血栓弹力图在急性脑梗死患者抗血小板治疗效果评价中的应用

目的探讨采用血栓弹力图(TEG)评价阿司匹林和氯吡格雷治疗急性脑梗死患者的抗血小板效果,以指导对急性脑梗死患者抗血小板聚集药物治疗的个体化调整。方法选择急性脑梗死患者82例,予阿司匹林100 mg和氯吡格雷75 mg联合治疗7 d后,采用TEG仪检测花生四烯酸(AA)途径诱导的血小板抑制率和腺苷二酸(ADP)受体途径诱导的血小板抑制率,比较患者经两种途径诱导的血小板抑制率以及患者对阿司匹林和氯吡格雷治疗反应的差异。同时选择急性脑梗死患者40例作为对照组,单用阿司匹林100 mg抗血小板治疗7d,对比两组TEG参数(R值、K值、angle角、MA值)。结果急性脑梗死予阿司匹林、氯吡格雷双抗血小板,阿司匹林对AA途径的抑制率明显高于氯吡格雷对ADP受体途径的抑制率,差异有统计学意义(P0.01);对阿司匹林反应良好的患者,4例对氯吡格雷无反应,15例反应低下;对氯吡格雷反应良好的患者,仅1例对阿司匹林反应低下。对氯吡格雷反应低下者,3例对阿司匹林无反应,5例低下,6例对阿司匹林有效,15例良好。两种疗效有一定关联性(P0.01)。对阿司匹林反应良好+有效为62例,反应低下+无效者20例;氯吡格雷反应良好+有效者42例;反应低下+无效者38例,两种药物疗效差异有统计学意义(P0.01)。单用阿司匹林组与双联抗血小板组比较两组患者R值、K值、α角、MA值均无明显差别(P0.05)。结论采用TEG仪检测对急性脑梗死患者抗血小板治疗的疗效评价有较高的临床价值。双联抗血小板中阿司匹林对急性脑梗死患者血小板聚集的抑制作用强于氯吡格雷。患者对阿司匹林和氯吡格雷治疗的反应有差异性,部分对氯吡格雷反应低下者,可能对阿司匹林反应良好或有效。双联抗血小板治疗对血凝的影响较单用阿司匹林无明显差别。     

阿司匹林与氯吡格雷抗血小板聚集作用效果观察

目的 探讨阿司匹林与氯吡格雷抑制血小板聚集的临床效果。方法 将107例急性脑梗死患者分为阿司匹林组34例、氯吡格雷组19例、联合组54例。阿司匹林组口服阿司匹林100 mg/d;氯吡格雷组口服氯吡格雷75 mg/d;联合组同时服用以上两种药物（剂量同前）。三组均连续服用7 d后采用血栓弹力图检测花生四烯酸（AA）途径血小板抑制率（AA%）及二磷酸腺苷（ADP）途径血小板抑制率（ADP%）。结果 阿司匹林组血小板抑制敏感率明显高于氯吡格雷组,P〈0.01;联合组AA%明显高于阿司匹林组,ADP%明显高于氯吡格雷组,P均〈0.01;联合组血小板抑制敏感率AA为90.7%（49/54）,ADP为70.4%（38/54）,较其余两组明显增高（P均〈0.01）。结论 阿司匹林与氯吡格雷联合应用可协同抑制血小板聚集。     

