pediatric cancer survivors.MethodsWe retrospectively reviewed the EST performed with cycle ergometer in asymptomatic PCS who received anthracycline and who are off treatment for more than one year. Peak heart rate (pHR), peak oxygen consumption (pVO2), and peak oxygen pulse (pOP) were assessed. Submaximal exercise parameters, anaerobic threshold (AT) and the slopes of VO2/heart rate (HR) changes (ΔVO2/ΔHR) and HR/workload (WL) changes (ΔHR/ΔWL), were also examined.Results25 PCS and 33 control patients (CTR) were studied (Table 1). Although there was no significant difference in pHR, both pVO2 and pOP were significantly reduced in PCS compared with CTR. AT was significantly lower in PCS than in CTR, but ΔVO2/ΔHR was comparable between the two. pVO2 had no correlation with total anthracycline dosage, but showed significant negative correlation with the age of chemotherapy (Figure 1).ConclusionsEST demonstrated significantly reduced exercise performance in PCS compared with CTR, especially a limitation in exercise-induced stroke volume increase, suggesting possible preclinical cardiac involvement in PCS. Surveillance EST in otherwise asymptomatic PCS may provide additional value in identifying PCS at risk for developing cardiotoxicity.