Medline ® Abstracts for References 18-20
of 'Perioperative management of patients receiving anticoagulants'
Intracardiac thrombus formation in cardiac impairment: the role of anticoagulant therapy.
Postgrad Med J. 1996;72(854):731.
The presence of intracardiac thrombus has been associated with many diseases and clinical states, although cardiac impairment is commonly also present. Despite this, there continues to be a lack of consensus on which patients with cardiac impairment should have anticoagulant therapy. This review discusses the relationship between thromboembolism and cardiac impairment secondary to ischaemic heart disease, and suggests possible mechanisms, methods of diagnosis and therapeutic strategies for anticoagulation in such patients. In particular, warfarin has been established as thromboprophylaxis in certain subgroups of patients with cardiac impairment secondary to ischaemic heart disease. A large-scale randomised controlled trial in ambulant patients with cardiac impairment to evaluate the effectiveness of anticoagulant therapy and antiplatelet therapy is, however, long overdue.
University Department of Medicine, City Hospital, Birmingham.
Ventricular dysfunction and the risk of stroke after myocardial infarction.
Loh E, Sutton MS, Wun CC, Rouleau JL, Flaker GC, Gottlieb SS, Lamas GA, MoyéLA, Goldhaber SZ, Pfeffer MA
N Engl J Med. 1997;336(4):251.
BACKGROUND: In patients who have had a myocardial infarction, the long-term risk of stroke and its relation to the extent of left ventricular dysfunction have not been determined. We studied whether a reduced left ventricular ejection fraction is associated with an increased risk of stroke after myocardial infarction and whether other factors such as older age and therapy with anticoagulants, thrombolytic agents, or captopril affect long-term rates of stroke.
METHODS: We performed an observational analysis of prospectively collected data on 2231 patients who had left ventricular dysfunction after acute myocardial infarction who were enrolled in the Survival and Ventricular Enlargement trial. The mean follow-up was 42 months. Risk factors for stroke were assessed by both univariate and multivariate Cox proportional-hazards analysis.
RESULTS: Among these patients, 103 (4.6 percent) had fatal or nonfatal strokes during the study (rate of stroke per year of follow-up, 1.5 percent). The estimated five-year rate of stroke in all the patients was 8.1 percent. As compared with patients without stroke, patients with stroke were older (mean [+/-SD]age, 63+/-9 years vs. 59+/-11 years; P<0.001) and had lower ejection fractions (29+/-7 percent vs. 31+/-7 percent, P=0.01). Independent risk factors for stroke included a lower ejection fraction (for every decrease of 5 percentage points in the ejection fraction there was an 18 percent increase in the risk of stroke), older age, and the absence of aspirin or anticoagulant therapy. Patients with ejection fractions of<or = 28 percent after myocardial infarction had a relative risk of stroke of 1.86, as compared with patients with ejection fractions of more than 35 percent (P=0.01). The use of thrombolytic agents and captopril had no significant effect on the risk of stroke.
CONCLUSIONS: During the five years after myocardial infarction, patients have a substantial risk of stroke. A decreased ejection fraction and older age are both independent predictors of an increased risk of stroke. Anticoagulant therapy appears to have a protective effect against stroke after myocardial infarction.
Hospital of the University of Pennsylvania, Philadelphia 19104, USA.
Left ventricular mural thrombus.
Arch Intern Med. 1983;143(8):1567.
The identification of mural thrombus in patients with left ventricular aneurysm and mural thrombus probably warrants consideration of long-term anticoagulation. In patients with acute, large, anterior or anteroapical, transmural myocardial infarctions, serial noninvasive examinations are warranted to define a group of patients at high risk for the development of left ventricular aneurysm and/or mural thrombus. Anticoagulants should be considered in patients in whom mural thrombi develop as a complication of their infarction. Patients with congestive cardiomyopathy should be considered for long-term anticoagulation. These recommendations are all tempered by the realization that the use of anticoagulant therapy is not without its own risks. The decision to anticoagulate must be balanced against each individual patient's suitability for such therapy and the individual likelihood of the development of side effects.