血栓弹力图对大面积脑梗死不同剂量抗血小板聚集药物疗效的评估价值

目的应用血栓弹力图(TEG)评估大面积脑梗死急性期患者高、低剂量阿司匹林联用氯吡格雷对血小板抑制率的影响。方法回顾性纳入北华大学附属医院接诊的急性大面积脑梗死患者,并按阿司匹林口服剂量的不同分为低剂量组(阿司匹林100 mg+氯吡格雷75 mg)52例和高剂量组(阿司匹林300 mg+氯吡格雷75 mg)62例。两组患者均于入院后开始服用阿司匹林及氯吡格雷,于服药第4天,采用TEG检测患者花生四烯酸(AA)途径血小板抑制率和二磷酸腺苷(ADP)途径血小板抑制率。比较两组患者血小板抑制情况及药物抵抗的发生情况。结果低剂量组AA抑制率及ADP抑制率与高剂量组均无统计学差异(均P>0.05)。低剂量组发生阿司匹林抵抗及氯吡格雷抵抗与高剂量组无统计学差异(均P>0.05)。低剂量组脑梗死出血转化发生率与高剂量组无统计学差异(P>0.05)。结论对大面积脑梗死患者,TEG评价的低剂量与高剂量抗血小板聚集治疗对血小板抑制效果无明显差异。     

血栓弹力图评价经PCI术后氯吡格雷及阿司匹林血小板抑制情况及作用机制

目的探讨血栓弹力图(TEG)监测经皮冠状动脉介入治疗(PCI)患者服用氯吡格雷和阿司匹林药物后TEG参数情况及血小板的抑制效果。方法选取135例老年冠心病患者,随机分为氯吡格雷组、阿司匹林组和氯吡格雷联合阿司匹林(联合用药)组。采用TEG仪监测分析花生四烯酸(AA)和二磷酸腺苷(ADP)途径诱导的血小板抑制率,并分析3组血小板抑制率的差异性。结果治疗后3组反应时间(R)、凝固时间(K)均升高,凝固角(α)、最大振幅(MA)均降低,联合用药组R、K高于氯吡格雷、阿司匹林组,α、MA低于氯吡格雷、阿司匹林组,差异有统计学意义(P0.05)。TEG检测结果发现阿司匹林组AA途径诱导和氯吡格雷组ADP途径诱导的血小板抑制率差异无统计学意义(P0.05);联合用药组AA、ADP途径血小板抑制有效率大于氯吡格雷组、阿司匹林组,差异有统计学意义(P0.05)。结论联合服用阿司匹林和氯吡格雷相较于单独使用药物具有更好的抗血小板作用。TEG能够敏感检测不同药物对抗血小板治疗的指标影响,进而调整治疗方案。     

血栓弹力图对支架辅助颅内栓塞动脉瘤不同剂量抗血小板聚集药物疗效的初步评价

目的采用血栓弹力图检查(TEG)评估支架辅助栓塞动脉瘤患者术前不同剂量阿司匹林及氯吡格雷联合治疗方案对血小板抑制率的影响。方法回顾性连续纳入南京军区南京总医院接受支架辅助栓塞动脉瘤的57例未破裂动脉瘤患者,并按阿司匹林口服剂量的不同分为低剂量组(阿司匹林100 mg+氯吡格雷75 mg)26例和高剂量组(阿司匹林300 mg+氯吡格雷75 mg)31例。两组患者均于术前开始服用阿司匹林及氯吡格雷,于服药第3天,采用TEG检测患者花生四烯酸(AA)途径血小板抑制率和二磷酸腺苷(ADP)途径血小板抑制率。比较两组患者血小板抑制情况以及药物抵抗的发生情况。结果 (1)服药3 d血小板抑制率:低剂量组AA抑制率及ADP抑制率分别为(76±21)%、(72±26)%;高剂量组AA抑制率及ADP抑制率分别为(80±21)%、(73±29)%,两组抑制率差异均无统计学意义(均P0.05)。(2)药物抵抗:低剂量组发生阿司匹林抵抗2例(7.7%),氯吡格雷抵抗1例(3.8%);高剂量组中发生阿司匹林抵抗3例(9.7%),氯吡格雷抵抗4例(12.9%);两组患者阿司匹林抵抗及氯吡格雷抵抗的发生率差异均无统计学意义(均P0.05)。(3)围手术期缺血并发症:低剂量组中1例(3.8%)发生围手术期缺血事件,高剂量组中2例(6.5%)发生围手术期缺血事件,两组围手术期缺血并发症发生率差异无统计学意义(P0.05)。结论对支架辅助栓塞动脉瘤患者,TEG评价的低剂量与高剂量抗血小板聚集治疗对血小板抑制效果无明显差异。     

