Blood Thinners Not a Firm Contraindication for tPA, Study Finds

PHILADELPHIA — Current anticoagulant or antiplatelet use is not necessarily a contraindication for administering tissue plasminogen activator (tPA) to a stroke patient in the emergency department, a researcher said here at the annual meeting of the American College of Emergency Physicians.

Traditionally, a patient being on blood thinners has been somewhat of a contraindication for tPA administration, said Salil Phadnis, MD, a third-year emergency medicine resident at Florida Atlantic University. “But at a lot of sites, especially ones without the most up-to-date academic stroke team, it ends up being more an absolute ‘shut down’ contraindication: ‘Oh, they’re on blood thinners; they can’t have tPA.’ So what we wanted to do was look at the rates of hemorrhage and disability that happens in patients who are on both medications.”

The researchers performed a retrospective chart review of patients evaluated in the emergency department for stroke who received either tPA or a procedural intervention, or both, between March 2018 and May 2020. They collected data on pre-stroke antiplatelet use, anticoagulant use, the patient’s initial NIH stroke score (NIHSS), postintervention modified Rankin score (mRS), and incidence of intracranial hemorrhage (ICH) at 3 months. They then compared ICH and mRS outcomes among patients based on their antithrombotic use for each of the intervention groups.

Out of 663 stroke activations, 251 patients received neurointervention, Phadnis said; that included 140 patients (55.8%) who received tPA only, 77 (30.7%) who received thrombectomy only, and 34 (13.5%) who received both. “The overall hemorrhage rate for intervention was 16.7%, with a mRS of 3,” he said. “That basically means [they had] some disability, but they are able to ambulate without having someone supporting them at all times.”

Overall, “the main result that we found was that there were no significant differences in incidence of intracranial hemorrhage between patients,” he said. This was true “regardless of what kind of antiplatelets they’re using, regardless of what kind of anticoagulant they’re using, or a combination of the two, whether they got tPA, whether they got thrombectomy, or whether they got both.”

There were a few other differences in mRS scores, however, he said: “Patients who were taking antiplatelets and got multiple interventions had a significantly higher mRS score,” at an average of 5. “Five means you’re bed-bound, essentially.” Similarly, patients who were taking multiple antithrombotics also had a higher mRS score, he added.

“I think the main takeaway from this is just that in those precious few moments when a stroke first comes in, there is that mad scramble to get information — their medication lists … and other factors that could be contributing to what we see in front of us, and there is such limited information and time,” said Phadnis. “Sometimes it seems like the medication list, and especially anticoagulant status, plays a bit of an outsize role.”

“I think maybe we’d be better off looking more at the individual patient and whether they stand to benefit from getting tPA and thrombectomy without letting anticoagulant status be a deal-breaker for us,” he added. “Or at the very least, we could do a little bit more as far as learning methods to rapidly reverse these medications, or determining a threshold below which you can get a consensus that tPA is safe — kind of like what we’ve done with warfarin and an INR [international normalized ratio] of 1.7.”

Limitations of the study included difficulties in consistently documenting the NIHSS score at every step of the evaluation, Phadnis noted. “And last known medication ingestion is something that we weren’t able to accurately track for every single patient. As you can probably tell, it makes a difference whether you took the [medication] the night before or the week before.”

Hopefully these results will be practice-changing, especially at smaller community hospitals, Phadnis told MedPage Today. “When you have a single ED [emergency department] provider making the decisions, hopefully having data like this would be a little bit more reassuring rather than to say, ‘Oh, they’re on [anticoagulants]; OK, we’re done.'”

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