Abstract Body: Introduction
Previous studies have shown the efficacy and safety of time-based intravenous thrombolysis (IVT) in elderly patients with ischemic stroke. However, there are safety concerns about bleeding associated with IVT due to their low body weight, renal dysfunction, and the concomitant use of antithrombotic drugs. Robust evidence on the effect of IVT, particularly in elderly patients with unknown onset stroke, is limited. This study aimed to evaluate the efficacy and safety of imaging-based IVT in this population.
Methods
Patients with an unknown onset stroke were evaluated using an individual patient-level database of randomized controlled trials comparing IVT with placebo or standard treatment from the Evaluation of unknown Onset Stroke thrombolysis trials (EOS) collaboration. The primary outcome was favorable outcome, defined as a mRS score of 0-1 at 90 days. Safety outcomes included symptomatic intracranial hemorrhage (sICH) at 22–36 hours and 90-day mortality. The effect of IVT was evaluated in each of patients aged ≥85 and <85 years using a mixed-effect logistic regression analysis.
Results
Among the 843 patients in the EOS dataset, 56 were aged 85 years or older (6.7%), and 787 were under 85 years (93.3%). The elderly group had a higher prevalence of atrial fibrillation (42.9% vs. 17.2%), hypertension (78.6% vs. 58.7%), and premorbid anticoagulation (13.6% vs. 3.1%). The baseline NIHSS score was also higher (median, 12 vs. 7) (all p<0.05). Overall, there was no significant interaction between age (≥85 or <85 years) and treatment on efficacy or safety outcomes (P interaction for the primary outcome 0.689). In the elderly group, favorable outcomes were observed in 33.3% of the IVT group and 19.2% of the control group, with an adjusted odds ratio (aOR) of 3.06 (95% CI 0.68-13.8). Mortality at 90 days was not significantly different between the IVT and control groups (20.0% vs. 19.2%, aOR 1.32 [0.30-5.79]), and there was only one case of sICH in the IVT group. In patients under 85 years, favorable outcomes were observed in 48.5% of the IVT group compared to 40.5% in controls (aOR 1.50, 95% CI 1.09-2.06). The IVT group had higher mortality (5.8% vs. 2.3%, aOR 2.56, [1.16-5.67]) and more frequent sICH (2.7% vs. 0.5%, aOR 5.35, [1.18-24.3]).
Conclusion
Imaging-based IVT with alteplase may improve outcomes in elderly patients with unknown onset stroke without significantly increasing the risk of death or sICH.