Sunday, April 17, 2011

Should Patients With Stroke Wear Compression Stockings?

Dr. Sprigg and colleagues note that they “do not believe that low-dose heparin should be used routinely for the prevention of VTE in most patients with stroke.” We agree that low-dose heparin should not be used routinely in patients with ischemic stroke and did not make such a suggestion (1). As Dr. Sprigg and colleagues also note, “Prophylactic low-dose anticoagulation may help to treat patients at high risk for VTE in whom the risk for VTE is likely to outweigh the risk for SICH.”
If CLOTS (Clots in Legs Or sTtockings after Stroke) Trial 1 (2) had found that graduated compression stockings were very effective at preventing VTE, we would recommend this intervention over low-dose heparin in all patients with stroke, including those at highest risk for VTE. However, it found that graduated compression stockings did not work (2), and therefore, an effective alternative to low-dose anticoagulation to prevent VTE in patients with ischemic stroke does not currently exist. Lack of an alternative to prevent VTE does not mean that low-dose anticoagulation should be used routinely but does strengthen the argument for, as we suggested, “the cautious use of these agents” in patients with acute ischemic stroke and immobility without additional contraindications to anticoagulant therapy.
We propose that the findings of the IST (3) and TAIST (4) are mostly of indirect relevance to this discussion and, indeed, are consistent with our position. TAIST compared high- and intermediate-dose tinzaparin with aspirin in the acute treatment of ischemic stroke (4). This trial did not evaluate whether low-dose tinzaparin, as used to prevent VTE, was beneficial.
The IST compared high-dose unfractionated heparin (12 500 U twice daily) and low-dose unfractionated heparin (5000 U twice daily) with no anticoagulation (3). High-dose therapy was associated with greater harm than benefit. Low-dose therapy was associated with greater benefit than harm; however, we agree that the findings of this subgroup analysis are not definitive. An additional consideration is that if the IST had enrolled only participants with stroke and immobility—that is, persons with a high risk for VTE, a population group similar to those who are the focus of this discussion and that were enrolled in the CLOT Trials—the balance of benefit (reduction in VTE) to harm (increased intracranial bleeding) may have further favored low-dose heparin.
Finally, both of these trials evaluated the use of heparin in the acute phase of stroke (within 48 hours of onset), when the risk for hemorrhagic transformation is greatest. In patients at increased risk for intracerebral hemorrhage, delayed introduction of low-dose heparin may further alter the balance of benefit to harm. It is hoped that the ongoing CLOTS Trial 3, which is comparing intermittent pneumatic compression with a control group, will identify an effective way to prevent VTE in patients with acute stroke and immobility without increasing the risk for bleeding. more read....