冠状动脉植入药物支架术后高维持剂量氯吡格雷治疗的近期疗效

目的:对比观察植入药物洗脱支架(durg eluting stent,DES)患者术后服用高维持剂量氯吡格雷150 mg/d的有效性及安全性。方法:前瞻性入选我院2007年1月~12月120例成功行DES植入术的患者。所有患者于术前顿服600 mg负荷量氯吡格雷,术后在服用阿司匹林基础上随机接受每日75 mg(n=60)或150 mg(n=60)维持量的氯吡格雷治疗30 d,30 d后所有患者接受每日75 mg的氯吡格雷治疗直至术后1年。分别检测2组服药前、服药后15和30 d二磷酸腺苷(ADP)诱导的血小板最大凝集率,随访术后30 d和9月主要临床心血管事件(包括死亡、心肌梗死、紧急靶血管血运重建、脑卒中等)和出血事件的发生情况。结果:氯吡格雷150 mg组与75 mg组患者术前ADP诱导的血小板聚集率和最大聚集时间比较无显著性差异,而术后15和30 d比较差异有显著性(P0.05)。氯吡格雷150 mg组30 d和9月主要临床心血管事件发生率较75 mg组显著减少(P0.05,P0.01)。2组30 d和9月出血事件差异均无统计学意义。结论:植入DES患者术后服用高维持剂量氯吡格雷150 mg较之常规维持剂量75 mg预治疗能更大程度抑制血小板凝集,同时降低DES植入术的患者术后近期发生不良事件的风险,可显著改善临床预后。     

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.     

A randomized comparison of high clopidogrel loading doses in patients with non-ST-segment elevation acute coronary syndromes: the ALBION (Assessment of the Best Loading Dose of Clopidogrel to Blunt Platelet Activation, Inflammation and Ongoing Necrosis) trial.

OBJECTIVES: We sought to compare the antiplatelet effects of three clopidogrel loading doses (LDs). BACKGROUND: Administration of a 300-mg clopidogrel LD is beneficial in situations requiring rapid platelet inhibition. Whether higher LDs can provide further benefits remains unknown. METHODS: Patients (n = 103) with non-ST-segment elevation acute coronary syndromes were randomized to receive a 300-mg, 600-mg, or 900-mg clopidogrel LD, given on top of other standard therapy (including acetylsalicylic acid). The main outcome measure was inhibition of adenosine diphosphate-induced inhibition of platelet aggregation (IPA); inhibition of platelet activation, inflammatory markers, troponin I release, and major adverse cardiac events also were evaluated; all measures were blindly evaluated. RESULTS: Compared with the 300-mg LD, greater doses were associated with significantly greater platelet inhibition, with dose-effect relationships observed for onset of action, maximal plateau, 24-h areas under the curves of IPA, and rates of low IPA (<10% at 6 h), using 20 micromol/l major adverse cardiac events. A significant dose-response was also observed for the vasodilator-stimulated phosphoprotein index, a measure of P2Y(12) receptor inhibition. Similar but nonsignificant trends were observed for troponin release and major adverse cardiac events. Bleeding rates were similar in each group. CONCLUSIONS: In low-to-moderate risk patients with non-ST-elevation acute coronary syndromes, clopidogrel LDs >300 mg provide a faster onset of action, a higher IPA plateau, and greater reductions in platelet activation during the first 24 h. A 900-mg LD may induce a greater antiplatelet effect than 600 mg, when compared with the standard 300-mg regimen. These findings require further clinical confirmation.     

Inhibition of platelet aggregation by AZD6140, a reversible oral P2Y12 receptor antagonist, compared with clopidogrel in patients with acute coronary syndromes.

