Argatroban tPA stroke study: study design and results in the first treated cohort

The benefit of intravenous recombinant tissue plasminogen activator (rtPA) in acute stroke is linked to clot lysis and artery recanalization. Argatroban is a direct thrombin inhibitor that safely augments the benefit of rtPA in animal stroke models. There are no human data on this combination.

We report the first phase of the Argatroban tPA Stroke Study, an ongoing prospective, open-label, dose-escalation, safety and activity study of argatroban and rtPA in patients with ischemic stroke. The primary outcome was incidence of intracerebral hemorrhage; secondary outcome, complete recanalization at 2 hours. After standard-dose intravenous rtPA administration, a 100-mug/kg bolus of argatroban followed by infusion of 1 mug/kg per minute for 48 hours was adjusted to a target partial thromboplastin time of 1.75 times that of the control group.

Fifteen patients (including 10 men) were enrolled, with a mean +/- SD age of 61 +/- 13 years. All patients had middle cerebral artery occlusions. Baseline median National Institute of Health Stroke Scale score was 14 (range, 4-25). The mean +/- SD time from symptom onset to argatroban bolus administration was 172 +/- 53 minutes. Symptomatic intracerebral hemorrhage occurred in 2 patients, including 1 with parenchymal hemorrhage type 2. Asymptomatic bleeding occurred in 1 patient and there was 1 death. Recanalization was complete in 6 patients and partial in another 4, and reocclusion occurred in 3 within 2 hours of rtPA bolus administration.

The safety of low-dose argatroban combined with intravenous rtPA may be within acceptable limits, and its efficacy for producing fast and complete recanalization is promising, but a larger cohort of patients is required to confirm these preliminary observations.