Here’s information concerning risk of chronic subdural hematoma resulting from tPA combined with blood thinners in stroke patients.

Many men and women take blood thinning drugs to help prevent stroke. Thicker blood is more likely to form dangerous clots, but thinner blood is more likely to cause bleeding in the body, such as a “chronic subdural hematoma.”

This is slow bleeding in the brain; patients over age 65 are at greatest risk compared to other age groups.

Suppose you’re on blood thinners but you have a stroke anyways. Prompt medical treatment will include tPA: a potent clot-busting drug.

But you already have blood thinners in your system, so won’t the addition of tPA put you at risk for a subdural hematoma: a brain bleed?

A new study from the University of Michigan Stroke Program says that risk of brain bleed, under these circumstances, is low for most patients on blood thinners.

The investigation looked at data from 830 patients who’d received tPA for their stroke. A little under 50 percent of these patients had been on the blood thinner Plavix, or aspirin, prior to their stroke.

After adjusting for variables, the researchers found no substantial difference in the rate of brain bleeding, based on brain scans. This included low-level bleeding that produced no symptoms.

Patients, plus ER teams, need to be reassured that administering tPA to stroke patients, who already have blood thinners in their system, isn’t dangerous or likely to cause bleeding in the brain. The full report is in the March 2013 Academic Emergency Medicine.

Patients Over Age 81 Had Small Increased Risk

The report mentions, however, that patients over 81 did sustain a small increased risk of brain bleeding, though non-symptomatic.

Which blood thinners?

The study examined patients on aspirin and Plavix, not the stronger blood thinners like heparin, warfarin (Coumadin), Pradaxa or Xarelto.

Unfortunately, the study team says that giving tPA to stroke patients on these stronger drugs needs more investigation.

“In light of the long-term benefit that patients receive from antiplatelet therapy,” says lead author William Meurer, MD, “the small increase in risk of intracranial hemorrhage after tPA treatment should not be a game-changer for emergency physicians.”

Dr. Meurer, assistant professor of emergency medicine at U-M Medical School, adds that this study shows that doctors should not hesitate to give tPA to stroke patients who’ve been taking aspirin or Plavix.

A “chronic” subdural hematoma is when the brain bleed doesn’t happen within several days of the causative agent, and instead, begins showing signs or is detected on scan anywhere from a few weeks to 90 days out.

Lorra Garrick has been covering medical, fitness and cybersecurity topics for many years, having written thousands of articles for print magazines and websites, including as a ghostwriter. She’s also a former ACE-certified personal trainer.