Oral Antiplatelet Drugs Research Articles

Enfermedad coronaria aguda y crónica. ¿Cómo tratamos los diferentes subgrupos?

La aparición de los nuevos antiagregantes orales que actúan bloqueando el receptor de adenosindifosfato P2Y 12 en las plaquetas ha supuesto un importante avance en el manejo de los pacientes con síndrome coronario agudo. En el espectro general de los síndromes coronarios agudos, tanto el prasugrel como el ticagrelor se han demostrado más eficaces que el clopidogrel en reducir el riesgo de nuevos eventos cardiovasculares, aunque con un discreto aumento en el número de hemorragias. Por otro lado, los pacientes que sufren un síndrome coronario agudo tienen un perfil heterogéneo, y tanto los beneficios como los riesgos en la utilización de estos nuevos tratamientos no son uniformes. En este contexto, el objetivo de este artículo es revisar los resultados de los análisis de subgrupos que comparan la eficacia y la seguridad del prasugrel y el ticagrelor frente al clopidogrel con la intención de definir los perfiles clínicos con el balance riesgo-beneficio más propicio al manejo con los nuevos bloqueadores orales del receptor P2Y 12 . The introduction of new oral antiplatelet drugs that act by blocking the adenosine diphosphate P2Y 12 receptor in platelets represents a substantial step forward in the treatment of patients with acute coronary syndrome. Both prasugrel and ticagrelor have been shown to be more effective than clopidogrel in preventing cardiovascular events in a broad spectrum of acute coronary syndromes, although there is also a small increase in the number of bleeding events. On the other hand, patients suffering from acute coronary syndromes form a heterogeneous group, which means that the benefits and risks of these new treatments may vary. With this variability in mind, the aim of this article was to review the results of a subgroup analysis that compared the efficacy and safety of prasugrel and ticagrelor with the efficacy and safety of clopidogrel and which had as its objective the identification of patients with clinical profiles associated with a favorable risk-benefit balance on treatment with the new oral P2Y 12 receptor antagonists.

New Oral Antiplatelet Agents

Antiplatelet agents play an essential role in the treatment of acute coronary syndrome (ACS). Aspirin and thienopyridines comprise the major classes of antiplatelet therapies demonstrated to be of benefit in the treatment of ACS. Thienopyridines are a class of drugs that function via inhibition of the adenosine diphosphate (ADP) P2Y12 platelet receptors. While clopidogrel remains in extensive use in clinical practice, it cannot meet the needs in many clinical conditions because of its pharmacological limitations. In recent years, newly developed P2Y12 antagonists, such as prasugrel and ticagrelor, have proven to be of higher efficacy and less resistance. As a third generation thienopyridine, prasugrel exerts a much more rapid and consistent inhibitory effect on platelet aggregation than clopidogrel. Treatment with ticagrelor, nonthienopyridine oral antiplatelet drug, significantly reduced the rate of death from vascular causes, myocardial infarction, or stroke without an increase in the rate of overall major bleeding as compared with clopidogrel. The present review aims to discuss the current knowledge on the safety and efficacy of new oral antiplatelet agents including prasugrel and ticagrelor. (Korean J Med 2013;85:10-14)

Oral anticoagulant and antiplatelet drugs used in prevention of cardiovascular events in elderly people in Poland.

