title: Optimal duration of anticoagulation. Provoked versus unprovoked VTE and role of adjunctive thrombophilia and imaging tests.
abstract: Once anticoagulation is stopped, the risk of recurrent venous thromboembolism (VTE) over years after a first episode is consistently around 30%. This risk is higher in patients with unprovoked than in those with (transient) provoked VTE, and among the latter in patients with medical than in those with surgical risk factors. Baseline parameters that have been found to be related to the risk of recurrent VTE are the proximal location of deep-vein thrombosis, obesity, old age, male sex and non-0 blood group, whereas the role of inherited thrombophilia is controversial. The persistence of residual vein thrombosis at ultrasound assessment has consistently been shown to increase the risk, as do persistently high values of D-dimer and the early development of the post-thrombotic syndrome. Although the latest international guidelines suggest indefinite anticoagulation for most patients with the first episode of unprovoked VTE, strategies that incorporate the assessment of residual vein thrombosis and D-dimer have the potential to identify subjects in whom anticoagulation can be safely discontinued. Moreover, new opportunities are offered by a few emerging anti-Xa and anti-IIa oral compounds, which are likely to induce fewer haemorrhagic complications than vitamin K antagonists while preserving the same effectiveness; and by low-dose aspirin, which has the potential to prevent the occurrence of both venous and arterial thrombotic events.
authors.affiliation: Dr. Paolo Prandoni, Department of Medicine, Vascular Medicine Unit, University of Padua, Via Giustiniani 2, 35128 Padua, Italy, Tel.: +39 049 8212656, Fax: +39 049 8218731, E-mail: paoloprandoni@tin.it.
authors.forename: Paolo
authors.initials: P
authors.lastname: Prandoni
authors.forename: Sofia
authors.initials: S
authors.lastname: Barbar
authors.forename: Marta
authors.initials: M
authors.lastname: Milan
authors.forename: Elena
authors.initials: E
authors.lastname: Campello
authors.forename: Luca
authors.initials: L
authors.lastname: Spiezia
authors.forename: Chiara
authors.initials: C
authors.lastname: Piovella
authors.forename: Raffaele
authors.initials: R
authors.lastname: Pesavento
mesh_terms: D000925:Anticoagulants / Q000008:administration & dosage* / Q000009:adverse effects; D001780:Blood Coagulation Tests; D003661:Decision Support Techniques; D003952:Diagnostic Imaging; D004334:Drug Administration Schedule; D020022:Genetic Predisposition to Disease; D006470:Hemorrhage / Q000139:chemically induced; D006801:Humans; D018579:Patient Selection; D011237:Predictive Value of Tests; D011655:Pulmonary Embolism / Q000097:blood / Q000175:diagnosis / Q000188:drug therapy* / Q000209:etiology; D012008:Recurrence; D012307:Risk Factors; D019851:Thrombophilia / Q000150:complications / Q000175:diagnosis / Q000235:genetics; D013997:Time Factors; D016896:Treatment Outcome; D054556:Venous Thromboembolism / Q000097:blood / Q000175:diagnosis / Q000188:drug therapy* / Q000209:etiology; D020246:Venous Thrombosis / Q000097:blood / Q000175:diagnosis / Q000188:drug therapy* / Q000209:etiology
chemical_list: D000925:Anticoagulants
keywords: Venous thromboembolism; anticoagulation; deep venous thrombosis; pulmonary embolism; residual thrombosis; thrombophilia; ultrasonography