LONDON—Intermittent pneumatic compression (IPC) may reduce the absolute risk of proximal deep vein thrombosis (DVT) by 3.6% in patients who have had a stroke and are immobile, according to findings presented at the 2013 European Stroke Conference and published online ahead of print May 31 in Lancet.
The incidence of proximal DVT at 30 days in the CLOTS 3 study (a large, randomized trial) was 8.5% with IPC and 12.1% with routine poststroke care alone. In addition, the risk of death at six months was 14% lower among patients who received IPC than among patients who received routine care alone. This finding was surprising, said principal investigator Martin Dennis, MD, Professor of Stroke Medicine at the University of Edinburgh’s Division of Clinical Neurosciences. IPC appears to be effective in various prespecified subgroups, including for ischemic and hemorrhagic stroke.
Comparing ICP With Routine Care
CLOTS 3 was the most recent trial performed by the Clots in Legs or Stockings after Stroke (CLOTS) Trials Collaboration. In the trials, researchers examined compression stockings as a possible means of preventing thrombotic complications in patients with stroke. Compression stockings had no benefit for patients with stroke in CLOTS 1 and CLOTS 2.
Between December 2008 and September 2012, a total of 2,876 immobile patients with stroke were enrolled in CLOTS 3. Immobility was defined as the inability to walk to the bathroom without the help of another person.
Patients were randomized within three days of stroke onset to receive either routine poststroke care alone or routine poststroke care with IPC delivered by Covidien’s Kendall SCD Express Sequential Compression System. The latter involved wearing thigh-high, inflatable sleeves continuously for as many as 30 days, during which time the device automatically provided IPC, depending on the patient’s position. The mean and median durations of wear were 12.5 days and 9.0 days, respectively.
DVT was assessed using duplex ultrasound at seven to 10 days and again at 25 to 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 conducted at six months through questionnaires mailed to patients’ primary care physicians. The questionnaires solicited information about patients’ vital status and the occurrence of venous thromboembolism since hospital discharge. Patients also received a questionnaire by mail and were telephoned if they did not respond.
IPC Was Relatively Safe
The effect on proximal DVT at 30 days was the primary outcome measure. Compared with routine care, IPC reduced the incidence of symptomatic DVT (6.3% vs. 4.6%) and any DVT (21.1% vs. 16.2%). Investigators observed no significant difference in the incidence of pulmonary embolism between study arms.
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. The researchers observed a significant difference in skin ulcers (3.1% with IPC vs 1.4% without), but close inspection of the data suggested that 10 (0.7%) cases resulted from IPC.
“During the study, [the manufacturers of the IPC device] brought out a new comfort sleeve,” Dr. Dennis noted. “Normally, these sleeves were being used for short periods in surgical patients, but we were using them for longer periods, so they brought out a softer sleeve.” Some patients found the sleeves uncomfortable or too hot, and others described the system as “noisy,” added Dr. Dennis.
Nevertheless, “IPC in people who are immobile with stroke reduces the risk of DVT,” said Dr. Dennis. “IPC is feasible in stroke patients, and it is relatively safe. It is an effective means of reducing venous thromboembolism after stroke, with a number needed to treat of about 28 for proximal DVT.”
IPC may also improve overall survival, “although we weren’t expecting to see that effect,” said Dr. Dennis. The number needed to treat to prevent one death in 30 days was 43.
Findings Could Change Clinical Practice
“This study is a major breakthrough, showing how a simple and safe treatment can save lives,” said Anthony Rudd, MD, a consultant stroke physician at Guy’s and St. Thomas’ NHS Foundation Trust in London. “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.”
“That something as simple as a compressive sleeve saves lives after stroke is fascinating,” said Christine Roffe, MD, consultant in stroke medicine and Professor of Medicine at Keele University in Stoke-on-Trent, UK. Dr. Roffe was not involved in the study.