A new treatment of choice for basilar thrombosis

This transcript has been edited for clarity.

Ladies and gentlemen, I am Christoph Diener from the University of Duisburg-Essen in Germany. This month, I would like to share with you the most important results of the 8th Congress of the European Stroke Organization, which was held in early May in Lyon, France. It was a big event, with around 2400 people attending in person.

Thrombectomy: a new treatment of choice for basilar thrombosis

There was some particularly exciting news about the treatment of basilar thrombosis. You may remember that there were two small trials in China, the BEST and BASICS trials. These were not able to show a benefit of thrombectomy over best medical care in people with basilar artery occlusion, which was a surprise. We now have two large randomized trials, again in China, which clearly show that thrombectomy is superior to the best medical treatment.

The first study is the BAOCHE (Basilar Artery Occlusion Chinese Endovascular) trial. Patients with a score of 6 or greater on the National Institutes of Health Stroke Scale presenting within 24 hours were included.

The primary endpoint of a modified Rankin Scale score of 0 to 3 after 90 days was achieved with thrombectomy in 51 of 110 patients (46%) and with best medical treatment in 26 of 107 patients ( 24%). The odds ratio was 2.92 and clearly significant. There were also significant advantages for mortality with thrombectomy (31% versus 42%). There was only a very small increased risk of symptomatic intracranial hemorrhage with thrombectomy.

Then there was data presented from the ATTENTION trial, which had a shorter time interval of 12 hours. Patients were randomized 2:1 to receive either endovascular treatment or better medical management.

Again, the endpoint was a modified Rankin Scale score of 0 to 3 after 90 days, which was achieved in 104 of 220 patients (46%) with thrombectomy versus 26 of 114 patients (23%) with the best medical care. This translated into a significant risk reduction of 2.1. There was also a significant reduction in mortality from 36% to 55%. Symptomatic intracranial hemorrhage was 5% with thrombectomy versus 0% with best medical management.

Investigators also presented results from the prospective ATTENTION registry, with more than 2,000 matched patients in China, of whom 1,670 received thrombectomy and 462 improved medical management. The result of a modified Rankin scale score from 0 to 3 after 90 days showed a clear benefit in favor of thrombectomy, which was 1.42. The absolute difference was 12%. The absolute difference in mortality reduction was 10%.

It’s amazing how consistent the results are. Our Chinese colleagues are to be commended for completing these trials in a very short time. I think the debate we had is over. It is now clearly demonstrated that thrombectomy is the treatment of choice for people with basilar thrombosis.

New data on thrombolysis

We have two substances for thrombolysis. One is tenecteplase, which is given as a bolus. We also have established alteplase, where you need an initial bolus and then a one hour infusion.

The Canadian Alteplase versus Tenecteplase trial compared tenecteplase at a dose of 0.25 mg/kg body weight with a standard dose of alteplase in 1,600 patients. The primary endpoint was a modified Rankin Scale score of 0 to 1 at day 90, and the time to inclusion was 4.5 hours.

There was no difference in the primary endpoint (37% for tenecteplase versus 35% for alteplase), and no difference in any secondary outcome parameters and safety parameters.

What does it mean? I think this shows that most likely tenecteplase is easier to use than alteplase and is equally as effective. But the caveat is that in many countries tenecteplase is not approved, not available, or not reimbursed. If that changes in the next few years, I don’t know.

There was also a second thrombolysis study done in Norway, the NOR-TEST 2 trial. This study used a higher dose of tenecteplase, 0.4 mg/kg body weight, versus alteplase. The study had to be stopped after the inclusion of 216 patients because there was a significant increase in the risk of bleeding with tenecteplase and higher mortality. The most likely explanation is that the dose of tenecteplase was too high.

There was also a Melbourne study in mobile stroke units in which tenecteplase was compared to alteplase. This was a small study and therefore no difference was shown in clinical outcomes. However, there was an advantage for ischemia size in CT perfusion with tenecteplase.

Then we had data on a very interesting new antithrombotic. Glenzocimab is a monoclonal antibody directed against the human platelet glycoprotein GPVI. This antibody inhibits thrombosis but does not lead – at least in animal experiments – to an increased risk of bleeding.

The ACTIMIS study evaluated the safety of 1000 mg of this new medicine compared to a placebo in 106 patients who received thrombolysis. There was no difference in bleeding, but there was a clear difference in favor of glenzocimab in the risk of symptomatic intracranial hemorrhage (1% versus 8%) and mortality (8% versus 19%). This now needs to be proven in the largest phase 3 trial.

Other studies of interest

There were also several other interesting trials which I would like to mention briefly. A study showed that lowering blood sugar with GLP-1 [glucagon-like peptide 1] the agonist exenatide in acute stroke patients is not effective in reducing disability.

Then we had a study of tranexamic acid in people who had intracranial hemorrhage with a non-vitamin K antagonist. The study didn’t show any benefit, although that’s not relevant because we now have seen reversal agents for both dabigatran and Xa inhibitors.

There was a meta-analysis of all patients in a randomized study in which local thrombolysis was studied in intraventricular hemorrhage versus best medical treatment. It showed a benefit for both functional outcome and a 50% reduction in mortality. Obviously, I think most of us in clinical practice will use this method.

There was a study of 330 patients, which compared thrombectomy with general anesthesia versus sedation. Investigators found no difference. Again, this is not really relevant because generally, thrombectomy is done under sedation. If sedation is not possible, general anesthesia is used.

Finally, there was a study in severely affected stroke patients in which early tracheostomy was compared to standard tracheostomy in 330 patients. This study also found no difference. So obviously we should keep our standard approach that we used updated.

I would also like to issue a final caveat. At this congress, a number of studies were presented that either had a very small sample size or were terminated prematurely for some reason. And my caveat is, please disregard the results of these studies. They have no impact on what we do with our patients in daily clinical practice.

Ladies and gentlemen, it was an exciting stroke conference in Lyon, with results that will change our practice for years to come.

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

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