BackgroundIn Poland, the prevalence of cardiovascular diseases is increasing. This might be associated with the constantly growing proportion of elderly people and inappropriate cardiovascular prevention. This study aimed to evaluate the frequency of use of oral antiplatelet (OAP) and oral anticoagulant (OAC) drugs among older people in Poland and to assess their association with cardiovascular risk factors.MethodsThe study was based on data collected during the implementation of a multicentre, publicly funded research project called PolSenior.ResultsThe study group consisted of 4,979 people with the average age of 79.35 ± 8.69 years. Among them, 1,787 people (35.9%) used at least one drug in the prevention of cardiovascular diseases. OAPs were used regularly by 1,648 (33.1%) elderly people and OACs were used by 165 elderly people (3.3%). Acetylsalicylic acid was used by 32.2% of elderly people. Use of drugs significantly depended on age (p < 0.01), sex (p < 0.01), place of residence (p < 0.001), level of education (p < 0.0001) and personal income (p < 0.0001). Among all the respondents treated with OAPs, therapy was applied as secondary cardiovascular prevention in 717 respondents (43.5%), and as primary prevention in 705 respondents (42.8%). Among the respondents treated with OACs, 117 (71%) elderly people had a history of atrial fibrillation. Secondary cardiovascular prevention should be considered in a further 482 respondents (15.1% of untreated elderly people), and primary cardiovascular prevention in 1,447 respondents (45.3%).ConclusionsOur study is the first to determine the frequency of use of OAP and OAC drugs among elderly people in Poland in relation to cardiovascular risk factors. The most commonly used drug for cardiovascular prevention is acetylsalicylic acid, but it appears that it is used too rarely in high-risk patients. Educational programs should be developed among general practitioners concerning current recommendations for pharmacological cardiovascular prevention.

Prasugrel metabolites inhibit neutrophil functions.

Clopidogrel and prasugrel belong to a thienopyridine class of oral antiplatelet drugs that, after having been metabolized in the liver, can inhibit platelet function by irreversibly antagonizing the P2Y(12) receptor. Furthermore, thienopyridines influence numerous inflammatory conditions, but their effects on neutrophils have not been evaluated, despite the important role of these cells in inflammation. Therefore, we investigated the effect of prasugrel metabolites on neutrophils to further clarify the role of thienopyridines in inflammation. Interestingly, a prasugrel metabolite mixture, produced in vitro using rat liver microsomes, significantly inhibited N-formyl-methionyl-leucyl-phenylalanine (fMLP)- and platelet-activating factor (PAF)-induced neutrophil activation. More specifically, prasugrel metabolites inhibited neutrophil transmigration, CD16 surface expression, and neutrophil-platelet aggregation. Moreover, prasugrel metabolite pretreatment also significantly decreased fMLP- or PAF-induced extracellular-signal-regulated kinase phosphorylation as well as calcium mobilization. To determine the target of prasugrel in neutrophils, the role of both P2Y(12) and P2Y(13) receptors was studied using specific reversible antagonists, AR-C69931MX and MRS2211, respectively. Neither antagonist had any direct effect on the agonist-induced neutrophil functional responses. Our findings indicate that prasugrel metabolites may directly target neutrophils and inhibit their activation, suggesting a possible explanation for their anti-inflammatory effects previously observed. However, these metabolites do not act through either the P2Y(12) or P2Y(13) receptor in neutrophils.

Severe and Recurrent Interface Hemorrhage after Endothelial Keratoplasty

To report the occurrence and management of recurrent hemorrhage after Descemet stripping endothelial keratoplasty (DSEK) in a patient with pseudophakic bullous keratopathy. An 84-year-old Chinese woman on two oral antiplatelet drugs underwent DSEK in her left eye. Preoperative best-corrected visual acuity was 20/30 OD and 14/200 OS. Intraoperative bleeding was noted from the iris root. Surgery was completed uneventfully, and interface was thoroughly irrigated in the end. Slit lamp examination on the first postoperative day showed a dense interface hemorrhage and an intraocular pressure of 24 mm Hg. Repeat interface irrigation was carried out on postoperative day 4, but the hemorrhage appeared again on the following day. Donor lenticule was well apposed to the corneal stroma, and visual acuity was hand motions in the operated eye. No further surgical interventions were performed. Corticosteroid eye drops were continued four times a day in the operated eye, and the patient was advised weekly follow-up. Over the next 4 weeks, the interface blood gradually started to clear from the central cornea. At the end of 4 months postoperatively, the interface hemorrhage disappeared completely. A final best-corrected visual acuity of 20/80 was achieved. Specular microscopy revealed an endothelial cell density of 1375 cells/mm2. Interface hemorrhage is a known complication after DSEK surgery. Recurrent hemorrhage may be expected in patients on oral antiplatelet treatment. In cases without associated graft dislocation, conservative management can still result in good visual outcome.

