Original article
Postoperative Increase in B-Type Natriuretic Peptide Levels Predicts Adverse Outcome After Cardiac Surgery

https://doi.org/10.1053/j.jvca.2010.07.002Get rights and content

Objective

To evaluate the prognostic implication of changes in postoperative B-type natriuretic peptide (BNP) concentrations in patients undergoing cardiopulmonary bypass for cardiac surgery.

Design

A retrospective analysis of prospectively collected clinical data.

Setting

Cardiothoracic surgery and an intensive care unit (ICU) in a university hospital.

Participants

The present study included a total of 407 consecutive patients undergoing cardiac surgery.

Interventions

None.

Measurements and Main Results

BNP concentrations were measured on admittance to the ICU (D0) and at day 1 after surgery. Patients were divided into quintiles according to their BNP level on admittance to the ICU. The predictive value of absolute changes in BNP levels during the first 24 hours postoperatively was analyzed with Kaplan-Meier estimates of survival and Cox multivariate proportional analysis. Prognostic factors for impaired midterm survival included elevation of the BNP level (HR, 7.3/ log10x; 95% confidence interval, 1.8-29, p = 0.005). The BNP levels of patients undergoing isolated valve surgery or valve and concomitant CABG surgery were significantly higher (p = 0.012 and p = 0.032, respectively) than those undergoing isolated coronary artery bypass graft surgery. Patients in higher quintiles required ventilation for a longer time (p < 0.001), and prolonged inotropic support (p < 0.001). The mean plasma BNP concentration of 172 pg/mL (median, 64; interquartile range, 172) on arrival at the ICU had a sensitivity of 75% and a specificity of 74% for predicting 1-year mortality.

Conclusions

Elevated BNP levels on admittance to the ICU and postoperatively increasing BNP levels are associated with adverse postoperative outcome and are predictive of impaired late survival. Sequential postoperative BNP monitoring facilitates the early identification of patients at an increased risk of heart failure and may be used as an adjunct for clinical decision making and optimized patient management.

Section snippets

Methods

Samples of blood for plasma BNP concentration analysis were taken from 407 patients between January and August 2007 after cardiac surgery at the Department of Cardiothoracic Surgery at Lund University Hospital. The spectrum of surgical interventions included isolated coronary artery bypass graft (CABG) surgery (n = 283), isolated valve replacement (aortic valve replacement [AVR], n = 45; mitral valve replacement [MVR], n = 18), and valve surgery with concomitant CABG surgery (AVR and CABG, n =

Results

Patient characteristics and surgical procedure are presented in Table 1. The median BNP level (D0) for the entire population was 64 pg/mL (IQR, 171; mean, 172 ± 284) and showed a nonnormal distribution (Kolmogorov-Smirnov p < 0.001). The observed overall 30-day mortality rate was 1.5% (6/407). The mortality rate for each procedure studied was 1.1% (3/283) for isolated CABG surgery, 0% (0/45) for isolated AVR and isolated MVR (0/18), 4.4% (2/45) for AVR with concomitant CABG surgery, and 6.3%

Discussion

The main finding of the present study was that an increase in BNP level during the first postoperative day is an independent predictor of late mortality after cardiac surgery. Of all the risk factors evaluated in the present study, an increasing value of log10 BNP showed the highest hazard ratio (7.3) for late mortality. Moreover, postoperative complications, especially prolonged requirement for inotropic support, were significantly more frequent in patients presenting with a high postoperative

References (24)

  • S. Provenchere et al.

    Plasma brain natriuretic peptide and cardiac troponin I concentrations after adult cardiac surgery: Association with postoperative cardiac dysfunction and 1-year mortality

    Crit Care Med

    (2006)
  • J. Bergler-Klein

    Natriuretic peptides in the management of aortic stenosis

    Curr Cardiol Rep

    (2009)

    • Cited by (0)

    View full text
    Copyright © 2011 Elsevier Inc. All rights reserved.