A study co-led by Charles Majoie, Professor of Neuroradiology, department of Radiology and Nuclear Medicine at Amsterdam UMC, and Yvo Roos, Professor of Neurology, department of Neurology at Amsterdam UMC, provided important insights into the combination of treatments for acute ischemic stroke, specifically focusing on intravenous thrombolysis and endovascular treatment. This study was published today in The Lancet.

Patients with acute ischemic stroke require immediate medical attention. Current international guidelines recommend that eligible patients should receive a combination of intravenous thrombolysis, a medication that can dissolve the clot causing the stroke but also carries a risk of intracranial bleeding, together with endovascular treatment, a procedure that mechanically removes the clot. However, the additional value of intravenous thrombolysis in patients directly admitted to endovascular treatment-capable centres has been a subject of debate.

Meta-analysis of six randomized trials

The Improving Reperfusion Strategies in Acute Ischemic Stroke (IRIS) collaboration performed a meta-analysis of six randomised trials executed between 2017 and 2022. These trials involved more than two thousand patients admitted directly to endovascular treatment-capable centers.

Little difference in outcomes

Among the 2,313 patients analyzed, the meta-analysis found minimal differences in clinical outcomes between those who received endovascular treatment alone and those who received a combination of intravenous thrombolysis and endovascular treatment. Neither approach showed significant advantages over the other.

It is crucial to recognize that the actual benefit of additional intravenous thrombolysis is likely to be small and may vary depending on factors such as the time from stroke onset, in stroke patients admitted directly to endovascular treatment centers. It is imperative that intravenous thrombolysis does not cause any delays, restrict access to, or take precedence over endovascular treatment, considering the limited and uncertain effect it has compared to the large impact of endovascular treatment itself.
Charles Majoie
Professor of Neuroradiology, department of Radiology and Nuclear Medicine at Amsterdam UMC and co-leader of this study

Individual variations

However, due to the statistical uncertainty surrounding the potential effect of the combined treatment, the study results could not exclude the possibility that omitting intravenous thrombolysis could lead to worse outcomes. The researchers believe that individual patient differences may affect the efficacy of thrombolysis, suggesting that some patients may benefit, while others may not or even do worse. For example, patients presenting shortly after the onset of their symptoms may benefit more from thrombolysis before endovascular treatment, whereas those presenting later may not benefit or even be harmed. Further investigation is planned through dedicated sub-studies to explore these possibilities.

Looking ahead

The findings of this study offer valuable insights into the optimisation of acute ischemic stroke treatment. Future treatment guidelines should incorporate more personalized decisions regarding intravenous thrombolysis before endovascular treatment.

This project was executed as part of the Collaboration of New Treatments in Acute Stroke (CONTRAST), which was funded by the Dutch Heart Foundation.