Stroke prevention in atrial fibrillationBMJ 1997; 315 doi: https://doi.org/10.1136/bmj.315.7114.1019 (Published 18 October 1997) Cite this as: BMJ 1997;315:1019
Suggested range of international normalised ratio may lead to overanticoagulation
- Frank Booth, Consultant haematologista,
- Arjun Mehta, Consultant physiciana
- a Torbay Hospital, Torquay TQ2 7AA
- b Division of Public Health and Primary Care, Radcliffe Infirmary, Oxford OX2 6HE
Editor—In their editorial on the use of anticoagulants in atrial fibrillation Tim Lancaster and colleagues suggest that a target international normalised ratio of 2.0-4.0 should be sought.1 We have reservations about this. Any intensity of oral anticoagulant treatment increases the risk of serious bleeding and particularly intracranial haemorrhage, which carries a mortality of 60%. With an international normalised ratio in the suggested range, the risk of intracranial bleeding is increased 7-10—fold and is proportionate to the intensity of anticoagulation.2 Furthermore, elderly patients, who are at higher risk of ischaemic stroke with atrial fibrillation, are also at the highest risk of bleeding due to oral anticoagulants. Intensity of anticoagulation is very much a balance of risks.
Lancaster and colleagues base their conclusions primarily on two reports. …