BACKGROUND

Intravenous administration of recombinant tissue plasminogen activator (rtPA) is approved treatment for acute ischemic stroke <3 h of symptom onset.

PURPOSE

To determine the impact of the timing and degree of recanalization on clinical outcome after rtPA infusion in patients.

MATERIAL AND METHODS

Seventy-five patients with ischemic stroke in the middle cerebral artery territory treated with intravenous rtPA within 3 h were studied consecutively. Magnetic resonance imaging (MRI), including magnetic resonance angiography (MRA), before, 6 h, and 24 h after thrombolytic therapy was undertaken. Depending on the MRA results acquired 6 h after rtPA infusion, recanalization was graded as: early recanalization (ER), delayed recanalization (DR), and no recanalization (NR). Clinical outcome was assessed using the National Institutes of Health Stroke Scale (NIHSS) and modified Rankin Scale (mRS).

RESULTS

Of patients in the ER, DR and NR groups, 71.4% (15/21), 13.3% (2/15), and 30.7% (12/39), respectively, showed dramatic improvement in NIHSS score 7 days after rtPA administration compared with those scores upon hospital admission. The 6-h and 24-h NIHSS scores and 3-month mRS scores of ER patients were significantly lower than those of the other two groups (P < 0.05). The 24-h, 7-d NHISS and mRS scores of DR patients were significantly higher than NR patients (P = 0.001, 0.002, 0.049, respectively). Three patients in the DR group died during follow-up.

CONCLUSION

These data suggest that DR is associated with clinical deterioration. Patients treated with rtPA thrombolysis should be under close observation for 6-24 h. Corresponding treatment should be considered once DR appears.