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-Dimer . | Wells’ “unlikely” PTP and negative VIDAS© D-dimer . | Geneva* “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-Dimer . | Wells’ “unlikely” PTP and negative VIDAS© D-dimer . | Geneva* “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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