High post-treatment platelet reactivity identified low-responders to dual antiplatelet therapy at increased risk of recurrent cardiovascular events after stenting for acute coronary syndrome

Summary.  Background and objectives: Low response to antiplatelet therapy may be a risk factor for the development of ischemic complications in patients with non-ST segment elevation acute coronary syndrome (NSTE ACS) undergoing coronary stenting. Methods: We prospectively studied the platelet response to both clopidogrel and aspirin in 106 NSTE ACS consecutive patients undergoing percutaneous coronary intervention (PCI) with stenting. A single post-treatment blood sample was obtained just before PCI and analyzed by platelet aggregometry using both ADP and arachidonic acid (AA) as agonists to explore the responses to clopidogrel and aspirin, respectively. Patients were divided into quartiles according to the ADP or AA induced maximal intensity of platelet aggregation. Patients of the highest quartile (quartile 4) were defined as the 'low-responders'. Results: Twelve recurrent cardiovascular (CV) events occurred during the 1-month follow-up. Clinical outcome was significantly associated with platelet response to clopidogrel [Quartile 4 vs. 1, 2, 3: OR (95% CI) 22.4 (4.6–109)]. Low platelet response to aspirin was significantly correlated with clopidogrel low response ( P  = 0.003) but contributed less to CV events [OR (95%CI): 5.76 (1.54–35.61)]. Conclusions: A post-treatment ADP-induced platelet aggregation performed just before PCI identifies low responders to dual antiplatelet therapy with an increased risk of recurrent CV events.     

Prasugrel in acute coronary syndrome patients undergoing percutaneous coronary intervention

Currently, dual antiplatelet therapy with aspirin and clopidogrel represents the key treatment strategy for the prevention of ischemic events in patients with acute coronary syndrome (ACS) and/or undergoing percutaneous coronary intervention (PCI). However, there is a broad inter-individual response variability to such treatment strategy, and a considerable number of patients persist with inadequate platelet inhibition, which has been associated with an increased risk of ischemic events. Overall, these findings underscore the need for novel antiplatelet agents able to achieve greater platelet inhibition; this can potentially reduce ischemic event rates. Prasugrel (CS-747; LY 640315), a novel third-generation oral thienopyridine, is a specific, irreversible antagonist of the platelet adenosine diphosphate P2Y₁₂ receptor. Laboratory studies have shown prasugrel to be associated with more prompt, potent and predictable degrees of platelet inhibition compared with clopidogrel. In a large-scale clinical study, which was comprised of high-risk ACS patients undergoing PCI, prasugrel was shown to significantly reduce the short- and long-term risk of ischemic events, including stent thrombosis. However, such significant reduction in ischemic events occurred at the expense of a higher risk of bleeding. Recent clinical trial data analyses have led to a better understanding of the efficacy and safety of prasugrel. This article reviews the currently available data regarding the efficacy and safety of prasugrel in ACS patients.     

The future of platelet function testing to guide therapy in clopidogrel low and enhanced responders

Dual oral antiplatelet therapy with aspirin and clopidogrel is the therapy of choice in patients with acute coronary syndromes and in patients undergoing coronary stent placement to lower the risk of thrombotic events. Responsiveness to aspirin and especially to clopidogrel is not uniform and is subject to considerable interindividual variability. Furthermore, there is a broad consensus that clopidogrel low response or so-called high on-treatment platelet reactivity is linked to the occurrence of ischemic events. On the other hand, evidence is accumulating that enhanced clopidogrel responders are at increased risk of bleeding. Newer antiplatelet drugs, such as prasugrel and ticagrelor, are more potent and produce more consistent inhibition of platelet aggregation via the P2Y(12) ADP platelet receptor. A variety of methods of platelet function testing are available for evaluating platelet inhibition in percutaneous coronary intervention-treated patients in order to help determine the individual risk for ischemic and bleeding complications. Although not yet routinely undertaken, platelet function testing offers the potential to tailor antiplatelet therapy for individual patients. Whether alteration of therapy based on platelet function testing improves patients' outcomes remains unclear and is currently under investigation. This article reviews the impact of antiplatelet drug responsiveness on clinical outcomes with a focus on P2Y(12) receptor inhibition as well as on current and future concepts for personalized antiplatelet strategies.     

