N-terminal B-natriuretic Peptide after coronary artery bypass graft surgery

To investigate N-terminal amino-acid sequence of the B-natriuretic peptide (NT-proBNP) release and its prognostic characteristics after coronary artery bypass graft surgery with and without cardiopulmonary bypass.

Observational study.

Teaching hospital.

One hundred eighty-four patients.

The authors determined plasma concentrations of NT-proBNP just before anesthesia induction and 24 hours after the end of the surgery.

NT-proBNP concentrations (median [interquartile range]) increased from 270 (75-716) pg/mL preoperatively to 1,664 (978-3,193) pg/mL on postoperative day 1 (p < 0.001), and all postoperative values were higher than the preoperative ones. NT-proBNP concentrations at day 1 were correlated to those at day 0 (r(2) = 0.34, p < 0.001). Patients showing elevated concentration of cTnI at day 1 (>14 ng/mL) had significantly (p = 0.04) higher plasma NT-proBNP levels than patients with a low cardiac troponin I concentration. Patients with prolonged intensive care unit (ICU) stay (>4 days) showed at day 1 significantly higher (p = 0.003) plasma NT-proBNP levels than patients with ICU stay <4 days. Elevated NT-proBNP at day 1 was significantly (p = 0.001) associated with in-hospital mortality, 18,584 (11,896-29,158) pg/mL versus 1,597 (965-3,034) pg/mL in survivors.

The present results show, for the first time, that postoperative NT-proBNP levels are associated with in-hospital mortality and prolonged ICU stay after CABG surgery. These findings support the prognostic value of postoperative plasma levels of NT-proBNP.