血栓弹力图评估经皮介入治疗后患者抗血小板药物抵抗发生情况及影响因素

目的探讨行经皮介入治疗(percutaneous coronary intervention PCI)后口服阿司匹林联合氯吡格雷双联抗血小板用药患者,经血栓弹力图(thrombelastography TEG)测得血小板抑制率等提示阿司匹林、氯吡格雷抵抗的发生率,分析其影响因素。方法 2012年08月—2015年08月期间,行PCI患者280例,TEG测得二磷酸腺苷通道血凝块最大强度(MAADP)、花生四烯酸(AA)和二磷酸腺苷(ADP)诱导的血小板抑制率等相关数据,以AA诱导血小板抑制率50%为阿司匹林抵抗,ADP诱导的血小板抑制率30%为氯吡格雷抵抗。收集临床及实验资料进行分析。结果全部患者中,阿司匹林抵抗(aspirin resistance)为82例,氯吡格雷抵抗(clopidogrel resistance)88例,发生率为29.3%、31.4%。年龄、吸烟、合并高血压、糖尿病等未影响抗血小板药物抵抗发生。合并用药方面,泮托拉唑未对抗血小板药物抵抗产生影响,使用两种他汀对抗血小板药物反应相似。结论 TEG检测阿司匹林、氯吡格雷抵抗发生率较高,一般临床因素及合并用药对其影响不明确,但应引起临床注意。     

血栓弹力图评估PCI后氯吡格雷不敏感患者抗血小板药物的疗效

目的应用血栓弹力图(TEG)评估冠状动脉粥样硬化性心脏病(冠心病)患者行经皮冠状动脉介入治疗(PCI)后氯吡格雷不敏感患者中不同抗血小板药物的疗效。方法对在应急总医院心内科行PCI并规律服用阿司匹林及氯吡格雷的冠心病患者278例,通过TEG检测血小板抑制率,ADP抑制率≥50%为达标组,ADP抑制率50%为未达标组;未达标组随机将氯吡格雷更换为替格瑞洛,为替格瑞洛组,应用氯吡格雷的患者为氯吡格雷组,分析替格瑞洛组换药前后AA抑制率和ADP抑制率的变化及其与达标组的差异,随访患者1年内呼吸困难、出血等不良反应。结果替格瑞洛组将氯吡格雷更换为替格瑞洛后ADP抑制率及AA抑制率均较前升高,差异有统计学意义(P0.05);替格瑞洛组换药前ADP抑制率和AA抑制率低于达标组,差异有统计学意义(P0.05),换药后ADP抑制率和AA抑制率与达标组相比,差异无统计学意义(P0.05);随访1年内两组均无严重出血及小出血事件发生,替格瑞洛组轻度呼吸困难发生率增多(P0.05),两组间轻微出血的发生无统计学差异(P0.05)。结论 TEG评估发现在PCI后对氯吡格雷不敏感(ADP抑制率50%)的患者中,替格瑞洛可以提高血小板在ADP途径和AA途径中对抗血小板药物的反应性,与对氯吡格雷敏感患者相比无明显差异。     

