VIDAS D-Dimer in Combination with Clinical Pre-Test Probability to Rule out Pulmonary Embolism. A Systematic Review of the Management Outcome Studies.

Abstract

Background: Clinical outcome studies have shown that it is safe to withhold anticoagulant therapy in patients with suspected pulmonary embolism (PE) who have a negative D-dimer result and a low pre-test probability (PTP) either using a PTP model or clinical gestalt.Purpose: To assess the safety of the combination of a non-high PTP using the Wells or Geneva models with a negative VIDAS© D-dimer result to exclude PE.Data Source: A systematic literature search strategy was conducted using MEDLINE, EMBASE, the Cochrane Register of Controlled Trials and all EBM Reviews.Study Selection: Seven studies (6 prospective management studies and 1 randomized controlled trial) reporting failure rates at three months were included in the analysis. Non-high PTP was defined has “unlikely” or “low/intermediate” PTP using either, the Wells' score, the Geneva, Revised Geneva Score, or gestalt estimation.Data extraction: Two reviewers independently extracted data onto standardized forms.Data Synthesis: A total of 5,622 patients with non-high PTP were assessed using the VIDAS© D-dimer. PE was ruled out by a negative VIDAS© D-dimer test in 40% (95% confidence intervals (CI) 38.7 to 41.2%) of patients. The three-month thromboembolic risk in patients left untreated was 0.14% (95% CI 0.05 to 0.4%).Table 1. Accuracy IndicesTotal non-high PTP and negative VIDAS© D-DimerWells' “unlikely” PTP and negative VIDAS© D-dimerGeneva* “low/intermediate” and negative VIDAS© D-dimerNumber of patients5,6222,0173,208Sensitivity (%, 95% CI)99.7 (99.0– 99.9)98.7 (96.2– 99.6)100.0 (99.4–100)Specificity (%, 95% CI)47.4 (46.0– 48.9)57.3 (55.0– 59.6)40.8 (38.9– 42.7)NPV (%, 95% CI)99.9 (99.6– 100)99.7 (99.1– 99.9)100.0 (99.6– 100)Conclusion: The combination of a non-high PTP with a negative VIDAS© D-dimer result, effectively and safely exclude PE in an important proportion of outpatients with suspected PE.