Moonis Majaz, Fisher Marc
Department of Neurology, University of Massachusetts Memorial Health Care, Worcester, Mass 01655, USA.
Stroke. 2002 Jul;33(7):1927-33. doi: 10.1161/01.str.0000019422.63054.5f.
The utility of parenteral anticoagulation therapy in acute ischemic stroke has engendered much controversy and discussion. Recent studies of low-molecular-weight heparins in multiple acute stroke subtypes have not demonstrated improved outcome or reduced recurrence risk. Beneficial treatment effects may occur in subgroups such as patients with large artery atherothrombotic stroke, but further studies will be needed to prove this possibility.
The benefits of unfractionated intravenous heparin for reducing early stroke recurrence and improving outcome remain to be established, with the current lack of appropriately powered trials in stroke subgroups at high risk for such early recurrence. To most clinicians, the primary reason to use early intravenous anticoagulation is to prevent early stroke recurrence, not to improve outcome of an established stroke. Unfortunately, effects of reduction of recurrent stroke risk may be counterbalanced by a substantial increased risk of intracerebral hemorrhage with intravenous anticoagulation.
Unfractionated intravenous heparin should therefore not be used routinely in acute ischemic stroke, but it may be considered in select stroke groups at high risk for early recurrent ischemic events (ie, patients with atrial fibrillation or acute myocardial infarction and large mural thrombi). However, even in these select populations, new clinical trials will be needed to define the risk-benefit ratio.
肠外抗凝治疗在急性缺血性卒中中的应用引发了诸多争议和讨论。近期针对多种急性卒中亚型的低分子量肝素研究并未显示出改善预后或降低复发风险的效果。在某些亚组中，如大动脉粥样硬化性血栓形成性卒中患者，可能会出现有益的治疗效果，但仍需进一步研究来证实这种可能性。
普通静脉肝素在降低早期卒中复发率和改善预后方面的益处仍有待确定，目前缺乏针对此类早期复发高危卒中亚组的足够有力的试验。对大多数临床医生而言，使用早期静脉抗凝的主要原因是预防早期卒中复发，而非改善已发生卒中的预后。不幸的是，静脉抗凝导致脑出血风险大幅增加可能会抵消降低复发卒中风险的效果。
因此，普通静脉肝素不应常规用于急性缺血性卒中，但对于早期复发性缺血事件高危的特定卒中组（即心房颤动或急性心肌梗死且有大量壁血栓的患者）可考虑使用。然而，即使在这些特定人群中，仍需要新的临床试验来确定风险效益比。