Prasugrel hydrochloride for the treatment of acute coronary syndrome patients

Introduction: Dual antiplatelet therapy (DAPT) with aspirin combined with either a thienopyridine (clopidogrel or prasugrel) or acyclopentyl-triazolo-pyrimidine (ticagrelor) plays a vital role in the management of acute coronary syndrome (ACS) especially in those undergoing percutaneous coronary intervention (PCI) but even those being managed medically. Observational studies and some formal studies have shown patients on the standard dual antiplatelet regimen (clopidogrel and aspirin) continue to have further ischemic events and can suffer stent thrombosis. It has been demonstrated that clopidogrel is associated with a delayed onset of action with a considerable inter-individual variation to treatment thus making it difficult to achieve an optimal level of platelet inhibition.

Areas covered: This article will review the current evidence that is available regarding the effectiveness and safety of prasugrel in ACS patients undergoing percutaneous coronary intervention (PCI).

Expert commentary: Prasugrel is an oral third-generation inhibitor of platelet activation and aggregation. Laboratory studies and early phase clinical trials show prasugrel has a faster onset of action, is more potent and has reduced inter-patient response variability compared to clopidogrel. The published studies so far demonstrated that prasugrel when compared to clopidogrel also shows a higher degree of effectiveness in the prevention of platelet-initiated thrombotic events in patients with ACS undergoing PCI, however these benefits are offset somewhat by an increased bleeding risk.     

Prasugrel

The antithrombotic therapy in patients with atherosclerotic vascular disease is subject of several new therapeutic approaches. Simultaneous treatment with aspirin and a thienopyridin (clopidogrel) represents the standard of care for patients with acute coronary syndrome and following coronary stenting recommended by many guidelines. Without true evidence this drug combination is used for the prevention of arterial thrombosis in many other vascular interventions (e.g. carotid stenting, aortic stenting, peripherial arterial stents). The main problems of dual antiplatelet therapy with aspirin and clopidogrel are the slow onset of action and the high interindividual variation in the degree of platelet inhibition. The thienopyridin prasugrel is a more potent platelet inhibitor with a more rapid onset of action and smaller interindividual variations in platelet inhibition. The therapeutic superiority of prasugrel with respect to coronary events and stent thromboses was proven in patients with acute coronary syndrome undergoing coronary interventions. Specifically patients with Diabetes mellitus and patients with ST-elevation myocardial infarction seemed to benefit most due to the improved inhibition of platelet activity. A higher rate of bleeding complications was seen in those over the age of 75 years and a body weight below 60 kg for which a daily dose of 5mg/day was approved. Further clinical studies with prasugrel in patients with non-invasively treated acute coronary syndromes are ongoing.     

Long-term care after percutaneous coronary intervention: focus on the role of antiplatelet therapy

Arterial wall injury caused by percutaneous coronary intervention (PCI) triggers transient platelet activation and mural thrombosis; these effects are superimposed on the preexisting platelet hyperreactivity associated with underlying atherothrombosis. Platelet activation has been implicated in the major complications of PCI: acute and subacute thrombosis and restenosis. Antithrombotic and anticoagulant therapy minimizes thrombotic complications after PCI. Aspirin plus a thienopyridine (ticlopidine or clopidogrel) is more effective than aspirin plus heparin and extended warfarin therapy in preventing periprocedural ischemic events and subsequent stent thrombosis and results in less major and minor bleeding. Dual antiplatelet therapy with aspirin and clopidogrel (the preferred thienopyridine because of its superior hematologic safety) is recommended for at least 4 weeks to prevent subacute stent thrombosis with bare-metal stents and 3 to 6 months to prevent late-stent thrombosis with drug-eluting stents. Coronary atherothrombosis is a diffuse vascular disease, and reduction of the risk of future ischemic events requires strategies that extend beyond the focal treatment of stenotic lesions. Optimal long-term care after PCI requires aggressive systemic pharmacotherapy (antiplatelet agents, statins, beta-blockers, and angiotensin-converting enzyme Inhibitors) in conjunction with therapeutic lifestyle changes (smoking cessation, weight reduction, dietary measures, and exercise). In this context, dual antiplatelet therapy (aspirin plus clopidogrel) is recommended for at least 12 months after PCI for prophylaxis of future atherothrombotic events.     

