Does it matter if my patient getting tPA is on prestroke antiplatelets?
The neurology and ED teams have decided to give tissue plasminogen activator (tPA). As an outpatient, the patient is on aspirin and clopidogrel dual antiplatelet therapy. Does it matter that they’re on aspirin and Plavix? Does prestroke antiplatelet therapy in acute ischemic stroke interact with tPA? Contraindications for the use of tPA in acute ischemic stroke have cited coagulopathies as risk factors for bad outcomes in thrombolysis. Specifically, an elevated INR > 1.7 has been listed as a contraindication for the use of tPA in acute ischemic stroke. But, what about antiplatelets? Prestroke antiplatelets have been the subject of a recent meta-analysis by Luo et al to evaluate outcomes of modified Rankin Score (mRS), symptomatic intracranial hemorrhage (sICH) and mortality in the setting of thrombolysis.
As the comorbidities between cardiac disease and cerebrovascular disease often overlap, ischemic stroke patients getting tPA may commonly be taking aspirin monotherapy or aspirin-clopidogrel combination therapy. As expected, Luo et al found the risk of sICH was higher in those patients on aspirin-clopidogrel dual therapy (OR 1.88, 95%CI 1.18-3.00). Despite this increased risk in bleeding, prestroke aspirin-clopidogrel dual therapy did not translate into higher mortality nor higher risk for unfavorable mRS. Prestroke aspirin monotherapy did not show any increased risks for mortality nor sICH; however, the odds ratio surprisingly trended towards benefit in terms of favorable mRS (OR 1.11, 95%CI 1.00-1.24).
The take-home point of the meta-analysis appears to be that prestroke aspirin-clopidogrel dual therapy puts patients at increased risk for sICH; however, this does not appear to translate into appreciable changes in functional outcome or mortality. Prestroke aspirin monotherapy does not confer this increased risk of sICH or mortality and may even trend towards beneficial functional mRS outcomes.
Thanks to Dr. Cappi Lay for the academic discussion on the above topic.
Luo S, Zhuang M, Zeng W, Tao J. Intravenous Thrombolysis for Acute Ischemic Stroke in Patients Receiving Antiplatelet Therapy: A Systematic Review and Meta-analysis of 19 Studies. J Am Heart Assoc. 2016;5(5)