BERLIN, GERMANY — Individualized elastic compression stocking (ECS) therapy can shorten the duration of treatment and is noninferior to the standard 2 years of stocking use to prevent post-thrombotic syndrome (PTS) in patients who have had a deep vein thrombosis (DVT) of the leg, a new study shows[1].
However, some selected patients can still benefit from a full 2 years of therapy, the randomized, single-blind, noninferiority trial showed.
Previous studies have shown that ECS for 2 years can lower the incidence of PTS from 50% to 20%–30%, the researchers note, but ECS is costly, inconvenient, demanding, sometimes uncomfortable, and even debilitating. So the present Individually Tailored Elastic Compression Against Long-Term Therapy DVT (IDEAL DVT) trial aimed to assess the efficacy of individualized, shorter duration ECS therapy.
“The main outcome was that there was no significant difference in PTS between the groups: 28.9% for the individualized treatment group and 27.8% for the standard therapy group,” Dr Arina ten Cate-Hoek (Maastricht University Medical Center, the Netherlands) told delegates here at the International Society on Thrombosis and Haemostasis 2017 Congress.
This represents, “an absolute difference of 1.1% with a 95% confidence interval upper limit not crossing a noninferior border.”
Adult participants were randomly assigned to ECS therapy (n=432) or an individualized therapy group (n=432) for 2 years. Investigators assessed PTS severity using the Villalta scale at 3, 6, 12, and 24 months.
There were also questionnaires for health-related quality of life (HRQoL), costs, and adherence to therapy. Participants had to have had adequate treatment within 24 hours of diagnosis. Among the exclusion criteria were previous ipsilateral DVT, contraindications for compression, treatment with thrombolysis, or a recurrent DVT within 6 months of inclusion in the study.
The groups were well matched for age (56–58 years), body mass index (28 kg/m2), and gender (50% male). Eight percent to 11% had a history of a contralateral DVT, two-thirds of each group had an unprovoked DVT, half were left-sided, half were in a popliteal vein, one-quarter in a femoral vein, and just over 20% in a common femoral vein.
About 90% of participants in each group were receiving vitamin K antagonists, about 20% direct oral anticoagulants, 15% to 20% low molecular-weight heparin, and the rest investigational anticoagulants. In both groups, people were on anticoagulant therapy for 6 months (range 179–217 days). Most participants (90.5%) completed the study.
“Adherence to therapy started out at 96% and stayed as high as 80% up to the end for both therapy groups,” ten Cote-Hoek said.
Essentially, two Villalta scores ≤ 4 at two successive time points allowed withdrawal of ECS. If for example, scores were ≤ 4 at 3 and 6 months, withdrawal would be at 6 months; if at 6 and 12 months, the patient could stop at 12 months. Otherwise, ECS therapy continued to 24 months.
“There was very good efficiency of the therapy,” ten Cate-Hoek said. “About 50% of patients could stop therapy as soon as 6 months, and another 11% could stop at 12 months.”
For the primary outcome of prevention of PTS, the individualized treatment group experienced only 1.1% more PTS compared with the standard treatment group (28.9% vs 27.8%, respectively), resulting in a hazard ratio of 1.13 (95% CI 0.88–1.46), which was not a significant difference, showing noninferiority of the individualized treatment.
Proportions of participants affected by recurrent DVT plus pulmonary embolism were about the same in the individualized (7.9%) and standard (8.5%) therapy groups.
There were slightly more deaths in the individualized vs standard therapy group (3.9% and 1.7%, respectively). Most of the deaths in each group were considered related to underlying malignancy (2.8% and 1.2%, respectively) and not to recurrent thrombosis. HRQoL scores were similar for both groups.
Contrary to some prior studies and in-line with others, previous results from the IDEAL study have shown a benefit of ECS on PTS (21.7%) compared with no ECS (35.7%). The relative risk of PTS with no compression was 1.6 compared with ECS of 30 to 40 mmHg for 6 months after DVT. The number needed to treat was 7.
“We concluded that individualized compression therapy shortens the duration of therapy and is noninferior to standard duration therapy for the prevention of PTS,” ten Cate-Hoek said. “However, extended treatment in selected patients shows significant benefit of ECS for the prevention of PTS.” She now plans a cost–benefit analysis comparing the two treatment durations.
Commenting on the study to theheart.org | Medscape Cardiology, session moderator Dr Sam Schulman (McMaster University, Hamilton, ON) noted there is always a chance for bias in a single-blind study.
“We have conflicting data here because from the only placebo-controlled, double-blind study[2], we have results that there was no effect of compression stockings, and this study was single blinded, so the patients knew that they were wearing real stockings and for how long,” he said.
As in IDEAL DVT, the single-blind OCTAVIA study yielded positive results for the use of compression stockings[3], “so there seems to be some placebo effect also that stockings help, but I believe that there is a subgroup of patients that has an effect of stockings and we need to identify those patients better,” he said.
When asked if some patients could use compression stockings for less than 2 years, Schulman recommended that if they are completely asymptomatic, an ultrasound may be a good idea to see if there is only minimal or no residual thrombosis. “That would probably help to predict that they’re not going to have future problems,” he said.
This study did not receive commercial funding. ten Cate-Hoek and Schulman had no relevant disclosures.
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