不同剂量氯吡格雷抑制血小板聚集功能时效探讨

目的 探讨氯吡格雷常用剂量下，血小板聚集率的变化规律及其临床意义。方法 40例经体检健康的志愿者，随机分为4组，每组10例，第一组一次服用75mg氯吡格雷；第二组服用氯吡格雷75mg／d，连服3天停药；第三组服用氯吡格雷75mg／d连服7天停药；第四组一次服用300mg氯吡格雷。各组分别在不同时间点进行采样，样本用二磷酸腺苷（ADP）进行血小板聚集实验。结果 第一组在停药后6天血小板聚集率恢复到服药前水平。第二组血小板聚集率在服药的3天、停药后的1天、2天与用药前差异有非常显著性（P〈0．01），第10天后恢复到服药前水平。第三组停药后4天内血小板聚集率受非常明显抑制（P〈0．01），6天内受明显抑制（P＜0．05）。第四组服药后2h即可观察到药物对血小板聚集率的非常明显的抑制作用（P〈0．01），停药4天后血小板聚集率恢复到服药前水平。结论 首服剂量越大，维持服药的时间越长，血小板聚集功能恢复所需时间越长。     

急性冠状动脉综合征冠状动脉支架术后应用他汀类药物对氯吡格雷抗血小板作用无影响

目的探讨急性冠状动脉综合征（ACS）患者行冠状动脉支架术后服用阿托伐他汀或普伐他汀对氯吡格雷抗血小板作用的影响。方法研究对象为150例2006年4至12月成功实施冠状动脉支架术的住院ACS患者,术后第1天起随机接受阿托伐他汀20mg／d（n=50）、普伐他汀20mg／d（／7,=50）或无他汀（n=50）治疗。围术期抗血小板治疗为阿司匹林300mg／d,当天氯吡格雷负荷量300mg,继以维持量75mg／d。观测各组患者术后第1天（基线值）及第3天的血小板膜糖蛋白P-选择素（CD62P）、血小板活化复合物（PAC-1）表达及20μmol／L二磷酸腺苷（ADP）诱导的血小板最大聚集率（MPAR）。结果三组患者临床及CD62P、PAC-1和MPAR的基线值差异均无统计学意义。各观测指标第二次测定值与基线值的差值显示,阿托伐他汀、普伐他汀和无他汀组的ACD62P[（4．69±16．78）％、（1．35±10．86）％和（2．97±10．21）％]、APAC-1[（12．78±22．07）％、（8．01±21．23）％和（10．65±21．39）％l及AMPAR[（5．44±18．68）％、（7．15±19．59）％和（3．76±23．42）％]差异均无统计学意义（P〉0．05）。急性心肌梗死患者亚组分析结果表明,ACD62P[（7．50±19．35）％、（3．24±11．18）％和（2．53±8．87）％]、APAC-1[（13．40±24．62）％、（11．28±19．90）％和（10．11±21．29）％]及AMPAR[（7．56±19．11）％、（7．87±23．60）％和（6．75±23．30）％]三组间差异亦均无统计学意义（P〉0．05）。结论接受冠状动脉支架术的ACS患者服用阿托伐他汀或普伐他汀后,短期内未发现对氯吡格雷的抗血小板作用产生显著影响。     

氯吡格雷低反应的危险因素及预后

目的：探讨冠心病患者氯吡格雷低反应的危险因素以及与支架植入术后心血管事件之间的关系。方法：冠心病患者400例,均口服氯吡格雷常规剂量75mg／d治疗3d以上或顿服氯吡格雷负荷量300mg 6h以上。以10μmol／L二磷酸腺苷（adenonisine disphosphate,ADP）为诱导剂,利用比浊法检测血小板聚集率,根据检测结果将患者分为氯吡格雷低反应和氯吡格雷正常反应两组,比较两组临床及生化指标的差异,运用Logistic回归分析进一步探讨氯吡格雷低反应的影响因素。并随访观察两组患者术后9个月的心血管事件,包括围术期心肌梗死、支架内血栓、急性心肌梗死、心因性死亡和卒中。结果：氯毗格雷低反应的发生率为19．8％。氯吡格雷低反应组和氯吡格雷正常反应组血小板聚集率分别为（49±9）％和（18±11）％（P〈0．01）。二元Logistic回归分析显示糖尿病（OR1．954,95％CI1．036—3．683,P〈0．05）、高脂血症（OR1．915,95％CI1．014—3．617,P〈0．05）及血浆纤维蛋白原（OR1．431,95％CI1．089—1．882,P〈0．05）是氯吡格雷低反应的危险因素。随访观察中氯吡格雷低反应组终点事件的发生率显著高于氯吡格雷正常反应组,差异具有统计学意义（20％眠12％,P〈0．05）。结论：糖尿病、高脂血症、血浆纤维蛋白原与既往PCI史是氯吡格雷低反应的影响因素。与氯吡格雷正常反应组相比,氯吡格雷低反应组终点事件的发生率显著增加。     

