Predictors of acute kidney injury after infrarenal abdominal aortic aneurysm repair in octogenarians

Objective: Acute kidney injury (AKI) is a common postoperative complication after abdominal aortic aneurysm (AAA) repair and is associated with significant morbidity and mortality. However, limited studies have investigated this complication in elderly patients. This study aims to evaluate AKI in octogenarians after open endovascular AAA repair (OAR) and endovascular AAA repair (EVAR). Methods: Data were obtained from the Vascular Quality Initiative database on all patients who underwent elective infrarenal AAA repair between January 2003 and April 2017. Univariate analysis was used to compare AKI rates as well as failure to rescue after AKI between octogenarians and nonoctogenarians in OAR and EVAR. Stepwise multivariable logistic regression analysis was implemented to identify independent predictors and develop a risk calculator of AKI in octogenarians undergoing AAA repair. Results: A total of 27,993 patients (12% OAR and 88% EVAR) were included, of which 6708 (24%) were octogenarians (OAR, 332; EVAR, 6376). Postoperative AKI was more common in octogenarians as compared with nonoctogenarians in OAR (15.1% vs 10.1%; P=.01) and EVAR (4.2% vs 2.7%; P<.001). Similarly, failure to rescue, defined as 30-day mortality after postoperative AKI, was higher in octogenarians whether undergoing OAR (28.0% vs 8.8%; P<.001) or EVAR (14.1% vs 7.5%; P<.01). On multivariable analysis, octogenarians undergoing OAR had a 3.5 times higher odds of AKI compared with those undergoing EVAR (odds ratio [OR], 3.52; 95% confidence interval [CI], 2.36-5.23; P<.001). Other independent risk factors for postoperative AKI in octogenarians included chronic obstructive pulmonary disease (OR, 1.48; 95% CI, 1.14-1.93), chronic kidney disease stage III (OR, 2.17; 95% CI, 1.26-3.76) and chronic kidney disease stage IV-V (OR, 5.7; 95% CI, 3.0-10.9), peripheral artery disease (OR, 1.99; 95% CI, 1.34-2.94), preoperative beta-blocker use (OR, 1.85; 95% CI, 1.45-2.38), and aneurysm diameter (OR, 1.25; 95% CI, 1.11-1.41). These predictors were incorporated in an interactive risk calculator of AKI after AAA repair in octogenarians (C-statistic = 0.728). Conclusions: AKI is a serious complication after AAA repair, especially in octogenarians, and is associated with high failure to rescue rates. A careful assessment of risk factors for AKI in elderly patients should be performed to inform clinical decision making.