Time to Treatment With Intravenous Thrombolysis Before Thrombectomy and Functional Outcomes in Acute Ischemic Stroke
https://jamanetwork.com/journals/jama/fullarticle/2815005
The study in question investigates the efficacy and time sensitivity of combining intravenous thrombolysis (IVT) with thrombectomy versus thrombectomy alone in treating acute ischemic stroke. Here's a breakdown according to the PICO format:
Population: The study focused on 2,313 participants presenting with anterior circulation large-vessel occlusion at thrombectomy-capable stroke centers across 15 countries. These participants were part of a larger pool from 6 randomized clinical trials. The median age was 71 years, with 44.3% female representation.
Intervention: The intervention group received IVT followed by thrombectomy.
Comparison: The comparison group underwent thrombectomy alone.
Outcome: The primary outcome measured was disability at 90 days post-treatment, assessed using the 7-level modified Rankin Scale (mRS), where scores range from 0 (no symptoms) to 6 (death). The study particularly looked at how the time from symptom onset to the expected administration of IVT influenced the treatment outcome.
Results Summary:
Median time from symptom onset to expected IVT administration was 2 hours and 28 minutes.
A statistically significant interaction was found between the time to IVT administration and the treatment outcome, indicating that the benefit of IVT plus thrombectomy diminishes over time.
Specifically, the adjusted odds ratio (OR) for improvement decreased from 1.49 at 1 hour to 1.04 at 3 hours post-symptom onset.
The predicted absolute risk difference for achieving an mRS score of 0-2 was 9% at 1 hour, decreasing to 1% at 3 hours.
The benefit was not statistically significant beyond 2 hours and 20 minutes, with the point estimate crossing the null association at 3 hours and 14 minutes.
Conclusions and Relevance for Intensivists:
This meta-analysis elucidates the critical time window within which IVT plus thrombectomy significantly enhances functional outcomes compared to thrombectomy alone in acute ischemic stroke patients with anterior circulation large-vessel occlusion. The findings underscore the importance of rapid assessment and treatment initiation in stroke care to maximize recovery chances. For intensivists, this highlights the need for streamlined stroke protocols and efficient inter-departmental coordination to expedite the treatment process. Understanding the diminishing return on treatment efficacy over time is crucial for clinical decision-making, patient counseling, and setting realistic expectations about recovery prospects.