Interindividual Variability in the Efficacy of Oral Antiplatelet Drugs: Definitions, Mechanisms and Clinical Importance

The modern era of antiplatelet therapy was founded by large clinical trials demonstrating the benefit of aspirin and clopidogrel in the treatment and prevention of acute coronary syndromes. The concept of antiplatelet drug "resistance" emerged during the 1990s with studies revealing considerable residual platelet aggregation in some patients despite aspirin treatment. In the wake of these reports, larger studies established an association between high on-treatment platelet reactivity and thrombotic events. The possible mechanisms explaining this phenomenon are manifold and reflect the complexity of platelet function, thrombus formation and cardiovascular disease. Some mechanisms apply to both drugs, while others apply only to one of them. In recent years, efforts have been made to translate this information into an improved clinical outcome by modifying antiplatelet drug regimens. Several studies investigated measurements of on-treatment platelet reactivity, but large clinical trials have failed to demonstrate substantial clinical benefit of individually tailored antiplatelet therapy according to platelet function tests. This article provides an integrated review of interindividual variability in the efficacy of aspirin and clopidogrel with particular emphasis on possible effect-modifying mechanisms and clinical implications.

Antiplatelet drugs in elective ENT surgery

Oral antiplatelet drugs are increasingly being encountered in patients scheduled for elective ENT surgery. Their pre-operative cessation can have potentially serious complications in some patients, particularly those with intracoronary stents. In order to gain an impression of current peri-operative management of patients taking antiplatelet drugs, an online survey was distributed to the Expert Panel of ENT UK, the British Association of Otolaryngologists Head and Neck Surgeons, between 13 January and 15 February 2011. Three hundred and three members were contacted. The response rate was 55 per cent (167 replies); 78 per cent of respondents were consultants. Results are presented in the main text. Patients can be categorised as high or low risk, depending on their indication for taking antiplatelet drugs. Recommendations taken from the literature are given on how best to manage these two groups.

Antiplatelet Therapy in Patients with Diabetes Mellitus

Platelets are key players in arterial thrombosis, and oral antiplatelet therapy is a cornerstone in the treatment and prevention of cardiovascular events. However, although currently approved antiplatelet drugs have proved successful in reducing cardiovascular events, platelet-dependent thrombosis remains an important cause of morbidity and mortality in patients with coronary artery disease. It is well-known that patients with diabetes mellitus (DM) have an increased risk of cardiovascular events and, therefore, understanding the mechanism of action and safety profile of antiplatelet drugs in this high-risk population is of particular interest. There is considerable inter-individual variation in the efficacy of established antiplatelet drugs, and high on-treatment platelet reactivity is associated with an increased risk of cardiovascular events, thus prompting the search for novel drugs against platelet-dependent thrombosis. New antiplatelet treatment strategies include drugs with more efficient and reversible platelet inhibition. This review discusses selective inhibitors of the platelet cyclooxygenase enzyme, thienopyridine and non-thienopyridine inhibitors of the platelet adenosine diphosphate receptor, phosphodiesterase inhibitors, and protease-activated receptor antagonists. An overview of currently available antiplatelet drugs is provided, focusing on benefits and limitations in patients with DM. Furthermore, the rationale for new oral antiplatelet drugs under development is discussed with particular focus on the potential role of these drugs to improve cardiovascular outcomes in patients with DM.

