Introduction:

Acute kidney injury is common after cardiac surgery and is associated with postoperative mortality. Cardiac biomarkers are more accessible and can help predict acute kidney injury.

Objectives:

To investigate the relationship between cardiac biomarkers with acute kidney injury (AKI) postoperatively in adults undergoing cardiac surgery.

Material and methods:

Prospective cohort study in post-operated cardiac surgery adults. We measured the following cardiac biomarkers in the first 6 hours of the postoperative period: B-type natriuretic peptide (BNP), ultrasensitive troponin I (USTI), creatine phosphokinase (CPK), creatine phosphokinase MB (CPK-MB) and myoglobin.

Results:

Of the 63 patients evaluated, 31 (49.2%) presented AKI. Patients with AKI had significantly higher levels of BNP, usTI, CPK-MB, and myoglobin. Myoglobin had a good area under the curve (AUC 0.81, 95% CI 0.66-0.95), followed by usTI (AUC 0.71, 95% CI 0.58-0.92) and BNP (AUC 0.71 95% CI 0.53-0.88) to detect AKI. Myoglobin levels ≥ 731 ng/mL had a positive likelihood ratio (7.73, 95% CI 1.04-57.24). The time of extracorporeal circulation (adjusted odds-ratio 6.11, 95% CI 1.55 to 9.55) and myoglobin elevation (Adjusted odds-ratio 1.00, 95% CI 1.00 to 1.01) were independent predictors of AKI.

Conclusions:

The postoperative levels of cardiac biomarkers are significantly higher in patients with AKI. Extracorporeal circulation (CCE) time and myoglobin elevation were shown to be predictors of AKI. These biomarkers may be suitable for identifying patients at high risk for AKI after cardiac surgery.