From the Guidelines
The ideal P2Y12 reaction unit (PRU) level for endovascular flow-diverting stent placement in cerebral aneurysms is between 60-150 PRU, with most practitioners targeting 60-120 PRU. Patients typically receive dual antiplatelet therapy (DAPT) with aspirin 325mg daily and a P2Y12 inhibitor such as clopidogrel 75mg daily, starting 5-7 days before the procedure 1. P2Y12 levels should be tested before intervention to ensure adequate platelet inhibition. If a patient shows clopidogrel resistance (PRU >150), alternative P2Y12 inhibitors like ticagrelor (90mg twice daily) or prasugrel (10mg daily) may be used 1. Adequate platelet inhibition is crucial to prevent thromboembolic complications while avoiding excessive inhibition that could increase bleeding risk. DAPT is typically continued for 3-6 months post-procedure, followed by aspirin monotherapy. Regular monitoring of P2Y12 levels may be necessary in the early post-procedural period to maintain optimal inhibition. Some key considerations for the management of patients with cerebral aneurysms undergoing endovascular flow-diverting stent placement include:
- The use of aspirin and a P2Y12 inhibitor as part of DAPT 1
- The importance of testing P2Y12 levels before intervention to ensure adequate platelet inhibition 1
- The potential need for alternative P2Y12 inhibitors in patients with clopidogrel resistance 1
- The typical duration of DAPT and the subsequent use of aspirin monotherapy 1
From the Research
Ideal P2Y12 Level for Endovascular Flow-Diverting Stent Placement
The ideal P2Y12 level for endovascular flow-diverting stent placement in cerebral aneurysms is a topic of ongoing research. Several studies have investigated the role of P2Y12 reactive units (PRUs) in patients undergoing stent-assisted coiling or flow diversion with ticagrelor therapy.
- A study published in 2020 2 suggested that the safe PRU range for patients receiving ticagrelor should be shifted to 0-100, which is lower than that of clopidogrel.
- Another study published in 2025 3 found that the majority of periprocedural ticagrelor PRUs were <100, and PRUs at the time point of thromboembolic complications were >120.
- A study from 2018 4 investigated the use of low-dose prasugrel in patients with resistance to clopidogrel and found that the mean PRU value decreased from 238.5 to 124.9 after prasugrel administration.
- A comparison of PRU results with thromboelastography (TEG) with platelet mapping (PM) found poor agreement between the two assays, with PRU likely overestimating clopidogrel resistance 5.
- A study published in 2019 6 found that the precision of VerifyNow P2Y12 assessment of clopidogrel response was often imprecise, with 24% of patients fluctuating between therapeutic categories when multiple P2Y12 assessments were drawn within a 24-h period.
Key Findings
- The ideal PRU range for patients receiving ticagrelor may be lower than that of clopidogrel, potentially 0-100 2, 3.
- PRU values >100 may be associated with an increased risk of thromboembolic complications 2, 3.
- The use of low-dose prasugrel may be effective in reducing PRU values in patients with resistance to clopidogrel 4.
- The agreement between PRU results and TEG-PM is poor, and PRU may overestimate clopidogrel resistance 5.
- The precision of VerifyNow P2Y12 assessment of clopidogrel response can be imprecise, and multiple assessments may be necessary to determine the optimal PRU range 6.