合并糖尿病的冠心病患者PCI治疗后氯吡格雷抵抗的影响因素

目的探讨合并糖尿病的冠状动脉粥样硬化性心脏病（冠心病）患者经皮冠状动脉介入（percutaneous coronary intervention,PCI）治疗后氯吡格雷抵抗的影响因素。方法159例行PCI治疗的冠心病患者,其中糖尿病患者56例,非糖尿病患者103例,术前予氯吡格雷300mg负荷剂量治疗,术后予75mg／d持续治疗。测其服药前、术后24h和术后5d以5μmol／L的二磷酸腺苷诱导的血小板最大聚集率。以血小板聚集抑制率≤10％定义为氯吡格雷抵抗。比较两组临床基线资料、相关常规检查、手术资料。Logistic回归分析糖尿病患者氯吡格雷抵抗的独立危险因素。结果糖尿病组发生氯吡格雷抵抗的比例为48．2％,显著高于非糖尿病组的20．4％,差异有统计学意义（P〈0．05）。糖尿病组三酰甘油浓度显著高于非糖尿病组,差异有统计学意义（P〈0．05）。两组其他基线资料比较,差异无统计学意义（P〉0．05）。Logistic回归分析结果显示糖尿病史（年）（β=0．243,OR=1．184,P=0．028）是糖尿病患者氯吡格雷抵抗的独立危险因素。结论合并糖尿病的冠心病患者存在更高的氯吡格雷抵抗比例。糖尿病史（年）是糖尿病患者PCI治疗后发生氯吡格雷抵抗的独立危险因素。     

不同剂量氯吡格雷对急性冠脉综合征并肾功不全患者血小板聚集率的影响

目的：比较不同剂量氯吡格雷对急性冠脉综合征（ACS）合并肾功能不全老年患者血小板聚集率的影响。方法：81例ACS并肾功能不全老年患者被随机分成两组,两组均予阿司匹林肠溶片300mg顿服后,甲组（41例）予氯吡格雷75mg／d维持,乙组（40例）予氯吡格雷50mg／d维持。入院后24h内和第28d分别测定血小板聚集率（PAR）,肝、肾功能并统计两组主要不良心血管事件和出血发生率。结果：（1）两组年龄,性别．血小板聚集率．肝、肾功能的基础状态无显著差异（P〉0．05）;（2）甲组第28d血小板聚集率[以0．5μmol／L、1μmol／L二磷酸腺苷为诱导刺,分别为（24±15）％、（40±16）％],与基础状态（53±10）％、（75±11）％比较明显下降（P〈0．05）;乙组第28d血小板聚集率（24±14）％、（41±15）％与基础状态（52±10）％、（74±12）％相比也显著下降（P〈0．05）;但两组血小板聚集率治疗后无显著差异（P〉0．05）。两组患者在28d内共发生心血管不良事件9例,甲组4例（9．8％）,乙组5例（12．5％）,两组无显著差异（P〉0．05）;（3）轻度出血,甲组5例（12．2％）,乙组1例（2．5％）,甲组明显增加（P〈0．05）;中重度出血甲组1例,乙组0例,两组无显著差异（P〉0．05）。结论：急性冠脉综合征合并肾功能不全老年患者,服用不同剂量氯吡格雷均安全有效,低剂量（50mg／d）可减少轻度出血并发症。     

