Letter to the Editor: "Increased Risk of Cardiac Dysfunction After Anthracyclines in Girls"
We read with great interest the comments made by Bu'Lock and colleagues [I] concerning our paper "Increased Risk of Cardiac Dysfunction After Anthracycline Toxicity in Girls" [2], and appreciate the opportunity to better describe our work. If we understand their concerns correctly, they made 5 major points: (1) Bu'Lock and colleagues reviewed their patients and failed to find a difference in echocardiographic shortening fraction according to the sex of the patient. (2) A suggestion was made that a possible selection bias may have been responsible for our results, although the type of bias was not delineated. (3) A concern was raised about the poor correlation between our findings of abnormal ejection fraction by gated nuclear angiography and maximal cardiac index by cycle ergometry. Since a poor correlation existed, they did not have confidence in our clinical laboratory with respect to cardiac monitoring. (4) The question was raised whether girls have a lower maximal cardiac index than boys, thereby explaining the increased rate of abnormalities found in girls. ( 5) Until confirmatory studies are reported, Bu'Lock et al. believe our findings should not influence the treatment of oncology patients. This letter will respond to each point.