Discussion
By comparing subjective clinical evaluation of a patient’s risk by experienced clinicians against the more objective validated assessment of post-operative outcomes via CPET, the present study has identified two important findings. First, we identified clear disagreement between subjective assessments of risk with a third of patients classified not frail considered unfit by notes review and almost nine out of ten patients suffering from mild to severe disease by ASA classification. Second, and consistent with our original hypothesis, subjective assessment underestimated surgical risk in up to a third of patients. Collectively, these findings highlight the benefits of a more objective and integrated approach offered by CPET that may help improve perioperative risk assessment and direct care provision in patients scheduled for ‘high-stakes’ open TAAA repair.