JAMA

International Stroke Conference: Timing of thrombolysis before thrombectomy has significant impact on outcome

February 13, 2024

The benefit of IV thrombolysis (IVT) for acute ischemic stroke declines with longer time from symptom onset, but it's been unclear whether a similar time dependency exists for IVT followed by thrombectomy. In this meta-analysis, researchers compared IVT plus thrombectomy vs. thrombectomy alone in six randomized trials. The findings, which were presented at the International Stroke Conference in early February, suggest that the benefit associated with IVT plus thrombectomy was time dependent and statistically significant only if the time from symptom onset to expected administration of IVT was short.

• Participants were enrolled between January 2017 and July 2021 at 190 sites in 15 countries. All participants were eligible for IVT and thrombectomy and presented directly at thrombectomy-capable stroke centers (n = 2,334), but for this meta-analysis, only patients with an anterior circulation large-vessel occlusion were included (n = 2,313; median age, 71 years; 44.3% female).
• The primary outcome analysis tested whether the association between the allocated treatment (IVT plus thrombectomy vs. thrombectomy alone) and disability at 90 days varied with times from symptom onset to expected administration of IVT.
• In 2,313 participants (1,160 in IVT plus thrombectomy group vs. 1,153 in thrombectomy alone group), the median time from symptom onset to expected administration of IVT was 2 hours, 28 minutes.
• There was a statistically significant interaction between the time from symptom onset to expected administration of IVT and the association of allocated treatment with functional outcomes (ratio of adjusted common odds ratio [OR] per 1-hour delay, 0.84; 95% confidence interval [CI], 0.72-0.97, P = .02 for interaction).
• The benefit of IVT plus thrombectomy decreased with longer times from symptom onset to expected administration of IVT (adjusted common OR for 1-step modified Rankin Scale [mRS] score shift toward improvement, 1.49; 95% CI, 1.13-1.96 at 1 hour; 1.25 [95% CI, 1.04-1.49] at 2 hours, and 1.04 [95% CI, 0.88-1.23] at 3 hours).
• For a mRS score of 0, 1, or 2, the predicted absolute risk difference was 9% (95% CI, 3-16%) at 1 hour, 5% (95% CI, 1-9%) at 2 hours, and 1% (95% CI, -3-5%) at 3 hours.
• After 2 hours 20 minutes, the benefit associated with IVT plus thrombectomy was not statistically significant and the point estimate crossed the null association at 3 hours 14 minutes.

Source:

Kaesmacher J, et al; IRIS Collaborators. JAMA. Time to Treatment With Intravenous Thrombolysis Before Thrombectomy and Functional Outcomes in Acute Ischemic Stroke: A Meta-Analysis. https://pubmed.ncbi.nlm.nih.gov/38324409/