OBJECTIVES: In a substudy of DISPERSE (Dose confIrmation Study assessing anti-Platelet Effects of AZD6140 vs. clopidogRel in non-ST-segment Elevation myocardial infarction)-2, we compared the antiplatelet effects of AZD6140 and clopidogrel and assessed the effects of AZD6140 in clopidogrel-pretreated patients. BACKGROUND: Clopidogrel, in combination with aspirin, reduces cardiovascular events in patients with acute coronary syndromes (ACS). However, patients with poor inhibition of platelet aggregation with clopidogrel may be less well protected. AZD6140 is a reversible oral P2Y(12) receptor antagonist that has been studied in ACS patients in comparison with clopidogrel (DISPERSE-2 study). METHODS: Patients were randomized to receive either AZD6140 90 mg twice a day, AZD6140 180 mg twice a day, or clopidogrel 75 mg once a day for up to 12 weeks in a double-blind, double-dummy design. One-half the patients allocated AZD6140 received a 270-mg loading dose. Patients randomized to receive clopidogrel were given a 300-mg loading dose unless they had already been treated with clopidogrel. Adenosine diphosphate-induced platelet aggregation was assessed by optical aggregometry on day 1 and at 4-week intervals. RESULTS: AZD6140 inhibited platelet aggregation in a dose-dependent fashion and both doses achieved greater levels of inhibition than clopidogrel (e.g., 4 weeks, 4-h postdose [mean (+/-SD)]: clopidogrel 64% [+/-22%], AZD6140 90 mg 79% [+/-22%], AZD6140 180 mg 95% [+/-8%]. AZD6140 also produced further suppression of platelet aggregation in patients previously treated with clopidogrel. CONCLUSIONS: AZD6140 exhibited greater mean inhibition of platelet aggregation than a standard regimen of clopidogrel in ACS patients. In addition, AZD6140 further suppressed platelet aggregation in clopidogrel pretreated patients.     

不同维持量氯吡格雷对ACS患者血小板聚集功能影响的观察

目的评估不同维持剂量氯吡格雷对择期PCI的ACS患者血小板聚集率的影响,探讨高维持剂量氯吡格雷对ACS患者的有效性及安全性。方法选择接受药物治疗、择期PCI的急性冠脉综合征患者150例,随机分为2组(各75例),2组均服用300mg负荷量氯吡格雷,然后分别给予氯吡格雷150mg/d、75mg/d治疗14d,14d后所有患者接受75mg/d氯吡格雷治疗直至PCI术后1年。分别于服药前、服药后第14天采2组患者静脉血,采用光学比浊法测定血小板聚集率(PA),同时计算血小板聚集抑制率(PAI)。观察住院14天内2组终点事件发生情况。结果试验组和对照组服药前血小板聚集率的差别无统计学意义(89.63±4.89vs.90.27±4.84,p>0.05);试验组服药第14天的血小板聚集率较对照组明显下降(41.36±5.13vs.51.69±3.98,p<0.05),血小板聚集抑制率较对照组明显增强(48.27±6.29vs.38.58±5.48,p<0.05),均有统计学差异。住院14天内,两组均无心血管死亡、严重的颅内出血和严重血小板减少,亚急性血栓形成发生率(1.3%vs4.0%,P>0.05)相近,轻微出血发生率(2.7%vs4.0%,P>0.05)无统计学差异。结论对高危急性冠脉综合症患者,150mg/日高氯吡格雷维持量可以明显降低血小板聚集率,从而降低血栓事件,且不增加短期出血风险,具有较好的耐受性和安全性。     

A double-blind, randomized study on platelet aggregation in patients treated with a daily dose of 150 or 75 mg of clopidogrel for 30 days.

