Nonculprit Lesion Myocardial Infarction Following Percutaneous Coronary Intervention in Patients With Acute Coronary Syndrome

BackgroundRecent emphasis on reduced duration and/or intensity of antiplatelet therapy following percutaneous coronary intervention (PCI) irrespective of indication for PCI may fail to account for the substantial risk of subsequent nontarget lesion events in acute coronary syndrome (ACS) patients.ObjectivesThe authors sought to examine the effect of more potent antiplatelet therapy on the basis of the timing and etiology of recurrent myocardial infarction (MI) or cardiovascular death following PCI for ACS.MethodsIn the TRITON-TIMI 38 study (Trial to Assess Improvement in Therapeutic Outcomes by Optimizing Platelet Inhibition With Prasugrel–Thrombolysis In Myocardial Infarction 38), which randomized patients to prasugrel or clopidogrel, 12,844 patients with ACS received at least 1 stent. MI and cardiovascular death were categorized as: 1) procedural (related to revascularization); 2) definite or probable stent thrombosis (ST); or 3) spontaneous (non-ST or non–procedure-related). Median follow-up was 14.5 months.ResultsAmong the first events occurring within 30 days, 584 (69.0%) were procedural, 126 (14.9%) ST-related, and 136 (16.1%) spontaneous. After 30 days, 22 (4.7%) were procedural, 63 (13.5%) were ST-related, and 383 (81.8%) spontaneous. Prasugrel significantly reduced the incidence of MI or cardiovascular death for ST-related (1.0% vs. 2.1%; p < 0.001) and spontaneous events (3.9% vs. 4.8%; p = 0.012), with a directionally consistent numerical reduction for procedural events (4.4% vs. 5.1%; p = 0.078). Prasugrel increased spontaneous, but not procedural, major bleeding.ConclusionsLong-term potent antithrombotic therapy reduces de novo (spontaneous) atherothrombotic events in addition to preventing complications associated with stenting of the culprit lesion following ACS. In patients undergoing PCI for ACS, spontaneous events predominate after 30 days, with the later-phase cardiovascular benefit of potent dual antiplatelet therapy driven largely by reducing de novo atherothrombotic ischemic events. (Comparison of Prasugrel [CS-747] and Clopidogrel in Acute Coronary Syndrome Subjects Who Are to Undergo Percutaneous Coronary Intervention; NCT00097591)     

Pharmacokinetics and pharmacodynamics of single and multiple doses of prasugrel in healthy native Chinese subjects

Aim:

To characterize the pharmacokinetics (PKs), pharmacodynamics (PDs), and tolerability of different dose regimens of prasugrel in healthy Chinese subjects.

Methods:

This was a single-centered, open-label, parallel-design study. Subjects received a single loading dose (LD) of prasugrel followed by once-daily maintenance dose (MD) for 10 d. They were enrolled into 3 groups: 60 mg LD/10 mg MD; 30 mg LD/7.5 mg MD; 30 mg LD/5 mg MD. Blood samples were collected after the first and last dose. The serum concentration of the active metabolite of prasugrel was determined using a LC/MS/MS method. Platelet aggregation was assessed using the VerifyNow-P2Y₁₂ assay.

Results:

Thirty-six healthy native Chinese subjects (19 males) aged 18–45 were enrolled; mean age and body weight were similar across the treatment groups (n=12 for each). The metabolite AUC_0–4 and C_max increased dose-proportionally across the dose range of 5 mg to 60 mg. The median T_max was 0.5 h in all groups. The PD parameters, indicated by the inhibition of ADP-induced platelet aggregation, were met more rapidly in the 60 mg group than the 30 mg group after the LD (94%–98%). This high degree of inhibition of platelet aggregation was maintained following the 10 mg MD (87%–90%) and was lower in the 7.5 mg and 5 mg MD groups (79%–83% and 64%–67%, respectively). Prasugrel was well tolerated in healthy Chinese subjects for single doses up to 60 mg and a MD of 10 mg for 10 d.

Conclusion:

The PKs and PDs of the active metabolite of prasugrel were similar to those in Chinese subjects reported by a previous bridging study, which demonstrated that the exposure to the active metabolite in Chinese subjects was higher than in Caucasians.     

