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Biomedical subjects

David A Vorchheimer

Publications and source records attributed to David A Vorchheimer.

4 recordsLinked to original sources

Platelets in atherothrombosis.

Atherosclerosis is a diffuse, systemic disease that affects the coronary, cerebral, and peripheral arterial trees. Disruption of atherosclerotic plaques leads to thrombus formation and arterial occlusion. This unpredictable and potentially life-threatening atherothrombotic sequence underlies clinical events such as angina, myocardial infarction, transient ischemic attacks, and stroke. One of the key components of a clot is the platelet. Although it was previously thought that platelets were relatively inactive cells that merely provided a framework for the attachment of other cells and proteins to mechanically stop bleeding due to injury, it is now known that this is not the case. Platelets secrete and express a large number of substances that are crucial mediators of both coagulation and inflammation. This article reviews the centrality of the platelet in atherothrombosis and briefly looks at the efficacy of antiplatelet agents in preventing and treating cardiovascular disease.

Atherosclerosis↗

What is QT interval prolongation?

QT interval prolongation is an irregularity of the electrical activity of the heart that places patients at risk for ventricular arrhythmias. Serious complications of drug-induced QT interval prolongation are rare; the identification of patients at risk may help to prevent these events.

Female↗

Multi-bed vascular disease and atherothrombosis: scope of the problem.

While atherosclerosis has traditionally been divided into three types of disease, coronary artery or coronary heart disease (CHD), cerebrovascular disease, and peripheral vascular or peripheral arterial disease (PAD), it is now clear that atherosclerosis is a systemic disease caused by the same pathologic processes regardless of the vascular bed involved. The burden of disease is enormous both in the US and around the world with 61,800,000 Americans affected with one or more types of CVD, responsible for 958,775 deaths annually at a cost of approximately US 329.2 billion dollars annually. Despite trends of decreasing cardiovascular mortality, the global burden of cardiovascular disease is expected to rise, with CHD and stroke becoming the first and fourth most common causes of mortality and morbidity globally. Atherosclerosis is a multibed process with a substantial portion of patients afflicted with disease in more than one bed, although often assymptomatic. Now that there are multiple therapies available to modify and treat atherosclerosis and atherosclerotic risk factors, identification and treatment of these patients are important since their leading cause of death is from co-existing cardiovascular disease.

Arteriosclerosis↗

Antithrombotic therapy for coronary artery disease: the Seventh ACCP Conference on Antithrombotic and Thrombolytic Therapy.

This chapter about antithrombotic therapy for coronary artery disease (CAD) is part of the Seventh ACCP Conference on Antithrombotic and Thrombolytic Therapy: Evidence Based Guidelines. Grade 1 recommendations are strong and indicate that the benefits do, or do not, outweigh risks, burden, and costs. Grade 2 suggests that individual patients' values may lead to different choices (for a full understanding of the grading see Guyatt et al, CHEST 2004; 126:179S-187S). Among the key recommendations in this chapter are the following: For patients presenting with non-ST-segment elevation (NSTE) acute coronary syndrome (ACS), we recommend immediate and then daily oral aspirin (Grade 1A). For patients with an aspirin allergy, we recommend immediate treatment with clopidogrel, 300-mg bolus po, followed by 75 mg/d indefinitely (Grade 1A). In all NSTE ACS patients in whom diagnostic catheterization will be delayed or when coronary bypass surgery will not occur until > 5 days, we recommend clopidogrel as bolus therapy (300 mg), followed by 75 mg/d for 9 to 12 months in addition to aspirin (Grade 1A). In NSTE ACS patients in whom angiography will take place within 24 h, we suggest beginning clopidogrel after the coronary anatomy has been determined (Grade 2A). For patients who have received clopidogrel and are scheduled for coronary bypass surgery, we recommend discontinuing clopidogrel for 5 days prior to the scheduled surgery (Grade 2A). In moderate- to high-risk patients presenting with NSTE ACS, we recommend either eptifibatide or tirofiban for initial (early) treatment in addition to treatment with aspirin and heparin (Grade 1A). For the acute treatment of NSTE ACS, we recommend low molecular weight heparins over unfractionated heparin (UFH) [Grade 1B] and UFH over no heparin therapy use with antiplatelet therapies (Grade 1A). We recommend against the direct thrombin inhibitors as routine initial antithrombin therapy (Grade 1B). For patients after myocardial infarction, after ACS, and with stable CAD, we recommend aspirin in doses from 75 to 325 mg as initial therapy and in doses of 75 to 162 mg as indefinite therapy (Grade 1A). For patients with contraindications to aspirin, we recommend long-term clopidogrel (Grade 1A). For primary prevention in patients with at least moderate risk for a coronary event, we recommend aspirin, 75 to 162 mg/d, over either no antithrombotic therapy or vitamin K antagonist (VKA) [Grade 2A]; for patients at particularly high risk of events in whom the international normalized ratio (INR) can be monitored without difficulty, we suggest low-dose VKA (target INR, 1.5) [Grade 2A].

Antithrombins↗