血栓弹力图评价急性冠状动脉综合征患者氯吡格雷反应低下的研究

目的 通过血栓弹力图(TEG)检测血小板聚集率,观察接受双联抗血小板药物治疗的急性冠状动脉综合征患者发生氯吡格雷反应低下的情况.方法 选取住院的急性冠状动脉综合征患者167例,在常规口服阿司匹林(100 mg/d)的基础上,随机给予氯吡格雷75 mg/d或顿服300 mg后继续75 mg/d.常规剂量组在连续用药5天后、负荷组在顿服300 mg后次日采血,通过TEG方法测定血小板聚集率,以二磷酸腺苷诱导的血小板聚集率≥70％为氯吡格雷反应低下,花生四烯酸诱导的血小板聚集率＞50％为阿司匹林反应低下.结果 总计50例患者出现氯吡格雷反应低下,发生率为29.9％,常规剂量组和负荷组比较差异无统计学意义(P＞0.05);16例(9.6％)患者发生阿司匹林和氯吡格雷反应双低下;氯吡格雷反应低下组与非低下组间阿司匹林反应低下的发生率比较差异有显著统计学意义(P＜0.01).氯吡格雷反应低下组与非低下组患者的年龄、高血压、糖尿病、合并用药等方面比较差异无统计学意义(P＞0.05),但两组性别、吸烟史、入院时总胆固醇水平比较差异具有统计学意义(P＜0.05).结论 接受标准抗血小板治疗的急性冠状动脉综合征患者存在氯吡格雷反应低下的现象,这一现象不受年龄、合并用药及氯吡格雷给药方式的影响,而女性、无吸烟史或烟龄短、年支数少、存在高总胆固醇血症或阿司匹林反应低下的患者更易发生氯吡格雷反应低下.     

血栓弹力图评估阿司匹林和氯吡格雷血小板抑制率的临床应用

目的 用血栓弹力图评估冠心病及冠心病支架术后患者正规使用阿司匹林及氯吡格雷后血小板抑制率的改变.方法 血栓弹力图检测300例住院患者血小板药物治疗后花生四烯酸(AA)通路和二磷酸腺苷(ADP)受体途径诱导的血小板抑制率.将抗血小板治疗的患者分为阿司匹林组、氯吡格雷组、阿司匹林和氯吡格雷联用组各100例.结果 阿司匹林与氯吡格雷组和阿司匹林和氯吡格雷联用组在血小板抑制率和临床治疗效果上无显著差异(P＞0.05).结论 阿司匹林与氯吡格雷联用在对血小板的抑制率无协同作用,由于患者可能存在阿司匹林或者氯吡格雷某一途径抵抗的情况下,可以得到另一途径的有效补充而使血小板抑制率达标.     

血栓弹力图评价老年患者抗血小板治疗的临床意义

目的应用血栓弹力图观察我院老年患者服用抗血小板药物后血小板抑制率的变化情况。方法选择我院门诊和住院的62例抗血小板治疗的老年患者,并将患者分成阿司匹林组、氯吡格雷组、阿司匹林+氯吡格雷组,16例未服用抗血小板药物的患者为对照组,应用血栓弹力图仪分别测得4组花生四烯酸(AA)和二磷酸腺苷(ADP)途径诱导的血小板抑制率值,并进行比较分析。结果阿司匹林组AA诱导的血小板抑制率为(78.93±11.73)%,氯吡格雷组ADP诱导的血小板抑制率为(53.4±21.5)%,阿司匹林+氯吡格雷组AA诱导和ADP诱导的血小板抑制率分别为(93.27±5.73)%和(55.8±24.6)%,血小板抑制率均显著高于对照组(P0.01)。结论血栓弹力图能客观反映老年患者服用抗血小板药物后血小板抑制率的变化。阿司匹林能起到较好的抗血小板作用,其抗血小板作用优于氯吡格雷,同时服用阿司匹林和氯吡格雷能起到更有效的抗血小板作用。     

Response to aspirin and clopidogrel in patients scheduled to undergo cardiovascular surgery

