Intravenous Tissue-Type Plasminogen Activator for Treatment of Acute Stroke

CONTEXT: Tissue-type plasminogen activator (tPA) is the only therapy for acute ischemic stroke approved by the Food and Drug Administration. OBJECTIVE: To assess the safety profile and to document clinical outcomes and adverse events in patients treated with intravenous tPA for acute stroke in clinical practice. DESIGN AND SETTING: Prospective, multicenter study of consecutive patients enrolled between February 1997 and December 1998 at 57 medical centers in the United States (24 academic and 33 community). INTERVENTION: Intravenous tPA (recombinant alteplase). PATIENTS: Three hundred eighty-nine patients with a mean age of 69 years (range, 28-100 years); 55% were men. MAIN OUTCOME MEASURES: Time intervals between stroke symptom onset, hospital arrival, and treatment with tPA; pretreatment computed tomographic scan results, intracerebral hemorrhage, and major systemic bleeding. The modified Rankin Scale score was used to assess clinical outcomes at 30 days. RESULTS: Median time from stroke onset to treatment was 2 hours 44 minutes, and the median baseline National Institutes of Health Stroke Scale score was 13. The 30-day mortality rate was 13%. At 30 days after treatment, 35% of patients had very favorable outcomes (modified Rankin score, 0-1) and 43% were functionally independent (modified Rankin score, 0-2). Thirteen patients (3.3%) experienced symptomatic intracerebral hemorrhage, including 7 who died. Twenty-eight patients (8.2%) had asymptomatic intracerebral hemorrhage within 3 days of treatment with tPA. Protocol violations were reported for 127 patients (32.6%), and included treatment with tPA more than 3 hours after symptom onset in 13.4%, treatment with anticoagulants within 24 hours of tPA administration in 9.3%, and tPA administration despite systolic blood pressure exceeding 185 mm Hg in 6.7%. A multivariate analysis found predictors of favorable outcome to be a less severe baseline National Institutes of Health Stroke Scale score, absence of specific abnormalities (effacement or hypodensity of >33% of the middle cerebral artery territory or a hyperdense middle cerebral artery) on the baseline computed tomographic scan, an age of 85 years or younger, and a lower mean arterial pressure at baseline. CONCLUSIONS: This study, conducted at multiple institutions throughout the United States, suggests that favorable clinical outcomes and low rates of symptomatic intracerebral hemorrhage can be achieved using tPA for stroke treatment.