Cardiac surgery associated acute kidney injury (CSA-AKI) has been recognized as the second most common cause of hospital acquired AKI. The development of CSA-AKI is independently associated with an increased risk of in-hospital death. There are currently no biomarkers that could identify patients at higher risk for AKI and current risk predictor scores that are based on clinical and demographic information are inadequate. Therefore, a diagnostic test for predicting AKI risk in this clinical context would assist clinicians to optimize surgical strategy and postoperative care to prevent CSA-AKI occurrence and improve patient outcomes.

The primary purpose of this study is to measure the association between baseline expression of senescence markers in blood using SenesceTest and the occurrence of CSA-AKI post surgery.

Inclusion Criteria:

Patients must fulfill all criteria to be eligible for this study:

• Adult patients (>18 yo) undergoing non-emergency cardiac surgery using cardiopulmonary bypass (CABG, combined CABG/valve, or valve surgery).

Exclusion Criteria:

Patients who fulfill any of the following criteria will be excluded:

• Emergency surgery.
• Off-pump coronary bypass grafting.
• Aortic aneurysm repair.
• Congenital heart disease repair.
• Heart transplant or LVAD patient.
• Severe heart failure (LVEF<25%).
• Hemodynamic instability or requiring preoperative vasopressors or IABP.
• Pre-existing end-stage kidney disease (eGFR< 15 mL/min/1.73 m2) or renal transplantation.
• Presence of major active infection (chronic or acute, e.g. sepsis, HIV, pneumonia).
• Chronic liver disease /cirrhosis.

All subjects entered into this study will be patients of the Duke University Health System.