Background and purpose: Intravenous administration of tissue plasminogen activator (t-PA) dissolves the clot and can improve clinical outcome in patients with acute ischemic stroke. However, lack of early recanalization frequently does not result in good outcome.
Methods: We prospectively studied acute stroke patients treated with t-PA and examined clinical factors associated with no early recanalization of occluded arteries after t-PA administration using serial magnetic resonance angiography (MRA). NIHSS score was obtained before and at 24h after t-PA administration.
Results: Subjects comprised 49 consecutive stroke patients treated with t-PA. Initial MRA before t-PA infusion demonstrated occluded arteries in 37 patients. Of the 37 occluded arteries, follow-up MRA within 30min after t-PA administration revealed complete recanalization in 6 patients, partial recanalization in 12, and no early recanalization in 19. Neurological worsening (total NIHSS score increased by > or =4) occurred in 0 of 18 patients with recanalization and 4 of 19 patients with no recanalization (P=0.039). Atrial fibrillation (AF) and hypertension were more frequent in patients with non-early recanalization than in patients with recanalization (73.7% vs. 38.9%, P=0.03; 73.6% vs. 38.9%, P=0.03, respectively). However, no differences were observed in other clinical factors between groups. Multivariate logistic regression analysis demonstrated AF (OR: 9.3; CI: 1.5-55.8, P=0.015) as the only independent factor associated with no recanalization.
Conclusion: No early recanalization after t-PA administration was observed in 51.4% of acute stroke patients with occluded arteries and was significantly associated with neurological worsening. AF was independently associated with no recanalization after t-PA administration.