Residual vein thrombosis for assessing duration of anticoagulation after unprovoked deep vein thrombosis of the lower limbs: the extended DACUS study
Sergio Siragusa, Alessandra Malato, Giorgia Saccullo, Alfonso Iorio, Mauro Di Ianni, Clementina Caracciolo, Lucio Lo Coco, Simona Raso, Marco Santoro, Francesco Paolo Guarneri, Antonino Tuttolomondo, Antonio Pinto, Iliana Pepe, Alessandra Casuccio, Vincenzo Abbadessa, Giuseppe Licata, Giovan Battista Rini, Guglielmo Mariani, Gaetana Di Fede, Sergio Siragusa, Alessandra Malato, Giorgia Saccullo, Alfonso Iorio, Mauro Di Ianni, Clementina Caracciolo, Lucio Lo Coco, Simona Raso, Marco Santoro, Francesco Paolo Guarneri, Antonino Tuttolomondo, Antonio Pinto, Iliana Pepe, Alessandra Casuccio, Vincenzo Abbadessa, Giuseppe Licata, Giovan Battista Rini, Guglielmo Mariani, Gaetana Di Fede
Abstract
The safest duration of anticoagulation after idiopathic deep vein thrombosis (DVT) is unknown. We conducted a prospective study to assess the optimal duration of vitamin K antagonist (VKA) therapy considering the risk of recurrence of thrombosis according to residual vein thrombosis (RVT). Patients with a first unprovoked DVT were evaluated for the presence of RVT after 3 months of VKA administration; those without RVT suspended VKA, while those with RVT continued oral anticoagulation for up to 2 years. Recurrent thrombosis and/or bleeding events were recorded during treatment (RVT group) and 1 year after VKA withdrawal (both groups). Among 409 patients evaluated for unprovoked DVT, 33.2% (136 of 409 patients) did not have RVT and VKA was stopped. The remaining 273 (66.8%) patients with RVT received anticoagulants for an additional 21 months; during this period of treatment, recurrent venous thromboembolism and major bleeding occurred in 4.7% and 1.1% of patients, respectively. After VKA suspension, the rates of recurrent thrombotic events were 1.4% and 10.4% in the no-RVT and RVT groups, respectively (relative risk = 7.4; 95% confidence interval = 4.9-9.9). These results indicate that in patients without RVT, a short period of treatment with a VKA is sufficient; in those with persistent RVT, treatment extended to 2 years substantially reduces, but does not eliminate, the risk of recurrent thrombosis.
Trial registration: ClinicalTrials.gov NCT00623987.
Copyright © 2011 Wiley-Liss, Inc.
Source: PubMed