Preoperative Risk Factors for 1 Year Mortality in Patients Undergoing Fenestrated Endovascular Aortic Aneurysm Repair in the US Aortic Research Consortium

Background Early survival (1-year) following elective repair of complex abdominal aortic aneurysms (AAA) or thoracoabdominal aortic aneurysms (TAAA) can be utilized as an indicator of successful repair and provides a reasonable countermeasure to the annual rupture risk based on diameter. We aimed to identify preoperative factors associated with 1-year mortality following F/BEVAR and develop a predictive model for 1-year mortality based on patient-specific risk-profiles. Methods The US-Aortic Research Consortium (US-ARC) database was queried for all patients undergoing elective F/BEVAR for complex AAA or TAAA from 2005-2022. The primary outcome was 1-year survival based on preoperative risk-profile. Multivariable Cox regression was used to determine preoperative variables associated with 1-year mortality overall and by extent of aortic pathology. Logistic regression was performed to build a predictive model for 1-year mortality based on number of risk factors present. Results A total of 2,099 patients met the inclusion criteria for this study (complex AAA: N=709, 34.3%; Type 1-3 TAAA: N=777, 37.6%; Type 4-5 TAAA: N=580, 28.1%). Multivariable Cox regression identified the following significant risk factors associated with 1-year mortality: current smoker, chronic obstructive pulmonary disease (COPD), congestive heart failure (CHF), Aortic diameter>7cm, Age>75, Extent 1-3, creatinine>1.7mg/dL, and hematocrit<36%. When stratified by extent of aortic involvement, multivariable Cox regression revealed risk factors for 1-year mortality in complex AAA (CHF max aortic diameter>7cm, hematocrit<36mg/dL, and current smoking status), Type 1-3 TAAA (COPD, CHF, and Age>75) and Type 4-5 TAAA (age>75, creatinine>1.7mg/dL, and hematocrit<36mg/dL). Logistic regression was then utilized to develop a predictive model for 1-year mortality based on patient risk-profile. Appraisal of the model revealed an area under the curve of 0.64, p-value<0.001, and observed to expected ratio of 0.85. Conclusions This study describes multiple risk factors associated with an increase in 1-year mortality following F/BEVAR. Given that elective repair of complex AAA or TAAA is offered to some patients in whom future rupture risk outweighs operative risk, these findings suggest that highly comorbid patients with smaller aneurysms may not benefit from repair. Descriptive and predictive models for 1-year mortality based on patient risk-profiles can serve as an adjunct in clinical decision-making when considering elective F/BEVAR.