Risk factor nomogram predicts likelihood for recurrent VTE
MedWire News: A simple scoring system can improve prediction of recurrent venous thromboembolism (VTE) in patients without strong thrombophilic defects, suggests research published in the journal Circulation.
If the results are confirmed in larger studies, the nomogram could be used to identify patients with a low risk for recurrent episodes that may be suitable for limited anticoagulation therapy, suggest Sabine Eichinger and co-workers from the Medical University of Vienna in Austria.
The researchers recruited 929 with a first idiopathic episode of VTE. None of the patients had the strong thrombophilic risk factors of deficiencies in antithrombin, protein S or protein C, lupus anticoagulant, cancer, pregnancy, recent trauma or surgery, or hormone use.
The patients were followed-up for a median of 43.3 months after discontinuation of anticoagulation, during which time 18.9% of patients experienced recurrent VTE.
Analysis was used to determine the impact of age, gender, body mass index, location of initial VTE, the factor V Leiden and prothrombin G20210A mutations, D-dimer levels, and in vitro thrombin generation on the patients’ risk for recurrent VTE.
Eichinger et al report that men were 1.9 times more likely to experience recurrence than women. Location of initial VTE also altered risk, with a hazard ratio (HR) of 2.08 for proximal versus distal deep vein thrombosis (DVT) and 2.60 for PE versus distal DVT.
Elevated D-dimer levels (HR=1.27 per doubling) also increased the risk for recurrent VTE.
Gender, location of VTE, and D-dimer level were combined in a risk model and patients were classified as having a low, intermediate–low, intermediate–high, and high risk. The 5-year probabilities of recurrence for the patient quartiles were 9.2%, 21.0%, 29.7%, and 33.1%, respectively.
Finally, these factors were used to construct a nomogram assigning points on the basis of each risk factor which can be used to predict the likelihood of recurrence 12 and 60 months after discontinuation of anticoagulation.
Recommending that their risk model and nomogram be externally validated, the team notes: “Our prediction model could be used to stratify patients according to their recurrence risk in randomized clinical trials that investigate the optimal duration of anticoagulation in patients with unprovoked DVT or PE.”
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By Lynda Williams