The predictive value of preoperative natriuretic peptide concentrations in adults undergoing surgery: a systematic review and meta-analysis.

BACKGROUND Several studies have evaluated preoperative B-type natriuretic peptides (NPs) for predicting mortality after surgery; however, the number of deaths in each study was small, limiting the power of these studies. We conducted a systematic review and meta-analysis of studies addressing preoperative NP levels to predict mortality after cardiac and noncardiac surgery. METHODS We searched MEDLINE and EMBASE using the terms "natriuretic peptides," "surgery or surgical procedures," and a validated combination of prognostic and diagnostic terms. Two investigators independently assessed studies for eligibility and extracted data. The end points were all-cause mortality at ≥6 months and at ≤90 days. We used a bivariate model to derive measures of prognostic accuracy and their heterogeneity. We calculated the pooled positive predictive value (PPV) and negative predictive value (NPV) by Bayesian Markov chain Monte Carlo methods. RESULTS Of the 1558 retrieved articles, 23 studies satisfied the predefined eligibility criteria. After cardiac surgery, the diagnostic odds ratio of NP was 4.11 (95% confidence interval, 2.22-7.60) for ≥6-month mortality, the PPV 0.17 (95% Bayesian confidence interval, 0.07-0.36), and the NPV 0.96 (0.90-0.98). After noncardiac surgery, the diagnostic odds ratio of NP was 4.97 (3.06-8.07) for ≥6-month mortality. The corresponding PPV was 0.24 (0.14-0.38) and the NPV 0.94 (0.88-0.97). Results were similar for ≤90-day mortality. CONCLUSIONS Preoperative NP concentrations were associated with mortality after cardiac and noncardiac surgery. NP had high NPVs for both types of surgery suggesting that preoperative NP concentrations may be helpful in preoperative risk stratification.