Intravenous tissue plasminogen activator (tPA) is known to improve outcomes after ischemic stroke. Many patients receive antiplatelet therapy before ischemic stroke, with the concern that those individuals might face an increased risk of bleeding when treated with tPA. This study assessed the risks and benefits associated with pre-stroke antiplatelet therapy among patients with ischemic stroke who received intravenous tPA.

Data were obtained from 85，072 adult patients with ischemic stroke who received intravenous tPA. Of these, 38，844 had been receiving antiplatelet therapy before hospital admission. The participants were followed for outcomes including symptomatic intracranial hemorrhage (sICH), in-hospital mortality, discharge ambulatory status and modified Rankin scale score (mRS).

After risk adjustment, the prior use of antiplatelet agents was found to be associated with a higher onset of sICH (OR 1.18), with a small, absolute increased risk of 0.68%. Prior antiplatelet therapy was not associated with a significantly greater risk of in-hospital mortality. Those receiving antiplatelet therapy had higher ratios of being discharged to home, of independent ambulation and of better mRS scores at discharge.

This study of patients with acute ischemic stroke who received tPA found that those receiving pre-stroke antiplatelet therapy were at increased risk of symptomatic intracranial hemorrhage, but also had better functional outcomes than those who had not received antiplatelet therapy.