Early prediction of acute kidney injury after transapical and transaortic aortic valve implantation with urinary G1 cell cycle arrest biomarkers.

BACKGROUND: Acute kidney injury (AKI) is a common complication following transcatheter aortic valve implantation (TAVI) leading to increased mortality and morbidity. Urinary G1 cell cycle arrest proteins TIMP-2 and IGFBP7 have recently been suggested as sensitive biomarkers for early detection of AKI in critically ill patients. However, the precise role of urinary TIMP-2 and IGFBP7 in patients undergoing TAVI is unknown. METHODS: In a prospective observational trial, 40 patients undergoing TAVI (either transaortic or transapical) were enrolled. Serial measurements of TIMP-2 and IGFBP7 were performed in the early post interventional course. The primary clinical endpoint was the occurrence of AKI stage 2/3 according to the KDIGO classification. RESULTS: Now we show, that ROC analyses of [TIMP-2]*[IGFBP7] on day one after TAVI reveals a sensitivity of 100 % and a specificity of 90 % for predicting AKI 2/3 (AUC 0.971, 95 % CI 0.914-1.0, SE 0.0299, p = 0.001, cut-off 1.03). In contrast, preoperative and postoperative serum creatinine levels as well as glomerular filtration rate (GFR) and perioperative change in GFR did not show any association with the development of AKI. Furthermore, [TIMP-2]*[IGFBP7] remained stable in patients with AKI ≤1, but its levels increased significantly as early as 24 h after TAVI in patients who developed AKI 2/3 in the further course (4.77 ± 3.21 vs. 0.48 ± 0.68, p = 0.022). Mean patients age was 81.2 ± 5.6 years, 16 patients were male (40.0 %). 35 patients underwent transapical and five patients transaortic TAVI. 15 patients (37.5 %) developed any kind of AKI; eight patients (20 %) met the primary endpoint and seven patients required renal replacement therapy (RRT) within 72 h after surgery. CONCLUSION: Early elevation of urinary cell cycle arrest biomarkers after TAVI is associated with the development of postoperative AKI. [TIMP-2]*[IGFBP7] provides an excellent diagnostic accuracy in the prediction of AKI that is superior to that of serum creatinine.

Urinary [TIMP-2]*[IGFBP7] for early prediction of acute kidney injury after coronary artery bypass surgery.

BACKGROUND: Acute kidney injury (AKI) is a common complication after cardiac surgery. Currently, prediction of AKI with classical tools remains uncertain. Therefore, it was the aim of the present study to evaluate two new urinary biomarkers-insulin-like growth factor-binding protein 7 (IGFBP7) and tissue inhibitor of metalloproteinases-2 (TIMP-2) in patients after coronary artery bypass surgery (CABG). METHODS: In a prospective cohort study, 60 consecutive patients undergoing isolated on-pump CABG were enrolled. Urine samples collected every 12 h in the postoperative course were analyzed for the product of TIMP-2 and IGFBP7. Urinary output, serum creatinine and estimated glomerular filtration rate (eGFR) were recorded simultaneously. Primary clinical endpoint was the development of AKI stage 2 or 3 according to the classification of the KDIGO within 48 h after surgery. RESULTS: 48 male and 12 female patients with a mean age of 69.61 ± 8.4 years were included. 19 patients developed an AKI (31.6 %), six patients met the endpoint with AKI 2 or 3 (10 %). Urinary [TIMP-2]*[IGFBP7] increased significantly as early as 4 h after CABG in patients with AKI 2/3 (1.83 ± 2.15 vs. 0.23 ± 0.45, p < 0.05) whereas serum creatinine did not increase until 48 h after surgery. The diagnostic accuracy of [TIMP 2]*[IGFBP7] on day one after surgery for the prediction of AKI 2/3 was significantly better (sensitivity 0.89, specificity 0.81, AUC 0.817, 95 % CI 0.622-1.0 SE 0.099, p = 0.022, cut-off 0.817) than for serum creatinine (AUC 0.359, sensitivity 0.50, specificity of 0.52, cut-off value 1.17 mg/dl) and eGFR. CONCLUSION: Urinary [TIMP-2]*[IGFBP7] represents a sensitive and specific biomarker to predict moderate to severe AKI very early after CABG. Analyses from our ongoing larger study are necessary to confirm these findings and probably increase sensitivity and specificity.

Tracheostomy After Cardiac Surgery With Median Sternotomy and Risk of Deep Sternal Wound Infections: Is It a Matter of Timing?

OBJECTIVE: To assess the impact of timing of percutaneous dilatational tracheotomy (PDT) on incidence of deep sternal wound infections (DSWI) after cardiac surgery with median sternotomy. DESIGN: Retrospective study between 2003 and 2013. SETTING: Single-center university hospital. PARTICIPANTS: Eight hundred seventy-nine patients after cardiac surgery with extracorporeal circulation and median sternotomy. INTERVENTIONS: PDT using the Ciaglia-technique with direct bronchoscopic guidance. MEASUREMENT AND MAIN RESULTS: Mean time from surgery and (re)intubation to PDT was 6.7±9.9 and 3.8±3.3 days, respectively. Incidence of DSWI was 3.9% (34/879). The incidence of DSWI was comparable between patients with PDT performed before postoperative day (POD) 10 and those with PDT after POD 10 (29/755 [3.8%] v 5/124 [4.0%], p = n.s.). However, the authors observed an association of timing of PDT and DSWI: The incidence of DSWI was significantly higher in patients with PDT performed≤POD 1 compared to those with PDT after POD 2 (12/184 [6.52%] v 22/695 [3.16%], p = 0.046). In multivariate analysis, obesity, use of bilateral internal mammary arteries, ICU stay>30 days and PDT<48 hours after surgery (OR 3.519, 95% CI 1.242-9.976, p = 0.0018) were independent predictors of DSWI. In 15/34 patients (44.1%), similarity of microorganisms between sternotomy site and tracheal cultures was observed, indicating a possible cross-contamination. CONCLUSIONS: PDT within the first 10 postoperative days after cardiac surgery with median sternotomy can be performed safely without an increased risk of DSWI. In contrast, very early PDT within 48 hours after surgery is associated with an increased risk of mediastinitis and should, therefore, be avoided.