Thromboprophylaxis in Stroke Patients
To the Editor:
The risk for venous thromboembolism (VTE) in medical patients, including those with stroke, is similar to that in moderate-risk surgery patients.1 In contrast to surgical patients, prevention of VTE has been less characterized in hospitalized medical patients because trials are generally limited in number and smaller in size. However, the rationale for thromboprophylaxis is based on solid principles and scientific evidence, including the high prevalence of VTE, the clinically silent nature of the disease, and the morbidity, costs, and potential mortality associated with unprevented thrombosis.2 Anticoagulants can significantly reduce the risk of VTE after stroke, but this benefit is offset by a small but definite risk of serious hemorrhages. Accordingly, there is good evidence that mechanical methods of prophylaxis (eg, graduated compression stockings, intermittent pneumatic compression, and venous foot pumps) are effective means for preventing VTE in several clinical settings, including medical patients, with little limitations and without any associated risk of bleeding. Therefore, the use of physical method of prophylaxis is currently considered an acceptable option, especially in patients at higher risk of bleeding, or when used in combination with anticoagulant prophylaxis to improve efficacy.2 Yet, the clinical staff must select the correct size of the device and must properly apply them to achieve definite advantages on prevention.
On this premise, we are rather surprised by the conclusions of the article of Grandi and colleagues, which recently appeared in this journal.3 After reviewing nearby 60 clinical investigations, the authors selected results of two trials to draw the conclusion that there is a lack of evidence on the balance of risk and benefit of these methods to prevent VTE in stroke. We agree with the first part of this statement because results on the efficacy of mechanical prophylaxis might be underestimated for the less intensive and reliable investigation when compared with anticoagulant-based options. However, we do not perceive the medical risk, besides discomfort, costs and resource utilization, of using such devices in stroke patients.
Current guidelines issued by the Seventh American College of Chest Physicians Conference on Antithrombotic and Thrombolytic Therapy, recommend the use of mechanical methods of prophylaxis primarily in patients who are at high risk of bleeding.3 This might apply to stroke patients, where the contraindication to anticoagulant therapy is rather frequent. Additionally, to our knowledge, physical methods have little limitations and no side effects.4 Therefore, although the influence of stocking use on outcomes is not definitely ascertained and the preventive benefit on VTE might be circumscribed to select medical settings, we find no clinical motivation to discourage the adoption of such a measure. In fact, we should consider that the relative low expenditure of some of these methods, especially the graduated compression stockings, might be entirely outweighed by the considerable economical savings achievable from preventing episodes of VTE.
Stark JE, Kilzer WJ. Venous thromboembolic prophylaxis in hospitalized medical patients. Ann Pharmacother. 2004; 38: 36–40.
Geerts WH, Pineo GF, Heit JA, Bergqvist D, Lassen MR, Colwell CW, Ray JG. Prevention of venous thromboembolism: the Seventh ACCP Conference on Antithrombotic and Thrombolytic Therapy. Chest. 2004; 126 (Suppl): III338–III400.
Grandi FC, Sandercock P, Miccio M, Salvi RM. Physical methods for preventing deep vein thrombosis in stroke. Stroke. 2005; 36: 1102–1103.
To respond to the letter of Prof Lippi, we want to say that we perfomed a Cochrane Review in which our aim was to assess the effectiveness and the safety of physical methods in patients with a recent stroke. We have to consider that only unconfounded randomized controlled trials compared physical methods for prevention of DVT with control in which prophylaxis was started within 7 days at the onset of stroke. We found only 2 randomized trials in acute stroke, and they do not provide conclusive evidence on the balance of risk and benefit.
As you know, besides discomfort, compression stockings are not indicated in patients with a diabetic neuropathy or a sensory polineuropathy. We know what current guidelines recommend, but if we consider the evidence-based medicine, we are not sure that compression stockings work, so we are waiting for CLOTS Trial results to review them and to arrive to a conclusive evidence.