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Letters to the Editor
Elastic compression stockings for prevention of the post-thrombotic syndrome in patients with and without residual vein thrombosis and/or popliteal valve reflux
The efficacy of elastic compression stockings (ECS) for the prevention of post-thrombotic syndrome (PTS) aris- ing after a proximal deep-vein thrombosis (DVT) is con- troversial.1,2 Although most randomized studies showed a substantial reduction of PTS with the use of ECS,3-5 the recent, large SOX clinical trial that used sham stockings as a comparator failed to confirm these findings.6 Accordingly, most international guidelines no longer rec- ommend routine use of ECS for the prevention of PTS.1,7 Nevertheless, ECS are still commonly prescribed in clini- cal practice.8
A recent systematic review showed that patients with DVT who at 6 weeks or later had either residual vein thrombosis (RVT) or popliteal valve reflux (PVR) had a higher risk of subsequent PTS than those without these findings.9 As these ultrasound features are associated with longstanding venous hypertension that could be modified by compression therapy,10 the early identifica- tion of RVT and PVR has the potential to identify a sub- group of patients who may still benefit from the use of ECS.
In a prospective cohort study of 869 patients with a proximal DVT that was either unprovoked or associated with transient risk factors, we observed an increased risk of PTS in those with RVT.11 Briefly, all patients received initial treatment with unfractionated or low-molecular- weight heparin followed by vitamin K antagonists according to international guidelines, with individual treatment duration (ranging between 3 and 24 months)
based on each patient’s preferences and risk profile.
Patients with recent (<2 years) ipsilateral DVT and those
requiring indefinite anticoagulation were not eligible.11
Patients were advised to wear ECS (30-40 mmHg at the
ankle) for at least 2 years, and were followed-up for 3
years. They were instructed to report in a booklet how
long they wore the stockings, the use of not permitted
stockings, and the occurrence of any adverse effects
impairing their use. At 3 months, an ultrasound assess-
ment was done to document the presence of RVT (vein
diameter under maximum compressibility >4 mm)11 and
PVR (retrograde flow through the popliteal valve after
manual compression of the mid-thigh >0.5 seconds,
which persisted after repeating the maneuver with a
tourniquet).12 The Villalta scale was used to assess the
development of PTS every 6 months. A score of 5 to 14
in two, even non-consecutive, assessments indicated
non-severe PTS, while a score ≥15 or the presence of a
skin ulcer in a single assessment indicated severe PTS.1,11,13
Here we report the risk of PTS in relation to therapeu- tic adherence to ECS and the presence of RVT, PVR or both in the 861 patients who survived at least 6 months. Two trained physicians who were unaware of the patients’ other details or study outcomes assessed the adherence to ECS. Patients who used the ECS for ≥70% of daytime for the first year were considered adherent (‘stockings’ group). Patients who did not accept the advised ECS, discontinued ECS use during the first year, or used the ECS <70% of daytime were considered non- adherent (‘non-stockings’ group).
The main demographic and clinical characteristics of the two groups were compared using standard methods. The hazard ratio (HR) for the effect of ECS on PTS devel- opment in the whole population, as well as in patients
Figure 1. Cumulative incidence of patients free of post-thrombotic syndrome in each of the four subgroups according to the presence of residual vein throm- bosis and/or popliteal valve reflux and the use of elastic compression stockings. PTS: post-thrombotic syndrome; ECS: elastic compression stockings; RVT: residual vein thrombosis; PVR: popliteal valve reflux.
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