经皮冠状动脉介入治疗后血小板聚集率高的患者强化抗血小板治疗的研究

目的研究经皮冠状动脉介入治疗（PCI）后血小板聚集率仍然高的患者强化抗血小板治疗与主要心脏事件的关系。方法选择2004年1月至2006年6月我院住院进行择期PCI的冠心病患者1556例,服药前、术后24小时、28天检测二磷酸腺苷（ADP）诱导的血小板聚集率。其中有402例患者[男178例,女224例,平均年龄（57．34±6．47）岁]术后血小板聚集率仍然高,其24小时的血小板聚集度与基线（服药前）的绝对值〈30％。把这部分患者随机分为两组,对照组（n=201）继续服用阿司匹林100mg、氯吡格雷75mg;治疗组（n=201）除继续服用阿司匹林100mg、氯吡格雷75mg,每天加西洛他唑200mg,分两次服用。连续应用6个月,观察两组患者6个月主要心脏不良事件（包括死亡、非致死性急性心肌梗死、急性或亚急性血栓、靶血管重建、脑卒中）以及出血等不良事件的发生率。结果28天血小板聚集的抑制〈30％患者对照组有89．6％（180／201）,治疗组有9．4％（19／201）,两组相比,差异有统计学意义（P〈0．05）。两组均无急性血栓发生;亚急性血栓对照组有3．0％（6／201）,治疗组有0．5％（1／201）,两组相比,差异无统计学意义（P〉0．05）;对照组有2例死亡,治疗组无死亡;两组均未发生脑卒中;非致死性急性心肌梗死对照组1．5％（3／201）,治疗组0．5％（1／201）;两组相比,差异无统计学意义（P〉0．05）;靶血管重建对照组有15．9％（32／201）,治疗组6．5％（13／201）,两组相比,差异有统计学意义（P〈0．01）;出血的发生率对照组4．0％（8／201）,治疗组6．0％（12／201）,两组相比,差异无统计学意义（P〉0．05）。主要心脏事件的累计危险率治疗组低于对照组,差异有统计学意义（P〈0．05）。结论PCI后应用抗血小板药物,血小板聚集率经治疗后仍然高（即血小板聚集抑制〈30％）的患者,强化抗血小板治疗可以减少主要心脏事件的累计危险率,而没有增加出血并发症。     

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。     

血栓弹力图评价急性冠脉综合征患者氯吡格雷抗血小板效果

目的：利用血栓弹力图评价老年急性冠脉综合征（ACS）非血运重建患者不同剂量氯吡格雷的抗血小板效果。方法：60例老年ACS未进行血运重建的患者被随机分为：甲组（30例,冠状动脉造影术后予氯吡格雷75mg／d维持）,乙组（30例,冠脉造影术后予氯吡格雷50mg／d维持）,两组冠脉造影术前均予氯吡格雷300mg口服。冠脉造影术前24h内及造影术后一周后分别测定两组患者肝肾功能及以血栓弹力图法测定血小板抑制率。并观察3个月内两组的主要心脏不良事件及不良反应。结果：与治疗前比较,治疗一周后两组患者ADP诱导的血小板抑制率[甲组：（25．8±11．4）％比（75．2±12．3）％,乙组：（24．2±13．3）％比（64．8±17．5）％]和花生四烯酸（AA）诱导的血小板抑制率[甲组：（16．7±21．6）％比（82．7±25．4）％,乙组：（23．8±22．2）％比（80．2±22．7）％,P〈0．053均明显升高,两组比较无显著差异（P〉0．05）。3个月内两组的心脏不良事件及不良反应无显著差异（P〉0．05）。结论：对非血运重建的急性冠脉综合征老年患者,低剂量氯吡格雷同样有效。     

