The article by van der Pal et al1 on cardiac function in survivors of childhood cancer is very concerning, reporting a 27% incidence of abnormal cardiac function. However, the authors define abnormal cardiac function as a left ventricular shortening fraction (LVSF) below 30%. This level appears to have been chosen based on extrapolation to an ejection fraction of 50%. This is considerably higher than many standard references that quote a lower limit for LVSF of 27% to 28%.2,3 Although difficult to extrapolate from the limited data provided, even a 20% decrease in the threshold for shortening fraction would dramatically decrease the incidence of abnormal left ventricular function. While the article by van der Pal et al1 provides valuable data on risk factors for late cardiac complications of cancer therapy, the inappropriately high threshold for cardiac function chosen by the authors yields a distortion in what may be the true incidence and is needlessly alarming.
Rosenberg H. Cardiac Function in 5-Year Survivors of Childhood Cancer. Arch Intern Med. 2011;171(3):264. doi:10.1001/archinternmed.2010.533