Is the benefit of early recanalization sustained at 3 months? A prospective cohort study.

BACKGROUND AND PURPOSE

Early arterial recanalization can lead to dramatic recovery (DR) during intravenous tissue plasminogen activator (tPA) therapy. However, it remains unclear whether this clinical recovery is sustained 3 months after stroke.

METHODS

We studied consecutive patients treated with intravenous tPA (0.9 mg/kg within 3 hours) who had M1 or proximal M2 middle cerebral artery occlusion on pretreatment transcranial Doppler according to previously validated criteria. Patients were continuously monitored for 2 hours after tPA bolus to determine complete, partial, or no early recanalization with the Thrombolysis in Brain Ischemia (TIBI) flow grading system. A neurologist obtained the National Institutes of Health Stroke Scale (NIHSS) and modified Rankin Scale (mRS) scores independently of transcranial Doppler results. DR was defined as a total NIHSS score of 0 to 3 points, and early recovery (ER) was defined improvement by > or =10 points at 2 hours after tPA bolus. Good long-term outcome was defined as an NIHSS score of 0 to 2 or an mRS score of 0 to 1 at 3 months.

RESULTS

Fifty-four patients with proximal middle cerebral artery occlusion had a median prebolus NIHSS score of 16 (range, 6 to 28; 90% with > or =10 points). The tPA bolus was given at 130+/-32 minutes (median, 120 minutes; 57% treated within the first 2 hours). DR+ER was observed in 50% of patients with early complete recanalization (n=18), 17% with partial recanalization (n=18), and 0% with no early recanalization (n=18) (P=0.025). Overall, DR+ER was observed in 12 patients (22%), and 9 (75%) had good outcome at 3 months in terms of NIHSS (P=0.009) and mRS (P=0.006) scores compared with non-DR and non-ER patients. If early recanalization was complete, 50% of these patients had good outcome at 3 months, and 78% with DR+ER sustained early clinical benefit. If recanalization was partial, 44% had good long-term outcome, and 66% of patients with DR+ER sustained the benefit. If no early recanalization occurred, 22% had good long-term outcome despite the lack of DR within 2 hours of tPA bolus (P=0.046). Mortality was 11%, 11%, and 39% in patients with complete, partial, and no early recanalization, respectively (P=0.025). Reasons for not sustaining DR in patients with early recanalization were subsequent symptomatic intracranial hemorrhage and recurrent ischemic stroke.

CONCLUSIONS

DR or ER after recanalization within 2 hours after tPA bolus was sustained at 3 months in most patients (75%) in our study. Complete or partial early recanalization leads to better outcome at 3 months after stroke. Fewer patients achieve good long-term outcome without early recanalization.