Elevated preoperative D-dimer is associated with acute kidney injury after non-cardiac surgery

aimed to analyze the relationship between preoperative D-dimer level and AKI following non-cardiac surgery. Method: This was a single-center retrospective cohort study for elective non-cardiac surgery from January 1, 2012, to December 31, 2018. The endpoint was the occurrence of AKI 7 days postoperatively in the hospital. The non-linear relationship was described using the generalized additive model. ROC and minimum P-value approach identified possible cut-off points. D-dimer's odds ratio as continuous, quantile, and dichotomous variables by various cut-off points for postoperative AKI were calculated in multivariate logistic regression models before and after propensity score weighting. Results: Of the 55439 surgery, 5.0% (2779 cases) suffered postoperative AKI. Non-linearity was found between D-dimer and postoperative AKI. The odds ratio for D-dimer before and after propensity score weighting was (≤ 0.380 µg/mL as reference, minimum P-value cut-off point) 1.35 (1.20-1.49), P < 0.001 and 1.25 (1.09-1.43), P = 0.001, respectively; (≤ 0.165 µg/mL as reference, ROC cut-off point) 1.24 (1.12-1.37), P < 0.001 and 1.18 (1.06-1.31), P = 0.002, respectively. Sensitivity analysis showed similar results. Heterogeneity subgroup analysis showed that patients with normal preoperative creatinine, hemoglobin level, and intraperitoneal surgery or more complex surgery seemed to be more vulnerable to elevated D-dimer. Conclusions: : Preoperative D-dimer was significantly associated with postoperative AKI following non-cardiac surgery. The optimal cut-off point for preoperative D-dimer was 0.165 µg/mL by ROC approach and 0.38 µg/mL by minimum P-value approach.