Abstract 2281: Full Dose IV-tPA Followed By IA Therapy For Acute Ischemic Stroke Does Not Increase Morbidity Or Mortality

Background and Purpose: “Bridging Therapy” is well described in the literature. However the dose of bridging tissue plasminogen activator (tPA) is a matter of debate given the well-established guideline of 0.9 mg/kg as the standard intravenous dose. Previous and ongoing bridging trials use lower doses of IV-tPA (0.6 mg/kg) with a goal of maximizing safety. Our aim was to explore whether full bridging dose IV-tPA at 0.9 mg/kg can be given safely in combination with intra-arterial (IA)-tPA. Methods: Data were collected prospectively on 47 consecutive patients with acute ischemic stroke who were treated with endovascular stroke therapy (EST, that is IA-tPA +/- mechanical embolectomy (ME)). Patients who were candidates for IV-tPA, who did not clinically improve after receiving full dose IV-tPA (0.9mg/Kg), underwent EST (bridging group, n=23, 15/23 IA-tPA + ME). These patients were compared to patients treated with EST alone because they were not candidates for IV-tPA (control group, n=24, 14/24 IA-tPA + ME). Symptomatic intracranial hemorrhage (ICH) rates were recorded, as defined in the NINDS IV-tPA trial. Death rates were recorded at one month and modified Rankin score was used to measure functional outcome (6 month mean follow-up). Results: Mean age was 62 years in the bridging group and 63 years in the control group. Baseline mean National Institute of Health Stroke Scale was 20 in the bridging group and 21 in the control group (p = 0.188). The mean IA-tPA dose was 14.4 mg in the bridging group and 18.3 mg in the control group (p = 0.371). There was an 8% risk of symptomatic ICH in the control group and no symptomatic ICH in the bridging group (p = 0.155). At 30 days, mortality was 17% in the bridging group and 29% in the control group (p = 0.313). The mean follow-up modified Rankin score was 3 in the bridging group and 4 in the control group (p = 0.20). Conclusion: This non-randomized retrospective cohort study suggests that full dose IV-tPA combined with IA-tPA administered during EST is safe in patients with acute ischemic stroke. Given the possibility that full bridging dose tPA may be more effective than lower dose IV-tPA, a prospective, randomized bridging trial using full dose IV-tPA may be warranted.