经皮冠状动脉介入术患者的氯吡格雷抵抗和心血管事件

目的：观察因急性冠脉综合征（ACS）行冠状动脉介入治疗（PCI）出现氯吡格雷抵抗及心血管事件的发生情况。方法：因ACS入院患者42例，予氯吡格雷负荷量300mg，继予75mg／d维持，在服用氯吡格雷前，服药后2h、4h、6h、24h、48h和服药后30d取血，测定ADP诱导的血小板聚集率，根据其抑制程度判断是否为氯吡格雷抵抗，观察氯吡格雷抵抗者心血管事件的发生情况。结果：给药后2h、4h、6h、24h、48h和30d时，氯吡格雷抵抗的发生率分别为59．5％、52．4％、38．1％、38．1％、47．6％和41．5％，16例24h时存在氯吡格雷抵抗者有3例出现心血管事件，虽未达统计学差异，但发生率明显高于无抵抗组。结论：PCI治疗的部分患者中存在氯格雷抵抗，并可能与心血管事件发生有关。     

氯吡格雷抵抗与老年代谢综合征患者体质指数及胰岛素抵抗的临床研究

目的本研究探讨“氯吡格雷抵抗”现象与老年代谢综合征患者体质指数（BMI）与胰岛素抵抗的临床意义。方法选取90例诊断为代谢综合征的老年住院患者,根据BMI的不同分为肥胖组（BMI〉28）、超重组（BMI24—28）、标准组（BMI〈24）,每组30例,3组均给予氯吡格雷75mg／d治疗,以5μmol二磷酸腺苷（ADP）作为血小板聚集的激动剂,测定每组的HOMA指数及治疗前后血小板聚集率％的绝对差值（A聚集率）,以△聚集率〈10％作为氯吡格雷抵抗阳性标准。结果90例患者中,发现△聚集率〈10％者13例（14．4％）,肥胖组△聚集率较标准组降低。肥胖组氯吡格雷抵抗发生率为30％,超重组为10％、标准组为3．3％,三组间差异有统计学意义（P〈0．05）;且在肥胖组,HOMA-指数较标准组明硅增加（P〈0．05）,结论老年代谢综合征患者中存在氯毗格雷抵抗现象,且与体质指数与胰岛素抵抗相关。     

Effect of 150-mg vs 300-mg loading doses of clopidogrel on platelet function in Japanese patients undergoing coronary stent placement

BACKGROUND: The loading dose of ticlopidine is 500 mg in both the US and Europe and 200 mg in Japan. A lower loading dose of clopidogrel might achieve adequate platelet inhibition in Japanese patients. METHODS AND RESULTS: Platelet aggregation was serially measured at baseline, and 2, 4, 6, and 8 h after 150-mg (n=20) and 300-mg (n=20) clopidogrel loading. Platelets were stimulated with 5 and 20 micromol/L adenosine diphosphate (ADP) and aggregation was assessed by optical aggregometry. Pretreatment ADP-induced platelet aggregation in the 150-mg clopidogrel group did not differ from that of the 300-mg group. The administration of 300-mg clopidogrel loading dose resulted in lower platelet aggregation 2 h after the administration (5 micromol/L ADP: 53+/-9% vs 61+/-12%, p<0.05 and 20 micromol/L ADP: 61+/-10% vs 68+/-9%, p<0.05). A lower platelet aggregation induced with 20 micromol/L ADP was still observed 4 h after the 300-mg clopidogrel loading (58+/-10% vs 65+/-9%, p<0.05). CONCLUSIONS: The 150-mg clopidogrel loading does not achieve rapid platelet inhibition. The 300-mg loading dose should be used to suppress platelet function rapidly even in Japanese patients undergoing coronary stent placement.     

Impact of body mass index on platelet aggregation after administration of a high loading dose of 600 mg of clopidogrel before percutaneous coronary intervention

This study assessed the effect of body mass index (BMI) on platelet aggregation after administration of a high loading dose of clopidogrel 600 mg. Blood samples of 402 patients before percutaneous coronary intervention were collected >or=2 hours after administration of clopidogrel 600 mg. Platelet aggregation was measured in response to adenosine diphosphate (ADP; 5 and 20 microM). Patients were categorized as normal weight (BMI <25 kg/m(2)) or overweight (BMI >or=25 kg/m(2)). ADP-induced platelet aggregation was significantly higher in overweight patients than in normal-weight patients (46.0 +/- 21.8% vs 38.2 +/- 19.3% for ADP 5 microM, p = 0.0007; 55.1 +/- 22.7% vs 45.2 +/- 21.7% for ADP 20 microM, p <0.0001). Multivariate analyses demonstrated high BMI as the only independent predictor for increased ADP-induced platelet aggregation (p 相似文献   

