American heart journal
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American heart journal · Nov 2000
ReviewMultimodality reperfusion therapy for acute myocardial infarction.
With the strong and direct relation between early reperfusion in acute myocardial infarction (AMI) and improved clinical outcomes, attention has focused on new means of improving rates of reperfusion and accelerating every stage of AMI evaluation and management, from the onset of symptoms of myocardial infarction to the achievement of reperfusion. Critical pathways to streamline the evaluation and management of AMI have cut minutes and even hours off in-hospital treatment times for patients with AMI; public health initiatives focus on educational efforts to shorten time to hospital arrival. ⋯ Bolus fibrinolytic agents are being evaluated for use in combination with other interventions to open occluded coronary arteries, including acute percutaneous coronary intervention, the glycoprotein IIb/IIIa platelet inhibitors, or both. The goal of this "multimodality" approach to AMI management is to minimize time to reperfusion and maximize the percentage of patients who achieve complete arterial patency and myocardial perfusion without bleeding complications.
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American heart journal · Oct 1999
Review Comparative StudyPharmacokinetics and pharmacodynamics of glycoprotein IIb-IIIa inhibitors.
Antagonists of the platelet receptor glycoprotein (GP) IIb-IIIa are a novel class of antithrombotic agents that provide more comprehensive platelet blockade than the combination of aspirin and heparin. Studies in patients scheduled for percutaneous coronary intervention and those with unstable angina or non-Q-wave myocardial infarction have shown that a combination of intravenous GP IIb-IIIa inhibitors with aspirin and heparin is associated with a reduction in death or myocardial infarction compared with therapy with aspirin and heparin alone. As with other antithrombotic agents, the principal safety issue with GP IIb-IIIa inhibitors is bleeding, because the potent antiplatelet effect of these drugs may adversely affect hemostasis. ⋯ Additionally, antagonists of GP IIb-IIIa may increase the risk of thrombocytopenia. The safety profiles of various GP IIb-IIIa inhibitors are largely a function of their pharmacokinetic and pharmacodynamic properties, most notably the reversibility of platelet inhibition and the rate of plasma clearance. Knowledge of the pharmacokinetic and pharmacodynamic properties of the GP IIb-IIIa inhibitors is critical for the appropriate utilization of this new class of drugs.
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American heart journal · Oct 1999
Review Comparative StudySafety of glycoprotein IIb-IIIa inhibitors: A heart surgeon's perspective.
Platelet-mediated coronary thrombosis is the primary pathophysiologic mechanism of acute coronary syndromes (ACS) and acute ischemic complications of percutaneous coronary intervention (PCI). The final common pathway of platelet aggregation that leads to thrombotic occlusion of coronary arteries involves cross-linking of receptor glycoprotein (GP) IIb-IIIa on adjacent platelets by adhesive plasma proteins, primarily fibrinogen. Clinical trials of several GP IIb-IIIa inhibitors have demonstrated an unequivocal clinical benefit of this potent antithrombotic therapy in patients with ACS as well as in those undergoing PCI. ⋯ Therefore, among patients requiring CABG after treatment with GP IIb-IIIa inhibitors, eptifibatide and tirofiban may be associated with fewer bleeding episodes than is abciximab. With recent approval of eptifibatide for patients with ACS and those scheduled for PCI and of tirofiban for patients with ACS, the number of patients receiving GP IIb-IIIa inhibitor therapy who subsequently undergo CABG is expected to increase significantly. Strategies for improved management of bleeding complications in these patients, including the choice of a GP IIb-IIIa inhibitor, are clearly needed and are discussed in detail.
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American heart journal · Aug 1999
ReviewOptimal treatment of patients with acute coronary syndromes and non-ST-elevation myocardial infarction.
Non-ST-elevation myocardial infarction is usually indistinguishable from unstable angina at the initial presentation. The diagnosis is made subsequently when cardiac enzymes are found to be elevated either at admission or within 18 hours. Our understanding of the pathophysiology of acute coronary syndromes has advanced dramatically, and coupled with this understanding has been the introduction of new antiplatelet and antithrombotic treatments. ⋯ Patients at intermediate risk should be treated with aspirin, unfractionated or low-molecular-weight heparin and, if unfractionated heparin is chosen, an adjunctive IIb/IIIa receptor antagonist. Patients at high risk should be treated with the same therapies and considered for expeditious angiography and revascularization as appropriate. A long-term secondary prevention strategy should be implemented.