D-dimer testing to determine the duration of anticoagulation therapy
Gualtiero Palareti, Benilde Cosmi, Cristina Legnani, Alberto Tosetto, Carlotta Brusi, Alfonso Iorio, Vittorio Pengo, Angelo Ghirarduzzi, Corrado Pattacini, Sophie Testa, Anthonie W A Lensing, Armando Tripodi, PROLONG Investigators, G Palareti, B Cosmi, C Legnani, C Brusi, S Testa, A Alatri, A Ghirarduzzi, A Iorio, A Tosetto, V Pengo, C Pegoraro, S Iliceto, S Siragusa, D Prisco, D Poli, F Baudo, R Cappelli, N Erba, L La Rosa, C Pattacini, R Quintavalla, L Ria, E Bucherini, E Ceré, V Rossi, E Tiraferri, C Agazzi, N Coffetti, C Villani, L Frigerio, G Scapoli, A Trifiletti, M Molinatti, P Dori Faccini, R Santi, G Scannapieco, G Lessiani, V Scarmozzino, V Imbimbo, A Schenone, G Palareti, B Cosmi, C Legnani, A Tosetto, A Tripodi, A Iorio, S Testa, A Ghiraduzzi, C Pattacini, V Pengo, Gualtiero Palareti, Benilde Cosmi, Cristina Legnani, Alberto Tosetto, Carlotta Brusi, Alfonso Iorio, Vittorio Pengo, Angelo Ghirarduzzi, Corrado Pattacini, Sophie Testa, Anthonie W A Lensing, Armando Tripodi, PROLONG Investigators, G Palareti, B Cosmi, C Legnani, C Brusi, S Testa, A Alatri, A Ghirarduzzi, A Iorio, A Tosetto, V Pengo, C Pegoraro, S Iliceto, S Siragusa, D Prisco, D Poli, F Baudo, R Cappelli, N Erba, L La Rosa, C Pattacini, R Quintavalla, L Ria, E Bucherini, E Ceré, V Rossi, E Tiraferri, C Agazzi, N Coffetti, C Villani, L Frigerio, G Scapoli, A Trifiletti, M Molinatti, P Dori Faccini, R Santi, G Scannapieco, G Lessiani, V Scarmozzino, V Imbimbo, A Schenone, G Palareti, B Cosmi, C Legnani, A Tosetto, A Tripodi, A Iorio, S Testa, A Ghiraduzzi, C Pattacini, V Pengo
Abstract
Background: The optimal duration of oral anticoagulation in patients with idiopathic venous thromboembolism is uncertain. Testing of D-dimer levels may play a role in the assessment of the need for prolonged anticoagulation.
Methods: We performed D-dimer testing 1 month after the discontinuation of anticoagulation in patients with a first unprovoked proximal deep-vein thrombosis or pulmonary embolism who had received a vitamin K antagonist for at least 3 months. Patients with a normal D-dimer level did not resume anticoagulation, whereas those with an abnormal D-dimer level were randomly assigned either to resume or to discontinue treatment. The study outcome was the composite of recurrent venous thromboembolism and major bleeding during an average follow-up of 1.4 years.
Results: The D-dimer assay was abnormal in 223 of 608 patients (36.7%). A total of 18 events occurred among the 120 patients who stopped anticoagulation (15.0%), as compared with 3 events among the 103 patients who resumed anticoagulation (2.9%), for an adjusted hazard ratio of 4.26 (95% confidence interval [CI], 1.23 to 14.6; P=0.02). Thromboembolism recurred in 24 of 385 patients with a normal D-dimer level (6.2%). Among patients who stopped anticoagulation, the adjusted hazard ratio for recurrent thromboembolism among those with an abnormal D-dimer level, as compared with those with a normal D-dimer level, was 2.27 (95% CI, 1.15 to 4.46; P=0.02).
Conclusions: Patients with an abnormal D-dimer level 1 month after the discontinuation of anticoagulation have a significant incidence of recurrent venous thromboembolism, which is reduced by the resumption of anticoagulation. The optimal course of anticoagulation in patients with a normal D-dimer level has not been clearly established. (ClinicalTrials.gov number, NCT00264277 [ClinicalTrials.gov].).
Copyright 2006 Massachusetts Medical Society.
Source: PubMed