Intravenous tissue-type plasminogen activator therapy for ischemic stroke: Houston experience 1996 to 2000.

Context: Intravenous tissue-type plasminogen activator (tPA) therapy using the National Institute of Neurological Disorders and Stroke criteria has been given with variable safety to less than 5% of the patients who have ischemic strokes nationwide. Our center is experienced in treating large numbers of stroke patients with intravenous tPA.
Objective: To report our total 4-year experience in the treatment of consecutive patients who had an ischemic stroke.
Design: Prospective inception cohort registry of all patients seen by our stroke team and an additional retrospective medical record review of all patients treated between January 1, 1996, and June 1, 2000.
Setting: A veteran stroke team composed of fellows and stroke-specialty faculty servicing 1 university and 3 community hospitals in a large urban setting.
Patients: Consecutive patients with ischemic stroke treated within the first 3 hours of symptom onset.
Intervention: According to the National Institute of Neurological Disorders and Stroke protocol, 0.9 mg/kg of intravenous tissue-type plasminogen activator was administered.
Main Outcome Measures: Number and proportion treated, patient demographics, time to treatment, hemorrhage rates, and clinical outcome.
Results: A total of 269 patients were treated between January 1, 1996, and June 1, 2000. Their mean age was 68 years (age range, 24-93 years); 48% were women. This represented 9% of all patients admitted with symptoms of cerebral ischemia at our most active hospital (over the final 6 months, 13% of all patients with symptoms of cerebral ischemia and 15% of all acute ischemic stroke patients). Before treatment the mean +/- SD National Institutes of Health Stroke Scale (NIHSS) score was 14.4 +/- 6.1 points (median, 14 points; range, 4-33 points). A tPA bolus was given at 137 minutes (range, 30-180 minutes); 28% of the patients were treated within 2 hours. The mean door-to-needle time was 70 minutes (range, 10-129 minutes). The symptomatic intracerebral hemorrhage rate was 5.6% of those patients with a second set of brain scans (4.5% of all patients), with a declining trend from 1996 to 2000. Protocol violations were found in 13% of all patients; the symptomatic intracerebral hemorrhage rate in these patients was 15%. At 24 hours, the NIHSS score was 10 +/- 8 points (median, 8 points; range, 0-36 points). In-hospital mortality was 15% and the patients' discharge NIHSS scores were 7 +/- 7 points (median, 3 points; range, 0-35 points).
Conclusions: Intravenous tPA therapy can be given to up to 15% of the patients with acute ischemic stroke with a low risk of symptomatic intracerebral hemorrhage. Successful experience with intravenous tPA therapy depends on the experience and organization of the treating team and adherence to published guidelines.