Among patients with a transient ischemic attack ( TIA ) or minor ischemic strokes, those with ipsilateral atherosclerotic stenosis of cervicocranial vasculature have the highest risk of recurrent vascular events.
In the double-blind THALES ( The Acute Stroke or Transient Ischemic Attack Treated With Ticagrelor and ASA for Prevention of Stroke and Death ) trial, researchers have randomized patients with a noncardioembolic, nonsevere ischemic stroke, or high-risk transient ischemic attack to Ticagrelor [ Brilique ] ( 180 mg loading dose on day 1 followed by 90 mg twice daily for days 2-30 ) or placebo added to Aspirin [ Acetylsalicylic acid; ASA ] ( 300–325 mg on day 1 followed by 75–100 mg daily for days 2–30 ) within 24 hours of symptom onset.
Researchers have reported a prespecified analysis in patients with and without ipsilateral, potentially causal atherosclerotic stenosis greater than or equal to 30% of cervicocranial vasculature.
The primary end point was time to the occurrence of stroke or death within 30 days.
Of 11 016 randomized patients, 2351 ( 21.3% ) patients had an ipsilateral atherosclerotic stenosis.
After 30 days, a primary end point occurred in 92/1136 ( 8.1% ) patients with ipsilateral stenosis randomized to Ticagrelor and in 132/1215 ( 10.9% ) randomized to placebo ( hazard ratio, HR= 0.73 [ 95% CI, 0.56–0.96 ], P=0.023 ) resulting in a number needed to treat [ NNT ] of 34 ( 95% CI, 19–171 ).
In patients without ipsilateral stenosis, the corresponding event rate was 211/4387 ( 4.8% ) and 230/4278 ( 5.4% ), respectively ( HR=0.89 [ 95% CI, 0.74–1.08 ]; P=0.23, P interaction=0.245 ).
Severe bleeding occurred in 4 ( 0.4% ) and 3 ( 0.2% ) patients with ipsilateral atherosclerotic stenosis on Ticagrelor and on placebo, respectively ( P=NS ), and in 24 ( 0.5% ) and 4 ( 0.1% ), respectively, in 8665 patients without ipsilateral stenosis ( HR=5.87 [ 95% CI, 2.04–16.9 ], P=0.001 ).
In this exploratory analysis comparing Ticagrelor added to Aspirin to Aspirin alone, researchers have found no treatment by ipsilateral atherosclerosis stenosis subgroup interaction but did identify a higher absolute risk and a greater absolute risk reduction of stroke or death at 30 days in patients with ipsilateral atherosclerosis stenosis than in those without.
In this easily identified population, Ticagrelor added to Aspirin provided a clinically meaningful benefit with a number needed to treat of 34 ( 95% CI, 19–171 ). ( xagena )
Source: Stroke, 2020