Thrombolytic Therapy for Acute Ischemic Stroke: Why the Majority of Patients Remain Ineligible for Treatment

Study objectives: Thrombolytic therapy has been advocated as an effective treatment for acute ischemic stroke. In an attempt to promote maximum benefit while reducing the risk of hemorrhagic complications, numerous exclusions to the use of thrombolytic therapy for acute ischemic stroke have been promulgated. This study was conducted to identify the number of acute ischemic stroke patients eligible for thrombolytic therapy and to determine the reasons those deemed ineligible were excluded. Methods: This observational study was conducted from September 15, 1996, to May 1, 1997, at an emergency department with an annual census of 70,000. Patients with a chief complaint suggestive of acute ischemic stroke were categorized as “eligible” if thrombolytic therapy was not contraindicated and could be initiated within 3 hours of symptom onset. Patients were deemed “ineligible” if the time to thrombolytic therapy would have exceeded 3 hours, or if other specific contraindications to thrombolytic therapy were present. For all categories, 95% confidence intervals (95% CI) were determined. Results: Of the 214 patients with acute ischemic stroke who were screened, 6 (2.8%±2.2%) were eligible. Ninety-five patients (44%±7%) were excluded solely on the basis of the time interval from onset of symptoms to eligibility for thrombolytic therapy exceeding 3 hours. Other common reasons for exclusion included resolution of symptoms in 31 patients (14%±4%), intracranial hemorrhage as determined by head computed tomography in 22 (10%±4%), and minor symptoms in 20 (9%±4%). Conclusion: The majority of acute ischemic stroke patients do not meet accepted criteria for thrombolytic therapy. Most are ineligible because of delays in obtaining treatment. Strategies should be devised to reduce the time to treatment if thrombolytic therapy is to achieve widespread use in the treatment of acute ischemic stroke. [O’Connor RE, McGraw P, Edelsohn L: Thrombolytic therapy for acute ischemic stroke: Why the majority of patients remain ineligible for treatment. Ann Emerg Med January 1999;33:9-14.]