Atrial fibrillation: Are anticoagulants underused?
In a recently published scientific study (BMJ 332, 2006), N.K. Choudhry investigated how American physicians react to bleedings, if their patients with atrial fibrillation are treated with anticoagulants. In this study, 530 physicians were included, whose patients suffered from atrial fibrillation. Additional inclusion criteria: one patient per physician had to be hospitalized due to bleedings and one patient per physician had to be hospitalized due to a stroke, regardless of previous anticoagulation therapy or not. It was evaluated how physicians changed their prescription behavior after these incidents. On one hand, physicians prescribed 21% of anticoagulants less after a bleeding event. On the other hand no change in the prescription behavior was observes if non-anticoagulated patients suffered from a stroke. The conclusion of the author was that patients with atrial fibrillation receive anticoagulants insufficiently, because physicians overestimate the bleeding risks of these drugs.
On the ISMAA/ISMAAP symposium during the European Cardiology Congress in Vienna (2nd Sept. 2007) E.M. Hylek, Boston, pointed out that 58 billion US dollars are spend every year for patients suffering from stroke alone. Improved INR monitoring and keeping the INR within the therapeutic range could prevent a significant number or strokes. Professor J. Ansell, Boston, stressed on the ISMAA/ISMAAP symposium that physicians still underestimate the stroke risk for patients with atrial fibrillation.
What can we conclude from this study? On one hand, atrial fibrillation always increases the risk to suffer from a stroke, on the other hand, treatment with anticoagulants significantly reduces the stroke risk. Keeping the INR within the recommended therapeutic range for atrial fibrillation (2.0 to 3.0) can be achieved by close INR monitoring, which also will significantly reduce the bleeding risk. Comparing risks and opportunities, treatment with anticoagulants appears to be the method of choice.
Christian Schaefer, Chairman of ISMAAP (July 2008)