Study design of the influence of SErotonin inhibition on patients with RENAl impairment or diabetes undergoing drug-eluting stent implantation (SERENADE) study: A multicenter,open-label,prospective, randomized study

BackgroundThe rates of stent failure after percutaneous coronary intervention have decreased since the introduction of the drug-eluting stent (DES). However, chronic kidney disease (CKD) and diabetes mellitus (DM) remain strong clinical predictors of poor prognosis despite DES implantation. Sarpogrelate, a selective serotonin (5-hydroxytryptamine (HT)2a [5-HT2A]) receptor antagonist, has antiproliferative effects, reducing neointimal hyperplasia and smooth muscle cell proliferation, as well as potent antiplatelet action, inhibiting 5-HT-induced platelet aggregation. However, efficacy and safety data for sarpogrelate in patients with CKD or DM are limited. We aim to determine whether sarpogrelate has beneficial effects in patients with CDK or DM treated with DES implantation.Methods/designThe SERENADE trial is a multicenter, open-label, prospective, randomized study that will test the superiority of triple anti-platelet therapy (TAT; aspirin, clopidogrel, and sarpogrelate) to conventional dual antiplatelet therapy (DAT; aspirin and clopidogrel) in preventing late lumen loss 9 months after the index procedure in patients with CKD or DM. A total of 220 patients diagnosed with coronary artery disease with DM or CKD will be randomized to the TAT or DAT groups (1:1 ratio) after DES implantation. The primary endpoint is late lumen loss at 9 months assessed by quantitative coronary angiography. Secondary efficacy endpoints are composites of major adverse cardiovascular events including cardiac death, nonfatal myocardial infarction, and target lesion revascularization. Secondary safety endpoints are major bleeding events and hepatic or renal impairment.DiscussionThe SERENADE trial will provide insight on the efficacy of adjunctive therapy with sarpogrelate after DES implantation for patients with high-risk profiles such as CKD or DM.Trial registrationNational Institutes of Health Clinical Trials Registry (ClinicalTrials.gov NCT02294643).     

A case–control study on platelet reactivity in patients with coronary stent thrombosis

Summary. Background: The pathophysiology of stent thrombosis (ST) has evolved from the identification of single causative factors to a complex multifactorial model. Objectives: The aim of the present study was to investigate whether patients with a history of ST exhibit heightened platelet reactivity to clopidogrel and aspirin. Patients/methods: Pretreatment and on‐treatment platelet reactivity to clopidogrel and aspirin, as well as dual antiplatelet therapy resistance, was determined in 84 patients with a history of definite ST (cases: 41 early ST; 43 late ST) and in 103 control patients with a previously implanted coronary stent but no ST after the index procedure. Platelet function was evaluated with optical aggregometry, the VerifyNow P2Y12 and aspirin assays, the PFA‐100 Innovance P2Y* cartridge, the flow cytometric vasodilator‐stimulated phosphoprotein assay and urine 11‐dehydrothromboxane B₂ measurement before and after the administration of a 600‐mg loading dose of clopidogrel and 100 mg of aspirin. The study was registered at ClinicalTrials.gov, number NCT01012544. Results: Patients with a history of early ST clearly demonstrated higher on‐clopidogrel platelet reactivity than controls. Patients with both early and late ST exhibited heightened on‐aspirin platelet reactivity status, and dual antiplatelet therapy resistance was more frequent. Conclusions: Patients with a history of early ST exhibit a poor response to clopidogrel. Furthermore, both early and late ST are strongly and independently associated with heightened on‐aspirin platelet reactivity, and dual antiplatelet therapy resistance is more frequent.     

