LONDON – Intermittent pneumatic compression reduced the absolute risk of proximal deep vein thrombosis in patients who had suffered a stroke and were immobile by 3.6% in a large, randomized trial.
The incidence of proximal DVT at 30 days in the CLOTS 3 study was 8.5% with intermittent pneumatic compression (IPC) and 12.1% with routine poststroke care alone (P = .001). The adjusted odds ratio was 0.65.
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Dr. Martin Dennis tests stroke patient Yvette Henderson with an intermittent pneumatic compression device to prevent poststroke deep vein thrombosis.
There was also a 14% reduction in the risk of death seen at 6 months favoring IPC use over routine care alone (P = .042). This was a surprising finding, said principal investigator Dr. Martin Dennis of the University of Edinburgh’s clinical neurosciences division and Western General Hospital in Edinburgh, Scotland.
Importantly, IPC appears to be effective across a variety of prespecified subgroups, including both ischemic and hemorrhagic stroke.
Findings will change practice
The findings, which were published online in the Lancet (2013 May 31 [doi:10.1016/ S0140-6736(13)61050-8]) to coincide with their presentation at the annual European Stroke Conference, are practice changing and suggest that national stroke guidelines need to be updated.
"This study is a major breakthrough, showing how a simple and safe treatment can save lives," Dr. Tony Rudd, a consultant stroke physician at Guy’s and St. Thomas’ NHS Foundation Trust, London, said in a statement issued by the University of Edinburgh.
"The challenge now will be to ensure that all patients who might benefit are offered treatment," added Dr. Rudd, who chairs the Royal College of Physicians’ Intercollegiate Stroke Working Party. "It is one of the most important research studies to emerge in the field of stroke in recent years," he noted.
Dr. Christine Roffe, consultant in stroke medicine and professor of medicine at Keele University in Stoke-on-Trent, England, also praised the study’s results. "That something as simple as a compressive sleeve saves lives after stroke is fascinating," she said in an interview at the conference. Dr. Roffe was not involved in the study.
The CLOTS 3 study
CLOTS 3 follows on from two other trials performed by the CLOTS (Clots in Legs or Stockings after Stroke) Trials Collaboration, in which compression stockings were examined as a possible means of preventing thrombotic complications in patients who had suffered a stroke. Results of CLOTS 1 (Lancet 2009;373:1958-65) and CLOTS 2 were negative, however, and no benefit of compression stockings was seen in stroke patients.
Between December 2008 and September 2012, a total of 2,876 patients were enrolled in CLOTS 3. For inclusion, patients had to be immobile and randomized within 0-3 days of having had a stroke. Immobility was defined as being unable to walk to the bathroom without the help of another person.
Patients were randomized to receive either routine poststroke care alone or with additional IPC delivered by Covidien’s Kendall SCD Express Sequential Compression System. The latter involved wearing thigh-high, inflatable sleeves continuously for up to 30 days, during which time the device automatically provided IPC depending on the position of the patient. The mean and median durations of wear were 12.5 days and 9.0 days, respectively.
DVT was assessed using duplex ultrasound at 7-10 days and again at 25-30 days if possible. Both patient groups wore compression sleeves to ensure that the ultrasound technicians remained blinded to the treatment group. Follow-up was at 6 months via postal questionnaires sent to patients’ primary care physicians asking about vital status and the occurrence of venous thromboembolism since hospital discharge. Patients were also sent a postal questionnaire and telephoned if they did not respond.
DVT risk reduced
The effect on proximal DVT at 30 days was the primary outcome measure, but IPC also reduced the incidence of symptomatic DVT (4.6% vs. 6.3%; P = .0045) and any DVT (16.2% vs. 21.1%; P = .001) versus routine care. There was no significant difference in the incidence of pulmonary embolism between study arms (2.0% vs. 2.4%, respectively, P = .453).
In terms of safety, there was no difference between the treatment groups in the number of falls with injury or fractures as a result of constantly wearing the compression sleeves. There was a significant difference in skin ulcers (3.1% with IPC vs. 1.4% without, P = .002), but close inspection of the data suggested that only 10 (0.7%) cases were due to IPC.
"During the study, [the manufacturers of the IPC device] brought out a new comfort sleeve," Dr. Dennis noted in an interview.