Preoperative risk score for the prediction of mortality after repair of ruptured abdominal aortic aneurysms

Abstract

Objective: Even in the ruptured endovascular aneurysm repair first era, there are still patients who will not survive their ruptured abdominal aortic aneurysm (rAAA). All previously published mortality risk scores include intraoperative variables and are not helpful with the decision to operate or in providing preoperative patient and family counseling. The purpose of this study was to develop a practical preoperative risk score to predict mortality after repair of rAAA.

Methods: Data of all patients with rAAA presenting between January 1, 2002, and October 31, 2013, were collected. Logistic regression was used to evaluate predictive variables both univariately and jointly, and the results of multivariate models guided the definition of the final simplified scoring algorithm.

Results: There were 303 patients who presented during the study period. Sixteen patients died in the emergency department, en route to surgery, or after choosing comfort care. Preoperative variables most predictive of mortality were age >76 years (odds ratio [OR], 2.11; confidence interval [CI], 1.47-4.97; P = .011), creatinine concentration >2.0 mg/dL (OR, 3.66; CI, 1.85-7.24; P < .001), pH <7.2 (OR, 2.58; CI, 1.27-5.24; P = .009), and systolic blood pressure ever <70 mm Hg (OR, 2.70; CI, 1.46-4.97; P = .002). Assigning 1 point for each variable, patients were stratified according to the preoperative rAAA mortality risk score (range, 0-4). For all repairs, at 30 days, patients with 1 point suffered 22% mortality; 2 points, 69% mortality; and 3 points, 80% mortality. All patients with 4 points died. There was a mortality benefit for ruptured endovascular aneurysm repair across all categories.

Conclusions: Our rAAA mortality risk score is based on four variables readily assessed in the emergency department and allows accurate prediction of 30-day mortality after repair of rAAAs. It also has a direct impact on clinical decision-making by adding prognostic information to the decision to transfer patients to tertiary care centers and aiding in preoperative discussions with patients and their families.

Keywords: Mortality risk score; REVAR; Ruptured abdominal aortic aneurysm; Treatment outcome.