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Query: UMLS:C0151744 (myocardial ischemia)
 31,282 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Thromboembolic disease is a common medical condition which, if untreated, carries a significant risk of morbidity and mortality. Treatment with anticoagulant therapy, while clearly beneficial, may expose patients to potentially serious side effects. A thoughtful risk-benefit assessment is therefore crucial before initiating therapy. Thromboembolic disease involves syndromes of both the venous and arterial circulation, and its pathogenesis is best understood by considering the elements of Virchow's Triad. This model defines the risk factors for venous thromboembolism and allows us to classify surgical and medical patients into low, moderate and high risk groups. Similar analysis allows risk assessment for patients prone to cardiogenic embolism resulting from nonvalvular atrial fibrillation, ischaemic heart disease, rheumatic heart disease and valvular prostheses. All anticoagulant therapy is prophylactic. Primary prophylaxis involves instituting anticoagulant therapy in patients at risk, before thromboembolism occurs, while secondary prophylaxis involves treating patients with established disease. The 2 major anticoagulants, heparin and warfarin, differ in their mechanism of action, mode of administration and methods of monitoring. Either may be used as primary or secondary prophylaxis. Heparin, because it acts immediately, is the drug of choice for the short term treatment of thromboembolic disease. Warfarin is the drug of choice for long term oral maintenance therapy. The principal complication of heparin therapy is haemorrhage, although thrombocytopenia and osteoporosis may also occur; the complications of warfarin include haemorrhage and skin necrosis. The risks of complications vary with the underlying thromboembolic disease. After the benefits of treatment are weighed against the risks of complications, recommendations for therapy can be established. The use of anticoagulants in pregnancy is especially complex. Here heparin is probably the preferred agent since, unlike warfarin, it does not cross the placenta and is nonteratogenic.
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PMID:Risk-benefit assessment of anticoagulant therapy. 202 54

In a number of cardiac conditions (acute myocardial infarction, chronic left ventricular aneurysm, dilated cardiomyopathy, infective endocarditis and atrial fibrillation in the absence of valvular disease), the risk of embolism gives cause for concern. Although anticoagulation with warfarin (Coumadin)-derivatives has been shown to be effective in some of these situations, there is no evidence regarding the role of antiplatelet agents. The common factor in the thromboembolic potential of acute myocardial infarction, chronic left ventricular aneurysm and dilated cardiomyopathy is mural thrombus. This can be detected by two-dimensional echocardiography and indium-111 platelet scintigraphy. Although of value in elucidating the natural history of mural thrombus, in most cases, management is not substantially aided by these investigations. In patients with extensive myocardial infarction, particularly anterior infarction, moderate intensity anticoagulation started soon after hospital admission reduces the rate of embolism. After 8 to 12 weeks, embolic risk is low so that anticoagulants can usually be discontinued. Patients with chronic left ventricular aneurysm have a low incidence of embolism; anticoagulation is, therefore, inappropriate. Dilated cardiomyopathy is associated with a high risk of embolism; moderate intensity anticoagulation may be advisable in many such cases. Little information is available regarding the incidence of thromboembolism or the role of antithrombotic therapy in the patient with a diffusely dilated left ventricle due to ischemic heart disease. In native valve infective endocarditis, the risk of hemorrhage is high, and the efficacy of conventional anticoagulants unclear; thus, anticoagulation should not be instituted for the cardiac condition as such. However, in prosthetic valve endocarditis, the risk of embolism seems to be very high, and anticoagulant therapy should be continued, but with great care because there is a substantial risk of cerebral hemorrhage. Atrial fibrillation in patients with valvular heart disease is dealt with in a previous review. Patients with nonvalvular atrial fibrillation are at varying risk of embolism, depending on the etiology of the arrhythmia; trials of antithrombotic therapy are needed for the various subsets of patients. In most elderly patients, the etiology is not known, and their stroke risk is high. The risk of embolism in younger patients with idiopathic atrial fibrillation is so low as to make any antithrombotic therapy unnecessary.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Thrombosis and embolism from cardiac chambers and infected valves. 353 72

