Half-dose ticagrelor versus standard-dose clopidogrel in a dual antiplatelet regimen for stent-assisted coiling or flow diversion of unruptured intracranial aneurysms: a cohort study

BACKGROUND: Intracranial hemorrhage is the major safety concern of standard-dose ticagrelor (90 mg twice daily) based dual antiplatelet therapy (DAPT). The bleeding avoidance strategy through dose de-escalation has been investigated in interventional cardiology. However, the preserved antithrombotic efficacy and better safety of half-dose (45 mg twice daily) ticagrelor remains unverified in patients undergoing stent-assist coiling (SAC) or flow diversion (FD) treating unruptured intracranial aneurysms (UIA). METHODS: A single-center, prospective, cohort study was conducted to compare DAPT with aspirin 100 mg daily plus half-dose ticagrelor vs standard-dose clopidogrel (75 mg daily) in UIA patients. The adenosine diphosphate inhibition (ADPi) rate was utilized to quantify the antagonization of adenosine diphosphate (ADP)-induced platelet aggregation. The patients were followed-up at 6 month after discharge. The primary efficacy outcome was the major adverse cardiovascular and cerebrovascular events (MACCE), and the primary safety outcome was major bleeding. The secondary outcome was minor hemorrhage. RESULTS: Our study included 322 UIA patients, of which 254 patients were eventually enrolled after propensity score matching. The ADPi of half-dose ticagrelor (51.56%±31.46%) was comparable (P=0.089) to that of clopidogrel (57.44%±22.76%). The outcomes were also comparable. Five (3.94%) patients in the ticagrelor group and eight (6.30%) patients in the clopidogrel group reported MACCE (P=0.393). One patient in the ticagrelor group was diagnosed with asymptomatic intracranial hemorrhage 1 month after stenting. There were 36 (28.35%) minor hemorrhagic events in the ticagrelor group and 35 (27.56%) in the clopidogrel group, (P=0.889). CONCLUSION: Half-dose ticagrelor was effective and safe as a potential alternative to clopidogrel in the DAPT regimen for patients undergoing SAC/FD for UIA.