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Hou X, Shi J, Sun H. Gene polymorphism of cytochrome P450 2C19*2 and clopidogrel resistance reflected by platelet function assays: a meta-analysis. Eur J Clin Pharmacol 2014; 70:1041-7. [PMID: 24996381 DOI: 10.1007/s00228-014-1714-x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2014] [Accepted: 06/27/2014] [Indexed: 01/11/2023]
Abstract
BACKGROUND The relationship between CYP2C19*2 gene polymorphism and clopidogrel resistance reflected by platelet function assays has been studied extensively in the past several years, while no clear conclusion can be drawn from the previous studies. To explore a more precise estimation of the relationship, a meta-analysis was conducted in the present study. METHODS The relevant studies were identified by searching PubMed, EMBASE, the Web of Science, Cochrane Collaboration Database, Chinese National Knowledge Infrastructure (CNKI), Wanfang Database, and China Biological Medicine (CBM) up to February, 2014. The meta-analysis was performed by the STATA 11. RESULTS Eight studies with a total of 2,331 subjects, including 1,066 patients with clopidogrel resistance and 1,265 patients without clopidogrel resistance were included. The pooled analysis showed that CYP2C19*2 gene polymorphism was probably associated with clopidogrel resistance (OR (95% CI): GA vs. GG: 2.10 (1.74-2.53); AA vs. GG: 3.05 (2.10-4.45); dominant model: 2.22 (1.85-2.65); recessive model: 2.33 (1.62-3.36)). No statistically significant difference was found in the analysis of the three subgroups. The statistical stability and reliability was also demonstrated by the sensitivity analysis and publication bias outcomes. CONCLUSION The meta-analysis suggests that CYP2C19*2 gene polymorphism may be associated with clopidogrel resistance.
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Affiliation(s)
- Xiaowen Hou
- Department of Clinical Epidemiology, Institute of Cardiovascular Diseases, The First Affiliated Hospital of China Medical University, NO.155 Nanjing North Street, Shenyang, 110001, China
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Depta JP, Bhatt DL. Aspirin and platelet adenosine diphosphate receptor antagonists in acute coronary syndromes and percutaneous coronary intervention: role in therapy and strategies to overcome resistance. Am J Cardiovasc Drugs 2012; 8:91-112. [PMID: 18422393 DOI: 10.1007/bf03256587] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Platelet activation and aggregation are key components in the cascade of events causing thrombosis following plaque rupture. Antiplatelet therapy is essential in the treatment of patients with acute coronary syndromes (ACS) and for those requiring percutaneous coronary intervention (PCI). Aspirin (acetylsalicylic acid) is a well established antiplatelet therapy and is mandated for secondary prevention of cardiovascular events following ACS. In patients with ACS, the addition of clopidogrel to aspirin is more effective than aspirin alone. For patients undergoing PCI, dual antiplatelet therapy with aspirin and clopidogrel is warranted. Aspirin should be continued indefinitely after PCI. Pretreatment of patients with clopidogrel prior to PCI lowers the incidence of cardiovascular events, yet the optimum timing of drug administration and dose are still being investigated, as is the duration of therapy following PCI. Late-stent thrombosis with drug-eluting stents has pushed the recommendation for duration of clopidogrel therapy up to 1 year and perhaps beyond, in patients without risks for bleeding. The concepts of aspirin and clopidogrel resistance are important clinical questions. No uniform definition exists for aspirin or clopidogrel resistance. Measurements of resistance are often highly variable and do not necessarily correlate with clinical resistance. Noncompliance remains the most prominent mode of resistance. Screening of selected patient populations for resistance or pharmacologic intervention of those patients termed 'resistant' warrants further study.
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Affiliation(s)
- Jeremiah P Depta
- Department of Internal Medicine, Cleveland Clinic, Cleveland, Ohio, USA.