Differential effects of esomeprazole on the antiplatelet activity of clopidogrel in healthy individuals and patients after coronary stent implantation

Clopidogrel plus aspirin is a standard antiplatelet aggregation regimen in cardiovascular diseases, especially after implantation of a coronary stent. Interaction between clopidogrel and proton pump inhibitors theoretically reduces clopidogrel's antiaggregation effect, but the evidence is controversial. A total of 30 healthy subjects and 74 patients with a coronary stent were given a 300 mg loading dose of aspirin and 300 mg clopidogrel and then 100 mg aspirin/75 mg clopidogrel daily for 14 days. Subgroups were concomitantly treated or not treated with esomeprazole (20 mg/day). Clopidogrel significantly reduced adenosine diphosphate-induced platelet aggregation in healthy and stent-implanted subjects on days 7 and 14. Healthy subjects receiving esomeprazole showed a significantly higher platelet aggregation rate than those not receiving esomeprazole, but esomeprazole had no effect in patients with a stent. Aspirin plus clopidogrel did not result in significant gastrointestinal complications. These differential effects of esomeprazole on the antiplatelet activity of clopidogrel in healthy individuals and patients after coronary stent implantation merit further investigation.     

不同抗血小板方案对急性冠状动脉综合征经皮冠状动脉介入术后患者的疗效与安全性研究

目的探讨不同强化抗血小板治疗方案对急性冠状动脉综合征（ACS）经皮冠状动脉介入术（PCI）后患者氯吡格雷抵抗（CR）发生率及超敏C-反应蛋白（hs-CRP）的影响。方法将125例确诊为ACS急诊行PCI术后的患者,随机分为三组,A组（n=42）：口服阿司匹林100 mg Qd＋氯吡格雷75 mg Qd;B组（n=42）：口服阿司匹林100 mg Qd＋氯吡格雷75 mg Bid;C组（n=41）：口服阿司匹林100 mg Qd＋氯吡格雷75 mg Qd＋西洛他唑50 mg Bid。利用全血电阻抗法检测治疗前、治疗第7天的血小板聚集率,酶联免疫吸附法测定PCI前、PCI术后24 h、PCI术后第7天的hs-CRP,计算并比较CR的发生率,观察住院期间主要不良心脏事件（MACE）发生率、出血并发症。结果 B组与C组的CR发生率无显著差异（16.7%vs.14.6%）,两组均明显低于A组（35.7%）（P〈0.05）;B组和C组PCI术后24 h、PCI术后第7天的hs-CRP水平无显著差异[（12.5±7.4）mg/L vs.（12.8±7.1）mg/L,（9.2±6.8）mg/L vs.（8.5±6.3）mg/L],两组均明显低于A组[（16.7±6.3）mg/L,（11.8±5.4）mg/L,P〈0.05];B组和C组MACE发生率明显低于A组[（2.4%,2.4%）vs.16.7%]（P〈0.05）;C组出血率明显高于A组和B组[14.6%vs（.2.4%,2.4%）]（P〈0.05）。结论两种强化抗血小板治疗方案均明显降低ACS急诊PCI术后患者CR发生率和hs-CRP水平,标准双联抗血小板联合西洛他唑方案的出血发生率明显低于阿司匹林联合双倍氯吡格雷方案。     

