Aspirin Beneficial in Early Secondary Stroke Prevention

Using aspirin immediately after mini-stroke could substantially reduce the risk of a major subsequent major stroke, according to a new study.

Researchers the University of Oxford (United Kingdom), Lund University (Sweden), and other institutions conducted a review of individual patient data from 12 studies involving 15,778 people taking aspirin for long-term secondary stroke prevention following a transient ischemic attack (TIA) or minor stroke, and a further 40,531 people participating in three trials of aspirin use in the treatment of acute stroke.

They found that in the three trials of aspirin for treating acute ischemic stroke, the overall effect of aspirin was indeed modest. However, among the 12 trials of secondary stroke prevention, aspirin reduced the 12-week risk of any stroke by half, disabling or fatal ischemic stroke by two-thirds, and acute myocardial infarction (MI) by two-thirds. The effect of aspirin was consistent among the trials and independent of patient characteristics, stroke etiology, and aspirin dose.

The effect of aspirin was greater in the first six weeks after randomization than the second six weeks, and attenuated further to be of limited long-term benefit thereafter. In seven trials that compared dipyridamole plus aspirin versus aspirin alone, the addition of dipyridamole had no effect on the risk or severity of recurrent ischemic stroke within 12 weeks, but did reduce risk thereafter, particularly of disabling or fatal ischemic stroke. The review was published on May 18, 2016, in The Lancet.

“We might have underestimated the effect of aspirin in preventing early recurrent stroke and myocardial infarction after TIA and ischemic stroke, overestimated the effect of aspirin in preventing long-term recurrent stroke, been unaware of the benefits of aspirin in reducing the severity of early recurrent ischemic stroke, and underestimated the effect of dipyridamole in preventing long-term recurrent stroke,” concluded lead author Professor Peter Rothwell, MD, PhD, head of the Oxford University Stroke Prevention Research Unit.

“A TIA is a medical emergency and urgent neurological assessment must always be sought. We welcome this research which shows that taking aspirin after TIA can dramatically reduce the risk and severity of further stroke,” commented Dale Webb, MD, director of research and information at the Stroke Association (London, United Kingdom). “The findings suggest that anyone who has stroke symptoms, which are improving while they are awaiting urgent medical attention can, if they are able, take one dose of 300 mg aspirin.”

Related Links:
University of Oxford
Lund University
Stroke Association