Echocardiographic Parameters Associated With Cardiorespiratory Fitness and Physical Activity in Childhood Acute Lymphoblastic Leukemia Survivors.

Background: Children's exposure to chemotherapeutic agents causes several long-term adverse effects but physical activity has been evidenced to be an effective strategy to improve cardiac function. This cross-sectional study aimed to explore the association between physical activity levels, cardiorespiratory fitness, and cardiac parameters measured by echocardiography.

Methods: Participants were 216n childhood acute lymphoblastic leukemia survivors who underwent a maximal cardiopulmonary exercise test and self-reported their daily minutes of moderate to vigorous physical activity. They underwent a complete transthoracic echocardiographic assessment. Systolic and diastolic function analysis and strain images analysis were performed. The associations were studied through the preventive fraction (examined with univariate crude and adjusted logistic regression models) of regular physical activity (≥150 min·wk-1) and adequate cardiorespiratory fitness levels (above the median ≥ 32.0 mL·kg-1·min-1) on cardiac parameters.

Results: Crude analysis shows that regular physical activity was associated with a significant preventive fraction in mitral E/A ratio (56%; P = .013), while adjusted analyses highlighted a nonsignificant reduction of 74% to 37% in the prevalence of cardiac parameters associated with physical activity. Similar associations of adequate cardiorespiratory fitness on cardiac parameters were observed. Adjusted analyses revealed a nonsignificant reduction of 7% to 86% in the prevalence of cardiac parameters associated with cardiorespiratory fitness.

Conclusion: This study reports that regular physical activity and adequate cardiorespiratory fitness were associated with a higher preventive fraction. Thus, engaging in physical activity prevents childhood acute lymphoblastic leukemia survivors' cardiac dysfunctions. These findings are novel and clinically relevant in pediatric cardiooncology and provide additional evidence to strengthen the benefits of exercise as long-term care in childhood cancer survivors.