Effectiveness of reloading to overcome clopidogrel nonresponsiveness in patients with acute myocardial infarction

Whether increasing doses of clopidogrel can overcome nonresponsiveness was evaluated. Clopidogrel nonresponsiveness was found in up to 25% of treated patients and was associated with worse prognosis in patients with acute coronary syndrome and patients undergoing coronary intervention. Adenosine diphosphate (ADP)-induced platelet aggregation was prospectively determined on day 4 of acute myocardial infarction in 200 consecutive patients, who received clopidogrel 300 mg as a loading dose and 75 mg/day thereafter. Thirty patients (15%) had ADP-induced platelet aggregation >or=80% using light transmittance aggregometry and were considered clopidogrel nonresponders. Nonresponders were reloaded with clopidogrel 600 mg, followed by 150 mg/day for 4 weeks. A 75-mg/day dose was resumed thereafter. ADP-induced platelet aggregation was reassessed 4 hours after reloading and biweekly for 10 weeks. Flow cytometry was used to determine platelet P-selectin expression and fibrinogen binding before and 4 hours after reloading. ADP-induced platelet aggregation significantly decreased 4 hours after reloading (from 83 +/- 6% to 56 +/- 14%; p <0.01). The decrease in platelet aggregation was maintained throughout the 4-week doubled maintenance dose. After resuming a maintenance dose of 75 mg/day, ADP-induced platelet aggregation returned to 66 +/- 12% (p <0.001), and 5 patients (17%) had ADP-induced platelet aggregation >or=80%. Flow cytometry showed a significant decrease in P-selectin expression (from 37 +/- 16% to 26 +/- 13%; p <0.01) and fibrinogen binding (from 84 +/- 7% to 70 +/- 13%; p <0.01) in ADP-stimulated platelets 4 hours after reloading. In conclusion, clopidogrel reloading and increased maintenance dose may overcome clopidogrel nonresponsiveness in patients with acute myocardial infarction.     

The relation of dosing to clopidogrel responsiveness and the incidence of high post-treatment platelet aggregation in patients undergoing coronary stenting

OBJECTIVES: We determined the effect of clopidogrel dosing on the incidence of nonresponsiveness (NR) and high post-treatment platelet aggregation (post-PA). BACKGROUND: We have reported NR after a 300-mg loading dose. Limited information is available on the comparative effect of a 600-mg loading dose on the incidence of NR and high post-PA. METHODS: Clopidogrel responsiveness and post-PA were measured in patients undergoing stenting (n = 190) randomly treated with either a 300-mg or a 600-mg clopidogrel load. Nonresponsiveness was defined as <10% absolute change in platelet aggregation, and high post-PA was defined as >75th percentile aggregation after 300 mg clopidogrel. RESULTS: Nonresponsiveness was lower after 600 mg compared to the 300-mg dose (8% vs. 28% and 8% vs. 32% with 5 and 20 microM ADP, respectively, p < 0.001). Among the patients with high post-PA after 300 mg clopidogrel, 62% to 65% had NR, whereas after the 600-mg dose, all of the patients with high post-PA had NR. CONCLUSIONS: A 600-mg clopidogrel loading dose reduces the incidence of NR and high post-PA as compared to a 300-mg dose. Higher dosing strategies and methods to confirm platelet inhibition should be further investigated in order to optimally use clopidogrel in patients undergoing stenting.     

P2Y12 gene H2 haplotype is not associated with increased adenosine diphosphate-induced platelet aggregation after initiation of clopidogrel therapy with a high loading dose.

