Prediction of Acute Kidney Injury after Aortic Surgery with [TIMP-2]*[IGFBP7]

Objectives: Acute kidney injury (AKI) is a common complication following thoracic aortic surgery with moderate hypothermic circulatory arrest (MHCA) increasing mortality and morbidity. Currently, prediction of AKI with classical tools remains uncertain but new biomarkers have been suggested for the early detection of AKI in other patient populations. Therefore, it was the aim of the present study to evaluate the role of the cell cycle arrest markers TIMP2 and IGFBP7 in patients after MHCA.

Methods: In a prospective cohort study, 102 consecutive patients undergoing thoracic aortic surgery with MHCA were enrolled. Measurements of urinary [TIMP-2]x[IGFBP7] were performed preoperatively and in the early postoperative course. Primary endpoint was the occurrence of AKI stage 2 or 3 according to the KDIGO classification.

Result: Mean age of patients was 69.1 ± 10.9 years, 35 patients were female (34%). Mean EuroSCORE-II and STS-Score were 7.3 ± 7.4 and 3.7 ± 3.6, respectively. 13 patients (13%) met the primary endpoint with AKI any stage 2 or 3. Patients with AKI had a prolonged ICU-stay (6.9 ± 7.4 days vs. 2.5 ± 3.1 days, p < 0.001) as well as a higher 30-day-mortality (9/28 versus 1/74, p < 0.001) than patients without AKI. Whereas preoperative serum creatinine (169.73 ± 148.97 μmol/L vs. 89.74 ± 30.04 μmol/L, p = 0.027) was higher in the AKI group, [TIMP-2]*[IGFBP7] before surgery did not differ between groups (0.29 ± 0.35 vs. 0.48 ± 0.69, p = n.s.). In patients developing AKI ⅔ within the first 48 postoperative hours, [TIMP-2]*[IGFBP7] increased significantly four hours after surgery (0.6 ± 0.69 vs. 0.37± 0.56, p = 0.03) but not 2 hours after surgery (1.2 ±1.29 vs. 0.28 ± 0.56, p = n.s.). Accordingly, [TIMP-2]*[IGFBP7] before surgery and 2 hour after surgery showed a low predictive capacity, but [TIMP-2]*[IGFBP7] 4 hour after surgery was able to predict postoperative AKI (AUC: 0.724, p = 0.020). Preoperative serum creatinine showed a sensitivity of 79.0% and a specificity of 76.8% for predicting AKI.

Conclusion: [TIMP-2]*[IGFBP7] represents a sensitive and specific biomarker to predict AKI in patients undergoing thoracic surgery with MHCA. However, preoperative serum creatinine showed comparative predictive properties.

Publication History

Article published online:
19 February 2021