Antithrombotic withdrawal heightens stroke risk

Allison Gandey

August 15, 2011

Cincinnati, OH - One in 20 ischemic strokes occurs soon after withdrawal of antithrombotic agents, warn researchers [1]. They report that 5.2% of all stroke patients in a single year had an antithrombotic or antiplatelet agent withdrawn within the previous 60 days. Many went on to have strokes within seven days of withdrawal.

Dr Joseph Broderick

"Physicians need to be aware of the risks associated with stoppage of antithrombotic medications in patients who are planning to undergo a medical or dental procedure where there is risk of bleeding," lead investigator Dr Joseph Broderick (University of Cincinnati, OH) said in an interview.

"There is a strong push by those performing the procedure to limit bleeding complications, often without the same attention paid to the risk of ischemic stroke or MI when stopping these medications," he said.

Broderick says recent withdrawal of antithrombotic medications represents about 5% of all ischemic strokes. His team's report was published online June 30, 2011 in Stroke.

Investigators studied patient records from the population-based Greater Cincinnati and Northern Kentucky Stroke Stud y. The researchers identified 2197 cases of ischemic stroke that occurred during 2005 to determine the association between these events and the prior withdrawal of antithrombotic medication.

They found that patients appeared to be at greatest risk within 60 days of medication withdrawal.

Ischemic stroke rate (n=2197)

Rate (%)
Within 60 d of medication withdrawal
After warfarin stopped
First-ever stroke
Recurrent stroke
After medication withdrawal by physician in the periprocedural period

"The withdrawal of anticoagulant and antiplatelet medications is associated with a substantial number of acute first-ever and recurrent ischemic strokes," the authors write. "This finding emphasizes the need for thoughtful decision-making concerning antithrombotic medication use in the periprocedural period and for recruitment in ongoing trials addressing this issue."

Broderick pointed out that there is uncertainty about when to use bridging therapy to limit the risk of ischemic events when a procedure is required.

Several bridging trials are ongoing, he noted, and patients who are having medical procedures should be included in these trials to address the best approaches to limit ischemic events as well as serious bleeding.

This study was supported by the National Institutes of Health . Broderick had no con flicts of interest. Disclosures for the coauthors are listed in the paper.


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