Study supports use of aspirin after transient ischemic attack (TIA)

by Bruce Sylvester: Following a transient ischemic attack (TIA), quick aspirin treatment can significantly reduce the risk of a major stroke in the next few days, researchers reported on May 18, 2016 in The Lancet.

Lead investigator Peter Rothwell, MD, professor of neurology and Director of the Stroke Prevention Research Unit, University of Oxford (UK) said, “The risk of a major stroke is very high immediately after a TIA or a minor stroke, about 1000 times higher than the background rate, but only for a few days. We showed previously in the ‘EXPRESS Study’ that urgent medical treatment with a ‘cocktail’ of different drugs could reduce the one-week risk of stroke from about 10% to about 2%, but we didn’t know which component of the ‘cocktail’ was most important.”

The researchers pooled data for 15,778 subjects in all twelve randomized trials of aspirin versus control in secondary prevention after TIA or ischemic stroke. They evaluated it for effects of aspirin on the risk and severity of recurrent stroke for less than 6 weeks, 6–12 weeks and more than 12 weeks after randomization.

Aspirin reduced 6-week risk of recurrent ischemic stroke by about 60%; 84 of 8,452 subjects in the aspirin group had an ischemic stroke vs 175 of 7,326 in the control group (p<0·0001).  And aspirin reduced disabling or fatal ischemic stroke by about 70% (36 of 8,452 for aspirin-treated subjects vs 110 of 7,326 for controls (p<0·0001).

The greatest benefit was among subjects with TIA or minor stroke. At 0–2 weeks, two of 6,691 subjects in the aspirin group with TIA or minor stroke had a disabling or fatal ischemic stroke vs 23 of 5,726 in the control group (p=0·0004). At 0–6 weeks, 14 in the aspirin group with TIA or minor stroke had a disabling or fatal ischemic stroke vs 60 control subjects (p<0·0001).

Rothwell added, “’Our findings confirm the effectiveness of urgent treatment after TIA and minor stroke – and show that aspirin is the most important component. Immediate treatment with aspirin can substantially reduce the risk and severity of early recurrent stroke. This finding has implications for doctors, who should give aspirin immediately if a TIA or minor stroke is suspected, rather than waiting for specialist assessment and investigations.”