Comparison of MRI-based thrombolysis for patients with middle cerebral artery occlusion ≤ 3 h and 3-6 h

Objective : To investigate the outcomes of magnetic resonance imaging (MRI)-based thrombolysis using recombinant tissue plasminogen activator (rt-PA) in patients with acute middle cerebral artery (MCA) occlusion in 3-6 hours.
Materials and Methods : MRI-selected patients (n=15) with acute ischemic stroke in MCA divided into two groups (#≤ 3h and 3-6 h) were treated with intravenous rt-PA. MR was performed before rt-PA, at 24 hours, 7 days, and 14 days after stroke. Recanalization was assessed 24 h after thrombolysis, and clinical status was evaluated before rt-PA treatment, 6 hours, 24 hours, 7 days, and 14 days after thrombolysis by the National Institutes of Health Stroke Scale (NIHSS). Modified rankin scale (MRS) was used to assess clinical outcome at 30 and 90 days after thrombolysis.
Results : There was no significant between ≤ 3 h and 3-6 h group in length of hospital stay, recanalization, MRS, and favorable outcome at 90 days. Recanalization within 24 hours occurred in 9 (60%), and nonrecanalization in 6 (40%). One patient in recanalization group and three in nonrecanalization group had an asymptomatic intracranial hemorrhage (ICH) within 24 h after thrombolysis (P =0.235). Recanalization with thrombolysis was associated with a better outcome regardless of the time point of rt-PA treatment. Comparison with nonrecanalization group, recanalization was also associated with a lower NIHSS score at 14 days (P =0.003), a lower TIMI grade at 7 days (P < 0.001), and a shorter length of hospital stay (P =0.018).
Conclusion : Our study suggested that MR-based thrombolysis using rt-PA was safe and reliable in patients with acute MCA occlusion in 3-6 hours.

Keywords
Magnetic resonance imaging, middle cerebral artery, recombinant tissue plasminogen activator, stroke, thrombolysis