Hospital team significantly reduced risk of further vascular events after 'mini strokes'

Patients who had a transient ischaemic attack (TIA), sometimes referred to as a "mini stroke", were much less likely to experience further vascular events in the first year if their care was co-ordinated by a special hospital team. That is the key finding from a study published in the November issue of the European Journal of Neurology.

Researchers from the Department of Neurology at Aarhus University Hospital in Denmark studied 306 patients admitted to the hospital with a TIA. They found that when the patients were treated by an acute TIA team their cumulated risk of having a stroke in the first seven days was 65% lower than expected. The cumulated risk in the first 90 days fell by 74%.

"The aim of our study was to see if patients had better clinical outcomes if they were under the care of a special team, which integrated outpatient care and stroke unit facilities and provided on-going nurse-led counselling" says lead author Dr Paul von Weitzel-Mudersbach.

"TIA, which is caused by a temporary lack of blood to part of the brain, is a serious condition associated with a high short-term risk of ischaemic stroke. Previous research has shown that the cumulated stroke risk in the first three months after a TIA is ten to 12% in unselected patients and more than 30% in patients with carotid stenosis, a dangerous narrowing of the largest blood vessels that deliver blood to the brain.

"Although urgent intervention has been shown to reduce the risk of stroke, a number of previous studies have shown poor long-term drug compliance in many patients."

The patients were referred directly to the acute TIA team by their family doctor or ambulance, bypassing the emergency department. Patients who had suffered a TIA in the last 48 hours, and those with multiple TIA, faced a high risk of stroke and were admitted to the stroke unit. This offered the option for immediate preventative action, including thrombolysis drugs, to break up blood clots in the case of recurrent stroke. The other patients were seen in the outpatients department within three days of referral.

A transient ischemic attack (TIA) is an acute episode of temporary neurologic dysfunction resulting from focal cerebral ischemia not associated with permanent cerebral infarction. The clinical symptoms of TIA typically last less than an hour, but prolonged episodes can occur. While the classical definition of TIA included symptoms lasting as long as 24 hours, advances in neuroimaging have suggested that many such cases represent minor strokes with resolved symptoms rather than true TIAs.

A group of cerebrovascular experts proposed a shift from the arbitrary time-based definition of TIA to a tissue-based definition in 2002 with a new definition for TIA as "a brief episode of neurological dysfunction caused by focal brain or retinal ischemia, with clinical symptoms typically lasting less than one hour, and without evidence of acute infarction." This proposed new definition was well received and endorsed by many clinicians. The American Heart Association and American Stroke Association (AHA/ASA) 2009 Guidelines endorsed this new definition, modifying it with the omission of the phrase "typically less than one hour," as there is no time cutoff that reliably distinguishes whether a symptomatic ischemic event will result in tissue infarction.