Background Recent data indicate that among patients undergoing percutaneous coronary intervention low platelet response to aspirin is associated with clopidogrel low response. It is unclear whether these findings extend to other patient populations. We, therefore, aimed to evaluate the relation between response to aspirin and clopidogrel among patients scheduled to undergo cardiac or vascular surgery. Methods Patients who were scheduled for cardiac or vascular surgery and had taken aspirin 81–325 mg daily for at least a week and clopidogrel 75 mg daily for at least 3 days underwent blood testing for platelet function. One hundred patients were included in the current analysis. Platelet function was evaluated by the modified TEG platelet mapping assay with addition of ADP or arachidonic acid (AA), and by the PFA-100 assay with collagen-epinephrine (CEPI) or collagen-ADP (CADP) cartridges. Low response to aspirin or clopidogrel was defined as inhibition ≤20% for TEG-AA or TEG-ADP, respectively. Results Thirteen patients (13%) were low responders to aspirin and 34 (34%) were low responders to clopidogrel. Eight patients were low responders to both drugs. There were no differences in clinical characteristics between drug low responders versus sensitive patients. Aspirin low responders had lower TEG-ADP inhibition (19.5 ± 6 vs. 35.8 ± 3%, P = 0.03) and tended to have lower PFA-CADP time (84.7 ± 7 vs. 105.6 ± 5 s, P = 0.1) than aspirin sensitive patients. Clopidogrel low responders had lower TEG-AA inhibition (58 ± 6 vs. 75.1 ± 4%, P = 0.01) and PFA-CEPI time (168 ± 13 vs. 200.4 ± 10 s, P = 0.07) than clopidogrel sensitive patients. Conclusions In patients scheduled to undergo cardiovascular surgery low response to aspirin is associated with low response to clopidogrel.     

Clopidogrel (Plavix) and cardiac surgical patients: implications for platelet function monitoring and postoperative bleeding

The use of clopidogrel (Plavix), an inhibitor of adenosine diphosphate (ADP)-induced platelet aggregation, has been proven to reduce ischemic events in cardiovascular patients, but little information is available for optimal monitoring of platelet function in patients receiving the drug preoperatively. In the first part of the study we compared different testing modalities (thrombelastography (TEG), platelet aggregometry, and whole blood aggregation) to assess platelet ADP receptor inhibition. Because clopidogrel is a pro-drug, we used an in vitro model of ADP inhibition with 5'-p-fluorosulfonylbenzoyladenosine (FSBA). FSBA at final concentration of 80 microM completely inhibited platelet aggregation but had no effect on TEG maximum amplitude (MA). In the second part of the study, antiplatelet effects of clopidogrel were clinically assessed and correlated to postoperative bleeding in 18 coronary bypass surgery patients. Preoperative TEG results were normal or hypercoagulable in clopidogrel-treated patients, although platelet aggregation responses to ADP were inhibited. Clopidogrel-treated patients who underwent cardiopulmonary bypass had a high incidence (84.6%) of platelet transfusion therapy due to increased chest tube drainage. In conclusion, we have demonstrated that normal preoperative TEG-MA does not preclude clopidogrel-induced ADP receptor blockade; however, TEG can be a reliable monitor for CPB-induced platelet dysfunction related to GPIIb/IIIa. For monitoring clopidogrel, it is necessary to perform more specific platelet function tests (aggregometry or platelet count ratio) using ADP as an activator.     

Increased risk in patients with high platelet aggregation receiving chronic clopidogrel therapy undergoing percutaneous coronary intervention: is the current antiplatelet therapy adequate?

OBJECTIVES: We sought to determine whether patients receiving chronic clopidogrel therapy undergoing nonemergent stenting who display high on-treatment preprocedural platelet aggregation measured by standard light transmittance aggregometry and thrombelastography (TEG) will be at increased risk for poststenting ischemic events. BACKGROUND: Patients exhibiting heightened platelet reactivity to adenosine diphosphate (ADP) might be at increased risk for recurrent ischemic events after coronary stenting. METHODS: A total of 100 consecutive patients receiving chronic antiplatelet therapy consisting of aspirin (325 mg qd) and clopidogrel (75 mg qd) were studied before undergoing nonemergent stenting. Patients were followed for 1 year after coronary stenting for the occurrence of death, myocardial infarction, stent thrombosis, stroke, or ischemia requiring a hospital stay. RESULTS: All patients were aspirin responsive. Patients with ischemic events (23 of 100, 23%) within 1 year had greater on-treatment prestent ADP-induced platelet aggregation than patients without ischemic events by aggregometry and TEG (p < 0.001 for both measurements). Of patients with an ischemic event, 70% and 87% displayed high on-treatment platelet reactivity at baseline by aggregometry and TEG, respectively. High on-treatment platelet reactivity as measured by aggregometry and TEG were the only variables significantly related to ischemic events (p < 0.001 for both assays). The administration of eptifibatide reduced periprocedural elevation in platelet reactivity, with no significant differences in bleeding events. CONCLUSIONS: Patients receiving chronic clopidogrel therapy undergoing nonemergent percutaneous coronary intervention who exhibit high on-treatment ADP-induced platelet aggregation are at increased risk for postprocedural ischemic events. These findings might have implications for the alteration in clopidogrel maintenance dose and use of glycoprotein IIb/IIIa inhibitors in selected patients.     