Chinese Herb and Formulas for Promoting Blood Circulation and Removing Blood Stasis and Antiplatelet Therapies

Atherothrombosis, which directly threatens people's health and lives, is the main cause of morbidity and mortality all over the world. Platelets play a key role in the development of acute coronary syndromes (ACSs) and contribute to cardiovascular events. Oral antiplatelet drugs are a milestone in the therapy of cardiovascular atherothrombotic diseases. In recent years, many reports have shown the possibility that “resistance” to oral anti-platelet drugs and many adverse reactions, such as serious bleeding risk, which provides an impetus for developing new anti-platelet drugs possesses highly efficiency and fewer adverse effects. Study on the blood stasis syndrome and promoting blood circulation and removing blood stasis is the most active field of research of integration of traditional and western medicine in China. Blood-stasis syndrome and platelet activation have close relationship, many Chinese herb and formulas for promoting blood circulation and removing blood stasis possess definite anti-platelet effect. This paper covers the progress of anti-platelet mechanism of Chinese herb and formulas for promoting blood circulation and removing blood stasis and is to be deeply discussed in further research.

Contemporary use of glycoprotein IIb/IIIa inhibitors

Platelet glycoprotein IIb/IIIa inhibitors (GPI) are antithrombotic agents preventing the binding of fibrinogen to GP IIb/IIIa receptors. Thus, GPI interfere with interplatelet bridging mediated by fibrinogen. Currently, three generic GPI with different antithrombotic properties are available for intravenous administration: abciximab, eptifibatide, and tirofiban. The development of oral GPI was abandoned, whereas intravenous GPI were introduced in various clinical settings during the 1990s, yielding substantial benefit in the treatment of acute coronary syndromes, particularly during percutaneous coronary interventions. Results of the many randomised trials evidenced the efficacy of this drug class, though these trials were conducted prior to the emergence of modern oral antiplatelet therapy with efficient P2Y(12) inhibitors. Subsequent trials failed to consolidate the strongly favourable impression of GPI, and indications for their use have been more restricted in recent years. Nonetheless, GPI may still be beneficial during coronary interventions among high-risk patients including acute ST-elevation and non-ST-elevation myocardial infarctions, particularly in the absence of adequate pretreatment with oral antiplatelet drugs or when direct thrombin inhibitors are not utilised. Intracoronary GPI administration has been suggested as adjunctive therapy during primary percutaneous coronary intervention, and the results of larger ongoing trials are expected to elucidate its clinical potential. The present review outlines the key milestones of GPI development and provides an up-to-date overview of the clinical applicability of these drugs in the era of refined coronary stenting, potent antithrombotic drugs, and novel thrombin inhibiting agents.

Oral antiplatelet agents in ischemic heart disease: a review of the latest clinical evidence

Platelet activation and aggregation play a central role in the pathophysiology of thrombogenesis in ischemic heart disease. Dual antiplatelet therapy with aspirin and clopidogrel is currently the golden standard in the prevention of cardiovascular complications after percutaneous coronary intervention. Newer antiplatelet drugs are continuously marketed to respond to the limitations of clopidogrel, namely a delayed onset of action, an irreversible inhibition of platelet aggregation as well as a substantial variability in antiplatelet effect, in part due to genetic polymorphism. The second-generation thienopyridine prasugrel is more potent than clopidogrel, but also manifests a greater bleeding risk. Ticagrelor, a third-generation thienopyridine, seems to have a better safety profile and has recently been approved as a first-choice antiplatelet treatment in acute coronary syndrome in Europe. This article will review the different oral antiplatelet drugs currently available, compare pharmacology and safety/e...