Coronary atherosclerosis is the process underlying virtually all the clinical manifestations of ischemic heart disease. When ulcer or fissure in the fibrous cap of the atheroma occur, platelet adhesion to subendothelium, aggregation and further platelet recruitment culminate in thrombus formation. These mechanisms are known to be responsible for most cases of acute events in patients with ischemic heart disease. Inside platelets, aspirin blocks the synthesis of thromboxane A2 by irreversibly inhibiting cyclooxygenase. Aspirin is recommended not only for treatment of patients with acute coronary syndromes (unstable angina, acute myocardial infarction), but also for secondary prevention of vascular events in chronic coronary syndromes. Aspirin prevents myocardial infarction in patients with chronic stable angina and reduces mortality, reinfarction and stroke in survivors of an acute myocardial infarction. Aspirin, alone or in combination with dipyridamole, prevents early and late occlusion of aortocoronary vein grafts. It is useful also in patients undergoing coronary angioplasty. Such benefits extend to all patients regardless of age, sex, history of hypertension or diabetes. Higher daily doses (900-1500 mg) are not more effective than lower doses (75-325 mg). Other antiplatelet drugs are not more effective than aspirin, which has the best risk-to-benefit and cost-to-benefit ratios. Ticlopidine is a reasonable alternative for use in preventing vascular events among patients intolerant to aspirin. Warfarin is an effective antithrombotic alternative to aspirin for secondary prevention after a myocardial infarction. However aspirin is easier to administer and follow-up when compared with warfarin. Warfarin should be preferred in high risk patients with left ventricular dysfunction with or without a mural thrombus, and those with associated atrial fibrillation.
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PMID:[Low-dose aspirin in the long-term treatment of the patient with ischemic heart disease]. 763 59

Warfarin has been widely used for an oral anticoagulant therapy against thrombotic diseases. For the monitoring of its anticoagulant intensities, prothrombin time (PT) ratio and percentage of thrombotest (TT) are commonly used in Japan. Recently, International Normalized Ratio (INR) was recommended by ICSH/ICTH. Practicality and usefulness of INR and its combined use of thrombin-antithrombin III complex (TAT) for the monitoring of oral anticoagulation therapy were evaluated among patients of ischemic heart disease with or without interventions, and of cardiomyopathies and valvular diseases. Difference in thromboplastin sensitivities have been shown to cause errors in PT elongation and in the evaluation of anticoagulant activity, so that the monitoring only by PT ratio is considered to be irrelevant, and that INR is recommended to be used. INR was comparable to the levels of TT. Majority of the patients, whose TAT levels were kept normal, were controlled below the proposed therapeutic ranges of INR. With the combination of INR and TAT monitoring, anticoagulant effect of warfarin could be achieved safer in lower dose than the levels that might cause bleeding accidents.
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PMID:[Monitoring for oral anticoagulant therapy]. 778 35

From March 1993 to February 1993, 36 patients with chronic renal failure underwent cardiac surgery with intraoperative hemodialysis (HD). We examined and compared the medium term results of those patients cased upon the time periods of operation and types of heart disease. With respect to the time periods of operation, the 1st term (n = 12) was between March 1985 and February 1989, and the 2nd term (n = 24) was between March 1989 and February 1993. Concerning types of disease, Group A was comprised of 24 patients with ischemic heart disease, and Group B was comprised of 12 patients with valvular or congenital heart disease. Only one early death was observed in the 1st term (8.3%: LOS). As for late death, 5 cases were observed in the 1st term (45.3%), and 2 cases were observed in the 2nd term (8.3%). The actuarial survival rate (post 3 years) was 72.7% in the 1st term and 91.3% in the 2nd term. In each case, the survival rate of the 2nd term was significantly better than the that of the 1st term (p < 0.025). When compared cased upon the types of disease, the actuarial survival rate (post 6 years) was 84.6% in Group A, and 45.5% in Group B, respectively. This difference was statistically significant (p < 0.05). Causes of late death were cerebral hemorrhage in 5 cases, sudden and unknown in one and DIC in the remaining one patient. There were many postoperative complications in this series in addition to the above stated fatal ones. The majority of them, however, were successfully treated, if early diagnosis of them was obtained. During the perioperative period through the long-term period, incidents of fatal hemorrhage among patients on chronic dialysis were reduced by 1) strict management of hypertension; 2) HD without use of Heparin; and 3) with respect to patients who required Warfarin after valve replacement, through the careful anti-coagulant therapy which maintained the thrombo-test (TT) value at precise levels.
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PMID:[Cardiac surgery in patients on chronic hemodialysis]. 891 Oct 41

