Perspective:

This study demonstrates a similar rate of progression of AS in patients with versus without prior history of XRT during an intermediate-term follow-up, although it is not known whether differences in progression would be observed during a longer follow-up period. Also, it is not known how many individuals had a bicuspid aortic valve. Given the young mean age (61 years), it is possible that bicuspid aortic valves were present in a significant number of patients and could have been more prevalent in the control group, potentially impacting the rate of progression. Despite the lack of differences in progression during the study interval, patients with XRT had increased rates of valve replacement. The reasons for this difference are not clear; it is possible patients with XRT had earlier onset of symptoms, or there may be unmeasured differences between groups. The increased mortality in patients with prior XRT is consistent with prior studies of individuals undergoing cardiac surgery, and needs to be considered when evaluating these patients for aortic valve replacement. The effect of transcatheter aortic valve replacement on long-term outcomes in this population also needs to be investigated.