AIMS: We sought to test whether an increase in the clopidogrel maintenance dose results in increased inhibition of platelet aggregation. METHODS AND RESULTS: Sixty patients after pre-treatment with 600 mg of clopidogrel and within 12 h after successful PCI were included in this trial. They were allocated to receive one of two clopidogrel daily maintenance doses (75 or 150 mg) for 30 days in a double-blind randomized manner. Platelet function was evaluated 30 days after the intervention with optical aggregometry and with a new point-of-care test (VerifyNowtrade mark P2Y12 assay). Maximal 5 microM ADP-induced platelet aggregation 30 days after PCI in the group treated with 150 mg/day clopidogrel (45.1 +/- 20.9%) was significantly lower than in the group treated with 75 mg/day (65.3 +/- 12.1%; P < 0.001). The VerifyNowtrade mark P2Y12 assay also indicated a higher degree of platelet function inhibition in the group treated with 150 mg/day (60.0 +/- 72.0 P2Y12 Reaction Units) than in the group treated with 75 mg/day (117.0 +/- 64.3 P2Y12 Reaction Units; P = 0.004). CONCLUSION: Administration of a 150 mg oral maintenance dose of clopidogrel results in more intense inhibition of platelet aggregation than administration of the currently recommended 75 mg maintenance dose.     

阿托伐他汀或瑞舒伐他汀与氯吡格雷合用在非ST段抬高型急性冠状动脉综合征患者支架置入术后的近期疗效比较

目的比较阿托伐他汀或瑞舒伐他汀与氯吡格雷合用在非ST段抬高型急性冠状动脉综合征(NSTE-ACS)支架置入术后患者的近期疗效。方法共154例NSTE-ACS的患者接受支架置入术后,随机分为服用阿托伐他汀组(74例)及服用瑞舒伐他汀组(80例),术前服用阿司匹林(100mg)5 d、氯吡格雷(75 mg)5 d以上或术前12 h以上顿服氯吡格雷300 mg及阿司匹林片300 mg,于术前服抗血小板药前、手术当天、术后3、7 d及术后1、6个月抽取静脉血测定二磷酸腺苷(ADP)(浓度为10μmol/L)诱导的血小板聚集功能,观察住院期间及6个月的主要不良心脏事件(MACE)。结果两组患者的临床基线资料及服药情况差异无统计学意义,服用氯吡格雷(75 mg)5 d或顿服300 mg能达到明显的血小板聚集率抑制作用,血小板聚集率在阿托伐他汀组由基线的(57.2±10.3)%降至手术当日的(32.5±11.2)%,而瑞舒伐他汀组分别为(59.1±9.8)%和(30.4±10.1)%(均为P<0.01),而且这种抑制作用稳定持续至6个月之后。6个月时两组间总的MACE发生率差异无统计学意义(13.0%比15.0%,P>0.05),两组心原性死亡、非致死性心肌梗死、靶血管重建术、支架内血栓形成及出血事件差异均无统计学意义(均为P>0.05)。结论接受冠脉支架置入术的NSTE-ACS患者,服用阿托伐他汀或瑞舒伐他汀后,短期内未发现对氯吡格雷抗血小板作用产生显著影响,且两组间的近期疗效相近。     

Aspirin and clopidogrel drug response in patients undergoing percutaneous coronary intervention: the role of dual drug resistance.