A large variability in the antiplatelet response to clopidogrel has been consistently reported. Recently, a P2Y12 haplotype was shown to be associated with enhanced adenosine diphosphate (ADP)-induced platelet aggregation in healthy volunteers. The aim of this study was to test in patients (n = 416) scheduled for coronary artery stenting whether P2Y12 haplotype H2 carriage is associated with increased ADP-induced platelet aggregation after administration of a 600 mg loading dose of clopidogrel. Blood was drawn from the arterial sheath at least 2 h after administration of 100 mg aspirin and 600 mg clopidogrel. ADP-induced platelet aggregation was assessed in platelet-rich plasma with light-transmission aggregometry. P2Y12 haplotypes (H1/H2) and P2Y12 C32T genotypes were determined with TaqMan assays. Haplotype combinations and genotypes were not associated with parameters of ADP-induced platelet aggregation after administration of a 600 mg loading dose of clopidogrel. Maximal ADP (5 mumol/l)-induced platelet aggregation was similar in patients carrying haplotype H2 and homozygous carriers of haplotype H1 (43.9 +/- 21.4 versus 43.2 +/- 21.1%, respectively; P = 0.77). Carriage of P2Y12 H2 haplotype does not seem to affect the platelet response to a 600 mg loading dose of clopidogrel in coronary artery disease patients prior to stenting.     

Beneficial effect of a loading dose of 600 mg of clopidogrel on platelet parameters in patients admitted for acute coronary syndrome

INTRODUCTION: Despite the beneficial effect of an aspirin-clopidogrel combination in acute coronary syndrome, the incidence of ischaemic recurrences remains significant and very probably implicates a variability in the response to anti-platelet agents. OBJECTIVE: We sought to demonstrate the evidence for a beneficial effect, in terms of anti-platelet effect, of a higher loading dose of 600 mg of clopidogrel compared to the usual 300 mg in patients admitted to our centre with acute coronary syndrome. MATERIALS AND METHODS: Platelet reactivity was evaluated with the ADP 10_mol test and the degree of platelet activation by the expression of P-selectin. 178 consecutive patients admitted for acute coronary syndrome received 250 mg of intravenous aspirin together with either a loading dose of 300 mg of clopidogrel (n = 104) or 600 mg (n = 74) administered 12 to 24 hours prior to coronary angiography. RESULTS: The patients who received 600 mg of clopidogrel had an average aggregation intensity to ADP and a rate of platelet high reactivity post treatment that was significantly lower [48+20 vs 58+18, p = 0.0011 and 11 patients (15%) vs 26 patients (25%), p = 0.0003 respectively]. The degree of platelet activation evaluated with P-selectin was significantly lower in patients receiving 600mg [0.33 + 0.17 vs 0.50+0.29, p < 0.001]. CONCLUSION: Our study provides evidence for a beneficial effect of a loading dose of 600mg of clopidogrel compared to the usual 300 mg in terms of platelet reactivity and platelet activation post treatment.     

High clopidogrel loading dose during coronary stenting: effects on drug response and interindividual variability.

AIM: To assess platelet inhibitory effects, interindividual variability in platelet inhibition as well as response to a 600 mg, compared to a standard 300 mg, clopidogrel loading dose (LD) after coronary stenting METHODS AND RESULTS: Platelet function profiles were assessed in 50 patients undergoing coronary stenting receiving either a 300 mg (n=27) or 600 mg clopidogrel LD. ADP (6 microM) and collagen (6 microg/mL) induced platelet aggregation, as well as ADP (2 microM) induced glycoprotein (GP) IIb/IIIa activation and P-selectin expression were assessed at baseline and 4, 24, and 48 h following clopidogrel front-loading. A more intense and rapid inhibition of platelet activation (both GP IIb/IIIa activation and P-selectin expression) were achieved using a 600 mg, compared to a 300 mg, LD throughout the entire 48 hours (p<0.001). Although there were no differences in platelet aggregation, overall a 600 mg LD increased the number of clopidogrel responders and this was also achieved earlier compared to a 300 mg LD. A 600 mg LD did not reduce interindividual variability of platelet response. CONCLUSION: The use of a 600 mg clopidogrel LD in patients undergoing coronary stenting optimises platelet inhibitory effects early after intervention and may provide a more effective protection against early thrombotic complications.     

