The use of expected value as an aid to decisions regarding anticoagulation in patients with atrial fibrillation.
BACKGROUND
The method described provides a rational means for determining whether to institute chronic anticoagulation to prevent stroke in patients with chronic atrial fibrillation under a variety of clinical circumstances.


RESULTS
The concept of expected value is used in conjunction with data from clinical studies to define the net value of anticoagulation to the patient. A full year of anticoagulation is warranted in patients with recent stroke or transient ischemic attack thought to be due to cardiogenic embolism who feel that stroke is a very serious event with nearly as much disvalue as death. If stroke has a lesser degree of negative value to the patient, or it is uncertain whether the stroke was in a large-vessel distribution, or it is uncertain whether a large-vessel distribution stroke was due to cardiogenic embolism, 6 months or less of anticoagulation may be warranted. Indefinite anticoagulation is justifiable in most patients with chronic atrial fibrillation without a history of stroke or transient ischemic attack but may be contraindicated in certain patients at extremely low risk for embolism and in patients who place a low value on stroke relative to death and who have a modest increase in risk for fatal hemorrhage.


CONCLUSIONS
The method described provides a means readily usable by clinicians to make anticoagulation decisions in patients with chronic atrial fibrillation that will address risk-benefit tradeoffs with somewhat greater precision than current approaches.
Nadeau
S E
SE
Geriatric Research, Education, and Clinical Center, Veterans Administration Medical Center, Gainesville, FL 32608-1197.
D000925:Anticoagulants / Q000009:adverse effects / Q000627:therapeutic use*; D001281:Atrial Fibrillation / Q000150:complications*; D002543:Cerebral Hemorrhage / Q000209:etiology / Q000517:prevention & control; D002544:Cerebral Infarction / Q000209:etiology / Q000517:prevention & control; D002561:Cerebrovascular Disorders / Q000517:prevention & control*; D003663:Decision Trees; D006801:Humans; D002546:Ischemic Attack, Transient / Q000517:prevention & control; D012008:Recurrence; D012307:Risk Factors
D000925:Anticoagulants