We evaluated the response to clopidogrel among aspirin-resistant versus aspirin-sensitive patients undergoing elective coronary stenting. Patients (n = 150) treated with aspirin but not clopidogrel had blood samples drawn at baseline and 24 h after clopidogrel loading. Depending on the definition used, 9% to 15% were resistant to aspirin and 24% to clopidogrel. About half of the aspirin-resistant patients were also resistant to clopidogrel. As a group, aspirin-resistant patients had lower response to clopidogrel (assessed by platelet aggregation and activation markers) than aspirin-sensitive patients. Both aspirin- and clopidogrel-resistant patients had higher incidence of creatine kinase-MB elevation than the respective sensitive patients. OBJECTIVES: We sought to evaluate the response to clopidogrel among aspirin-resistant versus aspirin-sensitive patients undergoing percutaneous coronary intervention (PCI). BACKGROUND: Wide variability has been reported in response to aspirin and clopidogrel. There are limited data on the simultaneous responses to both drugs. METHODS: Elective PCI patients (n = 150) who received aspirin for > or = 1 week but not clopidogrel were included. All patients received bivalirudin during PCI. Blood samples were drawn at baseline and 20 to 24 h after a 300-mg clopidogrel dose. Aspirin resistance was defined by > or = 2 of 3 criteria: rapid platelet function analyzer-ASA score > or = 550, 5 micromol/l adenosine diphosphate (ADP)-induced aggregation > or = 70%, and 0.5 mg/ml arachidonic acid-induced aggregation > or = 20%. Clopidogrel resistance was defined as baseline minus post-treatment aggregation < or = 10% in response to 5 and 20 micromol/l ADP. RESULTS: Nineteen (12.7%) patients were resistant to aspirin and 36 (24%) to clopidogrel. Nine (47.4%) of the aspirin-resistant patients were also clopidogrel resistant. Aspirin-resistant patients were more likely to be women and have diabetes than were aspirin-sensitive patients. They also had lower response to clopidogrel, assessed by platelet aggregation and activation markers (flow cytometry-determined PAC-1 binding and P-selectin expression). Elevation of creatine kinase-myocardial band after stenting occurred more frequently in aspirin-resistant versus aspirin-sensitive patients (38.9% vs. 18.3%; p = 0.04) and in clopidogrel-resistant versus clopidogrel-sensitive patients (32.4% vs. 17.3%; p = 0.06). CONCLUSIONS: Aspirin-resistant patients as a group have reduced response to clopidogrel. Furthermore, we have identified a unique group of dual drug-resistant patients who may be at increased risk for thrombotic complications after PCI.     

不同维持剂量氯吡格雷对择期经皮冠脉介入治疗患者术后血小板聚集率的影响

目的 探讨不同维持剂量氯吡格雷对择期经皮冠脉介入治疗(PCI)患者血小板聚集率的影响及其临床意义.方法 随机双盲将118例择期PCI患者分为A、B两组,术前600 mg负荷剂量相同,术后第1天开始分别给予不同剂量氯吡格雷(波立维、法国赛诺菲-安万特公司生产)75 mg/d或150 mg/d,于术前及术后1天、7天、14天和30天评估血小板聚集率.结果 A、B两组患者术前和术后1天ADP诱导的血小板聚集率和最大聚集时间比较无显著性差异,而术后7天、14天、30天比较差异有显著性.结论 较高剂量的氯吡格雷可以降低择期PCI患者的血小板聚集功能.     

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.     

血栓弹力图检测老年冠心病患者经皮冠状动脉介入治疗后血小板反应性

目的探讨经皮冠状动脉介入治疗术后,经血栓弹力图检测的氯吡格雷药物抵抗患者,不同药物剂量治疗下血小板反应性。方法筛选120例阿司匹林抑制良好而氯吡格雷抑制不敏感的患者,随机分为试验组(60例)和对照组(60例),对照组每天服用100 mg阿司匹林及75 mg氯吡格雷,试验组服用100 mg阿司匹林及150 mg氯吡格雷,检测6个月后氯吡格雷的作用效果,观察2组间6个月内心血管事件及出血事件的发生率。结果试验组心血管死亡、支架内血栓形成、不稳定性心绞痛、心肌梗死发生率分别为0,8.3%,21.7%,8.3%;对照组分别为3.3%,18.3%,35.0%,15.0%,试验组患者氯吡格雷药物抑制率较对照组明显升高(65.6±5.1)% vs (40.9±7.3)%,差异有统计学意义(P0.01)。结论对于血小板高反应性老年患者,每天75 mg氯吡格雷不能满足血小板抑制效果,长期加倍剂量服用能够在一定程度上有效减低药物抵抗发生率,改善血小板抑制效果,从而降低心血管缺血事件的发生率。     

Achieved platelet aggregation inhibition after different antiplatelet regimens during percutaneous coronary intervention for ST-segment elevation myocardial infarction