In general, aspirin is indicated to prevent thrombosis in conditions associated with high shear rates (i.e., atherosclerosis) and warfarin is indicated to prevent thrombosis in conditions associated with stasis (i.e., atrial fibrillation). While aspirin and warfarin should generally not be used together, their combined use is beneficial in selected patients (e.g., some patients with mechanical valve prostheses). Aspirin in a dose of 75-150 mg per day is indicated to prevent vascular events in patients with ischaemic heart disease and also in patients at high risk of ischaemic heart disease. All patients with atrial fibrillation should be considered for oral anticoagulant therapy, with the decision for its use based on an assessment of the balance between the risk of thromboembolism and bleeding. The recommended therapeutic INR (international normalised ratio) range in non-valvular atrial fibrillation is 2.0-3.0. Warfarin is contraindicated in pregnancy, particularly during the first trimester; however, it may still need to be used in the second and third trimesters in patients with mechanical valve prostheses.
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PMID:Warfarin or aspirin: both or others? 1056 Apr 51

The choice of conduit is the most important factor influencing long-term patency of coronary artery bypass grafts (CABGs); arterial grafts are far superior to saphenous vein bypass grafts (SVGs) in this regard. Aspirin therapy should be started early in the perioperative period and continued indefinitely. Warfarin (Coumadin; Dupont, Wilmington, DE) and other platelet inhibitors offer no added value to aspirin, but may be used with benefit in aspirin-intolerant patients. Every effort should be made to reduce low-density lipoprotein cholesterol (LDL-C) to a value well below 100 mg/dL. In most instances, this will require the use of an 3-hydroxy-3-methyglutaryl coenzyme A (HMG CoA) reductase inhibitor. Avoidance of cigarette smoking is imperative. Achieving a normal blood pressure, ideal body weight, and a regular exercise program are helpful. Those patients who have important obstruction in a SVG or arterial graft and who are symptomatic, or who have important myocardial ischemia with orjwithout symptoms should be treated with a procedure to improve perfusion to the myocardium supplied by the occluded bypass graft. Successful percutaneous transluminal coronary angioplasty (PTCA) and stenting of the obstructed graft usually will lead to improved myocardial perfusion, although in other clinical circumstances repeat CABG surgery will be required. On occasion, reperfusion of the myocardium can be achieved by PTCA of the native coronary artery with or without stenting while the degenerated graft is abandoned. When planning therapy for myocardial ischemia, the higher rate of PTCA related restenosis and the increased risks from repeat CABG must be carefully considered.
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PMID:Coronary Artery Bypass Graft Degenerative Disease. 1113 89

