Abstract
Background and Purpose: Thrombolytic treatment with alteplase at 0.6 mg/kg is approved for use within 3 h of stroke onset in Japan. Thus, only a small percentage of patients can benefit. A meta-analysis and more recent studies suggest a benefit to patients beyond 3 h with alteplase at 0.9 mg/kg or desmoteplase. We assessed the efficacy and safety of intravenous alteplase at 0.6 mg/kg more than 3 h after stroke onset in patients with acute MCA occlusion who were selected using perfusion-diffusion mismatch.
Methods: Patients with MCA occlusion eligible for intravenous alteplase within 3 h were selected using MRI (DW, FLAIR, T2*, T2)/MRA and beyond 3 h using evidence of perfusion-diffusion mismatch. Recanalization was evaluated using MRA within 24 h after treatment. Baseline characteristics, recanalization rates, early and late good clinical outcomes (NIHSS scores of 0 to 1 or 8-points or greater improvement at 24 h and mRS scores of 0 or 1 on the 90th day), symptomatic intracranial hemorrhage (within 72 h) and mortality (at the 90th day) were evaluated for both groups. Also for both groups, the relationships between recanalization and early and late good clinical outcomes were evaluated.
Results: 63 patients with MCA occlusion were treated using intravenous alteplase within 3 h (n=53) and beyond 3 h (n=10). No statistically significant differences were found between the two groups for recanalization rates (52.8 vs. 70.0%), early and late good clinical outcomes (early: 41.5 vs. 60.0%, late: 37.7 vs. 50.0%), symptomatic intracranial hemorrhage (0 vs. 0%), or mortality (1.9 vs. 0%).
Conclusion: Our data suggest that intravenous alteplase at 0.6 mg/kg beyond 3 h after MCA occlusion for patients selected using perfusion-diffusion mismatch has the same efficacy and safety as treatment within 3 h. However, a larger sample size is needed to evaluate the relationship between recanalization and clinical outcomes of the treatment beyond 3 h.
