Do Compression Stockings Prevent Post-Thrombotic Syndrome?
Abstract & Commentary
By Rahul Gupta, MD, MPH, FACP
Clinical Assistant Professor, West Virginia University School of Medicine, Charleston, WV
Dr. Gupta reports no financial relationships relevant to this field of study.
Synopsis: In a multicenter study of patients with an episode of first proximal deep venous thrombosis, elastic compression stocking use did not prevent the development of post-thrombotic syndrome.
Source: Kahn SR, et al; for the SOX Trial Investigators. Compression stockings to prevent post-thrombotic syndrome: A randomised placebo-controlled trial. Lancet 2013; Dec 5. Doi: 10.1016/S0140-6736(13)61902-9. [Epub ahead of print].
Post-thrombotic syndrome (pts) is a long-term complication of deep venous thrombosis (DVT) resulting from injury to the venous valvular system. It is often characterized by the development of symptoms such as pain, swelling, and skin changes in the affected limb following an episode of DVT. Venous dilation, pigmentation, and venous ulcers can often be seen upon examination. PTS has been estimated to affect up to 60% of individuals with DVT, frequently occurring within 2 years of the DVT episode.1 In a large study, researchers found that one in three patients with DVT will develop PTS within 5 years.2 Higher body mass index, persistent leg symptoms 1 month after acute DVT, anatomically extensive DVT, recurrent ipsilateral DVT, and older age appear to be the main risk factors for development of PTS following DVT. PTS can severely impact an individual's quality of life. Prevention of PTS is critical since treatments are not very effective. The current standard of care for the prevention of PTS following DVT is the use of elastic compression stockings (ECS). Of course, preventing initial DVT and DVT recurrence will prevent most cases of PTS in the first place.
A limited number of small research studies suggests that the daily use of elastic compression stockings for 2 years after proximal DVT appears to reduce the risk of PTS.3,4 However, a great deal of uncertainty exists surrounding the optimal duration of use as well as the compression strength. Additionally, it is not yet known whether the same principles would apply to distal DVTs.
Kahn et al conducted a large multicenter, randomized, placebo-controlled trial to establish evidence regarding the efficacy of the use of ECS to prevent PTS. Between 2004 and 2010 in institutions across the United States and Canada, patients who suffered from first proximal symptomatic DVT were randomly assigned to active vs placebo ECS study groups by a web-based randomization system. Patients were asked to wear the stocking on the affected leg from waking until retiring for 2 years, and were encouraged to stay active. The primary outcome was PTS diagnosed at 6 months or later. A total of 410 patients were randomly assigned to receive active ECS and 396 received placebo ECS.
Overall, 483 (60%) of 803 patients were men, mean age was 55.1 years (SD 15.5), and 699 (87%) of 803 study participants were outpatients. Mean time from DVT diagnosis to randomization was 4.7 days (SD 3.9). The most common proximal extent of DVT was in femoral vein (31.3%), followed by popliteal vein (30.3%), common femoral vein (26.9%), and iliac vein (11.6%).
The researchers found that the cumulative incidence of PTS was 14.2% in the active ECS group vs 12.7% in the placebo ECS group; the difference was not statistically significant (hazard ratio, 1.13; 95% confidence interval, 0.73-1.76; P = 0.58). Furthermore, the secondary analyses failed to reveal any between-group differences in the cumulative incidence of PTS, distribution of PTS severity category, or rate of ipsilateral leg ulcers. The study authors concluded that their findings demonstrate that compared with wearing placebo stockings, wearing a graduated ECS did not reduce the incidence of PTS at 2 years in patients with a first proximal DVT. They also stated that wearing ECS did not affect the occurrence of venous ulcers, rate of recurrent venous thromboembolism, prevalence of venous valvular reflux at 12 months, or generic or venous disease-specific quality of life.
COMMENTARY
These findings are unexpected. While the cumulative incidence of PTS was lower in both groups of the study than would be anticipated, it was primarily due to the type of criteria applied (Ginsberg's definition). However, the researchers had a consistent finding when the other criterion (Villalta definition) was applied in the secondary outcome of the study. Although 14% of the study patients either withdrew or were lost to follow-up, the study methodology was strong with the large number of study participants. These results are in striking contrast with the beneficial findings of ECS shown in previous, smaller, open-label trials. There may be several explanations for such conflicting findings including that in previous studies, patients using ECS may have performed other beneficial activities or the ECS may have provided benefits beyond the measurable compressions. However, with the largest study to date on the subject, along with utilizing a placebo arm, it is clear the research suggests that ECS do not reduce the subsequent development of PTS in patients with newly diagnosed DVT. This compels us to reconsider the existing paradigm. The utility of compression stockings in treating established PTS is yet to be addressed with further studies. Nevertheless, the best strategy for preventing PTS perhaps remains preventing the DVTs in the first place!
References
- Ashrani AA, Heit JA. Incidence and cost burden of post-thrombotic syndrome. J Thromb Thrombolysis 2009; 28:465-476.
- Prandoni P, et al. The long-term clinical course of acute deep venous thrombosis. Ann Intern Med 1996;125:1-7.
- Brandjes DPM, et al. Randomised trial of effect of compression stockings in patients with symptomatic proximal-vein thrombosis. Lancet 1997;349:759-762.
- Prandoni P, et al. Below-knee elastic compression stockings to prevent the post-thrombotic syndrome: A randomized, controlled trial. Ann Intern Med 2004;141:249-256.
