Major bleeds with warfarin in AF are often fatal

Open question for your doctor. You really don't want either the stroke from afib throwing a clot or the excess bleeding from warfarin. This may go back to wrong dosing. 75% at wrong dosage?
http://www.theheart.org/article/1479805.do?utm_medium=email&utm_source=20121128_EN_Heartwire&utm_campaign=newsletter
Results of a large observational study of warfarin use in AF patients suggest that major bleeding rates are higher than in clinical trials and are often fatal [1].

The authors, led by Tara Gomes (University of Toronto, ON), conclude that the study "provides timely estimates of warfarin-related adverse events that may be useful to clinicians, patients, and policy-makers as new options for treatment become available."

For the study, published online in CMAJ on November 26, 2012, Gomes and colleagues linked health administrative databases on prescription drugs and hospitalizations in Ontario. They identified 125 195 patients aged 66 years or over with AF who started warfarin between April 1997 and March 2008. Over the 13-year study period, the rate of major bleeding (defined as any visit to hospital for hemorrhage) was 3.8% per person-year.

Gomes told heartwire that these results were important, as "they reflect the bleeding rates with warfarin in the real world." She said the bleeding rate was "slightly higher than we expected, given that clinical trials have shown rates of major bleeding with warfarin between 1% and 3%."

Noting that some other observational studies have suggested higher bleeding rates than this, she pointed out that many of these studies had much shorter follow-up, and bleeding rates tend to be higher in the early treatment period. "We had a long follow-up period, and as time elapses patients tend to stabilize, so bleeding rates come down." 

Tables at the link.