Is C-reactive protein a biomarker for immediate clinical outcome after cardiac surgery?

OBJECTIVE

The purpose of this study was to determine the possible correlation between inflammatory activation after cardiac surgery with cardiopulmonary bypass, measured by postoperative C-reactive protein concentrations, and immediate intensive care unit outcome.

DESIGN

A prospective, clinical cohort study.

SETTING

A 10-bed surgical intensive care unit at a tertiary university hospital.

PATIENTS

Two hundred sixteen consecutive patients undergoing nonemergency cardiac surgery with cardiopulmonary bypass.

MEASUREMENTS AND MAIN RESULTS

Parsonnet and Acute Physiology and Chronic Health Evaluation scores, characteristics of the surgical intervention, intensive care unit length of stay, and mortality were recorded along with the following variables: cardiac (hours requiring inotropic support and new atrial fibrillation), respiratory (oxygenation index and hours requiring intubation), renal (difference between serum creatinine at admission and maximum creatinine), and analytic (C-reactive protein at admission and 6, 24, and 48 hours later; troponin I; CK-MB; and lactate).

RESULTS

Postoperative C-reactive protein concentrations did not correlate with variables such as time requiring inotropic support or intubation, oxygenation index, delta serum creatinine, and intensive care unit length of stay (with the exception of cardiopulmonary bypass time and the more frequent norepinephrine requirement in patients with higher C-reactive protein concentration at 48 hours); nor did C-reactive protein correlate with the analytic variables (with the exception of the lactate peak and C-reactive protein concentrations at 24 and 48 hours). There was no correlation between C-reactive protein and postoperative variables for coronary artery bypass graft surgery and valvular groups analyzed separately.

CONCLUSION

Postoperative C-reactive protein does not seem to be a useful marker in predicting outcome after 48 hours in the intensive care unit.