二磷酸腺苷介导血小板聚集率指导老年择期冠状动脉介入治疗患者术后抗血小板药物使用

目的 评价以二磷酸腺苷(ADP)介导血小板聚集率指导抗血小板药物在老年择期经皮冠状动脉介人治疗(PCI)患者中使用对心血管事件的影响.方法 选取我院2007-2008年老年择期西罗莫司涂层支架植入患者1230例,年龄60～80岁,平均(67.2±10.2)岁,随机选取615例入ADP组,首剂300 mg负荷量后,根据血小板聚集率调整氯吡格雷使用量,分别于用药前、用药第2天、第3天测定ADP介导的血小板聚集率,达标后(聚集率较用药前降低50%)75 mg/d.若未达标,第2、3天可逐次增加300 mg,累计至900 mg;若仍未达标,则改用氯吡格雷75 mg/d联合西洛他唑100 mg/d、阿司匹林100 mg/d三重抗血小板药物治疗持续1年.其余615例入常规组,以常规剂量和方法使用氯吡格雷(首剂300 mg负荷量后,继之以75 mg/d口服持续1年).分别于用药前、用药第3天测定ADP介导的血小板聚集率;两组患者均持续口服氯吡格雷1年.所有患者均在给药前、后进行安全性实验室检查.随访1年,记录心血管事件(心原性死亡、心肌梗死、血运重建、支架血栓事件)和药物不良事件发生率.结果 1230例患者首剂负荷量300 mg后.达标率44.9%ADP组累计总量至900 mg时,ADP组达标率增至67.5%,约32.5%的患者(203/615)仍未达标;改用氯吡格雷、西洛他唑、阿司匹林三重抗血小板药物治疗.相对于常规负荷剂量氯吡格雷,高负荷剂量氯吡格雷有更好的抑制血小板聚集的效果(常规负荷剂量对高负荷剂量,45%对67.5%,P=0.028).平均随访(10.0±2.4)个月,两组心血管事件发生率差异有统计学意义(2.8%对4.9%,P=0.035),常规组急性和亚急性支架血栓事件多于ADP组(4例对1例).所有患者均未出现大出血,两组间轻微出血病例差异无统计学意义,无药物不良反应.结论 PCI术后患者应该检测血小板对氯吡格雷的反应效果;ADP介导的血小板聚集率指导老年择期PCI患者围术期抗血小板药物使用安全、有效,可明显降低1年的心血管事件发生率.     

Comparison of antiplatelet effect of loading dose of clopidogrel versus abciximab during coronary intervention.

Randomized clinical trials have evidently shown that the addition of thienopyridines or abciximab to standard aspirin results in a significant reduction of ischaemic complications after coronary stent implantation. A head-to-head comparison of these antithrombotic drug regimens during coronary intervention is, however, lacking, and this was the main aim of the present study. Thirty-nine patients with angina pectoris who were scheduled for coronary stent implantation were assigned to either group 1 (160 mg aspirin + 500 mg ticlopidine post-stent), group 2 (160 mg aspirin + abciximab + 500 mg ticlopidine post-stent) or group 3 (160 mg aspirin + loading dose (375/450 mg) clopidogrel pre-stent and 75 mg clopidogrel post-stent). A loading dose of 450 mg clopidogrel was found to be more effective than the standard loading dose of 375 mg. Platelet aggregation induced by 4 micromol/l adenosine diphosphate (ADP) was assessed in samples collected before intervention and 10 min, 4 h and 20 h after intervention. Before intervention, a moderate antiplatelet effect because of aspirin intake was observed (ADP aggregation level, +/- 50%) in all study groups. After intervention, platelet aggregation tended to be enhanced in group 1 while it was strongly inhibited in the groups pre-treated with clopidogrel or abciximab: ADP induced an aggregation level early after intervention of 60 +/- 12% in group 1 (ticlopidine post-stenting) versus 30 +/- 10% in group 3 (loading dose clopidogrel) versus 3 +/- 6% in group 2 (abciximab). Abciximab achieved a more complete inhibition of aggregation than clopidogrel (P = 0.007). The overall complication rate was low with only one major bleeding and one death due to side-branch occlusion with re-infarction occurring, both in the abciximab group. Platelet aggregation during coronary intervention is strongly inhibited by both abciximab and by high loading dose of clopidogrel. Although abciximab showed a stronger antiplatelet effect than clopidogrel, it remains to be established whether this ex vivo superiority of abciximab also translates into an overall clinical benefit in patients with elective stent implantation.