冠状动脉支架术后个体化抗血小板治疗的临床疗效观察

目的 比较冠状动脉支架植入术后标准双联抗血小板治疗和根据血小板聚集率(PAR)个体化调整抗血小板治疗的疗效差异性.方法 收集2008年2月至2009年1月在北京安贞医院接受冠状动脉支架植入术的患者762例,随机分为对照组(n=376)及治疗组(n=386).对照组采用标准阿司匹林、氯吡格雷(波立维)双联抗血小板治疗;治疗组基础用药与对照组相同,根据患者PAR调整阿司匹林、波立维用量或加用西洛他唑(培达)直至PAR降至40%以下并维持3个月,再调整为标准方案.分析两组基线资料、冠状动脉造影和经皮冠状动脉介入治疗(PCI)的结果差异,观察两组主要终点和次要终点指标发生率的差别,以及个体化抗血小板治疗对氯吡格雷抵抗(CR)患者PAR的影响.结果 两组临床基线资料、冠状动脉造影及PCI结果差异无统计学意义.随访1个月及1年时个体化治疗的主要终点指标发生率明显低于标准化治疗,差异有统计学意义(1个月:3.9%vs 6.6%,P＜0.05;1年:5.4%vs 8.8%,P＜0.05);次要终点的发生率比较差异无统计学意义(1个月:0.8%vs 0.8%,P＞0.05;1年:1. 0%vs0.8%,P＞0.05).另外,个体化抗血小板治疗与标准治疗比较,能明显降低CR患者的PAR,(48.2±6.2)%vs(65.8±9.2)%(P＜0.05).结论 冠状动脉支架植入术后行个体化抗血小板治疗与标准治疗相比,可进一步降低主要不良心脑血管事件(MACCE)的发生率.同时并不增加出血风险.     

血栓弹力图测定老年急性冠脉综合征患者氯吡格雷抵抗的临床观察

【目的】通过血栓弹力图（TEG）分析仪检测血小板聚集率,观察接受标准双联抗血小板治疗的住院老年急性冠脉综合征（ACS）患者的氯吡格雷抵抗发生率及可能的影响因素。【方法】选取109例老年（年龄≥60岁）ACS患者,在常规服用阿司匹林100mg／d基础上,口服氯吡格雷75mg／d,5d以后采血,通过TEG方法测定患者服用氯吡格雷和阿司匹林的血小板聚集率。以二磷酸腺苷诱导的血小板聚集率≥70％为氯吡格雷抵抗,花生四烯酸诱导的血小板聚集率〉50％为阿司匹林抵抗。【结果】氯吡格雷抵抗发生率为31．2％（34例）,有10．1％（11例）发生阿司匹林和氯吡格雷双抵抗。氯吡格雷抵抗组与非抵抗组间阿司匹林抵抗的发生率有非常显著的统计学意义（P〈0．01）。两组患者在年龄、高血压、糖尿病、应用药物等方面差异无统计学意义（P〉0．05）;但氯吡格雷抵抗组中无吸烟史的患者更多,差异具有统计学意义（P=0．045）;此外还观察到女性（P=0．052）患者有容易发生氯吡格雷抵抗的趋势。【结论】接受标准抗血小板治疗的老年ACS患者中,31．2％存在氯吡格雷抵抗现象。这一现象不受年龄、合并疾病、服用药物等影响,而阿司匹林抵抗或从未吸烟的患者更易发生氯吡格雷抵抗。     

Modern antiplatelet agents in coronary artery disease

Dual antiplatelet therapy is well recognized in the prevention of thrombotic complications of acute coronary syndrome and percutaneous coronary interventions. Despite clinical benefits of aspirin and clopidogrel therapy, a number of limitations curtail their efficacy: slow onset of action, variability in platelet inhibitory response and potential drug–drug interactions. Furthermore, the single platelet-activation pathway targeted by these agents allows continued platelet activation via other pathways, ensuring incomplete protection against ischemic events, thus, underscoring the need for alternate antiplatelet treatment strategies. A number of novel antiplatelet agents are currently in advance development and many have established superior effects on platelet inhibition, clinical outcomes and safety profile than clopidogrel in high-risk patients. The aim of this review is to provide an overview of the current status of P2Y12 receptor inhibition and PAR-1 antagonists in determining a future strategy for individualized antiplatelet therapy.     

