Schwamm LH, et al. - Researchers tested the safety of intravenous thrombolysis ≤4.5 hours from the time of symptom discovery in patients with quantitative mismatch of diffusion-weighted MRI with lesion evolution on fluid-attenuated inversion recovery (FLAIR) (qDFM) in an open-label, phase 2a, prospective study. They deemed intravenous thrombolysis within 4.5 hours of symptom discovery as safe in patients with unwitnessed stroke selected by qDFM, who are beyond the recommended time windows. Findings also suggested the feasibility of a randomized trial testing efficacy using qDFM and the trial appeared to be needed in patients without large vessel occlusions.

Methods

• Across 14 hospitals, screening was performed on patients aged 18 to 85 years with acute ischemic stroke (AIS) of unwitnessed onset at 4.5 to 24 hours since they were last known to be well, treatable within 4.5 hours of symptom discovery with intravenous alteplase (0.9mg/kg) and presenting with qDFM.
• The risk of symptomatic intracranial hemorrhage (sICH) with preplanned stopping rules was the primary outcome.
• Symptomatic brain edema risk and functional outcomes of 90 day modified Rankin Scale (mRS) were among the secondary outcomes.

Results

• Between January 31, 2011 and October 4, 2015, 80 subjects were enrolled and treated with alteplase at median 11.2 hours (IQR = 9.5–13.3) from when they were last known to be well.
• Researchers identified 1 case of sICH (1.3%) and 3 cases of symptomatic edema (3.8%).
• They noted that 39% of subjects achieved mRS = 0–1, as did 48% of subjects who had vessel imaging and were without large vessel occlusions, at 90 days.