2009年心胸血管麻醉热点问题

全文汇总了2009年心胸血管麻醉领域权威性和学术性较高的临床研究资料．对去年本专业相关热点问题进行了概括性介绍。杂交手术室是心外科、心血管麻醉和心内科介入治疗三种专业人员进行经导管治疗的场所．经导管行主动脉瓣膜置换术的开展证明人们对腔内治疗技术变革的认同。通过药物预处理和缺血预处理实施的心肌保护具安全、有效的临床特点．因此它们是目前多项临床试验关注的重点。血管紧张素抑制、贫血以及内窥镜取大隐静脉技术可对冠状动脉旁路移植术（CABG）的预后造成不良影响。不停跳CABG与停跳cABG的临床预后对低风险患者等同．但后者有利于改善高风险患者预后。经皮冠状动脉介入治疗（PCI）能明显降低心肌梗死患者的病死率．然而主动脉内球囊反搏技术对此类患者的有效性证据却不尽如人意。普拉格雷已被批准用于PCI后的血小板抑制．但有可能被替卡格雷取代。PCl与CABG技术对冠脉血管多支病变患者临床预后的影响相似．但CABG对降低患者行再血管化治疗可能性．对耱尿病和年龄〉65岁患者术后生存率的提高更有益。羟乙基淀粉和N-乙酰半胱氨酸都能够增加心脏手术患者围术期出血量和输血量。Vll因子能够治疗致命性出血．但它的安全性有待进一步论证。具有够刺激血小板生成作用的血小板生成紊拟肽等药物可能在未来改善心脏手术后止血功能方面发挥作用。非诺多泮、心房利钠肽以及碳酸氢钠的肾保护作用有待进一步试验证实。强化胰岛素治疗并无改善临床预后作用．却明显增加低血糖的发生率。     

Ticagrelor: a P2Y12 antagonist for use in acute coronary syndromes

Agents that inhibit platelet function are used routinely in the treatment and prevention of acute coronary syndromes. The main antiplatelet treatments used combine aspirin with one of the thienopyridine P2Y₁₂ antagonists, either clopidogrel or prasugrel. By blocking the synthesis of thromboxane A₂ in platelets and by blocking the effects of ADP, respectively, these agents reduce platelet activity, platelet aggregation and thrombus formation. Ticagrelor (marketed by AstraZeneca as Brilinta? in the USA, and as Brilique^® or Possia^® in Europe) is a cyclopentyl-triazolo-pyrimidine, a new chemical class of P2Y₁₂ antagonist that is now approved for use in the wide spectrum of acute coronary syndromes. In this article we provide an overview of ticagrelor. We discuss the differences in mode of action compared with other P2Y₁₂ antagonists, examine its pharmacodynamic, pharmacokinetic and safety profile, and summarize the various clinical trials that have provided information on its efficacy in combination with aspirin. Ticagrelor appears to overcome some of the difficulties that have been encountered with other antiplatelet treatments, clopidogrel in particular.     

Clinical effects and outcomes with new P2Y12 inhibitors in ACS

Thienopyridines have become the cornerstone of treatment for percutaneous coronary intervention although no survival benefit has ever been shown with clopidogrel despite increasing loading doses. Newly developed P2Y12 inhibitors are more potent, more predictable, and have a faster onset of action than clopidogrel, characteristics that make them particularly attractive for high-risk percutaneous coronary intervention (PCI). Four new P2Y12 inhibitors have been tested each of them having particular individual properties. Prasugrel is an oral pro-drug leading to irreversible blockade of the P2Y12 receptor and is approved worldwide for ACS PCI. Ticagrelor is a direct-acting and reversible inhibitor of the P2Y12 receptor with potentially more pleiotropic effects. Cangrelor is an intravenous direct and reversible inhibitor of the P2Y12 receptor providing the highest level of inhibition, and elinogrel is an intravenous and oral P2Y12 antagonist with a direct and reversible action. Both prasugrel and ticagrelor, opposed to clopidogrel, have shown that stronger P2Y12 inhibition led respectively to significant 19 and 16% relative risk reduction of a similar primary end point combining cardiovascular death, non-fatal myocardial infarction, or non-fatal stroke. Both drugs showed a significant 0.6% absolute excess of TIMI major bleeding not related to CABG surgery. Because in clinical trials, patients perceived to be at higher risk of bleeding usually are excluded, the risk of major and even fatal bleeding might even be higher in a 'real-world' setting, i.e. in the elderly patient with comorbidities. On the other hand, these newly developed P2Y12 inhibitors decrease mortality after PCI compared with clopidogrel. The risk/benefit ratio is particularly favorable in PCI for patients with STEMI.     

Effect of CYP2C19 Genotype on Ischemic Outcomes During Oral P2Y12 Inhibitor Therapy: A Meta-Analysis

