Efficacy of IV tissue plasminogen activator in acute stroke - Does stroke subtype really matter?

Background: The National Institute of Neurological Disorders and Stroke (NINDS) trial reported that stroke subtype (e.g., large-artery atherothrombosis, cardioembolism, and lacunae) does not affect response to IV thrombolytic treatment. However, these conclusions were based upon stroke subtypes determined prior to extensive diagnostic evaluation. Because such initial diagnoses are frequently inaccurate, the efficacy of IV recombinant tissue plasminogen activator (rt-PA) based upon verified specific stroke subtypes remains uncertain. Methods: The records of consecutive acute stroke patients treated with IV rt-PA at two regional stroke centers were retrospectively reviewed. The final stroke subtype after complete diagnostic evaluation was determined. The relationship between final stroke subtype and response to thrombolytic therapy was then investigated and compared with the results reported in the NINDS trial. Results: Ninety consecutive patients were studied. After adjusting for baseline NIH Stroke Scale scores, no significant difference in final outcome based on confirmed stroke mechanism was identified. Conclusions: These data are consistent with those of the NINDS trial that reported that the efficacy of IV thrombolysis within the 3-hour time window is similar between different stroke subtypes. Based upon these data, allocating treatment of stroke patients with IV rt-PA based upon presumed stroke mechanism may be unnecessary. Such testing may result in time delays that could compromise the efficacy of treatment.