Dual antiplatelets in IV thrombolysis: How much is too much?

Even after >20 years of experience, IV thrombolysis (IVT) for acute ischemic stroke apparently continues to elicit concern, largely due to fear of symptomatic intracerebral hemorrhage (sICH). While many of the major predisposing factors are well established,1 gray zones of uncertainty remain, including concurrent exposure to antiplatelet therapy. Although not a formal contraindication to thrombolysis per se, many perceive it as increasing the risk of sICH. Prior exposure to a single antiplatelet agent is common, due to either overlap of stroke with other vascular comorbid conditions with antiplatelet therapy indications or over-the-counter use for presumed primary prevention benefits, despite evidence to the contrary.2 The greater antiplatelet effects of dual antiplatelet therapy (DAPT) might make it even riskier. Despite higher rates of sICH with single antiplatelet exposure in the context of IVT,3-5 this does not translate into higher mortality or worse functional status. In fact, a large observational registry-based study in the United States showed more favorable functional outcomes in those pretreated with antiplatelets.3 The available and controversial data pertaining to prestroke DAPT exposure have not clarified the risks after IVT, with some studies showing elevated sICH risk while others not.