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Namazi S, Kojuri J, Khalili A, Azarpira N. The impact of genetic polymorphisms of P2Y12, CYP3A5 and CYP2C19 on clopidogrel response variability in Iranian patients. Biochem Pharmacol 2012; 83:903-8. [DOI: 10.1016/j.bcp.2012.01.003] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2011] [Revised: 12/28/2011] [Accepted: 01/03/2012] [Indexed: 10/14/2022]
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Kubica A, Kozinski M, Grzesk G, Fabiszak T, Navarese EP, Goch A. Genetic determinants of platelet response to clopidogrel. J Thromb Thrombolysis 2012; 32:459-66. [PMID: 21706290 PMCID: PMC3181405 DOI: 10.1007/s11239-011-0611-8] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Antiplatelet agents are the mainstay treatment in the prevention and management of atherothrombotic complications. However, a substantial interpatient variability in response to clopidogrel has been reported. Furthermore, patients with coronary artery disease and lesser platelet inhibition in response to clopidogrel are at increased risk for cardiovascular events. Clopidogrel after absorption requires two-step oxidation by the hepatic cytochrome P450 to generate its active metabolite. Polymorphisms of genes encoding the cytochrome enzymes and P-glycoprotein involved in clopidogrel absorption are regarded as major determinants of the interindividual variability in the clopidogrel-induced platelet inhibition. In our review we discuss the prevalence and clinical significance of various alleles of the genes: CYP2C19 and ABCB1 in the setting of coronary artery disease. Allele CYP2C19*2 is associated with excess of ischaemic events including myocardial infarction and stent thrombosis. On the other hand, CYP2C19*17 allele poses a serious threat of bleeding. Data concerning the prognostic value of genetic variant 3435C→T of ABCB1 remain inconclusive.
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Affiliation(s)
- Aldona Kubica
- Department of Health Promotion, Collegium Medicum, Nicolaus Copernicus University, 3 Technikow Street, 85-801 Bydgoszcz, Poland
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Buch MH, Prendergast BD, Storey RF. Antiplatelet therapy and vascular disease: an update. Ther Adv Cardiovasc Dis 2011; 4:249-75. [PMID: 21303843 DOI: 10.1177/1753944710375780] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Atherosclerosis is a diffuse, systemic disorder of the large and medium-sized arterial vessels, affecting the coronary, cerebral and peripheral circulation. Chronic inflammatory processes are the central pathophysiological mechanism largely driven by lipid accumulation, and provide the substrate for occlusive thrombus formation. The clinical sequelae of acute arterial thrombosis, heart attack and stroke, are the most common causes of morbidity and mortality in the industrialized world. Such acute events are characterized by rupture or erosion of the atherosclerotic plaque leading to acute thrombosis. The atherosclerotic process and associated thrombotic complications are collectively termed atherothrombosis. The platelet is a pivotal mediator of various endothelial, immune, thrombotic and inflammatory responses and therefore a key player in the initiation and progression of atherothrombosis. A robust evidence base supports the clear clinical benefits of antiplatelet agents in the primary and secondary therapy of atherothrombotic disorders. Percutaneous coronary and peripheral interventions have an established central role in the management of atherothrombotic disease and demand a greater understanding of platelet biology. In this article, we provide a clinically orientated overview of the pathophysiology of arterial thrombosis and the evidence supporting the use of the various established antiplatelet therapies, and discuss new and future agents.
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Affiliation(s)
- Mamta H Buch
- Cedars-Sinai Medical Center, Cardiovascular Intervention Center, 8631 W Third Street, Room 415E, Los Angeles, CA 90048, USA.