Antiplatelet options for secondary prevention in acute coronary syndromes

Current guidelines recommend dual antiplatelet therapy, a combination of aspirin and a P2Y₁₂ inhibitor, for 6–12 months after percutaneous coronary intervention with drug-eluting stent implantation in all patients and for 1 year in all patients after an acute coronary syndrome (ACS), irrespective of revascularization strategy. Clopidogrel has a pharmacokinetic and pharmacodynamic profile that results in a delayed and/or subtherapeutic antiplatelet effect, and wide variability in antiplatelet response. New P2Y₁₂ inhibitors, such as prasugrel and ticagrelor, have favorable pharmacodynamics and clinical efficacy over clopidogrel and offer an alternative antiplatelet treatment strategy in specific patients. Prasugrel has more potent, rapid, and consistent effects on inhibiting ADP-induced platelet aggregation than clopidogrel. Ticagrelor also appears to have more rapid and consistent antiplatelet effects than clopidogrel. The higher levels of antiplatelet inhibition provided by prasugrel and ticagrelor compared with standard-dose clopidogrel result in improved ischemic outcomes in patients with ACS. Despite an increase in bleeding risk, prasugrel and ticagrelor appear to have a better net clinical benefit, especially in higher-risk patients with ACS.     

Antiplatelet options for secondary prevention in acute coronary syndromes

Current guidelines recommend dual antiplatelet therapy, a combination of aspirin and a P2Y(12) inhibitor, for 6?12 months after percutaneous coronary intervention with drug-eluting stent implantation in all patients and for 1 year in all patients after an acute coronary syndrome (ACS), irrespective of revascularization strategy. Clopidogrel has a pharmacokinetic and pharmacodynamic profile that results in a delayed and/or subtherapeutic antiplatelet effect, and wide variability in antiplatelet response. New P2Y(12) inhibitors, such as prasugrel and ticagrelor, have favorable pharmacodynamics and clinical efficacy over clopidogrel and offer an alternative antiplatelet treatment strategy in specific patients. Prasugrel has more potent, rapid, and consistent effects on inhibiting ADP-induced platelet aggregation than clopidogrel. Ticagrelor also appears to have more rapid and consistent antiplatelet effects than clopidogrel. The higher levels of antiplatelet inhibition provided by prasugrel and ticagrelor compared with standard-dose clopidogrel result in improved ischemic outcomes in patients with ACS. Despite an increase in bleeding risk, prasugrel and ticagrelor appear to have a better net clinical benefit, especially in higher-risk patients with ACS.     

Prasugrel: Clinical development and therapeutic application

Dual antiplatelet therapy with aspirin and clopidogrel is a cornerstone of the management of patients with acute coronary syndromes and following percutaneous coronary intervention. Despite the proven benefits, clear limitations of clopidogrel exist. Prasugrel is a third-generation thienopyridine antiplatelet agent with pharmacologic characteristics that overcome some of the limitations of clopidogrel, but at the expense of increased bleeding. The promising results seen with prasugrel in large, randomized trials led to its recent approval by the US Food and Drug Administration for reducing thrombotic cardiovascular events in patients with acute coronary syndromes managed with percutaneous coronary intervention. This article will review the limitations of standard antiplatelet therapy and discuss the clinical application of prasugrel.     

经皮冠状动脉介入治疗术双抗治疗1年后患者单用阿司匹林或氯吡格雷远期预后对比分析

目的:比较经皮冠状动脉介入治疗(PCI)术双抗治疗1年后患者服用阿司匹林或氯吡格雷远期预后差异,并分析原因。方法:回顾性分析2017年8月至12月植入药物涂层支架后采用双抗血小板治疗1年的168例患者的临床资料。依据患者抗血小板治疗1年后服药情况,将其分为阿司匹林组(100 mg/d,85例)和氯吡格雷组(75 mg/d,83例)。继续观察18个月,比较两组患者主要不良心血管事件(MACEs)以及服药期间出血情况。结果:两组患者心血管相关死亡、再发心绞痛、支架内再狭窄等观察终点事件差异无统计学意义,且均未发生严重出血事件。阿司匹林组轻中度出血比例明显高于氯吡格雷组(16.5%vs 4.8%,P=0.015),主要为胃出血事件增多(8.2%vs 1.2%,P=0.032)。Kaplan-Meier生存曲线结果表明,随访期间两组MACEs发生率差异无统计学意义(log rank=0.014,P=0.905),但氯吡格雷组轻中度出血事件明显少于阿司匹林组(log rank=5.986,P=0.014)。发生出血事件的患者中女性比例(61.1%vs 34.0%,P=0.024)以及年龄[(71.89±8.37)岁vs(64.75±9.02)岁,P=0.002)]高于未出血患者。多因素logistic回归分析发现,年龄[Exp(B)=4.771, 95%CI 1.313～17.344,P=0.018]、性别[Exp(B)=0.361, 95%CI 0.129～1.009,P=0.049]为出血事件的独立危险因素。结论:PCI术双抗治疗1年后患者单用氯吡格雷或阿司匹林远期获益相似,但单用氯吡格雷后轻中度出血风险降低;PCI术双抗治疗1年后的高龄女性患者可考虑长期服用氯吡格雷片75 mg/d治疗。     

