Developing new treatments for stroke is an NHS research priority, and despite improvements made in specialist care provision following the publication of the National Stroke Strategy (DH, 2007), it remains both a disabling condition and a high health and social care burden. To facilitate rapid growth in knowledge, the UK Stroke Research Network is funded by the National Institute for Health Research (NIHR) and includes eight Hyperacute Stroke Research Centres and the infrastructure needed to support trials of emergency treatments such as those described below.
Among the therapies currently available for acute ischaemic stroke, the greatest proof of clinical effectiveness exists for intravenous thrombolysis. Evidence supports treatment up until 4.5 hours after symptom onset (Hacke et al, 2008), but the 3rd International Stroke Trial (IST3) is shortly to report whether some patients may have benefit up until 6 hours, while the DIAS-4 study is investigating treatment up until 9 hours if urgent angiography demonstrates a blocked cerebral artery. The main complication following stroke thrombolysis is cerebral haemorrhage, and the Enhanced Control of Hypertension and Thrombolysis Stroke Study (ENCHANTED) is examining whether there is less risk of bleeding with a lower treatment dose and/or a more pro-active approach to acute blood pressure control. Approximately 10 % of stroke admissions are due to intracerebral haemorrhage but most are not suitable for surgical treatment. INTERACT2 is a study examining whether very active reduction in blood pressure within 6 hours of cerebral haemorrhage can prevent an increase in size of the haematoma, and consequently reduce the disability experienced by the patient.
Whether to treat hypertension in the acute phase of stroke in general remains a complex question. Although a poorer prognosis is associated with higher levels, trials do not yet support routine intervention (Sandset et al, 2011). In order to explore whether very early treatment might be beneficial it would be necessary to design a trial which starts the intervention at the earliest opportunity (i.e. during initial paramedic assessment). In 2011, UKSRN supported the Paramedic Initiated Lisinopril For Acute Stroke Treatment (PILFAST) pilot study that tested the feasibility of independent research trained paramedics obtaining consent for participation in a trial of blood pressuring lowering treatment (sublingual lisinopril) (Shaw et al, 2011).
There are many other studies in development which will be supported by UKSRN and likely, paramedics will have a greater active role in the future of stroke research. It is important to remember that an urgent public and professional response to stroke symptoms is not only to reduce the risk of permanent disability and early complications, but to offer patients and their families the opportunity to participate in the generation of new evidence through clinical trials.