Functional status as a predictor of outcomes in open and endovascular abdominal aortic aneurysm repair.

BACKGROUND

Functional status is a simple and rapidly assessable metric that may be used as a predictor for surgical outcomes. This study examined the association of functional status with short-term mortality after abdominal aortic aneurysm (AAA) repair in octogenarians to characterize the utility of functional status as a means of preoperative risk assessment.

METHODS

All patients who underwent endovascular and open AAA repair from 2002 to 2010 within the Veterans Affairs Surgical Quality Improvement Program (VASQIP) database were identified. Functional status, defined as an ordinal scale from 1 to 3 (1, independent; 2, partially dependent; 3, totally dependent), was examined using multivariate regression models with 30-day mortality as the primary outcome. For the purpose of analysis, this 3-point scale was converted into a binomial scale of function, with "normal" including 1 (completely independent) and "abnormal" including 2 or 3 (partially to totally dependent).

RESULTS

We identified 9030 patients who underwent AAA repair (46.6% open and 53.4% endovascular). Mortality at 30 days was 2.8% for the entire cohort (4.2% open, 1.7% endovascular; P < .001). There were 1340 patients aged ≥80 years, of which 67.3% underwent endovascular AAA repair. Among all age groups, functional status was a significant predictor of 30-day mortality (<80 years, P < .001; ≥80 years, P < .001). The ≥80 cohort with abnormal function status also demonstrated increased operative mortality (P = .002), length of stay (P = .001), and incidence of pulmonary complications (P = .025) compared with the cohort with normal functional status. Multivariate logistic regression demonstrated that within the ≥80-year-old cohort, only functional status remained a significant predictor of mortality (P < .001). In addition, the strength of the association between functional status and mortality was greater in the older cohort than in the younger one (Cox regression hazard ratio: 3.13 vs 2.18).

CONCLUSIONS

Functional status is a simple and rapidly applicable predictor of mortality within AAA patients and may be a useful tool to help preoperatively risk-stratify elderly patients presenting with AAA in need of repair. Further studies are needed to understand how best to apply these data to the clinical setting to guide preoperative decision making.