Proenkephalin A 119-159 as an early biomarker of acute kidney injury in complex endovascular aortic repair: an explorative single-center cross-sectional study with the utilization of two measurement methods.

Background: Acute kidney injury (AKI) remains a significant complication following endovascular aneurysm repair (EVAR). Current diagnostic methods often detect kidney damage too late for effective intervention. This study evaluated proenkephalin A 119-159 as an early AKI biomarker after EVAR procedures, comparing point-of-care testing with the ELISA method.

Methods: Between April 2022 and June 2024, 68 patients undergoing elective EVAR were enrolled. Blood samples were collected preoperatively and for three consecutive postoperative days.

Results: AKI was diagnosed according to the KDIGO criteria, with proenkephalin A 119-159 measured via point-of-care (penKid) testing and laboratory ELISA method. AKI occurred in 18 patients (26.5%). penKid showed a superior diagnostic performance to ELISA, demonstrating moderate agreement with KDIGO criteria (Gwet's AC1 = 0.52, p < .001). While penKid exhibited high sensitivity (80% day 1), specificity was moderate (51%). AKI patients had significantly higher median penKid levels (96.47 pmol/L vs 63.01 ng/mL, p = .001), longer hospital stays (12 vs 9 days, p = .028), and lower 6-month survival (50% vs 88.1%, p = .006).

Conclusions: penKid testing shows promise as an early AKI biomarker following EVAR procedures, particularly for identifying low-risk AKI patients. However, its moderate specificity suggests it should complement existing clinical assessment tools rather than replace them. These findings support incorporating penKid monitoring into structured AKI care bundles for improved perioperative kidney outcomes.