TIA management – speed and expertise are key

Stroke affects approximately 15 million people worldwide yearly and causes considerable morbidity and mortality. Rates are likely to rise in developed and developing countries because of population ageing and the increasing prevalence of atherosclerosis. Although acute treatments for stroke are available, prevention is the most effective means of reducing the overall disease burden. Because TIAs (transient ischaemic attacks) precede approximately one quarter of strokes, treatment of TIA offers one approach to stroke prevention. Research into the treatment of TIA has developed rapidly over the last 10 years. Prospective observational studies have demonstrated the high risk of stroke within the immediate hours and days of the event [1]. The ABCD2 and ABCD-I scores have been developed to predict early stroke risk. The EXPRESS [2] and SOSTIA [3] studies have shown that urgent specialist management reduces early stroke risk. In this issue, von Weitzel-Mudersbach and colleagues publish results from an observational study of the 1 year outcomes of 306 consecutive TIA patients treated by a specialist acute TIA team (AIT) in a university hospital in Aarhus, Denmark [4]. Patients were managed either on a stroke unit or as outpatients with rapid access to brain and vascular imaging and cardiac investigations. After the acute management, patients were followed up by telephone by a nurse at 7 and 90 days when the importance of secondary prevention and lifestyle modification was emphasized and reviewed by a vascular neurologist at 1 year. There were 5 (1.6%) ischaemic strokes at 7 days and 6 (2.0%) at 90 days; after 1 year, a combined outcome of stroke, non-fatal MI or vascular death had occurred in 16 (5.2%). The AIT anti-platelet regimen included aspirin and dipyridamole for most and a short course of aspirin and clopidogrel for those with pre or intracerebral artery stenosis. Overall rates of haemorrhagic complications were not reported, but given that no intracerebral haemorrhages had occurred at 1 year, it is likely that the safety profile was acceptable. When considered alongside the similar outcome rates from comparable studies of acute TIA treatment, these results confirm the benefit of this model of care. Despite recent advances, several aspects of TIA treatment remain controversial and introduction of specialist services is patchy. Practice differs widely in terms of the setting for delivery of acute TIA services. In the UK, guidelines recommend that TIA be managed on an outpatient basis, with triage according to the ABCD2 score, while in Germany, TIA patients are managed as inpatients with lengths of stay sometimes in the region of 1 week. Although both the EXPRESS [2] and SOS-TIA [3] studies were conducted in outpatient settings, they were based on subtly different premises. The EXPRESS Study, conducted in the UK where the standard of care was weekly clinics, demonstrated the benefit of an urgent versus an appointment-based outpatient model. The SOS-TIA Study, based on France where the standard care is inpatient management, emphasized the safety of urgent outpatient care and concluded that use of TIA clinics with 24-hour access and immediate initiation of treatment might greatly reduce length of hospital stay. TIAregistry.org is a multicentre cohort study of TIA and minor stroke, with target recruitment of 5000 patients from specialist clinics, which will evaluate the event rates and safety of care in the outpatient setting. Uncertainty also surrounds the optimal choice of anti-platelet agents for initial treatment. The CARESS [5] and the FASTER Pilot [6] studies suggested the superiority of combined aspirin and clopidogrel versus aspirin alone for high-risk TIA or minor stroke although in the latter study, a high rate of haemorrhage was observed with more aggressive therapy. Many centres, including the Aarhus AIT, recommend aspirin/ clopidogrel combination acutely especially when large artery disease is identified. Two ongoing trials will provide further data on choice of anti-platelet in the acute phase after TIA or stroke. The Triple Antiplatelets for Reducing Dependency after Ischaemic Stroke (TARDIS) Trial (http://www.tardistrial.org, accessed 10/5/2011) is comparing the addition of clopidogrel to aspirin and dipyridamole, while the CHANCE trial [7] is comparing the combination of aspirin and clopidogrel with aspirin alone. TIA treatment research has appropriately focused on stroke prevention in the acute phase, but this overlooks two further aspects of TIA services, namely the management of TIA mimics and longer-term outcomes. Early and accurate diagnosis of mimics referred to TIA services undoubtedly leads to improved management for other potentially serious conditions, such as brain tumours and epilepsy, but further data are required to evaluate cost effectiveness. Despite high rates of compliance and risk factor control in the Aarhus Study, a 5.2% rate of combined