Effectiveness of intermittent pneumatic compression in reduction of risk of deep vein thrombosis in patients who have had a stroke (CLOTS 3): a multicentre randomised controlled trial

BACKGROUND: Venous thromboembolism is a common, potentially avoidable cause of death and morbidity in patients in hospital, including those with stroke. In surgical patients, intermittent pneumatic compression (IPC) reduces the risk of deep vein thrombosis (DVT), but no reliable evidence exists about its effectiveness in patients who have had a stroke. We assessed the effectiveness of IPC to reduce the risk of DVT in patients who have had a stroke. METHODS: The CLOTS 3 trial is a multicentre parallel group randomised trial assessing IPC in immobile patients (ie, who cannot walk to the toilet without the help of another person) with acute stroke. We enrolled patients from day 0 to day 3 of admission and allocated them via a central randomisation system (ratio 1:1) to receive either IPC or no IPC. A technician who was masked to treatment allocation did a compression duplex ultrasound (CDU) of both legs at 7-10 days and, wherever practical, at 25-30 days after enrolment. Caregivers and patients were not masked to treatment assignment. Patients were followed up for 6 months to determine survival and later symptomatic venous thromboembolism. The primary outcome was a DVT in the proximal veins detected on a screening CDU or any symptomatic DVT in the proximal veins, confirmed on imaging, within 30 days of randomisation. Patients were analysed according to their treatment allocation. TRIAL REGISTRATION: ISRCTN93529999. FINDINGS: Between Dec 8, 2008, and Sept 6, 2012, 2876 patients were enrolled in 94 centres in the UK. The included patients were broadly representative of immobile stroke patients admitted to hospital and had a median age of 76 years (IQR 67-84). The primary outcome occurred in 122 (8·5%) of 1438 patients allocated IPC and 174 (12·1%) of 1438 patients allocated no IPC; an absolute reduction in risk of 3·6% (95% CI 1·4-5·8). Excluding the 323 patients who died before any primary outcome and 41 without any screening CDU, the adjusted OR for the comparison of 122 of 1267 patients vs 174 of 1245 patients was 0·65 (95% CI 0·51-0·84; p=0·001). Deaths in the treatment period occurred in 156 (11%) patients allocated IPC and 189 (13%) patients allocated no IPC died within the 30 days of treatment period (p=0·057); skin breaks on the legs were reported in 44 (3%) patients allocated IPC and in 20 (1%) patients allocated no IPC (p=0·002); falls with injury were reported in 33 (2%) patients in the IPC group and in 24 (2%) patients in the no-IPC group (p=0·221). INTERPRETATION: IPC is an effective method of reducing the risk of DVT and possibly improving survival in a wide variety of patients who are immobile after stroke. FUNDING: National Institute of Health Research (NIHR) Health Technology Assessment (HTA) programme, UK; Chief Scientist Office of Scottish Government; Covidien (MA, USA)

The Clots in Legs Or sTockings after Stroke (CLOTS) 3 trial : a randomised controlled trial to determine whether or not intermittent pneumatic compression reduces the risk of post-stroke deep vein thrombosis and to estimate its cost-effectiveness

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The Clots in Legs Or sTockings after Stroke (CLOTS) 3 trial: a randomised controlled trial to determine whether or not intermittent pneumatic compression reduces the risk of post-stroke deep vein thrombosis and to estimate its cost-effectiveness.

