Stroke, Bleeding Risks High in A-fib Patients With Contraindications to Anticoagulation

Many patients with atrial fibrillation are not taking oral anticoagulation because of an elevated bleeding risk, and this subset faces substantial risks of both ischemic and hemorrhagic stroke, a new analysis affirms.

Stroke risk is particularly high among those with a prior hemorrhagic stroke or intracranial bleeding, lead author Björn Redfors, MD, PhD (Cardiovascular Research Foundation, New York, NY), and colleagues report in a study published online September 27, 2017, ahead of print in JACC: Clinical Electrophysiology.

“Alternative methods for stroke prevention that do not increase bleeding risk should be considered for these patients, particularly if they have previously suffered an intracranial hemorrhage,” they say. “Carefully conducted studies of treatment alternatives for patients with [A-fib] and bleeding-related contraindications for [oral anticoagulation] are needed.”

Geoffrey Barnes, MD (University of Michigan, Ann Arbor), who was not involved in the study, told TCTMD he is not surprised by the results because he sees these types of patients frequently in his practice. The study confirms that stroke risk is high in this subgroup, he said, adding that “in many patients, the stroke risk might outweigh the bleeding risk. And so it [starts] to raise the point that we probably need to look really carefully at exactly what does it mean to be contraindicated.”

In the study, 85.4% of patients had a major bleeding event, defined as GI, genitourinary, or respiratory tract bleeding that required transfusion or surgical intervention as their recorded contraindication for oral anticoagulation. “For me, those are things that are identifiable and reversible, yet a stroke is something that usually has long-lasting implications,” Barnes said. “I don’t see a GI bleed as being an absolute contraindication. I see it as something that needs to be identified and treated, and then once it’s safe, [you can] reinitiate that person on anticoagulation because the stroke risk is so high.”

Using a ballpark estimate, he said half to two-thirds of patients with a recorded contraindication to oral anticoagulation could probably be anticoagulated safely after addressing the initial reason for the contraindication.

Especially High Risk With History of Hemorrhagic Stroke, Intracranial Bleeding

For the study, Redfors et al scanned administrative claims from the Truven Health MarketScan Commercial and Medicare Supplemental Research databases, identifying about 1.3 million patients with A-fib included between 2009 and 2013. Of those, 43,248 had a contraindication to oral anticoagulation—a prior severe bleeding event or a sufficiently high bleeding risk—and either died in the hospital or remained off anticoagulation for at least a year.

In the contraindication group, more than 80% had a CHA2DS2-VASc score greater than 1 and 42.9% had a score of 4 or higher.

Overall rates of ischemic and hemorrhagic stroke were 4.1% and 3.6%, respectively, and those figures rose along with increasing CHADS2 and CHA2DS2-VASc scores.

Patients with prior hemorrhagic stroke or intracranial bleeding formed a particularly high-risk subgroup, with ischemic and hemorrhagic stroke rates of 12.2% and 20.3%, respectively. In contrast to what was observed in the rest of the contraindicated patients, event rates were not clearly related to stroke risk scores.

That “further complicates clinical decision-making,” the authors say. “It is possible that this is a distinct group of [A-fib] patients for whom the relationship between the traditional predictors of thromboembolic events and serious bleeding differ from the general [A-fib] population. Regardless, our data show that this subset of patients would benefit greatly from alternative methods of stroke prevention that do not impose an increased bleeding risk.”

Although Redfors et al do not mention left atrial appendage closure in their paper, Barnes said that could be a possible solution for patients with a contraindication to oral anticoagulation.

“I think that there is clearly a role for left atrial appendage occluders in many patients,” he said, adding, however, that “the majority of patients probably could be safely treated with anticoagulation . . . and would not necessarily have to undergo a procedure.”

Barnes said understanding the implications of using left trial appendage occlusion, which requires some form of short-term antithrombotic therapy, in a patient with a very high bleeding risk is an important area for future research.

Additionally, he’d like learn more about how doctors are making decisions about restarting or withholding anticoagulation in patients with recorded contraindications, as well as about how patients balance risks of stroke and bleeding when choosing the best treatment for them.

“I think there’s an important set of research [to be completed] to help us guide the shared decision-making discussion that needs to happen,” Barnes said.

Note: Redfors and co-author Ori Ben-Yehuda, MD, are employees of the Cardiovascular Research Foundation, the publisher of TCTMD.