OBJECTIVES: To evaluate the extent of platelet aggregation inhibition in patients with ST-segment elevation myocardial infarction (STEMI) undergoing percutaneous coronary intervention (PCI), treated with different antiplatelet agents and dosages. BACKGROUND: The extent of platelet aggregation inhibition is an independent predictor of major cardiac events after elective PCI. In STEMI patients undergoing PCI, routine dose of antiplatelet agents may be associated with less effective platelet aggregation inhibition. METHODS: Patients were treated with clopidogrel before angiography and randomized to abciximab, tirofiban, high-dose tirofiban, or no glycoprotein (GP) IIb/IIIa inhibitor; GP IIb/IIIa inhibitor bolus, followed by maintenance infusion, was administered after angiography, but before PCI. Platelet aggregation inhibition was assessed before angiography, immediately after PCI, and 1 and 6 h afterwards. RESULTS: The total study population consisted of 112 patients. Platelet aggregation inhibition was variable for individuals and suboptimal for all agents, particularly in the periprocedural period. Only with high-dose tirofiban, mean periprocedural platelet aggregation inhibition exceeded 80%. Angiographic parameters after PCI were not different between the groups. No relationship was found between the level of platelet aggregation and parameters of PCI success (Thrombolysis In Myocardial Infarction frame count and myocardial blush grade), after combining the data from all four groups studied. CONCLUSIONS: Platelet aggregation inhibition in STEMI patients undergoing PCI, treated with antiplatelet agents, is variable and suboptimal for all agents and dosages studied. Only with high-dose tirofiban, mean periprocedural platelet aggregation inhibition exceeded 80%. However, no relationship of platelet aggregation inhibition and angiographic outcome was found in this patient cohort.     

Ticagrelor versus prasugrel in patients with high on-clopidogrel treatment platelet reactivity after PCI: The ISAR-ADAPT-PF study

Patients with high on-treatment platelet reactivity (HTPR) on clopidogrel are at high risk for adverse cardiovascular events after percutaneous coronary intervention (PCI). The aim of the ISAR-ADAPT-PF study was to assess the antiplatelet efficacy of ticagrelor versus prasugrel in patients with HTPR on clopidogrel. In a prospective and randomized clinical study, 70 patients with HTPR on clopidogrel loading dose (LD) within 24 h post PCI were assigned to receive either ticagrelor [180 mg LD followed by 90 mg maintenance dose (MD) twice daily] or prasugrel (60 mg LD followed by 10 mg MD once daily). The adenosine diphosphate-induced platelet aggregation assessed on the Multiplate analyzer on day 2 after randomization (primary end point) was as follows: the mean difference between the two treatment groups was 6 aggregation units (AU) × min with an upper 95% confidence interval (CI) of 41 AU × min, which was greater than the predefined noninferiority margin of 18 AU × min (P for noninferiority = 0.29). However, no significant differences in absolute platelet reactivity levels between ticagrelor- versus prasugrel-treated patients at that time point were observed (138 ± 100 AU × min vs. 132 ± 64 AU × min, P for superiority = 0.77). In conclusion, neither drug was statistically more effective for inhibition of platelet aggregation in patients with HTPR on clopidogrel post PCI, although the study could not formally demonstrate the assumed noninferiority of ticagrelor versus prasugrel.     

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.     

Effects of triple antiplatelet therapy (aspirin, clopidogrel, and cilostazol) on platelet aggregation and P-selectin expression in patients undergoing coronary artery stent implantation

