Age-adjusted D-dimer to rule out deep vein thrombosis: findings from the PALLADIO algorithm.
J Thromb Haemost. 2017 Nov 10;:
Authors: Riva N, Camporese G, Iotti M, Bucherini E, Righini M, Kamphuisen PW, Verhamme P, Douketis JD, Tonello C, Prandoni P, Ageno W, PALLADIO Study Investigators
BACKGROUND: Age-adjusted D-dimer has been proposed to increase specificity for the diagnosis of venous thromboembolism (VTE). However, the accuracy of this threshold has been recently questioned.
OBJECTIVES: To assess the diagnostic performance of age-adjusted D-dimer combined with clinical pre-test probability (PTP) in patients with suspected deep vein thrombosis (DVT).
METHODS: PALLADIO (NCT01412242) was a multicentre management study that validated a new diagnostic algorithm, incorporating PTP, D-dimer (using manufacturers' cut-off), and limited or extended compression ultrasonography (CUS) in outpatients with clinically suspected DVT. Patients with unlikely PTP and negative D-dimer had DVT ruled out without further testing (group 1); patients with likely PTP or positive D-dimer underwent limited-CUS (group 2); patients with likely PTP and positive D-dimer underwent extended-CUS (group 3). Patients with DVT ruled out at baseline had a 3-month follow-up. In this post-hoc analysis we evaluated age-adjusted D-dimer cut-off (defined as age times 10μg/L, or age times 5μg/L for D-dimers with lower manufacturers' cut-off, in patients >50 years).
RESULTS: 1162 patients were enrolled. At initial visit, DVT were detected in 4.0% of patients in group 2 and 53.0% in group 3. The age-adjusted D-dimer, compared to the fixed cut-off, resulted in 5.1% (95%CI, 4.0-6.5%) reduction of CUS. The incidence of symptomatic VTE during follow-up was: 0.24% (95%CI, 0.04-1.37) in group 1; 1.12% (95%CI, 0.44-2.85) in group 2; 1.89% (95%CI, 0.64-5.40) in group 3.
CONCLUSIONS: The PALLADIO algorithm using age-adjusted D-dimer slightly decreased the number of required imaging tests, but this approach should be confirmed in large management studies. This article is protected by copyright. All rights reserved.
PMID: 29125695 [PubMed - as supplied by publisher]