Mortality and Cost of Acute and Chronic Kidney Disease after Vascular Surgery

Background: Both acute kidney injury (AKI) and chronic kidney disease (CKD) are common yet underappreciated risk factors for adverse perioperative outcomes. We hypothesize that AKI and CKD are associated with similar increases in 90-day mortality and cost in patients undergoing major vascular surgery. Methods: We used multivariable regression analyses to evaluate the associations between AKI and CKD and incremental 90-day mortality and hospital cost in a single-center cohort of 3646 adult patients undergoing major vascular surgery. We defined AKI using Kidney Disease: Improving Global Outcomes criteria as change in creatinine >= 0.3 mg/dL or >= 50% increase from the reference value. CKD was determined from medical history. Regression models were adjusted for demographic and socioeconomic characteristics, comorbid conditions, surgery type, and postoperative complications. Results: The prevalence of kidney disease among vascular surgery patients is high with 49% of patients developing AKI during hospitalization and 17% presenting with CKD on admission. In risk-adjusted logistic regression analysis, perioperative AKI (odds ratio 2.2, 95% confidence interval 1.5-3.3) was the most significant predictor of 90-day mortality. The risk-adjusted average cost was significantly higher for patients with any type of kidney disease. The incremental cost of having any type of kidney disease ranged from $9100 to $19,100, even after adjustment for underlying comorbidities and other postoperative complications. Conclusions: Kidney disease after major vascular surgery is associated with significant increases in 90-day mortality and cost with the highest risk observed among patients with AKI regardless of previous CKD.