Untreated LVO Stroke Tied to Poor Outcomes in Children

Erik Greb

March 08, 2022

Children with large-vessel occlusion (LVO) stroke have poorer outcomes if they do not receive mechanical thrombectomy, new data suggest.

In a retrospective, population-based study of almost 200 children with LVO stroke, patients who did not undergo mechanical thrombectomy were six times more likely to have significant disability than those who did.

"Our findings show that children with untreated LVO stroke will likely have long-term moderate to severe disability if the blockage is not cleared," investigator Kartik Bhatia, MBBS, PhD, pediatric neurointerventionist at Sydney Children's Hospital Network, Sydney, Australia, told Medscape Medical News. "This allows pediatric neurologists to let parents know the likely outcome if we don't offer treatment and makes it easier to justify off-label use of thrombectomy or to consider IV thrombolysis."

Bhatia presented his results at the International Stroke Conference 2022, which was held in New Orleans and virtually because of the pandemic.

Retrospective, Population-Based Study

In adults, LVO is associated with severe and disabling stroke. LVO stroke was a main motivator for the seven trials that supported the safety and efficacy of mechanical thrombectomy. These trials excluded children, however. In addition, data about the natural history of pediatric LVO stroke are lacking. As a result, neurologists often hesitate to treat when they face a child with LVO stroke.

The current researchers hypothesized that, contrary to common beliefs, children with untreated LVO stroke have poor outcomes. To test their hypothesis, the investigators conducted a population-based study in the state of New South Wales, Australia.

In this retrospective study, the investigators collected data from all three of the state's pediatric hospitals and from one adult hospital that treats older adolescents. They pooled data on admissions for ischemic stroke in all patients younger than 17 years. Data were collected from 2010-2019, a period that includes the time before clot retrieval was introduced for adults. This period thus enables an assessment of the natural history of LVO stroke.

The investigators assessed all patients for LVO on imaging and compared patients with LVO who did and did not undergo mechanical thrombectomy. The latter group was taken to represent the natural history of LVO stroke.

The study's outcomes were pediatric modified Rankin Scale (mRS) score at 3 months and at final assessment. The investigators performed ordinal logistic regression analysis to compare patients who received mechanical thrombectomy with those who did not.

In addition, the researchers examined whether patients were eligible for thrombectomy according to the criteria used in the MR CLEAN and DAWN trials of adults. They also examined the time between clinical presentation and when patients had last been seen well.

Significant Long-Term Disability

The investigators included 39 children with LVO stroke and 122 children with non-LVO stroke in their analysis. Mean age was 5.4 years for children with non-LVO stroke and 8.2 years for children with LVO stroke (P = .007). The proportion of male patients was 67.2% in the non-LVO group and 59% in the LVO group. This difference was not statistically significant.

One patient in the non-LVO group and three in the LVO group received IV thrombolysis. No patients in the non-LVO group and 13 patients in the LVO group underwent thrombectomy.

At 3 months, about 73% of patients with LVO stroke who did not receive thrombectomy had an mRS of 3 to 6, which is considered a poor outcome. They had worse outcomes than patients with LVO stroke who underwent thrombectomy (odds ratio [OR], 3.75; P = .042). In addition, patients who did not receive thrombectomy had worse outcomes than patients with non-LVO stroke (OR, 3.64; P = .001).

Mean follow-up was 53 months (4 years, 5 months). At final assessment, 57.7% of patients with LVO stroke who did not undergo thrombectomy had an mRS of 3 to 6. They again had worse outcomes compared with patients who had undergone thrombectomy (OR, 6.07; P = .010) and with patients with non-LVO stroke (OR, 3.23; P = .003). Two thirds of patients who underwent thrombectomy had a favorable outcome (that is, an mRS of 0 to 2) in the long term.

About 90% of children presented within 24 hours of the time they were last seen well, which refutes the idea that children present too late to receive reperfusion therapy, said Bhatia. In addition, 82% of patients with LVO stroke would have met MR CLEAN or DAWN criteria, apart from their age.

"We were surprised by how early children with LVO stroke tend to present to hospital," said Bhatia. Previous stroke studies have suggested that children with stroke often present too late to receive reperfusion treatment, but those studies did not look specifically at LVO strokes.

"Whilst parents and kids might sit on a minor deficit from a small stroke, such as minor weakness in the fingers or tingling in the arm, they know very quickly that something is wrong when the child suddenly can't move one side of their body or cannot speak — a typical presentation when there is an LVO," said Bhatia.

The early presentation of children with LVO stroke in this study "shows that neurologists should be looking to transform their emergency department triage, imaging, and stroke management pathways, in combination with the anesthesia teams, to streamline identification and treatment of kids with LVO," said Bhatia.

"More Confirmatory Than New"

Commenting on the findings for Medscape Medical News, Lori Jordan, MD, PhD, director of the pediatric stroke program and pediatric neurologist at Vanderbilt University Medical Center, Nashville, said that the study sample appears to be free from bias. It is a good population-based study, she added.

Dr Lori Jordan

Quick arrival at the hospital allows patients to be eligible for more interventions. "In this region of Australia, children presented for medical care more rapidly than we have seen in the United States, and more than has been published in Canada," said Jordan.

What distinguishes the current study from the similar Save ChildS Study is its inclusion of a direct comparison group of children with LVO who did not undergo thrombectomy. "The study is more confirmatory than new, but is important, because thrombectomy has not been studied well in children," said Jordan.

Most children with stroke don't present to a center that can perform a thrombectomy in a child. "This speaks to the need to identify these kids and transfer them quickly," said Jordan.

The study was conducted without external funding. Bhatia and Jordan have disclosed no relevant financial relationships.

International Stroke Conference 2022: Presentation LB22. Presented February 11, 2022.

Follow Erik Greb on Twitter: @MedscapeErik .

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