In Reply Drs Paraskevas and Veith discuss CREST subgroup analyses1 to suggest CEA would have had a lower stroke risk than CAS in the patient presented in the Grand Rounds article. In each study, the subgroup analysis was done using the factor of interest (age or sex), but these treatment-by-factor relationships were not affected by symptomatic status. Their assessment is mitigated by 3 factors: (1) lack of statistical power, (2) the treatment of stroke as an event of singular severity, and (3) the use of data that combines symptomatic and asymptomatic patients.
Beckman JA. Treatment Options for Asymptomatic Carotid Artery Stenosis—Reply. JAMA. 2014;311(5):527. doi:10.1001/jama.2013.285169