Background: The role of biomarkers such as B-type natriuretic peptides (BNP and NT-proBNP) and troponins in risk stratification of acute pulmonary embolism (APE) is still debated. We performed a meta-analysis to assess the association between elevated natriuretic peptide levels alone or in conjunction with troponins, and all-cause and APE-related mortality, serious adverse events and echographic right ventricular dysfunction.
Methods: We searched MEDLINE and EMBASE, and hand searched conference abstracts up to February 2008. Studies were included if a 2X2 table could be constructed based on natriuretic peptide results and at least one of the outcomes.
Results: Twenty three studies were included (1127 patients). Elevated natriuretic peptide were significantly associated with all-cause mortality (OR 6.2; 95% confidence interval [CI]: 3.0 - 12.7), APE-related mortality (OR 5.0; CI: 2.2 - 11.5) and serious adverse events (OR 6.7; CI: 3.9 - 11.6), with homogeneity across studies. Among patients with elevated natriuretic peptide levels, increased serum troponins were associated with further increase in risk of adverse outcomes. The analysis of natriuretic peptide accuracy in detection of right ventricular dysfunction was limited by heterogeneity across studies. BNP appeared to have better sensitivity and specificity than NT-proBNP in detection of right ventricular dysfunction.
Conclusions: Elevated B-type natriuretic peptides identified a subset of patients with APE at higher risk of adverse outcomes. Among patients with elevated natriuretic peptide levels, increased troponins were documented as an independent prognostic marker. The results of this meta-analysis may have important clinical implications in the management of APE.