The purpose of this study was to determine the effect of the addition of cilostazol to aspirin plus clopidogrel on platelet aggregation after intracoronary stent implantation. Twenty patients who underwent coronary stent placement were randomly assigned to therapy with aspirin plus clopidogrel (dual-therapy group, n = 10) or aspirin plus clopidogrel plus cilostazol (triple-therapy group, n = 10). A loading dose of clopidogrel (300 mg) and cilostazol (200 mg) was administered immediately after stent placement, and clopidogrel (75 mg/day) and cilostazol (100 mg twice daily) were given for 1 month. Platelet aggregation in response to adenosine diphosphate (ADP; 5 and 20 micromol/L) or collagen and P-selectin (CD-62P) expression was assayed at baseline, 2 hours, 24 hours, 1 week, and 1 month after stent placement. Inhibition of ADP-induced platelet aggregation was significantly higher in patients receiving triple therapy than those receiving dual therapy from 24 hours after stent placement, and inhibition of collagen-induced platelet aggregation was significantly higher in the triple-therapy group beginning 1 week after stent placement. P-Selectin expression was significantly lower in the triple-therapy than dual-therapy group at 1 week and 30 days. In conclusion, compared with dual antiplatelet therapy, triple therapy after coronary stent placement resulted in more potent inhibition of platelet aggregation induced by ADP and collagen. These findings suggest that triple therapy may be used clinically to prevent thrombotic complications after coronary stent placement.     

Comparison of higher clopidogrel loading and maintenance dose to standard dose on platelet function and outcomes after percutaneous coronary intervention using drug-eluting stents

Adequate antiplatelet therapy is paramount for good clinical outcomes in patients undergoing percutaneous coronary intervention (PCI). The purpose of this study was to determine whether a high-dose regimen of clopidogrel in patients undergoing PCI is superior to standard dosing. A total of 119 patients undergoing PCI were blindly randomized in 2:1 fashion to receive clopidogrel loading 600 mg on the table immediately before PCI and 75 mg 2 times/day for 1 month (high-dose group) versus standard dosing (300 mg loading and 75 mg/day; low-dose group). Platelet aggregation was measured using light transmission aggregometry at baseline, 4 hours, and 30 days. The composite of cardiovascular death, myocardial infarction, and target vessel revascularization was studied at 30 days in addition to major and minor bleeding. Baseline characteristics and baseline platelet aggregation were similar in the 2 groups. Percent inhibitions of platelet activity were 41% and 27% in the high-dose group versus 19% and 10% in the low-dose group at 4 hours and 30 days (p = 0.046 and 0.047, respectively). Composite clinical end points were 10.3% in the high-dose group and 23.8% in the low-dose group (p = 0.04). No difference was noted in major or minor bleeding. In conclusion, a higher loading and maintenance dose of clopidogrel in patients undergoing PCI results in superior platelet inhibition and decreased cardiovascular events without increasing bleeding complications.     

经皮冠状动脉介入术后氯吡格雷抵抗的临床观察

目的观察因急性冠脉综合征（ACS）行冠状动脉介入治疗（PCI）患者应用氯吡格雷后血小板聚集率的变化及氯吡格雷抵抗的发生情况。方法ACS患者37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2、4、6、24、48h以及服药后30d取血,测定ADP诱导的血小板聚集率,观察血小板聚集率变化并根据抑制程度判断氯吡格雷抵抗发生率。结果给药后2、4、6、24、48h及30d时,氯吡格雷抵抗的发生率分别为62%、46%、32%、38%、49%和43%,氯吡格雷抵抗者用药后血小板抑制率明显低于反应者,其中1例抵抗者出现亚急性支架内血栓形成。结论PCI治疗的部分患者中存在氯吡格雷抵抗。     

Effect of 450-mg loading dose of clopidogrel on platelet function in Japanese patients undergoing coronary stent placement

Usefulness of higher (>300 mg) loading doses of clopidogrel has been demonstrated in studies from the United States and Europe. The present study evaluated platelet aggregation after the administration of a 450-mg loading dose of clopidogrel in Japanese patients undergoing coronary stenting. Platelet aggregation was serially measured at baseline, and 2, 4, 6, and 8 h after 450-mg clopidogrel loading in 25 patients undergoing coronary stenting. Platelets were stimulated with 5 and 20 μmol/l adenosine diphosphate (ADP) and aggregation was assessed by optical aggregometry. Platelet aggregation (5 μmol/l ADP 42.8% ± 13.5% and 20 μmol/l ADP 51.2% ± 11.6%) was significantly suppressed ≤4 h after 450-mg clopidogrel loading. There were no adverse events except one minor nasal bleed. The present study shows that platelet inhibition is achieved ≤4 h after the administration of a 450-mg clopidogrel loading dose in Japanese patients.     