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Poppe LB, Roederer MW. Global Formulary Review: How Do We Integrate Pharmacogenomic Information? Ann Pharmacother 2011; 45:532-8. [DOI: 10.1345/aph.1p557] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
Objective: To summarize a standard formulary decision process and provide recommendations for the integration of pharmacogenomic (PGx) information within the formulary decision-making process. Data Sources: With use of MEDLINE (1920-March 2010). the terms “formularies, hospital” and “pharmacogenetics” were searched in the MeSH database, yielding no results. The MeSH terms were then searched separately in addition to searching for “rational drug therapy” and “essential medicines list” through the main PubMed database. Study Selection and Data Extraction: Articles deemed relevant to both terms were assessed, interpreted, and incorporated as key pieces to the review of formularies and the integration of PGx information as a part of the formulary review process. The articles referenced were deemed appropriate and categorized into 5 areas: formulary management systems and pharmacy and therapeutics (P&T) committees, international formularies, formulary decision-making. PGx evidence, and recommendations regarding integrating PGx into formulary decision-making. Data Synthesis: The field of PGx is rapidly evolving as the evidence supporting genetically guided individualized therapy continues to grow. To bring this evidence from the bench to the bedside, institutions will need to evaluate PGx data to integrate individualized therapy into practice. Few standardized methods exist to analyze and apply clinical PGx data and incorporate the information into drug evaluation at the formulary level. Several online sites provide resources to aid in formulary review and can be used when incorporating clinically relevant PGx information into a formulary decision. In addition, there are key questions that organizations can ask as they evaluate the PGx information in each step of the decision-making process. Conclusions: P&T committees should formulate a plan to integrate a search for pharmacogenomic data with each drug evaluation and integrate the results into the formulary decision process to enhance the appraisal of drug efficacy, safety, and cost.
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Affiliation(s)
- Lindsey B Poppe
- Department of Pharmacy, University of North Carolina Hospitals, Chapel Hill, NC
| | - Mary W Roederer
- Institute for Pharmacogenomics and Individualized Therapy, Eshelman School of Pharmacy, University of North Carolina; Clinical Assistant Professor, Department of Family Medicine, University of North Carolina
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Kang HS, Kwon BJ, Kim JE, Han MH. Preinterventional clopidogrel response variability for coil embolization of intracranial aneurysms: clinical implications. AJNR Am J Neuroradiol 2010; 31:1206-10. [PMID: 20223886 DOI: 10.3174/ajnr.a2051] [Citation(s) in RCA: 83] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
BACKGROUND AND PURPOSE Thromboembolism is one of the most serious complications in coil embolization for intracranial aneurysms, and antiplatelet premedication may reduce this complication. However, interindividual variation exists in the efficacy of CPG. This study sought to elucidate the clinical implications of preinterventional CPG response variability in patients who undergo coil embolization for intracranial aneurysms. MATERIALS AND METHODS CPG premedication was given to 186 consecutive patients with 209 aneurysms who underwent elective coil embolization, and the response to the premedication was measured by a point-of-care antiplatelet function test (VerifyNow assay). Patients were stratified into 4 quartiles according the test results, and their correlation with the occurrence of periprocedural complications was analyzed. The contribution of a variety of variables to the high PRU was also tested. RESULTS In this cohort, rates of thromboembolic events and all adverse events were 7.5% and 9.1%, respectively. The quartiles of the P2Y12 reaction unit of the ADP channel (PRU) showed a significant tendency toward thromboembolic events (P = .013) and all procedure-related adverse events (P = .009), while those of the BASE and percentage inhibition did not. Thromboembolic events occurred in 17.0% and procedure-related adverse events, in 21.3% of the patients in the fourth quartile. Female sex was the only significant factor related to the fourth quartile of PRU in the multiple logistic regression analysis (P = .014). CONCLUSIONS Procedure-related thromboembolic events occurred more frequently in patients in the upper quartile with higher PRU, especially in the fourth quartile. Further study including a large number of patients is expected to confirm this finding.
