Abstract
Background Systemic inflammation contributes to cardiac surgery–associated acute kidney injury
(AKI). Cardiomyocytes and other organs experience hypothermia and hypoxia during cardiopulmonary
bypass (CPB), which induces the secretion of cold-inducible RNA-binding protein (CIRP).
Extracellular CIRP may induce a proinflammatory response.
Materials and Methods The serum CIRP levels in 76 patients before and after cardiac surgery were determined
to analyze the correlation between CIRP levels and CPB time. The risk factors for
AKI after cardiac surgery and the in-hospital outcomes were also analyzed.
Results The difference in the levels of CIRP (ΔCIRP) after and before surgery in patients
who experienced cardioplegic arrest (CA) was 26-fold higher than those who did not,
and 2.7-fold of those who experienced CPB without CA. The ΔCIRP levels were positively
correlated with CPB time (r = 0.574, p < 0.001) and cross-clamp time (r = 0.54, p < 0.001). Multivariable analysis indicated that ΔCIRP (odds ratio: 1.003; 95% confidence
interval: 1.000–1.006; p = 0.027) was an independent risk factor for postoperative AKI. Patients who underwent
aortic dissection surgery had higher levels of CIRP and higher incidence of AKI than
other patients. The incidence of AKI and duration of mechanical ventilation in patients
whose serum CIRP levels more than 405 pg/mL were significantly higher than those less
than 405 pg/mL (65.8 vs. 42.1%, p = 0.038; 23.1 ± 18.2 vs. 13.8 ± 9.2 hours, p = 0.007).
Conclusion A large amount of CIRP was released during cardiac surgery. The secreted CIRP was
associated with the increased risk of AKI after cardiac surgery.
Keywords
acute kidney injury - CIRP - cardiac surgery - inflammation
