Utility of B-type natriuretic peptide in predicting postoperative complications and outcomes in patients undergoing heart surgery

Abstract

Objectives: The purpose of the present study was to assess whether preoperative and postoperative B-type natriuretic peptide (BNP) levels could be used as predictors of postoperative complications and outcomes in patients after open-heart surgery.

Background: A variety of multifactor indexes have been proposed for preoperative risk assessment of patients undergoing cardiac surgery, but they have shown limited ability and utility in accurately predicting postoperative complications, hospital stay, and mortality.

Methods: Subjects consisted of 98 male patients (63 +/- 9.1 years) undergoing open-heart surgery at the San Diego Veterans Administration Health System during a 19-month period. B-type natriuretic peptide levels were analyzed, and postoperative data recorded.

Results: There was a higher preoperative BNP level in patients requiring the use of intra-aortic balloon pumps (IABPs) (mean BNP = 387 +/- 112 pg/ml vs. 181 +/- 25 pg/ml), in patients who died within one year (357 +/- 93 pg/ml vs. 184 +/- 26 pg/ml), and in patients with postoperative hospital stays of 10 days or more (307 +/- 68 pg/ml vs. 179 +/- 27 pg/ml). Receiver operating characteristic curves demonstrated preoperative BNP levels as predictors of postoperative IABP use, hospital stay <or=10 days, and mortality <1 year with areas under the curve of 0.70, 0.64, and 0.70, respectively. A BNP cut-off value above 385 pg/ml demonstrated high specificity (=90% in each) and accuracy (=86%, 79%, 85%, respectively) for predicting each of these end points.

Conclusions: Preoperative BNP levels >385 pg/ml predict the postoperative complications and one-year mortality after heart surgery. Postoperatively, elevated peak BNP levels and elevated change to peak BNP levels were associated with prolonged hospital stay and mortality within one year.