Trends in acute myocardial infarction treatment between 1998 and 2007 in a Belgian area (Charleroi)

To describe the evolution of the therapeutic practices over 10 years of follow-up of acute myocardial infarction (AMI) in Charleroi and to analyse the factors influencing the choice of treatments and the mortality of these patients. The Charleroi register of ischaemic cardiopathies is the oldest register of infarctions in the French-speaking community of Belgium and is one of the very rare registers that allows identifying tendencies over 25 years. Analyses presented hereafter relate only patients in the 25-69-year age range over time from 1998 to 2007. The data were analysed in five periods of 2 years. Treatment evolutions over time were analysed using chi-squared tests for trend and logistic regression analyses identify factors influencing the type of treatment. The present study shows a marked increase in the utilization of percutaneous transluminal coronary angioplasty (PTCA) between 1998-1999 and 2006-2007. The use of thrombolytic agents on approximately one-third of the patients treated remained fairly stable between 1998 and 2007. A lower proportion of patients with a history of AMI received thrombolytic agents. Thrombolysis seems beneficial for men and without effect for women. The use of β-blockers continued to increase until the 2000-2001 period and remained fairly stable for the two following periods. 42% of patients were administered three medications (angiotensin-converting enzyme inhibitors, antiplatelet drugs, and β-blockers). Association of PTCA with antiplatelet drugs, β-blockers, and thrombolysis was observed for 58.7, 50.6, and 25.7%, respectively. These associations were still observed after adjustment for gender, age, and comorbidity. The factors associated with fatality were specifically old-aged patients, antecedents of diabetes, hypercholesterolaemia and oral antiplatelet drugs, and β-blockers therapies and PTCA. The evolution of the therapeutic data on AMI in this register confirms the use and the efficacy of thrombolytic therapy. PTCA becomes the main coronary reperfusion treatment with less risk of bleeding. Angiotensin-converting enzyme inhibitors were without effect on mortality.

Ticagrelor

The complex mechanism of platelet activation creates an optimal target for pharmacological treatment in patients with acute coronary syndromes. Current antiplatelet medications that are used in addition to aspirin include the thienopyridines, clopidogrel and prasugrel, but there are several limitations to the use of these medications. Clopidogrel and prasugrel irreversibly bind to the P2Y12 receptor, creating a prolonged antiplatelet effect which can be undesirable when surgery is needed. Clopidogrel requires hepatic activation and produces variable platelet inhibition based on genetic polymorphisms. Prasugrel has more consistent platelet inhibition than clopidogrel but carries with it an increased risk of serious bleeds. Ticagrelor is a drug in a new chemical class that reversibly binds the P2Y12 receptor and noncompetitively blocks adenosine diphosphate-induced platelet activation. It was specifically designed to address the limitations of the available antiplatelet agents while maintaining comparable or better antiplatelet effects. It does not require metabolic activation and demonstrates greater platelet inhibition, a faster offset of action and comparable bleeding risk compared to clopidogrel. The pivotal PLATO (The Study of Platelet Inhibition and Patient Outcomes) trial in patients with an acute coronary syndrome demonstrated improved cardiovascular outcomes, including a reduction in myocardial infarctions and vascular events using ticagrelor as compared to clopidogrel with comparable rates of major bleeds. A puzzling finding from that trial was the lack of benefit with ticagrelor in patients enrolled from the United States, which has led to ticagrelor not being approved at this time in this country. The main adverse events with ticagrelor are bleeding and dyspnea, the latter of which is of unclear etiology and of unknown long-term clinical concern. In summary, ticagrelor is an exciting new oral antiplatelet drug that seems to be more efficacious than clopidogrel, with comparable safety. Whether issues of geographic disparities in response and the unusual side effect of dyspnea ultimately prove problematic has yet to be determined. Nonetheless, ticagrelor is a drug that has the potential to change the standard of care of patients with acute coronary syndromes.

Aspirin and Antiplatelet Agent Resistance

Oral antiplatelet drugs, including aspirin, clopidogrel and extendedrelease dipyridamole, are widely prescribed for the secondary prevention of vascular events, including stroke. Despite the benefits of antiplatelet therapy, 10–20% of patients experience a recurrent vascular event while taking antiplatelet medication. This article discusses the concept of antiplatelet resistance in general, focusing on aspirin resistance in particular, as a poorly defined cause of recurrent vascular events. Factors such as the lack of a standardized method to diagnose aspirin resistance and a poor clinical correlation with laboratory assays make the treatment of aspirin nonresponders difficult. In addition, there are confounding conditions such as diabetes mellitus that can affect aspirin resistance and determine a different course of treatment for these patients. Other antiplatelet options may also have resistant subpopulations; thus, alternative strategies for the secondary stroke patient must be explored.

