The Relationship Between Physical Activity and Left Ventricular Remodeling in Childhood Cancer Survivors Treated With Anthracyclines: A Cross‐Sectional Study

Introduction Anthracycline‐related cardiac remodeling precedes heart failure in childhood cancer survivors. The objectives of this study were to determine the relationships between patient‐specific factors, moderate‐to‐vigorous physical activity (MVPA), and cardiac remodeling. Methods We performed a prospective, observational, cross‐sectional study in ≥ 2‐year survivors treated with anthracyclines. We derived MVPA from accelerometry and cardiac parameters (indexed end‐diastolic left ventricular [LV] mass [LVMi], volume [LVEDVi], mass:volume ratio, and LV ejection fraction [LVEF]) from cardiovascular magnetic resonance imaging. We assessed predictors of MVPA and the association between MVPA and cardiac parameters using multivariable linear regression. Results Among 112 participants, mean age was 18.2 years (standard deviation [SD] 3.0) and mean anthracycline dose was 239 mg/m 2 (SD 146). Mean MVPA was 134 min/week (SD 124) and 72 (64%) participants had < 150 min/week. Independent predictors of lower MVPA were lower age, female sex, and Hispanic ethnicity (all p < 0.05). Higher age and male sex were associated with higher LVMi and LVEDVi; higher age at cancer diagnosis, male sex, and obesity were associated with higher mass:volume ratio; and higher anthracycline dose was associated with lower LVEF (all p < 0.05). Every 100 additional weekly minutes of MVPA was associated with a 1.4 g/m 2 higher LVMi ( p = 0.008) and 1.9 mL/m 2 higher LVEDVi ( p = 0.039). Conclusion Physical activity levels were suboptimal and higher levels of MVPA were associated with higher LV mass and volume. Our findings suggest the need to promote physical activity in childhood cancer survivors and that exercise may mitigate anthracycline‐related cardiac remodeling. Trials Registration ClinicalTrials.gov identifiers: NCT04262830