Clopidogrel resistance response in patients with coronary artery disease and metabolic syndrome: the role of hyperglycemia and obesity

Background Despite the proven benefits of clopidogrel combined aspirin therapy for coronary artery disease (CAD), CAD patients with metabolic syndrome (MS) still tend to have coronary thrombotic events. We aimed to investigate the influence of metabolic risk factors on the efficacy of clopidogrel treatment in patients with CAD undergoing percutaneous coronary intervention (PCI). Methods Cohorts of 168 MS and 168 non-MS subjects with CAD identified by coronary angiography (CAG) were enrolled in our study. MS was defined by modified Adult Treatment Panel III criteria. All subjects had taken 100 mg aspirin and 75 mg clopidogrel daily for more than 1 month, and administered loading doses of 600 mg clopidogrel and 300 mg aspirin before PCI. Blood samples were taken 24 h after the loading doses of clopidogrel and aspirin. Platelet aggregation was measured using light transmittance aggregometry (LTA) and thrombelastography (TEG). Clopidogrel resistance was defined as more than 50% adenosine diphosphate (ADP) induced platelet aggregation as measured by TEG. Results Platelet aggregation inhibition rate by ADP was significantly lower in patients with MS as measured both by TEG (55% ± 31% vs. 68% ± 32%; P < 0.001) and LTA (29% ± 23% vs. 42% ± 29%; P < 0.001). In the multivariate analysis, elderly [OR (95% CI): 1.483 (1.047–6.248); P = 0.002], obesity [OR (95% CI): 3.608 (1.241–10.488); P = 0.018], high fasting plasma glucose level [OR (95% CI): 2.717 (1.176–6.277); P = 0.019] and hyperuricemia [OR (95% CI): 2.583 (1.095–6.094); P = 0.030] were all statistically risk factors for clopidogrel resistance. CAD patients with diabetes and obesity were more likely to have clopidogrel resistance than the CAD patients without diabetes and obesity [75% (61/81) vs. 43% (67/156); P < 0.001]. Conclusions CAD patients with MS appeared to have poorer antiplatelet response to clopidogrel compared to those without MS. Obesity, diabetes and hyperuricemia were all significantly associated with clopidogrel resistance.     

国产氯吡格雷个体化用药在经皮冠状动脉介入术患者中使用的评价

目的通过观察经皮冠状动脉介入治疗（PCI）患者常规使用氯吡格雷后的血小板聚集率情况,并根据血小板聚集率以及是否存在PCI术后支架内血栓形成的高危因素来个体化调整氯吡格雷的使用剂量,以评价氯吡格雷的个体化用药在PCI术患者中使用的疗效及安全性。方法将在我院行PCI术的冠心病患者182例随机分为个体化用药组（88例）和常规用药组（94例）,两组术前3天起常规服用阿司匹林100 mg/d＋氯吡格雷75 mg/d或术前顿服阿司匹林300 mg＋氯吡格雷300 mg,术后两组均予氯吡格雷75 mg/d。常规用药组使用氯吡格雷75 mg/d维持至术后一年。而个体化用药组则可根据患者的血小板聚集率以及是否存在PCI术后支架内血栓形成的高危因素来调整氯吡格雷的用量。结果个体化用药组的出血并发症明显少于常规用药组（2/88比12/94,P〈0.01）。两组间主要心血管不良事件（MACE）的发生率差异无统计学意义（P〉0.05）,支架内再狭窄发生率差异无统计学意义（2/33比3/38,P〉0.05）。结论国产氯吡格雷在PCI患者中使用是有效并且安全的,而个体化调整氯吡格雷剂量能更进一步减少并发症,增加安全性。