Ischemic heart disease is an important and common contributor to the development of heart failure. Theoretically, all patients with heart failure may benefit from treatment designed to retard progressive ventricular dysfunction and arrhythmias. Patients with ischemic heart disease may also theoretically benefit from the relief of ischemia, the prevention of coronary occlusion, and revascularization. However, there is little evidence to show that the presence or absence of coronary disease modifies the benefits of effective treatments such as angiotensin-converting enzyme inhibitors and beta-blockers. Moreover, there is no evidence that treatment directed specifically at myocardial ischemia or coronary disease alters outcome in patients with heart failure. Treatments aimed at relieving painless myocardial ischemia have not been shown to alter prognosis. Lipid-lowering therapy is theoretically attractive for patients with heart failure and coronary disease; however, theoretical concerns also exist about the safety of such agents, and patients with heart failure have been excluded from large outcome studies very effectively. Some agents, such as aspirin, designed to reduce the risk of coronary occlusion seem ineffective or harmful in patients with heart failure, although warfarin may be safe and possibly effective. There is no evidence yet that revascularization improves prognosis in patients with heart failure, even in patients who are shown to have extensive myocardial hibernation. On current evidence, revascularization should be reserved for the relief of angina. Large-scale, randomized controlled trials are currently underway that are investigating the role of specific treatments targeted at coronary syndromes. The Carvedilol Hibernation Reversible Ischemia Trial: Marker of Success study is investigating the effects of carvedilol in a large cohort of patients with and without hibernating myocardium. The Warfarin and Antiplatelet Therapy in Chronic Heart Failure study is comparing the efficacy of aspirin, clopidogrel, and warfarin. The Heart Revascularization Trial-United Kingdom study is assessing the effect of revascularization on mortality in patients with heart failure and myocardial hibernation. Smaller scale studies are assessing the safety and efficacy of statin therapy in patients with heart failure. Only once the outcomes to these and other planned trials are known can the medical community know how best to treat their patients.
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PMID:What is the optimal medical management of ischemic heart failure? 1125 Nov 29

Our understanding of the pathogenesis of congestive heart failure (CHF) has improved remarkably in recent years. However, despite better knowledge and novel pharmaceutical strategies, this disease is still one of the most brutal killers in the Western world. The pathophysiology of CHF is complex, and much of our comprehension revolves strictly around the neurohormonal and mechanical mechanisms involved. It has been suggested that CHF is associated with altered hemostasis, but whether a prothrombotic state contributes to the pathogenesis and progression of the disease is still not well known. The purpose of this review article is to discuss our current knowledge of platelet activation in patients with CHF and the potential role of antiplatelet agents in preventing these hemostatic abnormalities. Clopidogrel is an established medication that reduces the incidence of stroke, myocardial ischemia, or vascular death. It is currently the drug of choice in the prophylaxis of subacute stent thrombosis and postischemic stroke treatment. Promising results of the most resent trials (Clopidogrel versus Aspirin in Patients at Risk of Ischemic Events [CAPRIE] and Clopidogrel in Unstable angina to prevent Recurrent Events [CURE]) may expand future indications of this ADP receptor antagonist for prevention of thrombotic complications in the CHF population. Currently conducted clinical trials (Warfarin and Antiplatelet Therapy in Chronic Heart Failure [WATCH] and Plavix Use for Treatment of Congestive Heart Failure [PLUTO-CHF] should clarify the role of clopidogrel in these patients.
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PMID:Platelet activation in patients with congestive heart failure: do we have enough evidence to consider clopidogrel? 1266 Jun 60

A 68-year-old woman with anti-phospholipid antigen syndrome (APS) was proposed to undergo partial pulmonary resection for lung cancer. She suffered from mild cerebellar ataxia. Exercised 201Tl myocardial scintigraphy was performed due to abnormal Q wave in preoperative electrocardiography and showed old myocardial infarction in inferior-to-posterior area without myocardial ischemia. Cardiac function was marginally decreased in cardiac echographic evaluation. Arterial thrombosis by APS might cause cerebellar ataxia and myocardial infarction. Low molecular weight heparin (LMWH) was continuously infused from 1 hour prior to arrival in an operation room. Elastic stockings (ES) were worn from the morning of the operation in combination with the use of intermittent pneumatic compression apparatus (IPC). Significant bleeding was not observed perioperatively. Hypothermia was avoided by forced-air-warming therapy. She was transferred to ICU after the end of the operation. She was returned to her ward without IPC on the first postoperative day. Warfarin was given with the beginning of ambulation on the second postoperative day to keep PT-INR about 2. On the third postoperative day LMWH was discontinued and ES were taken off. The postoperative course was uneventful.
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PMID:[Prophylaxis of perioperative pulmonary thromboembolism in a patient with anti-phospholipid antigen syndrome]. 1629 75


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