Associations of preoperative pan-immune inflammation value with postoperative acute kidney injury following open-heart surgery: a retrospective analysis.

BACKGROUND

Cardiac surgery-associated acute kidney injury (CSA-AKI) is prevalent and results in significant morbidity. The pan-immune inflammation value (PIV), derived from routine blood counts, captures innate, adaptive, and coagulation-inflammation pathways; however, its preoperative association with CSA-AKI remains unclear.

METHODS

This retrospective cohort study encompassed 725 patients undergoing open-chest cardiac surgery with cardiopulmonary bypass. CSA-AKI was defined according to KDIGO criteria. The relationship between PIV and CSA-AKI was evaluated using multivariable logistic regression. A nonlinear relationship was investigated through restricted cubic spline (RCS) analysis. Subsequent subgroup analysis and interaction effect tests were conducted. The incremental predictive value of PIV was assessed using integrated discrimination improvement (IDI) and net reclassification improvement (NRI).

RESULTS

CSA-AKI was identified in 256 (35.3%) patients. Elevated preoperative PIV exhibited a dose-dependent association with increased CSA-AKI incidence (adjusted odds ratio per 50-unit increase: 1.04; 95% confidence interval: 1.02-1.06; p = 0.005). The preoperative PIV demonstrated a monotonic yet attenuating association with CSA-AKI incidence (p-non-linear = 0.087). Results were consistent across subgroups, with no significant interaction effect detected. PIV demonstrated a statistically significant yet clinically modest improvement in IDI and continuous NRI.

CONCLUSION

An elevated preoperative PIV correlates with a heightened risk of CSA-AKI. Integrating PIV into preoperative risk algorithms may enhance risk stratification and facilitate targeted preventive measures.