Preoperative B-type natriuretic peptide is as independent predictor of ventricular dysfunction and mortality after primary coronary artery bypass grafting

Abstract

Objective: Elevated B-type natriuretic peptide is associated with increased morbidity and mortality in ambulatory patients with congestive heart failure or acute coronary syndromes. Its utility in predicting adverse cardiac surgical outcomes is less certain. We hypothesized that preoperative plasma B-type natriuretic peptide would independently predict in-hospital postoperative ventricular dysfunction, hospital stay, and up to 5-year mortality after primary coronary artery bypass grafting.

Methods: This is a prospective, longitudinal study of 1023 patients at two institutions undergoing primary coronary artery bypass grafting with cardiopulmonary bypass. Ventricular dysfunction was defined as requirement for at least two inotropes or new intra-aortic balloon pump or ventricular assist device support after coronary artery bypass grafting. Multivariable analyses assessed independent roles of preoperative B-type natriuretic peptide in predicting postoperative ventricular dysfunction, hospital stay, and 5-year all-cause mortality.

Results: Preoperative plasma B-type natriuretic peptide concentration predicted ventricular dysfunction, hospital stay, and mortality in univariate and multivariable analyses. Logistic regression demonstrated preoperative B-type natriuretic peptide to independently predict ventricular dysfunction (odds ratio 1.92, 95% confidence interval 1.12-3.29, P = .018), after adjustment for preoperative left ventricular ejection fraction, congestive heart failure severity, and other clinical predictors. Multivariable Cox proportional hazards models showed preoperative B-type natriuretic peptide to independently predict hospital stay (hazard ratio 1.42, 95% confidence interval 1.18-1.72, P = .0002) and mortality (hazard ratio 1.89, 95% confidence interval 1.08-3.33, P = .026).

Conclusion: Preoperative plasma B-type natriuretic peptide independently predicted in-hospital ventricular dysfunction, hospital stay, and up to 5-year all-cause mortality after primary coronary artery bypass grafting.

Figures

Figure 1

Kaplan-Meier survival curves for all patients up to 5 years after primary CABG surgery according to whether patients experienced postoperative ventricular dysfunction (VnD). 95% confidence intervals are shown for the survival estimates for each year of postoperative follow-up.

Figure 2

Perioperative plasma B-type natriuretic peptide (BNP) concentrations for all patients stratified according to whether patients did or did not develop postoperative, in-hospital ventricular dysfunction (VnD), with 10th, 25th, 50th, 75th and 90th percentile values shown for each subgroup at each time point. * signifies P

Figure 3

Receiver operating characteristic curve describing preoperative plasma B-type natriuretic peptide (BNP) concentrations in relation to in-hospital ventricular dysfunction (VnD) after primary CABG surgery.

Figure 4

Receiver operating characteristic curve describing preoperative plasma B-type natriuretic peptide (BNP) concentrations in relation to up to 5 year mortality after primary CABG surgery.

Figure 5

Kaplan-Meier survival curves for all patients up to 5 years after surgery, stratified by preoperative BNP >292 pg/mL versus ≤ 292 pg/mL (A) and by preoperative BNP >141 pg/mL versus ≤ 141 pg/mL (B). 95% confidence intervals are shown for the survival estimates for each year of postoperative follow-up.