Study of Platelet Activation by Severe Aortic Stenosis and Its Correction by Transcatheter Aortic Valve Implantation (TAVI) Platelet Activation in TAVI
试验速览
- 阶段
- 不适用
- 状态
- 已完成
- 入组人数
- 44
- 试验地点
- 1
- 主要终点
- the change of kinetics of platelet activation
研究概览
简要总结
Study of platelet activation by severe aortic stenosis and its correction by Transcatheter Aortic Valve Implantation (TAVI)
详细描述
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Background: TAVI has emerged as an alternative to surgical aortic valve replacement for patients with severe, symptomatic aortic stenosis (AS) and is expanding worldwide with more than 50,000 patients treated to date.
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Purpose Changes in haemostasis, particularly in platelet activation or reactivity before, during and after TAVI have never been studied. Valve replacement is known to alleviate von Willebrand factor abnormalities associated with AS. A potential improvement of platelet function could also occur after TAVI. Indeed, circulating platelets may be desensitized and under-reactive due to multiple passages through the stenotic valve and could recover normal reactivity after TAVI. Besides, TAVI presents a risk of major ischemic complications. The investigators can hypothesize the involvement of high reactive platelets in peri-procedural thrombotic or ischemic events. This study of the platelet activation kinetics will be performed by comparing several specific markers before and at various times after valve implantation.
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Primary outcome To evaluate the kinetics of platelet activation before and at various times after valve implantation, by comparing several specific markers in peripheral venous blood samples before (day 0) and at days 1 and 5±1 after the procedure.
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Study design and number of subjects: This is a prospective, monocentric, study. The test group includes up to 15 patients treated by transfemoral TAVI using a MedTronic CoreValve (MCV) prosthesis. Platelet activation will be studied before and after the procedure and compared to a reference established with an age-matched, aspirin-treated, atherosclerotic population (30 patients in the control group).
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Eligibility criteria:
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inclusion criteria: test group: patients with severe aortic stenosis and transfemoral TAVI with MCV aspirin treatment . Control group: age-matched patients with stable coronary artery disease treated by aspirin but without aortic stenosis.
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exclusion criteria: recent (1 month) acute coronary syndrome; treatment by anti platelet agents other than aspirin
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Procedures: Specific platelet activation markers, circulating platelet/monocytes aggregates, platelet reactivity and vWF will be assessed in peripheral venous blood before, 1 and 5 days after TAVI and in ascending aorta during the procedure.
研究设计
- 研究类型
- Interventional
- 分配方式
- Non Randomized
- 干预模型
- Parallel
- 主要目的
- Other
- 盲法
- None
入排标准
- 年龄范围
- 50 Years 至 —（Adult, Older Adult）
- 性别
- All
- 接受健康志愿者
- 否
入选标准
- •Test group
- •Severe symptomatic AS (Aortic valve area < 0,6 cm2/m2 SC), deemed, after multidisciplinary heart team evaluation, contra-indicated or at high risk for surgery and suitable for TF TAVI with a MCV prosthesis.
- •Aspirin treatment (75-160 mg/d for at least one week)
- •Control group
- •Stable coronary artery disease, unscathed of AS
- •Aspirin treatment (75-160 mg/d for at least one week)
排除标准
- •Test group:
- •Acute coronary syndrome 1 month before inclusion
- •Any co-morbidity limiting life-expectancy < 1 year
- •Terminal chronic kidney disease requiring hemodialysis thrombocytopenia <100 G/L, anemia (Hb < 10 g/dl)
- •Treatment by another antiplatelet agent within 10 days before the procedure
- •Control group:
- •Acute coronary syndrome 1 month before inclusion
- •Any co-morbidity limiting life-expectancy < 1 year
- •Terminal chronic kidney disease requiring hemodialysis
- •Thrombocytopenia <100 G/L
- •Treatment by another antiplatelet agent within 10 days before the procedure
研究组 & 干预措施
test group
Patient with severe, symptomatic AS (Aortic valve area < 0,6 cm2/m2 SC), deemed, after multidisciplinary heart team evaluation, contra-indicated or at high risk for surgery and suitable for TF TAVI with a MCV prosthesis.
干预措施: test (Other)
control group
Patient with stable coronary artery disease, unscathed of AS Patient under aspirin treatment (75-160 mg/d for at least one week)
干预措施: control group (Other)
结局指标
主要结局
the change of kinetics of platelet activation
时间窗: 1 min before TAVI and 5±1 after TAVI
Evaluate the kinetics of platelet activation before and at various times after valve implantation, by comparing several specific markers in peripheral venous blood samples before (day 0) and at 5±1 days after the procedure using flow cytometry (FACS).
the change of kinetics of platelet activation
时间窗: 1 min before TAVI and at days 1after TAVI
Evaluate the kinetics of platelet activation before and at various times after valve implantation, by comparing several specific markers in peripheral venous blood samples before (day 0) and at day 1 after the procedure using flow cytometry (FACS).
次要结局
- Changes of platelet activation(1 min before and 10 min after TAVI)
- Changes of platelet activity(1 min before and day 5 after TAVI)
- changes in von Willebrand factor(1 min before and day 1 and 5 after TAVI)
- Changes of platelet activity(1 min before and day 1 after TAVI)