Impaired Pre-operative Ambulatory Capacity in Patients Undergoing Elective Endovascular Infrarenal Abdominal Aortic Aneurysm Repair is Associated with Increased Peri-operative Death

Objective: While ambulatory capacity is a readily assessable clinical indicator of functional status, its association with outcomes after endovascular aneurysm repair (EVAR) remains underexplored. This study aimed to investigate the association between pre-operative ambulatory status and outcomes following elective EVAR. Methods: A retrospective review of the multi-institutional Vascular Quality Initiative database was conducted for all patients who underwent elective infrarenal EVAR from 2009- 2022. Patients were categorised into independent ambulation and impaired ambulation groups. A propensity score matched analysis was performed to produce two well matched cohorts in a 1:1 ratio without replacement. The primary outcome was 30 day death. Secondary outcomes included one year survival and in hospital major complications. Results: Among 11474 patients, 10539 (91.8%) were independently ambulatory pre-operatively. Propensity score matching resulted in 885 matched pairs. The impaired ambulation group, although older (mean 77.6 vs. 76.3 years; p = .001), showed comparable baseline characteristics. Post-operatively, the impaired ambulation group had higher cumulative in hospital complications and death as well as 30 day death. Even after adjustment for age, impaired pre-operative ambulation was associated with increased in hospital and 30 day death (hazard ratio [HR] 2.27, 95% confidence interval [CI] 1.26- 3.95; p = .006). Multivariable analysis demonstrated increasing cumulative risk of 30 day death in the setting of impaired pre-operative ambulatory status with age > 75 years requiring postoperative red blood cell transfusion > 2 units (HR 5.75, 95% CI 2.09- 15.88; p < .001). Beyond 30 days, impaired pre-operative ambulation was not associated with increased one year death (HR 1.09, 95% CI 0.81- 1.48; p = .57). Conclusion: Among patients who underwent elective infrarenal EVAR in this matched analysis, impaired preoperative ambulatory capacity was associated with an increased risk of in hospital and 30 day death, further compounded by advanced age and post-operative transfusion. As such, a threshold higher than the traditional size criteria should be considered in shared decision making when determining options for the management of abdominal aortic aneurysm in this high risk cohort.