D-Dimer for risk stratification in patients with acute pulmonary embolism

Background: Risk stratification is currently recommended for the initial management of patients with acute pulmonary embolism (PE). Methods: We performed a meta-analysis of studies in patients with acute PE to assess the prognostic value of elevated D-dimer levels for short-term (within 30 days) and 3-month mortality. The association between D-dimer levels and markers of PE severity was also reviewed. Unrestricted searches were performed using the terms D-dimer and pulmonary embolism. Studies reporting on D-dimer levels and mortality and/or markers of PE severity were included in the review. A random-effects model was used to pool study results, funnel-plot inspection to evaluate publication bias and I squared testing to test for heterogeneity. Results: Five studies (2,885 patients) reported on D-dimer levels and short-term mortality. D-dimer levels above a prognostic cut-off were significantly associated with short-term mortality in the overall population (OR: 2.76; 95% CI: 1.83-4.14; I-2 = 0%) and in hemodynamically stable patients (three studies, 874 patients; OR: 4.28; 95% CI: 1.88-9.71; I-2 = 0%). Four studies (1,254 patients) reported on D-dimer levels and 3-month mortality. D-dimer levels above a prognostic cut-off were associated with 3-month mortality (OR: 4.29; 95% IC: 1.70-10.79; I-2 = 0%). Overall, 14 studies assessed the association between D-dimer and markers of PE severity. An association has been observed between D-dimer levels and the degree of pulmonary artery obstruction. Conclusion: In patients with acute PE elevated D-dimer is associated with increased short-term and 3-month mortality, suggesting the potential of using this test for both diagnosis and risk stratification.