Lancet
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Although interest in clinical guidelines has never been greater, uncertainty persists about whether they are effective. The debate has been hampered by the lack of a rigorous overview. ⋯ We conclude that explicit guidelines do improve clinical practice, when introduced in the context of rigorous evaluations. However, the size of the improvements in performance varied considerably.
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Randomized Controlled Trial Multicenter Study Clinical Trial
Secondary prevention in non-rheumatic atrial fibrillation after transient ischaemic attack or minor stroke. EAFT (European Atrial Fibrillation Trial) Study Group.
Several studies have established the value of anticoagulation for primary prevention of thromboembolic events in patients with non-rheumatic atrial fibrillation (NRAF). However, in patients with a recent transient ischaemic attack (TIA) or minor ischaemic stroke the preventive benefit of anticoagulation or aspirin remains unclear. Physicians in 108 centres from 13 countries collaborated to study this question. 1007 NRAF patients with a recent TIA or minor ischaemic stroke were randomised to open anticoagulation or double-blind treatment with either 300 mg aspirin per day or placebo (group 1, 669). ⋯ We conclude that anticoagulation is effective in reducing the risk of recurrent vascular events in NRAF patients with a recent TIA or minor ischaemic stroke. In absolute terms: 90 vascular events (mainly strokes) are prevented if 1000 patients are treated with anticoagulation for one year. Aspirin is a safe, though less effective, alternative when anticoagulation is contraindicated; it prevents 40 vascular events each year for every 1000 treated patients.
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Comparative Study Clinical Trial
Failure of new biochemical markers to exclude acute myocardial infarction at admission.
In a substantial proportion of patients with suspected myocardial infarction, biochemical markers are needed for clinical decision-making at the time of admission, because electrocardiographic (ECG) recordings are inconclusive. We have assessed the usefulness for exclusion of myocardial infarction at admission of the newer markers creatine kinase MB (CK-MB) mass concentration, troponin T, and myoglobin in comparison with the routinely used markers creatine kinase (CK) and CK-MB activity. 290 consecutive patients were enrolled. Acute myocardial infarction was diagnosed on the basis of clinical history, ECG criteria, and time-dependent changes in CK and CK-MB activity. 153 patients had definite acute myocardial infarction. ⋯ However, troponin T also had the highest "false-positive" rate; of 137 patients without myocardial infarction, 36 (26%) had high troponin T concentrations. Sensitivity, specificity, and positive and negative predictive values were calculated in relation to time between onset of chest pain and hospital admission. Although CK-MB mass concentration was, by a small margin, the best marker in patients admitted within 8-10 h of onset of chest pain, all the markers had negative predictive values too low to allow exclusion of acute myocardial infarction at admission in patients with symptoms suggestive of myocardial infarction of less than 10 h duration.