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.

SUMMARY OF COMMENT

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.