Application of Platelet Function Test in Prevention of Ischemic Events After Stent Placement in Intracranial Aneurysms

Study Overview
=================
Brief Summary
-----------------
This study was designed to identify high platelet reactivity (HPR) who might have in-stent thrombosis in unruptured aneurysm with intracranial stent placement with light transmittance platelet aggregometry (LTA). For HPR patients, higher ischemic stroke rate maybe occurred, and we hypothesis that dose adjustment of aspirin and clopidogrel based on LTA monitoring maybe reduces the rate of ischemic stroke compared to a standard strategy after intracranial stent implantation at early periprocedural period and 1 month follow-up period.

Detailed Description
-----------------
For the patients of unruptured intracranial aneurysms with stent placement, standard antiplatelet therapy (100mg aspirin + 75mg clopidogrel) is considered to be the most effective antiplatelet regimen in reducing ischemic complications. However, despite the use of standard antiplatelet therapy, a number of patients continue to have ischemic events. A hypothesis is that high platelet reactivity (HPR) patients identified by platelet function test have higher ratio of the ischemic events, and dose adjustment of HPR patients reduces the rate of the ischemic complications at early periprocedural period and follow-up period. Objectives: The study aim to evaluated the superiority of the strategy of platelet function test(Monitoring Arm) with the modified strategy in HPR patients compared to the standard strategy (Conventional Arm) whether reduce the primary endpoint after intracranial stent implantation at early periprocedural period (7 days) and 1 months follow-up period.

Official Title
-----------------
A Study of Platelet Function Test in the Application of Prevention of Ischemic Events After Stent Placement in Intracranial Aneurysms

Conditions
-----------------
Unruptured Intracranial Aneurysm, Stents, Antiplatelet Drugs

Intervention / Treatment
-----------------
* Drug: Aspirin and clopidogrel/Ticagrelor
* Device: Light transmittance aggregometry
* Drug: Aspirin and clopidogrel/Ticagrelor


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: Age 18 - 80, male or non-pregnant female; patients have unruptured aneurysm who plan to undergo intracranial stent placement; patients with less than 2 of modified Rankin scale score at the day of enrollment; patients who is able to understand the objective of the trial, agrees and signs the written informed consent form. Exclusion Criteria: The complications related to operation or material quality, such as guidewire pierces out blood vessel, coil herniation, incompletely opened stent, etc; Simultaneous treatment of other cerebrovascular diseases, such as intracranial arteriovenous malformation, Intracranial arteriovenous fistula, etc; Patient with history of hypersensitivity of aspirin, clopidogrel, or ticagrelor; Patients with preoperative prophylactic use of tirofiban; Patients with a high possibility of active bleeding, such as symptomatic intracranial hemorrhage or active gastric ulcer; or patients with coagulopathy; Patients with thrombocytopenia (platelet count <100,000/mm3 within three months before enrollment); patient using anticoagulant; Pregnant or lactating women; Patients with malignant diseases, such as liver disease, kidney disease, congestive heart failure, malignant tumors, etc; Poor compliance patients.

Ages Eligible for Study
-----------------
Minimum Age: 18 Years
Maximum Age: 80 Years

Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
No

Study Plan
=================
How is the study designed?
-----------------

Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Monitoring Arm<br>Randomization: based on light transmittance aggregometry, modified dose of antiplatelet therapy(aspirin and ticagrelor) was used for high platelet reactivity(HPR) patients with intracranial stent placement, and standard antiplatelet regimen(aspirin and clopidogrel) was used in non-HPR patients. | Drug: Aspirin and clopidogrel/Ticagrelor<br>* The modification of aspirin and clopidogrel/ticagrelor maintenance doses based on a biomarker assays.<br>Device: Light transmittance aggregometry<br>* point-of-care method to assess platelet function by light transmittance aggregometry.<br>Drug: Aspirin and clopidogrel/Ticagrelor<br>* maintenance dose of aspirin, clopidogrel and ticagrelor.<br>|
| Experimental: Conventional Arm<br>Randomization: without light transmittance aggregometry, standard antiplatelet regimen was used for unruptured aneurysm patients with intracranial stent. | Drug: Aspirin and clopidogrel/Ticagrelor<br>* maintenance dose of aspirin, clopidogrel and ticagrelor.<br>|

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| A thromboembolic event during the early periprocedural period (within 7 days after stent placement) | The thromboembolic events were assessed by clinical examination. The thromboembolic events was a composite of ischemic stroke, transient ischemic attack, stent thrombosis, urgent revascularization, myocardial infarction, cerebrovascular death. | within 7 days of patients' enrolled. | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| A thromboembolic event during the 1 month follow-up periods. |  | within 1 month of patients' enrolled. | 

 Terms related to the study
=================
Keywords Provided by Centre Hospitalier Valida
-----------------
Platelet function test, high platelet reactivity, light transmittance platelet aggregometry