Reperfusion and metabolic recovery of brain tissue and clinical outcome after ischemic stroke and thrombolytic therapy

Abstract

Background and purpose: It is unclear from recent clinical trials whether thrombolytic agents are capable of facilitating reperfusion and metabolic recovery over time or whether a beneficial effect is counteracted by an increase in the risk of brain hemorrhage. We studied the effect of thrombolytic treatment on metabolic recovery after reperfusion and clinical outcome.

Methods: Patients were prospectively studied with (99m)Tc-ethyl cysteinate dimer single photon emission computed tomography ((99m)Tc-ECD-SPECT) before treatment with recombinant tissue plasminogen activator (rTPA; 0.9 mg/kg IV; n=26) or placebo (n=26) 6 to 8 hours after treatment and at 7+/-1 days. Activity deficits were graded, compared between the treatment groups, and correlated with clinical outcome and the incidence of brain hemorrhage. Metabolic recovery of ischemic brain tissue was defined as a 25% decrease on the SPECT graded scale.

Results: Patients with metabolic recovery (n=28) had a better chance of being functionally unimpaired 3 months after stroke than patients without recovery (n=24) (OR 4.5, 95% CI 1.09 to 18.89) and had smaller infarcts on follow-up CT (36+/-38 versus 167+/-162 mL), regardless of whether metabolic recovery was observed within 6 to 8 hours of treatment or at 7 days. None of the 28 patients with metabolic recovery had a fatal parenchymal hemorrhage versus 5 of 24 patients without recovery (P=0.016). Treatment did not affect the incidence of brain tissue metabolic recovery.

Conclusions: Brain tissue metabolic recovery after ischemic stroke was associated with a beneficial effect on clinical outcome and was not facilitated by treatment with 0.9 mg of intravenous rTPA.