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 Indices

Total non-high PTP and negative VIDAS© D-DimerWells’ “unlikely” PTP and negative VIDAS© D-dimerGeneva* “low/intermediate” and negative VIDAS© D-dimer
Number of patients 5,622 2,017 3,208 
Sensitivity (%, 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) 
Total non-high PTP and negative VIDAS© D-DimerWells’ “unlikely” PTP and negative VIDAS© D-dimerGeneva* “low/intermediate” and negative VIDAS© D-dimer
Number of patients 5,622 2,017 3,208 
Sensitivity (%, 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.

Disclosures: No relevant conflicts of interest to declare.

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