4 New Stroke Studies and Guidelines to Know

This transcript has been edited for clarity.

Dear colleagues, I am Christoph Diener, a neurologist from the University of Duisburg-Essen in Germany. This month, I'd like to highlight four new publications on stroke.

Two Studies Highlight Importance of Early Diagnosis and Treatment

In the acute treatment of stroke, there is a new way to get patients into hospitals: mobile stroke units. These are ambulances equipped with CT scanning, a small laboratory, and a stroke physician. In providing these services, the goal is to shorten the time to get the patient to thrombolysis.

A study recently published in JAMA featured data from Berlin, Germany, a city with 3.5 million inhabitants and three mobile stroke units. Investigators compared outcomes among patients with acute ischemic stroke brought to the hospital with either a mobile stroke unit or a conventional ambulance (749 vs 794 patients, respectively). The groups were well matched in terms of severity of stroke.

Investigators showed that use of a mobile stroke unit significantly improved outcome at 3 months, as measured by modified Rankin Scale. Mobile stroke units reduced the time to thrombolysis by approximately 30 minutes. The rate of thrombectomy was the same between the groups, which is not surprising given that how a patient gets to the hospital is independent for this outcome. Given that mobile stroke units represent an expensive way to get patients to a hospital, it remains unknown whether this is a cost-effective approach.

A separate study published in Lancet Neurology dealt with how best to identify patients with occlusions of the large intracranial arteries who would be candidates for thrombectomy. Researchers in the Netherlands tested eight different stroke scales to see how these patients with suspected stroke (defined using the gold-standard Face-Arm-Speech-Time test) could be best identified.

Paramedics were trained to use these eight scales on mobile apps. After comparing their predictive outcomes with the National Institutes of Health Stroke Scale score at admission to the hospital, it turned out that all were considered very good.

The unresolved issue is if a patient has indications of a large-artery occlusion, whether they should go directly to a center that provides thrombectomy around the clock or should first go to a local stroke unit, undergo CT angiography, and then be transported.

Elevated Stroke Risk in Patients With High-Grade Stenosis

Another important issue is the risk for stroke in people with asymptomatic carotid stenosis. There was previously conflicting data on whether the degree of stenosis was relevant for predicting stroke.

In another study appearing in Lancet Neurology, investigators used data from the Oxford Vascular Study and performed a meta-analysis of both observational cohort studies and the medical treatment groups of randomized trials to determine the 5-year ipsilateral stroke risk in people with asymptomatic carotid stenosis.

They clearly observed that people who have 70%-99% stenosis of the internal carotid artery have a significantly higher risk for ipsilateral stroke compared with those with between 50% and 69% stenosis, with an odds ratio of 2.1 (P < .0001). They also found significant heterogeneity between the randomized trials, which was accounted for by three trials of endarterectomy for asymptomatic stenosis.

These results indicate that perhaps people who have a high degree of asymptomatic carotid stenosis would benefit from carotid surgery or stenting.

New European Stroke Organisation (ESO) Guidelines

Finally, the ESO published new guidelines on IV thrombolysis in people with acute ischemic stroke. The authors strongly recommend IV thrombolysis 0.9 mg/kg with alteplase within 4.5 hours of stroke, and within 4.5-9 hours in people where CT or MRI perfusion shows a mismatch.

In patients with an acute ischemic stroke less than 4.5 hours in duration, they would not recommend any antithrombotic treatment within 24 hours after thrombolysis. They do promote thrombolysis in patients above 80 years of age who are frail, have large strokes on imaging, disabling strokes, improving stroke symptoms but still disabling stroke, who have high blood pressure, high blood glucose, or diabetes, and/or are on dual-antiplatelet therapy.

They recommend idarucizumab in people who have a stroke on dabigatran, but they do not recommend the use of andexanet alfa in people who are on an Xa inhibitor. If someone is on a vitamin K antagonist, then thrombolysis can be performed if the international normalized ratio is ≤ 1.7.

The authors do not recommend thrombolysis in people with minor stroke who clearly have high blood pressure (this must be lowered first), with a high level of previously reported microbleeds (> 10), and/or who have had acute coronary syndrome within the past 7 days.

These are just a few of the ESO's recommendations. I suggest reading this very important guideline on the use of thrombolysis in people with acute ischemic stroke to learn these details, as well as the other publications offering interesting new data on asymptomatic carotid stenosis, preclinical stroke scales, and mobile stroke units.

I'm Christoph Diener from the University of Duisburg-Essen in Germany. Thank you very much for watching and listening.

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