Novel Risk Score Model for Prediction of Survival Following Elective Endovascular Abdominal Aortic Aneurysm Repair

Abstract

Objective: The purpose of this study was to identify significant predictors of long-term mortality after elective endovascular abdominal aortic aneurysm repair (EVAR). Methods: We included all cases with elective EVAR based on a national data set from the Society for Vascular Surgery Patient Safety Organization. Clinical and anatomic variables were analyzed with a Kaplan-Meier and Cox-regression model to determine predictors of mortality and develop a score equation to categorize patients into low, medium, and high long-term mortality risk. Results: A total of 5678 patients with EVAR were included with an average age of 73.6 ± 8.2 years. The majority were male (81.6%) with a history of smoking (86.1%). There were 3 deaths within 30 days (0.1%). Several factors were associated with poor survival: unstable angina (hazard ratio [HR], 2.8; P = .008), dialysis (HR, 3.7; P < .001), estimated glomerular filtration rate (eGFR) <30 (HR, 1.7; P = .044), eGFR 30 to 59 (HR, 1.4; P = .002), age >80 (HR, 3.2; P < .001), age 75 to 79 (HR, 2.2; P < .001), chronic obstructive pulmonary disease on oxygen (HR, 3.3; P < .001), aortic diameter >5.8 cm (HR, 1.2; P = .043), and high risk for surgery (HR, 1.4; P = .043). Preoperative aspirin use and body mass index 25 to 35 were both found to be protective (HR, 0.78; P = .017 and HR, 0.8; P = .024, respectively). With our scoring model, 5- and 10-year survival rates for patients with low, medium, and high risk were 89.2%, 80.7%, and 64.1% and 77.2%, 60.1%, and 40.1%, respectively ( P < .001). Conclusion: Ten-year survival following EVAR in patients with a high-risk score utilizing the model provided was 40.1%. Patients with multiple comorbidities at risk for decreased long-term survival can be identified with our model, which is more applicable for high-volume contemporary institutions.