Publisher version available.Background: Venous thromboembolism (VTE) is a common cause of death and morbidity in stroke patients. There are few data concerning the effectiveness of intermittent pneumatic compression (IPC) in treating patients with stroke. Objectives: To establish whether or not the application of IPC to the legs of immobile stroke patients reduced their risk of deep vein thrombosis (DVT). Design: Clots in Legs Or sTockings after Stroke (CLOTS) 3 was a multicentre, parallel-group, randomised controlled trial which allocated patients via a central randomisation system to IPC or no IPC. A technician blinded to treatment allocation performed compression duplex ultrasound (CDU) of both legs at 7-10 days and 25-30 days after enrolment. We followed up patients for 6 months to determine survival and later symptomatic VTE. Patients were analysed according to their treatment allocation. Setting: We enrolled 2876 patients in 94 UK hospitals between 8 December 2008 and 6 September 2012. Inclusion Criteria: patients admitted to hospital within 3 days of acute stroke and who were immobile on the day of admission (day 0) to day 3. Exclusion Criteria: age < 16 years; subarachnoid haemorrhage; and contra-indications to IPC including dermatitis, leg ulcers, severe oedema, severe peripheral vascular disease and congestive cardiac failure. Interventions: Participants were allocated to routine care or routine care plus IPC for 30 days, or until earlier discharge or walking independently. Main Outcome Measures: The primary outcome was DVT in popliteal or femoral veins, detected on a screening CDU, or any symptomatic DVT in the proximal veins, confirmed by imaging, within 30 days of randomisation. The secondary outcomes included death, any DVTs, symptomatic DVTs, pulmonary emboli, skin breaks on the legs, falls with injury or fractures and duration of IPC use occurring within 30 days of randomisation and survival, symptomatic VTE, disability (as measured by the Oxford Handicap Scale), quality of life (as measured by the European Quality of Life-5 Dimensions 3 Level questionnaire) and length of initial hospital stay measured 6 months after randomisation. Results: We allocated 1438 patients to IPC and 1438 to no IPC. The primary outcome occurred in 122 (8.5%) of 1438 patients allocated to IPC and 174 (12.1%) of 1438 patients allocated to no IPC, giving an absolute reduction in risk of 3.6% [95% confidence interval (CI) 1.4% to 5.8%] and a relative risk reduction of 0.69 (95% CI 0.55 to 0.86). After excluding 323 patients who died prior to any primary outcome and 41 who had no screening CDU, the primary outcome occurred in 122 of 1267 IPC participants compared with 174 of 1245 no-IPC participants, giving an adjusted odds ratio of 0.65 (95% CI 0.51 to 0.84; p = 0.001). Secondary outcomes in IPC compared with no-IPC participants were death in the treatment period in 156 (10.8%) versus 189 (13.1%) (p = 0.058); skin breaks in 44 (3.1%) versus 20 (1.4%) (p = 0.002); and falls with injury in 33 (2.3%) versus 24 (1.7%) (p = 0.221). Among patients treated with IPC, there was a statistically significant improvement in survival to 6 months (hazard ratio 0.86, 95% CI 0.73 to 0.99; p = 0.042), but no improvement in disability. The direct cost of preventing a DVT was £1282 per event (95% CI £785 to £3077). Conclusions: IPC is an effective and inexpensive method of reducing the risk of DVT and improving survival in immobile stroke patients. Future Research: Further research should test whether or not IPC improves survival in other groups of high-risk hospitalised medical patients. In addition, research into methods to improve adherence to IPC might increase the benefits of IPC in stroke patients.The start-up phase of the trial (December 2008-March 2010) was funded by the Chief Scientist Office of the Scottish Government (reference number CZH/4/417). The main phase of the trial was funded by the National Institute for Health Research Health Technology Assessment programme (reference number 08/14/03). Covidien Ltd (Mansfield, MA, USA) lent its Kendall SCD™ Express sequential compression system controllers to the 105 centres involved in the trial and donated supplies of its sleeves. It also provided logistical help in keeping our centres supplied with sleeves and training materials relevant to the use of their devices. Recruitment and follow-up were supported by the National Institute for Health Research-funded UK Stroke Research Network and by the Scottish Stroke Research Network, which was supported by NHS Research Scotland

Testing devices for the prevention and treatment of stroke and its complications

We are entering a challenging but exciting period when many new interventions may appear for stroke based on the use of devices. Hopefully these will lead to improved outcomes at a cost that can be afforded in most parts of the world. Nevertheless, it is vital that lessons are learnt from failures in the development of pharmacological interventions (and from some early device studies), including inadequate preclinical testing, suboptimal trial design and analysis, and underpowered studies. The device industry is far more disparate than that seen for pharmaceuticals; companies are very variable in size and experience in stroke, and are developing interventions across a wide range of stroke treatment and prevention. It is vital that companies work together where sales and marketing are not involved, including in understanding basic stroke mechanisms, prospective systematic reviews, and education of physicians. Where possible, industry and academics should also work closely together to ensure trials are designed to be relevant to patient care and outcomes. Additionally, regulation of the device industry lags behind that for pharmaceuticals, and it is critical that new interventions are shown to be safe and effective rather than just feasible. Phase IV postmarketing surveillance studies will also be needed to ensure that devices are safe when used in the ‘real-world’ and to pick up uncommon adverse events