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Affiliation(s)
- H-S Kang
- Department of Neurosurgery, Seoul National University College of Medicine, Chongno-gu, Seoul, Korea
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Momary KM, Dorsch MP. Factors associated with clopidogrel nonresponsiveness. Future Cardiol 2010; 6:195-210. [DOI: 10.2217/fca.10.1] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Clopiodgrel therapy is the standard of care in patients with acute coronary syndrome and in those undergoing percutaneous coronary intervention. However, there is a significant amount of interindividual variability in clopidogrel responsiveness. Clopidogrel is a prodrug and requires metabolism via several CYP450 enzymes in order to exert its antiplatelet effects. Interference in these activation steps is the primary cause of clopidogrel nonresponsiveness. This review focuses on genetic polymorphisms in, and drug interactions with, the CYP450 enzymes that are associated with clopidogrel nonresponsiveness. In addition, clinical factors that effect clopidogrel responsiveness are also reviewed. Particular emphasis is placed on those factors that are not only associated with a change in clopidogrel pharmacokinetics or pharmacodynamics, but are also associated with an increased risk of adverse cardiovascular events. Currently, the majority of data assessing clopidogrel nonresponsiveness focus on genetic variation in CYP2C19 and drug interactions with proton pump inhibitors. However, genetic variation in other CYP450 enzymes, other drug interactions and clinical causes have been studied and are also reviewed here. It is important for healthcare practitioners to recognize all of the causes of clopidogrel nonresponsiveness, especially as novel antiplatelet alternatives become available.
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Affiliation(s)
- Kathryn M Momary
- Mercer University College of Pharmacy and Health Sciences, Department of Pharmacy Practice, 3001 Mercer University Drive, Atlanta, GA 30341, USA
| | - Michael P Dorsch
- Department of Pharmacy Services, University of Michigan Health System and Department of Clinical, Social & Administrative Sciences, University of Michigan College of Pharmacy, Ann Arbor, MI, USA
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Depta JP, Bhatt DL, Kottke-Marchant K, Gupta R, Murugesan G, Jain A, Lincoff AM, Ellis SG. Management of patients with aspirin and clopidogrel impaired response. Interv Cardiol 2009. [DOI: 10.2217/ica.09.4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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El-Menyar A, Hussein H, Al Suwaidi J. Coronary stent thrombosis in patients with chronic renal insufficiency. Angiology 2009; 61:297-303. [PMID: 19689994 DOI: 10.1177/0003319709344574] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Renal insufficiency (RI) is a strong predictor of unfavorable outcomes after percutaneous coronary intervention (PCI). After PCI, stent thrombosis (ST) is a considerable concern. The risk of ST in RI has not been independently evaluated before. The mechanism of ST is frequently related to dual antiplatelet underuse. We reviewed the publications listed on Medline, Scopus, and EBSCO Host research database in the last two decades to identify the risk of ST in patients with RI. There are no enough data on the incidence of ST in RI patients. Platelet reactivity, appropriate period of dual antiplatelet therapy, coronary anatomy, selection of stent, and patient compliance are vital issues that warrant detailed evaluation in RI patients. Moreover, prospective trials and new therapeutic strategies are needed for proper assessment and management of ST in high-risk patients.
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Affiliation(s)
- Ayman El-Menyar
- Department of Cardiology and Cardiovascular Surgery, Hamad General Hospital, HMC, Doha, Qatar.
