Chronic Kidney Disease Severity and 30-Day Hospital Readmission Following Endovascular Aneurysm Repair, With Secondary Assessment of One-Year Mortality.

OBJECTIVES: Chronic kidney disease (CKD) is prevalent among patients undergoing endovascular aneurysm repair (EVAR) and is associated with increased cardiovascular and perioperative risk. While the adverse impact of advanced CKD on long-term survival is well documented, its association with early hospital utilization remains less clearly defined. This study evaluates the association between CKD stage and 30-day readmission following EVAR in a large, contemporary, multicenter cohort. METHODS: A retrospective cohort study was conducted using TrinetX, a multicenter, federated electronic health record research network. Patients undergoing non-ruptured infrarenal EVAR were identified by CPT codes and stratified by CKD stage using ICD-10 diagnosis codes, with non-CKD patients as the reference cohort. The primary outcome was 30-day all-cause readmission; secondary outcomes were 30-day postoperative complications (respiratory complications, stroke, myocardial infarction) and one-year mortality. The primary comparison (CKD vs non-CKD) used 1:1 propensity score matching on demographics and comorbidities; a separate analysis compared early (<3b) and advanced (≥3b) CKD. RESULTS: A total of 14,652 patients undergoing non-ruptured infrarenal EVAR were identified, of whom 5,418 had CKD. After matching (4,208 per arm), CKD was associated with higher 30-day readmission (27.3% vs 19.5%; odds ratio [OR] 1.55, 95% confidence interval [CI] 1.40-1.72; P<0.001). Readmission rose across CKD severity in a graded but non-monotonic pattern (Cochran-Armitage trend P<0.001), with the highest rates in stage 4, stage 5, and end-stage renal disease (ESRD). Notably, readmission in stage 2 (30.6%) exceeded that in both stage 3a (23.6%) and stage 3b (25.8%), an early-stage non-monotonic peak. A day-2 sensitivity analysis showed the association was not an artifact of index-stay capture. CKD was also associated with higher respiratory complications (10.6% vs 5.6%), stroke (2.6% vs 1.7%), and myocardial infarction (3.5% vs 1.6%; all P≤0.002). One-year all-cause mortality was higher among CKD patients (14.2% vs 8.7%; hazard ratio [HR] 1.70, 95% CI 1.48-1.95), and advanced CKD (≥3b) was independently associated with mortality relative to earlier stages (adjusted HR 1.49, 95% CI 1.29-1.73). CONCLUSIONS: CKD severity is associated with a graded, stage-dependent increase in early readmission, postoperative complications, and one-year mortality following EVAR, with the largest and most consistent risk concentrated in advanced (≥3b) disease rather than at a discrete threshold. Granular CKD staging may aid perioperative risk stratification and post-discharge planning.