Comparison of platelet P2Y(12) ADP receptor-mediated pathway inhibition in triple versus dual antiplatelet therapy as assessed by VASP-phosphorylation in Japanese patients undergoing coronary stenting

Despite wide interindividual variability in response to clopidogrel, platelet P2Y(12) ADP receptor inhibition in Japanese patients has not been fully studied using specific methodology. This study compared platelet P2Y(12) ADP receptor inhibition during treatment with clopidogrel versus clopidogrel plus cilostazol in patients undergoing coronary stenting. Forty-two patients in whom platelet function was measured within 2 months after coronary stenting were enrolled. All patients were treated with aspirin 100 or 200 mg/day, and were divided into a dual therapy group (aspirin plus clopidogrel 75 mg/day; n = 34) and a triple therapy group (aspirin plus clopidogrel 75 mg/day plus cilostazol 200 mg/day; n = 8). Vasodilator-stimulated phosphoprotein (VASP) phosphorylation analysis and 5 and 20 μmol/L-induced maximal platelet aggregation were assessed. No differences were found in baseline characteristics except for a higher incidence of diabetes mellitus (DM) in the triple therapy group. Although there were no differences in platelet aggregation between the 2 groups, VASP index was significantly lower in the triple therapy group than in the dual therapy group (23.1 ± 15.3% versus 51.2 ± 19.9%; P = 0.001). The rate of low responsiveness to clopidogrel, defined by VASP index > 50%, was lower in the triple therapy group than in the dual therapy group (12.5% versus 55.9%; P = 0.047). Similarly, in DM patients the triple therapy group had a lower VASP index compared with the dual therapy group (23.1 ± 15.3% versus 47.0 ± 23.5%; P = 0.015).Clopidogrel plus cilostazol is more effective in inhibiting the platelet P2Y(12) ADP receptor pathway than clopidogrel alone. This may be useful for reducing clopidogrel resistance in Japanese patients.     

血栓弹力图法和光密度比浊法对双联抗血小板治疗患者的血小板聚集率检测的比较

目的分析血栓弹力图法（TEG法）和光密度比浊法（LTA法）对经双联抗血小板治疗的急性冠脉综合征（ACS）患者的血小板聚集率检测的相关性。方法募集2010年9月至2012年9月,在解放军总医院住院期间行氯吡格雷和阿司匹林双联抗血小板治疗的ACS患者共93名。在患者经口服双联抗血小板药物稳定剂量后取血,分别采用LTA法和TEG法,检测腺苷二磷酸（ADP）和花生四烯酸（AA）诱导的血小板聚集率,并对不同方法的检测指标进行相关回归分析。结果在93名ACS受试者中,应用LTA法和TEG法检测的ADP诱导的血小板聚集率分别为（59.3±21．34）％和（63．67±28．15）％,两者之间的相关系数为0．814（P〈0．0001）,回归方程为^Y（燃）=0．2＋0．617血栓弹力图法oLTA法和TGA法检测的AA诱导的血小板聚集率分别为（40．87±35．16）％和（46．02±39．26）％,两者的相关系数为0．965（P〈0．0001）,回归方程为“Y（＆{虫{击）=1．077Xm＆#女目＊＋O．02。结论在双联抗血小板治疗的ACS患者中,采用TEG法和u．A法检测的血小板功能具有较好的一致性。     

Measurement of platelet aggregation during antiplatelet therapy in ischemic stroke