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11
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Elevated coronary calcium scores are associated with higher residual platelet aggregation after clopidogrel treatment in patients with stable angina pectoris. Int J Cardiol 2009; 135:132-5. [DOI: 10.1016/j.ijcard.2008.02.020] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/02/2007] [Accepted: 02/08/2008] [Indexed: 11/19/2022]
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12
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Faxon DP, Freedman JE. Facts and controversies of aspirin and clopidogrel therapy. Am Heart J 2009; 157:412-22. [PMID: 19249409 DOI: 10.1016/j.ahj.2008.11.019] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/25/2008] [Accepted: 11/25/2008] [Indexed: 11/28/2022]
Abstract
Because of the central role of platelets in mediating ischemic events, antiplatelet agents are critical components of atherothrombosis prevention. Given their robust safety and efficacy profiles, aspirin and clopidogrel are consistently recommended by evidence-based treatment guidelines. Despite these recommendations, controversies surrounding the appropriate application of aspirin and clopidogrel remain. Questions of appropriate dosing, length of therapy, and use of combination therapy are most pressing, and considerable debate exists regarding the variability of response to antiplatelet therapy, including the definition, measurement, and clinical relevance of responsiveness. This review discusses the facts and controversies surrounding the use of aspirin and clopidogrel. Overall, despite the existing controversies, antiplatelet therapy with aspirin and/or clopidogrel remains a proven and essential therapeutic tool for safe and effective management of atherothrombotic risk in specific clinical settings.
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Affiliation(s)
- David P Faxon
- Department of Medicine, Brigham and Women's Hospital, Boston, MA 02120, USA.
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Layton KF, Cloft HJ, Gray LA, Lewis DA, Kallmes DF. Balloon-assisted coiling of intracranial aneurysms: evaluation of local thrombus formation and symptomatic thromboembolic complications. AJNR Am J Neuroradiol 2007; 28:1172-5. [PMID: 17569982 PMCID: PMC8134166 DOI: 10.3174/ajnr.a0490] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
BACKGROUND AND PURPOSE Remodeling balloons are used to assist in endovascular coiling of aneurysms. We evaluated our experience with balloon-assisted coiling (BAC) in an attempt to determine whether this technique increased the rate of thrombus formation or symptomatic thromboembolic complications. MATERIALS AND METHODS In 3 years, we treated 221 patients with intracranial aneurysms. Statistical analysis was performed to assess whether BAC increased the rate of thrombus formation or symptomatic thromboembolic complications. Patient demographics, aneurysm size, location, neck width, antiplatelet therapy, and rupture status were evaluated. RESULTS We detected no statistically significant difference in rates of thrombus formation (14% versus 9% with and without BAC, respectively, P=0.35) or symptomatic thromboembolic events (7% versus 5% with and without BAC, respectively, P=0.76), though our power to detect small differences was limited. There was also no correlation with age, sex, rupture status, aneurysm size, or location. There was a significant increase in the rates of thrombus formation (6% versus 16%, P=0.02) and symptomatic thromboembolic complications (3% versus 10%, P=0.04) in aneurysms that were classified as narrow- or wide-necked, respectively. The use of clopidogrel was associated with a decrease in the rate of complications (P=0.01). CONCLUSION In this series, we detected no significant increase in the rates of either intraprocedural thrombus formation or symptomatic thromboembolic events in patients treated with BAC. Larger studies are required to confirm our observations. Wide-necked aneurysms were independently associated with increased rates of thrombus formation and symptomatic thromboembolic complications, whereas the use of clopidogrel was protective (P=0.01).
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Affiliation(s)
- K F Layton
- Department of Radiology, Mayo Clinic, Rochester, MN, USA.
