Limited warfarin benefit for patients at low risk of stroke, study finds
Warfarin has no overall benefit in those with non-valvular atrial fibrillation and at low risk of stroke, a study of 13,559 US patients has found.
The risk of haemorrhagic stroke - with its greater clinical impact - balanced the risk of thrombotic stroke and other systemic emboli in those with a lower risk of stroke measured by a score based on the presence or absence of heart failure, hypertension, age, diabetes and a previous history of stroke.
In those at higher risk the net benefit of warfarin was 2.22% per year of treatment. There was a similar net benefit of warfarin in those over 85.
The study was a mixed retrospective and prospective cohort study that looked at data from 66,000 years of person follow-up.
Annals of Internal Medicine 2009; 151 (5): 297-305.