The timing, extent, progression and regression of deep vein thrombosis in immobile stroke patients: observational data from the CLOTS multicenter randomized trials

BACKGROUND: Deep vein thrombosis (DVT) is an important complication of stroke, but the evidence to support commonly used prophylactic strategies is conflicting. OBJECTIVES: To describe the incidence, extent, associated clinical features and evolution of DVT after stroke. PATIENTS/METHODS: The CLOTS trials 1 and 2 together randomized 5632 immobile stroke patients in 135 hospitals in nine countries. We screened patients for asymptomatic DVT with compression duplex ultrasound (CDU) at about 7-10 days and again at about 25-30 days after enrollment. RESULTS: Six hundred and forty-one (11.4%) of 5632 patients had DVT detected on the first CDU scan at a median of 8 days (interquartile range [IQR] 7-10 days) after enrollment, and an additional 176 (3.1%) had a DVT on the second CDU scan at a median of 28 days (IQR 26-30 days). Of the 817 with DVTs, 289 (35%) were symptomatic and 39 (5%) had pulmonary embolism (PE) confirmed by imaging. Six hundred and seventy-six (83%) were unilateral, 141 (17%) were bilateral, 322 (39%) were limited to calf veins, 172 (21%) were popliteal, and 323 (40%) were femoral. Among the 542 patients with DVT and a weak leg, the DVT affected the weaker leg in 396 (73%), the stronger leg in 59 (11%), and was bilateral in 87 (16%). Among the 318 patients with a DVT detected on the first CDU scan who had a second scan, the DVT regressed in 148 (47%), stayed the same in 140 (44%), and progressed in only 30 (9%). CONCLUSIONS: Although most DVTs develop within the first week, some develop later, and some early DVTs progress. Any prophylaxis needs to be started early but ideally continued for at least 4 weeks

Effect of intermittent pneumatic compression on disability, living circumstances, quality of life, and hospital costs after stroke: secondary analyses from CLOTS 3, a randomised trial

SummaryBackgroundThe results of the CLOTS 3 trial showed that intermittent pneumatic compression (IPC) reduced the risk of deep vein thrombosis and improved survival in immobile patients with stroke. IPC is now being widely used in stroke units. Here we describe the disability, living circumstances, quality of life, and hospital costs of patients in CLOTS 3.MethodsIn CLOTS 3, a parallel group trial in 94 UK hospitals, immobile patients with stroke from days 0 to 3 of admission were assigned with a computer-generated allocation sequence in a 1:1 ratio to IPC or no IPC through a central randomisation system. We followed up patients at about 6 months with postal or telephone questionnaire to assess the secondary endpoints: disability (Oxford Handicap Scale [OHS]), living circumstances, health-related quality of life (EQ5D-3L), and hospital costs (based on use of IPC and length of hospital stay). Patients and carers who completed the postal questionnaires were not masked to treatment allocation, but telephone follow-up in non-responders was masked. All analyses were by intention to treat. This trial is registered, number ISRCTN93529999.FindingsBetween Dec 8, 2008, and Sept 6, 2012, we enrolled 2876 patients, with 1438 in each group. Despite the previously reported reduction in the risk of proximal deep vein thrombosis at 30 days (primary endpoint), there were no significant differences in disability (OHS 0–2 vs 3–6, adjusted odds ratio [OR] 0·98, 95% CI 0·80 to 1·19, p=0·83; adjusted ordinal analysis common OR 0·97, 95% CI 0·86 to 1·11), living circumstances (institutional care vs not; adjusted OR 1·11, 95% CI 0·89 to 1·37; p=0·358), or health-related quality of life (median utility value 0·26, IQR −0·07 to 0·66 with IPC, and 0·27, −0·06 to 0·64, with no IPC; p=0·952). The estimated cost of IPC was £64·10 per patient (SD 28·3). The direct costs of preventing a deep vein thrombosis and death were £1282 (95% CI 785 to 3077) and £2756 (1346 to not estimable), respectively, with IPC. Hospital costs increased by £451 with IPC compared with no IPC because of a longer stay in hospital (mean 44·5 days [SD 37·6] vs 42·8 days [37·2]; mean difference 1·8 days, 95% CI −1·0 to 4·5). By 6 months, despite an increase in survival (IPC 152·5 days [SD 60·6] vs no IPC 148·1 days [64·3]; mean difference 4·5 days, 95% CI −0·2 to 9·1), there was a non-significant increase in quality-adjusted survival associated with IPC (IPC 27·6 days [SD 40·6] vs no IPC 26·7 days [39·6]; mean difference 0·9 days, 95% CI −2·1 to 3·9).InterpretationIPC is inexpensive, prevents deep vein thrombosis, improves survival but not functional outcomes, and does not lead to a significant gain in quality-adjusted survival. When deciding whether to treat patients with IPC, clinicians need to take into account all these potential effects.FundingNational Institute of Health Research Health Technology Assessment Programme, Chief Scientist Office of Scottish Government, and Covidien

