APACHE III score on ICU admission predicts hospital mortality after open thoracoabdominal and open abdominal aortic aneurysm repair

Background: No prior studies, to our knowledge, have examined the performance of the Acute Physiology and Chronic Health Evaluation (APACHE) III score in predicting mortality of patients undergoing open thoracoabdominal aortic aneurysm (TAAA) or open abdominal aortic aneurysm (AAA) repair. We sought to evaluate APACHE III scores in the prediction of postoperative mortality in elective TAAA and AAA repairs. Methods: Over a 9-year period (July 1998 through June 2007), prospective data (demographics, admitting diagnosis, APACHE III score, intensive care unit [ICU] and hospital length of stay, ICU and hospital mortality) were collected by a dedicated APACHE III coordinator for all patients admitted to a tertiary academic surgical ICU (20 beds). Observational and comparative analyses were performed. Emergent repairs for ruptured aneurysms were excluded from the study. Results: Forty-one patients underwent open elective repair of TAAA and 404 underwent open elective repair of AAA. Mean age of the TAAA group was 63.4 ± 9.8 years and the AAA group was 70.3 ± 8.3 years. Mean APACHE III score was 54 (range: 10-103) for the TAAA group and 45 (range: 11-103) for the AAA group. The in-hospital mortality rate for TAAA patients was 4.9% (n = 2) and for AAA patients was 2.0% (n = 8). Mean APACHE III scores on ICU admission were significantly greater in nonsurvivors versus survivors (79 vs. 45, p < 0.0001). For the entire patient cohort, the APACHE III score on ICU admission was an excellent discriminator of hospital mortality (receiver operating characteristic and area under the curve 0.92 [standard error of 0.05, 95% CI: 0.83-1.0]). Conclusions: APACHE III is an accurate predictor of survival to hospital discharge in both open elective TAAA and AAA repairs.