OC 04.4 - Comparison of different D-dimer assays to exclude pulmonary embolism using the age-adjusted D-dimer cutoff: a secondary analysis of the ADJUST-PE study

Background: The multicenter prospective management outcome study ADJUST-PE study proved the safety of using an age-adjusted D-dimer cutoff (AADD) to exclude pulmonary embolism (PE).

Aims: To assess the safety of different D-dimer (DD) assays to exclude PE using the AADD in patients included in the ADJUST-PE study in Geneva compared to the originally used VIDAS D-dimer Exclusion test®.

Methods: This was a pre-planned secondary analysis. The VIDAS DD Exclusion test® was repeated to insure reproducible results in thawed samples compared to the time of patient inclusion. The other tests performed were: Innovance DD test®, STA Liatest®, Tina-quant DD®, and the point-of-care LumiraDx test. The primary objective was the venous thromboembolic risk (VTE) at initial testing or within 3 months after PE exclusion by a negative DD test using the AADD (“failure rate”). Secondary objective was to compare each assay with the VIDAS in the classification of patients as having a negative versus positive DD result.

Results: 602 patients were included and 597 were available for analysis. 14% of these patients had PE confirmed at baseline. The failure rates for all tests are displayed in Table 1. The risk of having a change in classification from positive original VIDAS DD to negative DD result was similar to the repeated VIDAS test (comparator) for Innovance and LumiraDx , and significantly higher for STA Liatest and Tinaquant (Table 2). For the two latter assays, 3 and 5 patients with negative DD result had PE, respectively.

Conclusion(s): In the cohort of Geneva patients of the ADJUST-PE study, Innovance DD and LumiraDx assays had similar safety in excluding PE by the AADD compared to VIDAS assay. STA Liatest and Tinaquant assays classified a higher proportion of patients as having a negative D-dimer, among whom 3 and 5 had PE, respectively (false negative).