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Hobikoglu GF, Norgaz T, Aksu H, Ozer O, Erturk M, Destegul E, Akyuz U, Unal Dai S, Narin A. The effect of acetylsalicylic acid resistance on prognosis of patients who have developed acute coronary syndrome during acetylsalicylic acid therapy. Can J Cardiol 2007; 23:201-6. [PMID: 17347690 PMCID: PMC2647867 DOI: 10.1016/s0828-282x(07)70744-4] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022] Open
Abstract
AIM The relationships between clinical events and acetylsalicylic acid resistance (AR), as well as its frequency, have been established in stable patients with coronary artery disease (CAD). Although acute coronary syndrome (ACS) patients taking acetylsalicylic acid have been accepted as a high-risk population, the role of AR has not been investigated in these patient groups. Thus, in the present study, the impact of AR was investigated in patients with ACS who were taking acetylsalicylic acid. METHODS Between January 2001 and February 2003, 140 ACS patients were included in the present prospective study. All patients had ACS while taking acetylsalicylic acid. Coronary angiographic scores for severity and extent of CAD were determined for all patients. The effect of acetylsalicylic acid on platelet function was assessed by the platelet function analyzer PFA-100 (Dade Behring, USA). The primary end point was the composite of death, myocardial infarction, cerebrovascular accident and revascularization. The mean follow-up period was 20 months. RESULTS Patients with AR were older than patients without AR (63.8+/-10.8 years versus 58.3+/-11.2 years; P=0.005). Moreover, myocardial damage was higher in patients with AR according to cardiac troponin T values (1.11+/-1.3 mug/L versus 0.41+/-0.5 mug/L; P=0.01). The composite end point of death, myocardial infarction, cerebrovascular accident or revascularization was present in 16 of 45 patients (35%) with AR and in 13 of 79 patients (16%) without AR (hazard ratio 2.46, 95% CI 1.18 to 5.13; P=0.016). After adjustment for age, platelet count, cardiac troponin T value and CAD severity score, AR remained an independent predictor for long-term adverse events (hazard ratio 3.03, 95% CI 1.06 to 8.62; P=0.038). CONCLUSIONS The clinical event rate was found to be higher in ACS patients with AR than in those without AR. Thus, it may be concluded that there is a strong correlation between a worse prognosis and AR in these patients.
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Affiliation(s)
- Gultekin F Hobikoglu
- Siyami Ersek Thorax and Cardiovascular Surgery Center, Department of Cardiology, Istanbul, Turkey.
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Ruef J, Kranzhöfer R. Coronary stent thrombosis related to aspirin resistance: what are the underlying mechanisms? J Interv Cardiol 2007; 19:507-9. [PMID: 17107365 DOI: 10.1111/j.1540-8183.2006.00196.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
Acute coronary stent thrombosis represents a serious complication for which aspirin resistance could be a potential cause. The actual case is a myocardial infarction treated with immediate stenting of the right coronary artery followed by elective stenting of the left anterior descending artery 4 days later. Despite standard antiplatelet therapy, stents in both arteries occluded 2 days after the last procedure. The patient's blood samples were analyzed and revealed the presence of aspirin resistance as well as elevated thromboxane B(2) plasma levels. No thrombophilic disorder was detected. Today the mechanism of aspirin resistance is mostly unknown. Further research as well as recommendations for laboratory screening and for alternative pharmacological treatment options are required.
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Affiliation(s)
- Johannes Ruef
- Red Cross Hospital Cardiology Center, Frankfurt, Germany.
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Abstract
Clopidogrel (Plavix), Iscover) selectively and irreversibly inhibits adenosine diphosphate (ADP)-induced platelet aggregation. Long-term administration of clopidogrel was associated with a modest but statistically significant advantage over aspirin in reducing adverse cardiovascular outcomes in patients with established cardiovascular disease in the CAPRIE trial. In other large well designed multicentre trials, such as CURE, COMMIT and CLARITY-TIMI 28, the addition of clopidogrel to aspirin therapy improved outcomes in patients with acute coronary syndromes. However, some issues regarding the use of clopidogrel remain unresolved, such as the optimal loading dose in patients undergoing percutaneous coronary interventions (PCI) and the optimal treatment duration following drug-eluting intracoronary stent placement. Results of several large randomised trials, therefore, have established clopidogrel as an effective and well tolerated antiplatelet agent for the secondary prevention of ischaemic events in patients with various cardiovascular conditions, including those with ischaemic stroke or acute coronary syndromes. In addition, treatment guidelines from the US and Europe acknowledge the importance of clopidogrel in contemporary cardiovascular medicine.
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Affiliation(s)
- Greg L Plosker
- Wolters Kluwer Health | Adis, Auckland, New Zealand, an editorial office of Wolters Kluwer Health, Conshohocken, Pennsylvania, USA.
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