Predictors of post-thrombotic syndrome recognized in patients with DVT
MedWire News: Residual thrombosis of the proximal veins and valvular reflux in the superficial veins are associated with an increased risk for post-thrombotic syndrome (PTS) after a first episode of symptomatic deep vein thrombosis (DVT), researchers report.
Proximal localization of thrombosis at diagnosis, age over 50 years, and male gender may also predict PTS, note Mark Kramer (VU University Medical Center, Amsterdam, The Netherlands) and colleagues.
To assess the incidence and potential predictors of PTS, Kramer and team studied 111 patients (47% women, mean age 48 years) with a first episode of DVT of the leg.
The researchers used non-invasive venous examinations to measure residual thrombosis, valvular reflux, calf muscle pump function, and venous outflow resistance in each of the patients at 6 weeks, 3 and 6 months, and at 1 and 2 years after initial diagnosis.
All patients were treated with low molecular weight heparin and vitamin K antagonists for 6 months, and instructed to wear elastic compression stockings for at least 2 years.
The researchers report that the cumulative incidence of PTS (defined as a Clinical, Etiologic, Anatomic, and Pathophysiologic classification of 3 or above) was 46% at 3 months and did not increase with time.
They found that patients with proximal thrombosis at diagnosis had a 2.3-fold increased risk for PTS compared with patients with distal thrombosis.
When residual thrombosis was detected in the proximal veins at 6-weeks (62% of patients), the PTS risk was raised 1.6-fold compared with patients without residual proximal thrombosis (38%).
The presence of valvular reflux in the superficial veins at 6-weeks also predicted PTS, with a 1.6-fold increased risk compared with patients without superficial reflux.
In addition, the PTS risk was 1.4-fold higher among men than women, and 1.4-fold higher among patients over 50 years compared with those aged 50 years or younger.
Writing in the Journal of Thrombosis and Haemostasis, the researchers propose that to identify those at high risk for PTS, simplified duplex scanning should be performed in all patients at 6 weeks post-DVT.
They add that this non-invasive procedure would also help to differentiate between symptomatic recurrent thrombosis and residual thrombosis with post-thrombotic complaints.
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By Laura Dean