Anti-Platelet Therapy and Aspirin Resistance – Clinically and Chemically Relevant?

Platelets play a central role in the pathogenesis of the atherothrombosis which ultimately causes myocardial infarction, stroke and peripheral vascular disease. Commonly used oral anti-platelet drugs include aspirin (an irreversible inhibitor of cyclo-oxygenase), clopidogrel (an ADP receptor antagonist), other thienopyridines such as ticlopidine and prasgruel, and dipyridamole (an inhibitor of adenosine reuptake and platelet phosphodiesterase). Newer agents are in development and one, ticagrelor, a reversible ADP receptor antagonist has shown promise. Despite their proven benefit, recurrent vascular events still occur in those taking anti-platelet drugs. This has led to the concept of anti-platelet resistance, most commonly aspirin resistance as this drug is the cornerstone of most regimens. The causes of aspirin resistance are numerous but potential mechanisms include lack of patient adherence, non COX-1 mediated thromboxane A2 synthesis, increased activity of alternate platelet activation pathways, interference of aspirin action by other drugs and probably pharmacogenetic factors. Measurement of platelet response to aspirin is made possible using a number of in-vitro laboratory assays of platelet function which include measurement of thromboxane A2 metabolites as well as newer point-of-care assays of platelet aggregation. The phenomenon of aspirin resistance is important as it raises the possibility of developing strategies to identify those who respond best to a particular anti-platelet regimen, or to development of newer anti-platelet therapies to which more patients respond. This review discusses important aspects of aspirin resistance both in terms of clinical medicine, alternative anti-platelet strategies, and the potential to overcome its various causes.

Oral antiplatelet agents in ACS: from pharmacology to clinical differences

Antiplatelet agents play an essential role in the treatment of acute coronary syndrome (ACS). Numerous clinical trials have established the value of antiplatelet therapies for ACS. Aspirin (ASA), thienopyridines and GP IIb/IIIa antagonists comprise the major classes of antiplatelet therapies demonstrated to be of benefit in the treatment of ACS. Thienopyridines are a class of drugs that function via inhibition of the adenosine diphosphate (ADP) P2Y12 platelet receptors. Currently, clopidogrel, a second generation thienopyridine, is the main drug of choice and the combination of aspirin and clopidogrel is administered orally for the treatment of ACS. Recently, a third generation of thienopyridines has been introduced represented by prasugrel that has demonstrated promising results in ACS patients treated with percutaneous coronary intervention (PCI). A number of nonthienopyridine oral antiplatelet drugs are under development, and one of them, ticagrelor has already been tested in a major phase III clinical trial, PLATO, with the inclusion of a broad spectrum of patients with ACS. The present review aims to discuss the present knowledge about the safety and efficacy of oral antiplatelet treatment of patients with ACS.

Use of antiplatelet therapies during primary percutaneous coronary intervention for acute myocardial infarction

Inhibition of platelet function is necessary to achieve successful and long-lasting primary percutaneous coronary intervention (PCI) for acute myocardial infarction. For many years, antiplatelet therapy in the setting of primary PCI consisted of two drugs that inhibit platelet activation (aspirin and clopidogrel) and an intravenous blocker of platelet aggregation (abciximab). The development of new, more potent oral antiplatelet drugs (prasugrel and ticagrelor) as well as new data on clopidogrel dosing regimens limited the use of abciximab after pretreatment with aspirin and clopidogrel. Thus, intracoronary administration of abciximab and the use of small molecule glycoprotein IIb/IIIa blockers (tirofiban or eptifibatide) challenge the contemporary schemes of antiplatelet treatment in primary PCI. We review recently published data with particular attention on patients and drug characteristics and propose an update of existing recommendations.

