The role of procalcitonin and N-terminal pro-B-type natriuretic peptide in predicting outcome after cardiac surgery.

OBJECTIVE(S): Determine the thresholds of procalcitonin (PCT) and N-terminal pro-B-type natriuretic peptide (Nt-pro-BNP) associated with poor prognosis after heart surgery with CPB.

DESIGN

Prospective observational study.

SETTING

Academic Medical Center Habib Bourguiba.

PARTICIPANTS

Adult patients consecutively operated for coronary or valve surgery with CPB, elective or semi-urgent.

INTERVENTIONS

Serum concentrations of PCT and Nt-pro-BNP were determined before and after CPB, in the fourth postoperative hour (H4) and every day during the first 4 days. Receiver-operating characteristic curves and cut-off values were used to assess the ability of these markers to predict length of intensive care unit (ICU) stay >3 days.

MEASUREMENTS AND MAIN RESULTS

Forty patients were included in the study. Systemic inflammatory response syndrome (SIRS) occurred in 35 (87.5%) patients. Seventeen of them (42.5%) showed severe SIRS. Significantly higher serum concentrations of Nt-pro-BNP and PCT were found in patients with severe SIRS. Receiver operating characteristic (ROC) analysis showed that the threshold of PCT was 0.737 ng/mL and that of Nt-pro-BNP was 1235 pg/mL on day 1 could predict an ICU stay of more than 3 days. The association of Nt-pro-BNP to procalcitonin (p=0.009) better predicted the ICU stay than PCT alone (p=0.02) or Nt-pro-BNP alone (p=0.03). The best combination is Nt-pro-BNP + PCT + C-reactive protein (CRP) (p=0.007).

CONCLUSIONS

PCT and Nt-pro-BNP on day 1 may be associated with severe SIRS and predict the length of stay. A biomarker approach combining PCT, CRP and BNP is superior to a traditional single marker for predicting ICU stay.