Development of a scoring system to estimate mortality in abdominal aortic aneurysms management

Abstract

Introduction

This study aimed to define risk factors associated with inpatient mortality in patients undergoing elective repair for unruptured abdominal aortic aneurysm and utilize these factors to create a scoring system to estimate risk of mortality.

Methods

A retrospective analysis was completed using the Nationwide Inpatient Sample from 1998 to 2011. Patients who underwent elective abdominal aortic aneurysm repair were identified using ICD-9 codes. Demographics, comorbidities, length of stay, insurance status, and mortality were recorded. Statistically significant variables were identified using a multivariate analysis, and a discriminant analysis was used to identify factors predictive of inpatient mortality.

Results

Over a 14-year period, 28,448 patients underwent elective repair of an unruptured abdominal aortic aneurysm. Independent variables associated with inpatient mortality included: age >60, female gender, congestive heart failure, peripheral artery disease, renal failure, malnutrition, and hypercoagulability. Endovascular aneurysm repair was protective against inpatient mortality. The area under the curve for the discriminant function was 0.83 (95% CI, 0.81–0.85) and successfully classified 87.9% of patients within the Nationwide Inpatient Sample (25,006/28,448 patients).

Conclusion

Seven factors that predict an increased risk of mortality and one factor that decreased the risk of mortality were identified. Preoperative risk factor mitigation may improve mortality following elective abdominal aortic aneurysm repair.