Aspirin, ticlopidine and clopidogrel are used as a pharmacological means to efficiently decrease the number of reoccurrence of ischemic stroke (100-325 mg/d). This antiplatelet treatment could prevent the secondary stroke by approximately 22%. Laboratory effective platelet inhibition for the clinician, and methods for routine screening evaluation for the laboratory were studied. (1) For the standardisation of platelet aggregation technology blood samples of 150 healthy persons were studied in 5 centres. CARAT TX computerised optical aggregometer was used for measuring with collagen (2 microg/ml), epinephrine (10 microM), arachidonic acid 0.5 mM and ADP 5 microM as inductors. (2) Laboratory tests were compared in each centres performed in platelet-rich plasma of ischemic cardiovascular and stroke patients (n=823) taking 100-325 mg aspirin/d. (3) Blood samples of 555 ischemic stroke patients treated with aspirin (100-325 mg/d), 96 patients treated with ticlopidine (500 mg/d), and 67 patients treated with clopidogrel (75 mg/d) were evaluated, respectively.(1) The mean of maximal aggregation (%) - 2SD of untreated controls (n=150) were detected for collagen with 64%, epinephrine 59% and ADP 62%. (2) In 823 aspirin treated patients were found similar inhibition in different centres with same methods for standardisation. The mean inhibition level was in case of collagen 38%, epinephrine 37% and ADP 61%. (3) The distribution of ineffective platelet inhibition was detected in 17% of aspirin group (collagen and epinephrine), 4% of ticlopidine and 18% of clopidogrel group with ADP, respectively. Our findings were in the stroke cohort: effective inhibition levels: 36% in aspirin group, 73% in ticlopidine and 25% treated with clopidogrel. Platelet aggregation tests could help to find the optimal, and "custom taylored" dose of antiaggregating drugs in the secondary prevention of ischemic stroke.     

血栓弹力图评价抗血小板药物疗效对颅内外动脉支架术后再狭窄的影响

目的分析血栓弹力图仪（TEG）检测颅内外动脉支架置人术（PTAS）后患者服用阿司匹林和氯吡格雷后血小板聚集的抑制率，了解其疗效对PTAS术后支架内再狭窄（ISR）的影响。方法收集颅内外动脉TAS术后因缺血性中风复发或者术后6～12个月常规行脑动脉数字减影血管造影（DSA）随访且行TEG检测的49例患者（64处病变血管）的临床资料。根据DsA结果分为ISR组和对照组（无ISk），比较两组间的各种血管病危险因素、血清超敏C反应蛋白（hs-CRP）水平、花生四烯酸（AA）途径和腺苷二磷酸（ADP）受体途径诱导血小板抑制率间的差异，探讨影响ISR形成的因素。结果（1）卒中复发组与无复发组比较：复发组（男：女=1：5）与无复发组（男：女=39：4）组间性别组成的差异有统计学意义（P〈0．01）；复发组血清hs—CRP水平显著高于无复发组[（8．9±11．0）VS（2．9±4．1）mg／L，P〈0．05]；而其余各变量间差异均无统计学意义（P〉0．05）。（2）ISR兰且与对照组比较：ISR组患病年龄显著小于对照组[（58．0±12．8）VS（64．6±9．8）岁；P〈0．051；两组间糖尿病患者的比例差异具有统计学意义（P〈0．05）；ISR-C-R颅内外支架再狭窄比例（6／14VS8／14）与对照组（7／50VS43／50）间的差异有统计学意义（P〈0．05）；IS咄血清hs—CRP浓度显著高于对照组[（6．1±7．6）VS（2．1±2．1）mg／L，P=0．028]；ISR组AA和ADP平均抑制率分别为（58．0±43．8）％和（28．1±26．1）％，显著低于对照组的（83．4±23．1）％和（52．8±29．5）％（均P〈0．01）。（3）Logistic~归分析显示，在校正了其他因素的影响后，仅ADP抑制率（氯吡格雷疗效）与ISR的形成呈负相关（HR=0．959；95％C10．921～0．998；P：0．039）。结论氯吡格雷抗血小板聚集的疗效与ISR的形成呈负相关，即氯吡咯雷抵抗在ISR的形成中起非常重要的作用。     