Effectiveness of intermittent pneumatic compression in reduction of risk of deep vein thrombosis in patients who have had a stroke (CLOTS 3): a multicentre randomised controlled trial

BACKGROUND: Venous thromboembolism is a common, potentially avoidable cause of death and morbidity in patients in hospital, including those with stroke. In surgical patients, intermittent pneumatic compression (IPC) reduces the risk of deep vein thrombosis (DVT), but no reliable evidence exists about its effectiveness in patients who have had a stroke. We assessed the effectiveness of IPC to reduce the risk of DVT in patients who have had a stroke. METHODS: The CLOTS 3 trial is a multicentre parallel group randomised trial assessing IPC in immobile patients (ie, who cannot walk to the toilet without the help of another person) with acute stroke. We enrolled patients from day 0 to day 3 of admission and allocated them via a central randomisation system (ratio 1:1) to receive either IPC or no IPC. A technician who was masked to treatment allocation did a compression duplex ultrasound (CDU) of both legs at 7-10 days and, wherever practical, at 25-30 days after enrolment. Caregivers and patients were not masked to treatment assignment. Patients were followed up for 6 months to determine survival and later symptomatic venous thromboembolism. The primary outcome was a DVT in the proximal veins detected on a screening CDU or any symptomatic DVT in the proximal veins, confirmed on imaging, within 30 days of randomisation. Patients were analysed according to their treatment allocation. TRIAL REGISTRATION: ISRCTN93529999. FINDINGS: Between Dec 8, 2008, and Sept 6, 2012, 2876 patients were enrolled in 94 centres in the UK. The included patients were broadly representative of immobile stroke patients admitted to hospital and had a median age of 76 years (IQR 67-84). The primary outcome occurred in 122 (8·5%) of 1438 patients allocated IPC and 174 (12·1%) of 1438 patients allocated no IPC; an absolute reduction in risk of 3·6% (95% CI 1·4-5·8). Excluding the 323 patients who died before any primary outcome and 41 without any screening CDU, the adjusted OR for the comparison of 122 of 1267 patients vs 174 of 1245 patients was 0·65 (95% CI 0·51-0·84; p=0·001). Deaths in the treatment period occurred in 156 (11%) patients allocated IPC and 189 (13%) patients allocated no IPC died within the 30 days of treatment period (p=0·057); skin breaks on the legs were reported in 44 (3%) patients allocated IPC and in 20 (1%) patients allocated no IPC (p=0·002); falls with injury were reported in 33 (2%) patients in the IPC group and in 24 (2%) patients in the no-IPC group (p=0·221). INTERPRETATION: IPC is an effective method of reducing the risk of DVT and possibly improving survival in a wide variety of patients who are immobile after stroke. FUNDING: National Institute of Health Research (NIHR) Health Technology Assessment (HTA) programme, UK; Chief Scientist Office of Scottish Government; Covidien (MA, USA)