Background/Aims: Contrast induced acute kidney injury (CI-AKI) remains a
serious complication of contrast media enhanced procedures like coronary
angiography. There is still a lack of established biomarkers that help to
identify patients at high risk for short and long-term complications. The aim
of the current study was to evaluate plasma kynurenine as a predictive
biomarker for CI-AKI and long-term complications, measured by the combined
endpoint "major adverse kidney events" (MAKE) up to 120 days after CM
application. Methods: In this prospective cohort study 245 patients undergoing
coronary angiography were analyzed. Blood samples were obtained at baseline,
24h and 48h after contrast media (CM) application to diagnose CI-AKI. Patients
were followed for 120 days for adverse clinical events including death, the
need for dialysis, and a doubling of plasma creatinine. Occurrence of any of
these events was summarized in the combined endpoint MAKE. Results:
Preinterventional plasma kynurenine was not associated with CI-AKI. Patients
who later developed MAKE displayed significantly increased preinterventional
plasma kynurenine levels (p<0.0001). ROC analysis revealed that
preinterventional kynurenine is highly predictive for MAKE (AUC=0.838;
p<0.0001). The optimal cutoff was found at ≥3.5 µmol/L Using this cutoff, the
Kaplan-Meier estimator demonstrated that concentrations of plasma kynurenine
≥3.5 µmol/L were significantly associated with a higher prevalence of MAKE
until follow up (p<0.0001). This association remained significant in
multivariate Cox regression models adjusted for relevant factors of long-term
renal outcome. Conclusion: Preinterventional plasma kynurenine might serve as
a highly predictive biomarker for MAKE up to 120 days after coronary
angiography