血栓弹力图评价经皮冠脉介入治疗患者服用抗血小板药物效果的研究

目的评价采用血栓弹力图观察经皮冠脉介入治疗（PCI）患者服用抗血小板药物后血小板抑制效果。方法选择住院的135例冠心病患者,其中120例接受PCI治疗并联合服用阿司匹林与氯吡格雷的患者作为联合用药组,15例未接受PCI治疗的患者（单独用药组）分别单独服用阿司匹林（阿司匹林组,8例）或氯吡格雷（氯吡格雷组,7例）。采用血栓弹力图检测花生四烯酸（AA）和磷酸腺苷（ADP）途径诱导的血小板抑制率,并比较两组抗血小板治疗的效果。结果阿司匹林组AA途径诱导的血小板抑制率为（61．66±21．44）％,高于氯吡格雷组ADP途径诱导的血小板抑制率[（55．23±13．44）％],但差异无统计学意义（P〉0．05）;联合用药组AA和ADP途径诱导的血小板抑制率分别为（65．52±24．61）％和（58．67±22．75）％,高于阿司匹林组AA途径和氯吡格雷组ADP途径,但差异无统计学意义（P均〉0．05）;联合用药组抗血小板治疗的疗效（良好率）均优于单独应用阿司匹林或氯吡格雷组（40．00％郴12．50％,26．67％ vs 0,P均〈0．01）。结论阿司匹林与氯吡格雷均能起到很好的抗血小板作用,但氯吡格雷稍差,联合服用阿司匹林和氯吡格雷能起到更强的抗血小板作用。血栓弹力图是评价血小板抑制率的有效工具,可根据AA／ADP抑制率的情况发现对阿司匹林和／或氯吡格雷抵抗的患者,进而调整用药方案。     

氯吡格雷吸收和代谢通路相关基因变异与临床个体化用药实践

氯吡格雷是一种新型噻吩吡啶类抗血小板药物,联合应用氯吡格雷及阿司匹林已经成为急性冠脉综合征及经皮冠状动脉介入支架术后患者的标准治疗方案。与氯吡格雷吸收和代谢通路相关的基因变异,使得患者对氯吡格雷的临床反应性存在显著的个体差异,部分患者出现氯吡格雷抵抗现象,增加临床不良事件的发生。确定相关基因变异对指导临床个体化用药实践意义重大。     

ST-elevation myocardial infarction: the role of adjunctive antiplatelet therapy

Antiplatelet therapy to reduce the risks of recurrent myocardial infarction and restenosis after primary percutaneous coronary intervention is critically important to optimize the early treatment of ST-segment elevation myocardial infarction (STEMI). Traditionally, acetylsalicylic acid (ASA; aspirin) has been recommended for patients with suspected STEMI, but this agent targets only one of several pathways of platelet aggregation. Antiplatelet agents with different inhibitory mechanisms may act synergistically with ASA. Glycoprotein IIb/IIIa inhibitors are generally not used with fibrinolytic agents in acute STEMI management; indeed, glycoprotein IIb/IIIa inhibitors plus bolus fibrinolytics increase the risk of intracranial hemorrhage. Aggressive antiplatelet therapy with clopidogrel reduces mortality in STEMI patients and offers significant clinical benefits, without an associated increase in major bleeding events. Recent trials support the development of an early and aggressive approach to more complete platelet inhibition using clopidogrel, in combination with ASA, for patients with STEMI.