Chronic Kidney Disease is a Stronger Predictor for Mortality than Charlson Comorbidity Index after Abdominal Aortic Aneurysm Repair

Abstract

Background: Patients undergoing abdominal aortic aneurysm (AAA) repair face elevated mortality risk associated with advanced age and comorbidities, including chronic kidney disease (CKD). CKD alone demonstrates an increased risk for mortality in patients. Our cohort study aimed to identify whether CKD and/or comorbid burden using the Charlson Comorbidity Index (CCI) are potential contributors toward negative outcomes in patients who underwent AAA repair.

Methods: We conducted a single-center retrospective cohort study on patients undergoing AAA repair between 2014 and 2024. The primary outcome is comorbidity burden (measured with CCI) and disease-specific burden (CKD measured by glomerular filtration rate (GFR)), as contributors to increased risk for mortality. Secondary outcomes included 30-day and mid-term complications and reinterventions after AAA repair. Propensity score matching was also conducted based on age, sex, hypertension, diabetes, smoking status, and coronary artery disease to assess for CKD and CCI burden.

Results: A total of 212 matched patients underwent AAA repair, with 106 patients in the no CKD (GFR ≥60 mL/min) group and 106 in the CKD (GFR <60 mL/min) group. Sociodemographic variables, including age (no CKD: 75.29 ± 8.17 vs. CKD: 75.94 ± 8.80; P = 0.576), sex proportions (P = 0.846), and mean household income (no CKD: $99,199.08 ± 37,846.82 vs. CKD: $91,333.38 ± 32,128; P = 0.091), were similar between groups. Patients with CKD had significantly higher CCI scores (no CKD: 4.99 ± 1.96 vs. CKD: 6.11 ± 2.26; P < 0.001). Thirty-day complications (no CKD: 5.7% vs. CKD: 7.5%; P = 0.580) and aortic-related reintervention rates (no CKD: 13.2% vs. CKD: 12.3%; P = 0.837) were comparable between groups. Mortality was significantly higher in the CKD group (no CKD: 17.9% vs. CKD: 32.1%; P = 0.017). Logistic regression analysis demonstrated that stage 5 CKD (odds ratio (OR): 9.33, 95% confidence interval (CI): 1.26-97.09; P = 0.04), CKD (OR: 2.16 95% CI: 1.15-4.17; P = 0.018), and CCI score (OR: 1.42, 95% CI: 1.26-1.67; P < 0.001) are significantly associated with mortality.

Conclusion: Higher CCI and CKD stage are risk factors for a higher mortality rate in patients who underwent AAA repair. Subgroup analysis between CKD stages demonstrated that stage 5 has a stronger association with mortality than CCI. Strategies to decrease mid-term mortality rates might include enhanced preoperative optimization and individualized approach to care.