The effectiveness of thrombolysis with intravenous alteplase for acute ischemic stroke in daily practice

Background: Thrombolysis with intravenous alteplase has been proven an effective treatment for patients with acute ischemic stroke in randomized clinical trials. In daily practice, the effect of thrombolysis may be less, and complications may occur more often. Aims: The aim of this study was to assess effectiveness and safety of thrombolysis in an unselected observational cohort of patients. Methods: During a two-year period, all patients over 18 years with acute stroke who were admitted within four-hours from onset of symptoms in 12 centers were registered. We compared outcomes in patients who were treated with alteplase with patients who were not treated with alteplase. The primary outcome was good functional outcome at three-months measured with the modified Rankin Scale ≤2). The safety end point was symptomatic intracranial hemorrhage and mortality. We used a multivariable logistic regression model to adjust for baseline imbalances and multilevel analysis to take into account within center correlations. Results: Overall, 1657 patients with ischemic stroke were admitted within four-hours from onset of symptoms and 696 (42%) were treated with alteplase. Treatment with alteplase was associated with a favorable outcome (adjusted odds ratio 1·3; 95% confidence interval 1·0 to 1·7). After further adjustment for potential clustering effects, the adjusted odds ratio for good outcome was 1·4 (95% confidence interval 1·0 to 1·8). Thirty-six (5%) of the 696 patients treated with alteplase had a symptomatic intracranial bleeding complication. Conclusions: Thrombolysis for ischemic stroke with intravenous alteplase is an effective treatment also in an unselected observational cohort of patients.