ObjectivesThe aim of this study was to examine the effect of CYP2C19 genotype on clinical outcomes in patients with coronary artery disease (CAD) who predominantly underwent percutaneous coronary intervention (PCI), comparing those treated with ticagrelor or prasugrel versus clopidogrel.BackgroundThe effect of CYP2C19 genotype on treatment outcomes with ticagrelor or prasugrel compared with clopidogrel is unclear.MethodsDatabases through February 19, 2020, were searched for studies reporting the effect of CYP2C19 genotype on ischemic outcomes during ticagrelor or prasugrel versus clopidogrel treatment. Study eligibility required outcomes reported for CYP2C19 genotype status and clopidogrel and alternative P2Y₁₂ inhibitors in patients with CAD with at least 50% undergoing PCI. The primary analysis consisted of randomized controlled trials (RCTs). A secondary analysis was conducted by adding non-RCTs to the primary analysis. The primary outcome was a composite of cardiovascular death, myocardial infarction, stroke, stent thrombosis, and severe recurrent ischemia. Meta-analysis was conducted to compare the 2 drug regimens and test interaction with CYP2C19 genotype.ResultsOf 1,335 studies identified, 7 RCTs were included (15,949 patients, mean age 62 years; 77% had PCI, 98% had acute coronary syndromes). Statistical heterogeneity was minimal, and risk for bias was low. Ticagrelor and prasugrel compared with clopidogrel resulted in a significant reduction in ischemic events (relative risk: 0.70; 95% confidence interval: 0.59 to 0.83) in CYP2C19 loss-of-function carriers but not in noncarriers (relative risk: 1.0; 95% confidence interval: 0.80 to 1.25). The test of interaction on the basis of CYP2C19 genotype status was statistically significant (p = 0.013), suggesting that CYP2C19 genotype modified the effect. An additional 4 observational studies were found, and adding them to the analysis provided the same conclusions (p value of the test of interaction <0.001).ConclusionsThe effect of ticagrelor or prasugrel compared with clopidogrel in reducing ischemic events in patients with CAD who predominantly undergo PCI is based primarily on the presence of CYP2C19 loss-of-function carrier status. These results support genetic testing prior to prescribing P2Y₁₂ inhibitor therapy.     

Genetics of platelet inhibitor treatment

Dual antiplatelet therapy with aspirin and a P2Y₁₂ receptor antagonist is the standard of care in patients undergoing percutaneous coronary intervention (PCI) and in patients with acute coronary syndromes (ACS) because this regimen has markedly decreased the rate of cardiovascular events. The substantial variability in pharmacodynamic response as well as the moderate antiplatelet efficacy of clopidogrel has raised major concerns, since high on-clopidogrel platelet reactivity has consistently been associated with increased risk for ischaemic events in PCI patients. Baseline demographic and clinical variables contributing to the observed variability have been identified. Besides this, research within the past decade has focused on the impact of genetic polymorphisms encoding transport systems or enzymes involved in the absorption and metabolism of these drugs. Loss-of-function polymorphisms in CYP2C19 are the strongest individual variables affecting pharmacokinetics and antiplatelet response to clopidogrel, but explain no more than 5 to 12% of the variability in adenosine diphosphate-induced platelet aggregation on clopidogrel. No genetic variables contributing to clinical outcomes of patients treated with the newer P2Y₁₂ receptor antagonists, prasugrel or ticagrelor, have been identified so far. This review aims to provide an update on the current status of genotype-based personalized therapy with clopidogrel.     

Tailored antiplatelet therapy to improve prognosis in patients exhibiting clopidogrel low-response prior to percutaneous coronary intervention for stable angina or non-ST elevation acute coronary syndrome

Aim: To investigate whether an intensified antiplatelet regimen could improve prognosis in stable or non-ST elevation in acute coronary syndrome (ACS) patients exhibiting high on-treatment platelet reactivity (HTPR) on clopidogrel and treated with percutaneous coronary intervention (PCI). There is a wide variability in the platelet reactivity to clopidogrel and HTPR has been associated with a poor prognosis. Methods: In this observational study, 923 consecutive patients without ST-elevation myocardial infarction (STEMI) and adequately pre-treated with clopidogrel were screened for HTPR with multiple electrode aggregometry after assessment of the coronary anatomy. Patients were grouped based on their response to clopidogrel and the assigned antiplatelet strategy. The primary endpoint was a composite of cardiovascular death, myocardial infarction, stroke, or stent thrombosis. Results: HTPR was demonstrated in 237 patients (25.7%). Of these, 114 continued on conventional clopidogrel therapy, while the remaining 123 received intensified antiplatelet therapy with either double-dose clopidogrel (150?mg daily, n?=?55) or the newer P₂Y₁₂-inhibitors, prasugrel or ticagrelor (n?=?68) for at least 30 days after the index procedure. The median follow-up was 571 days (interquartile range, 373–746). Intensifying antiplatelet therapy reduced the rate of the composite endpoint (p?<?0.001). After adjustment for potential confounders, HTPR in combination with conventional clopidogrel therapy remained independently associated with an increased risk of cardiovascular events (hazard ratio (HR), 2.92; 95% CI, 1.90–4.48), whereas intensified treatment reduced the risk to a level equivalent to that of patients exhibiting normal platelet reactivity (HR, 1.08; 95% CI, 0.59–1.99). Conclusion: Tailored antiplatelet therapy significantly reduced the event rate in patients exhibiting HTPR prior to PCI.