Antiplatelet effects of clopidogrel compared with aspirin after myocardial infarction: enhanced inhibitory effects of combination therapy

OBJECTIVES: We sought to compare the inhibitory effects of the combination of two doses of aspirin plus clopidogrel with either drug alone on platelet aggregation and activation. BACKGROUND: Enhanced platelet inhibitory effects of clopidogrel by aspirin on platelet aggregation and activation are suggested by experimental studies but have not been shown in humans. METHODS: The effects of clopidogrel 75 mg or aspirin 100 (300) mg on platelet aggregation and activation by flow cytometry after stimulation with various agonists were determined in 30 patients with a past history of myocardial infarction. RESULTS: Clopidogrel alone or in combination with aspirin markedly inhibited adenosine diphosphate (ADP)-mediated platelet aggregation compared with monotherapy with aspirin (24.6 +/- 3.3% or 26.6 +/- 2.7% vs. 44.7 +/- 2.9%; p < 0.001). Combined treatment significantly inhibited collagen-induced aggregation compared with aspirin and clopidogrel (16.4 +/- 2.4%, 36.5 +/- 4.2% and 59.3 +/- 5.1%, respectively;, p < 0.001) and resulted in considerable inhibition of aggregation induced by thrombin receptor agonist peptide (TRAP, p < 0.03). Clopidogrel with or without aspirin significantly suppressed expression of platelet activation markers CD 62p, CD 63 and PAC-1 after stimulation with ADP or thrombin (p < 0.001). In addition, the combined treatment was more effective than either agent alone after activation with low dose thrombin (p < 0.05). Both doses of aspirin equally potentiated the platelet inhibitory effects of clopidogrel. CONCLUSIONS In this prospective clinical ex vivo platelet study, clopidogrel was more effective than aspirin in inhibiting ADP-mediated platelet aggregation and activation. Clopidogrel in combination with aspirin showed synergistic inhibitory effects after stimulation with collagen and thrombin compared with monotherapies. Thus, this dual antiplatelet treatment strategy deserves further evaluation in clinical trials for secondary prevention of acute myocardial infarction or unstable angina.     

How to test the effect of aspirin and clopidogrel in patients on dual antiplatelet therapy?

Dual antiplatelet therapy with clopidogrel and aspirin is frequently used for the prevention of recurrent ischemic events. Various laboratory methods are used to detect the effect of these drugs administered in monotherapy, however their value in dual therapy has not been explored. Here, we determined which methods used for testing the effect of clopidogrel or aspirin are influenced by the other antiplatelet agent. One arm of the study included 53 ischemic stroke patients being on clopidogrel monotherapy showing effective inhibition of the P2Y₁₂ ADP receptor. Laboratory tests routinely used for the detection of aspirin resistance (arachidonic acid (AA)-induced platelet aggregation/secretion, AA-induced thromboxane B₂ (TXB₂) production in platelet-rich plasma and VerifyNow Aspirin assay) were carried out on samples obtained from these patients. The other arm of the study involved 52 patients with coronary artery disease being on aspirin monotherapy. Methods used for testing the effect of clopidogrel (ADP-induced platelet aggregation and secretion, flow cytometric analysis of vasodilator-stimulated phosphoprotein (VASP) phosphorylation and a newly developed P2Y₁₂-specific platelet aggregation (ADP[PGE₁] test)) were performed on samples obtained from these patients. Clopidogrel monotherapy significantly inhibited AA-induced platelet aggregation and secretion, moreover, AA-induced TXB₂ production was also significantly decreased. VASP phosphorylation and AA-induced platelet aggregation showed fair correlation in patients taking clopidogrel only. Clopidogrel did not inhibit the VerifyNow Aspirin test significantly. Aspirin monotherapy influenced ADP-induced platelet aggregation and secretion, but did not have an effect on VASP phosphorylation and on the ADP[PGE₁] platelet aggregation test.