Combination Antithrombotic Therapies

Atherothrombosis is the major pathophysiological process responsible for the occurrence of severe ischemic events in patients with cardiovascular diseases. In the United States, atherothrombosis strongly influenced mortality in 2004: One in 2.8 deaths was due to CVD, 1 in 5 deaths to coronary heart disease, and 1 in 17 deaths to stroke.1 Because cardiovascular disease is a progressive and systemic disease, long-term antithrombotic therapies that effectively target the entire arterial vasculature and modulate the key components responsible for thrombus generation are essential to improve patient outcomes. Because platelet activation is determined by multiple receptor-mediated signaling pathways, clinical studies have evaluated the efficacy of multidrug administration in the prevention of atherothrombotic complications.2,3 The major concern with these therapies is the critical balance between anti-ischemic effect and bleeding risk. This review summarizes our understanding of the role of combination antiplatelet therapies in the treatment and prevention of atherothrombosis. Platelet activation and aggregation play a pivotal role in the generation of occlusive thrombus at the site of coronary arterial plaque rupture. In addition, platelets influence various endothelial and inflammatory responses during the initiation and progression of atherosclerosis. Under normal conditions, anucleate circulating platelets are in a quiescent state. Healthy vascular endothelium prevents adhesion and activation of platelets by producing antithrombotic factors such as CD39 (ectoADPase), prostaglandin I2, nitric oxide, heparin, matrix metalloproteinase-9, protein S, and thrombomodulin.3,4 Endothelial activation and denudation and frank atherosclerotic plaque rupture expose the subendothelial matrix and release prothrombotic factors during acute coronary syndromes (ACS) and percutaneous interventions. These processes result in localized platelet adhesion and platelet activation. After adhesion to the exposed subendothelial matrix, platelets are activated by shear and the soluble agonists thromboxane A2 (TxA2), ADP, and thrombin. TxA2 is produced from arachidonic acid, which originates from membrane phospholipids and …

Evaluation of bleeding risk and measurement methods in dental patients

The present study explores bleeding manifestations in routine dental surgical procedures, evaluates the influence of antithrombotic drugs upon bleeding risk, and validates the efficiency of a clinical method for the measurement of bleeding. A prospective observational study was made involving a cohort of 99 patients in the setting of normal clinical practice, with the added conduction of prior hematological tests including baseline hemostasis and platelet function, based on a new method (Multiplate System®). For evaluation of the bleeding manifestations, a clinical method was selected that evaluates bleeding on the basis of its duration and the hemostatic measures needed to resolve the problem. Almost one-third of the patients (27.3%) were receiving treatment with oral antiplatelet drugs, while 19.2% received oral anticoagulants and 9% received combined therapy with acetylsalicylic acid plus clopidogrel. In turn, an 8% incidence of moderate bleeding episodes was detected correlated to the ASPI platelet function test and to advanced patient age. The incorporation of platelet function tests increases the safety of oral surgery in elderly patients subjected to antiplatelet treatment, particularly with acetylsalicylic acid and clopidogrel.

Oral Antiplatelet Therapy in Unstable Angina/Non–ST-Segment Elevation Myocardial Infarction, ST-Segment Elevation Myocardial Infarction, and Percutaneous Coronary Intervention: Is it Time for a Guideline Update?

Oral antiplatelet drugs are central in the management of acute coronary syndromes, including unstable angina/non-ST-segment elevation myocardial infarction, ST-segment elevation myocardial infarction, and percutaneous coronary intervention. However, the mechanisms that confer the benefits of these agents also increase bleeding risk. Thus, the selection of appropriate pharmacotherapy requires close attention to the delicate balance between reducing the risk of ischemic events and minimizing bleeding risk. A critical review of the 2007 guidelines in these areas and new clinical data with currently available and soon-to-be-approved antiplatelet agents are presented.