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Hyperintense acute reperfusion marker on MRI portends worse outcomes and may help identify patients needing adjunctive care.

 

Using more than one pass with an endovascular device in an effort to achieve vessel revascularization among patients with acute ischemic stroke increases the risk for blood-brain barrier disruption, a new study shows.

Moreover, hyperintense acute reperfusion marker (HARM) detected on MRI within 24 hours was more common among patients who underwent more than one attempt to recanalize the affected vessel, helping to make a case for follow-up MRI in these patients, authors say.

HARM “was [first] identified in the context of IV thrombolysis as reperfusion injury,” lead author Marie Luby, PhD (National Institute of Neurological Disorders and Stroke, Bethesda, MD), told TCTMD. “It is representative of imaging confirmation that there was some breakdown of the blood-brain barrier, and it’s a marker of [poorer] outcome. . . . But it also represents that reperfusion actually occurred. However, given the [susceptible] vascular state, there may be damage to the blood-brain barrier.”

With the advent of endovascular therapy, reperfusion occurs more rapidly than it did with IV thrombolysis. As a result, “we have seen a dramatic increase in the incidence of HARM,” Luby explained. She added that the underlying question of this analysis was: “What could aggravate or facilitate that secondary injury?”

The research was published online June 26, 2019, ahead of print in Stroke.

Postprocedural MRI Imaging

Luby et al identified 80 patients screened between January 2015 and February 2019 who received a diagnosis of acute ischemic stroke of the anterior circulation, were treated with or without IV tissue plasminogen activator (tPA), consented to participate in the NINDS Natural History Study, and received MRI imaging before receiving endovascular therapy. Consensus image reads for HARM and hemorrhagic transformation were performed.

Patients’ median age was 65 years, 64% were female, and 51% were black/African American. Their median admission National Institutes of Health Stroke Scale score was 19. Most were treated with IV tPA (56%) and achieved a Thrombolysis In Cerebral Infarction (TICI) score of 2b/3 (84%), which represents complete vessel reperfusion.

Patients treated with multiple passes of the endovascular device were older (69 vs 57 years; P = 0.003), had poorer modified Rankin Score (mRS) scores (3 vs 2; P = 0.001), and had slightly higher creatinine levels (1.10 vs 0.85 mg/dL; P = 0.003).

The key finding of this analysis was that undergoing multiple passes was significantly linked with higher rates of severe HARM at 24 hours as well as the presence of any hemorrhagic transformation and poor clinical outcome, the authors say.

Only age (OR 1.1; 95% CI 1.01-1.12) and severe HARM at 24 hours post-endovascular therapy (OR 7.2; 95% CI 1.93-26.92) were significantly associated with multiple passes.

Speaking with TCTMD, Luby warned that this is an exploratory analysis with only 80 patients based on MRI analysis, which is not used in all centers. It also compared one pass with multiple passes only, rather than exploring the full spectrum of impact of the incremental increase in the number of passes.

But there are two important observations from this study for centers that perform these procedures, she said. The first is that multiple passes puts patients at increased risk for HARM. “You can imagine physiologically going in with a device and disrupting the vasculature that’s already susceptible,” she explained. “The endothelium is getting disrupted mechanically with the shearing forces, etc. If you do that multiple times, chances are, especially if you have an older patient, the wear and tear of that is going to make them more at risk.”

The second implication, she said, relates to the potential of neuroprotective therapies. In the paper, the authors note that most centers performing endovascular interventions would also have the capacity to perform follow-up MRI at 24 hours to check for HARM. In doing so, patients with signs of HARM could be earmarked for other therapies that might reduce the impact of multiple passes.

“If you can facilitate support of the blood-brain barrier with adjunctive therapy,” she said, “you could potentially prime the vasculature to prevent harm and potentially improve the outcomes of these patients.”

This story was originally published by  TCTMD.com on July 5, 2019. 

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