Antithrombotic therapy in transient ischemic attack patients.

Historically, studies of antithrombotic therapy in ischemic cerebrovascular disease have included both stroke and transient ischemic attack (TIA). Thus, therapy regimes are very similar. Aspirin (75-325 mg within 48 h after onset of symptoms) is still the standard antithrombotic treatment because other agents have performed similarly (or worse). Combinations of agents have shown mixed results. Aspirin combined with clopidogrel has failed to show a significant reduction of stroke/TIA recurrences but increased the bleeding risk if taken for more than several months. The combination of aspirin and dipyridamole is slightly better than aspirin alone and in particular reduced nonfatal stroke/TIA - hence it is recommended as an alternative and may be used in patients with recurrent events while on regular aspirin. In contrast, combined treatment is regularly recommended after endovascular interventions and if both cardio- and cerebrovascular diseases are present. Warfarin and similar compounds have long been the standard treatment for most patients with permanent, paroxysmal or intermittent non-valvular atrial fibrillation, for which there is excellent evidence in most patients (CHADS-VASc score >1). New compounds have been approved in recent years and shown to reduce either ischemic events, intracranial bleeding complications or both when compared with warfarin. None of them requires regular therapy monitoring. Because there are no head-to-head comparisons of these newer agents, definite recommendations as to which to choose, and when, are hard to make. However, there are some notable differences as well as new approved entities.